Practices of Field Crop Production

Principles of Field Crop Production(AAG101 Course)

Practical PartByDr.Mahmoud El Gohary Ragab MekkeiPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 1

Classification of Crop PlantsImportance of classifying the Crop Plants:1. To get acquainted with crops. 2. To understand the requirement of soil & water different crops. 3. To know adaptability of crops. 4. To know the growing habit of crops. 5. To understand climatic requirement of different crops. 6. To know the economic produce of the crop plant & its use. 7. To know the growing season of the crop 8. Overall to know the actual condition required to the cultivation of plant. Classification based on climate: 1. Tropical: Crops grow well in warm & hot climate. E.g. Rice, sugarcane, Jowar etc 2. Temperate: Crops grow well in cool climate. E.g. Wheat, Oats, Gram, Potato etc. Classification Based on growing season: 1. Winter/cold seasons crops: require winter season to grow well from Oct to May month. Crops grow well in cold and dry weather. Require longer day length for flowering. E.g. Wheat, Berseem, Barely, Faba bean, etc. 3. Summer crops: crops grown in summer month from March to October. Require warm day weather for major growth period and longer ay length for flowering. E.g. Groundnuts, Rice, Sunflower, Cotton, Maize, Sesame, etc.. Use/Agronomic classification: 1. Grain crops: may be cereals as millets cereals are the cultivated grasses grown for their edible starchy grains. The larger grain used as staple food is cereals. E.g. rice, Jowar, wheat, maize, barley, and millets are the small grained cereals which are of minor importance as food. 2. Pulse/legume crops: seeds of leguminous crops plant used as food which is rich in protein. E.g. faba bean, lentil, chickpea, pea etc. 3. Oil seeds crops: crop seeds are rich in fatty acids, are used to extract vegetable oil to meet various requirements. E.g. Groundnut, Rape seed, Sunflower, Sesame, linseed etc.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 2

4. Forage Crop: It refers to vegetative matter fresh as preserved utilized as food for animals. Crop cultivated & used for fickler, hay, silage. Ex- sorghum, elephant grass, guinea grass, berseem & alfalfa etc. 5. Fiber crops: crown for fiber yield. Fiber may be obtained from seed. E.g. Cotton, steam, jute, Mesta, sun hemp, flax. 6. Roots crops: Roots are the economic produce in root crop. E.g. sweet, potato, sugar beet, carrot, turnip etc. 7. Tuber crop: crop whose edible portion is not a root but a short thickened underground stem. E.g. Potato, elephant, yam. 8. Sugar crops: the two important crops are sugarcane and sugar beet cultivated for production for sugar. 9. Starch crops: grown for the production of starch. E.g. tapioca, potato, sweet potato. 10. Dreg crop: used for preparation for medicines. E.g. tobacco, mint, pyrethrum. 11. Spices & condiments/spices crops: crop plants as their products are used to flavor taste and sometime color the fresh preserved food. E.g. ginger, garlic, chili, cumin onion, coriander, cardamom, pepper, turmeric etc. 12. Vegetables crops: may be leafy as fruity vegetables. E.g. Palak, mentha, Brinjal, tomato. 13. Green manure crop: grown and incorporated into soil to increase fertility of soil. E.g. sun hemp. 14. Medicinal & aromatic crops: Medicinal plants includes cinchona, isabgoli, opium poppy, senna, belladonna, rauwolfra, iycorice and aromatic plants such as lemon grass, citronella grass, palmorsa, Japanese mint, peppermint, rose geranicem, jasmine, henna etc. Classification based on life of crops/duration of crops: 1. Seasonal crops: A crop completes its life cycle in one seasonKarin, Rabi. summer. E.g. rice, Jowar, wheat etc. 2. Two seasonal crops: crops complete its life in two seasons. E.g. Cotton, turmeric, ginger. 3. Annual crops: Crops require one full year to complete its life in cycle. E.g. sugarcane. 4. Biennial crops: which grows in one year and flowers, fructifies & perishes the next year? E.g. Banana, Papaya.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 3

5. Perennial crops: crops live for several years. E.g. Fruit crops, mango, guava etc.

Classification based on root system: 1. Tap root system: The main root goes deep into the soil. E.g. Tur, Grape, Cotton etc. 2. Adventitious/Fiber rooted: The crops whose roots are fibrous shallow & spreading into the soil. E.g. Cereal crops, wheat, rice etc. Classification based on economic importance: 1. Cash crop: Grown for earning money. E.g. Sugarcane, cotton. 2. Food crops: Grown for raising food grain for the population and & fodder for cattle. E.g. Faba bean, wheat, rice etc. Classification based on No. of cotyledons: 1. Monocots or monocotyledons: Having one cotyledon in the seed. E.g. all cereals & Millets. 2. Dicots or dicotyledonous: Crops having two cotyledons in the seed. E.g. all legumes & pulses. Classification based on photosynthesis (Reduction of CO2/Dark reaction): 1. C3 Plants: Photo respiration is high in these plants C3 Plants have lower water use efficiency. The initial product of C assimilation in the three C compounds. The enzyme involved in the primary carboxylation is ribulose-1,-Biophospate carboxylose. E.g. Rice, soybeans, wheat, barley cottons, potato. 2. C4 plants: The primary product of C fixation is four carbon compounds which may be malice acid or acerbic acid. The enzymes responsible for carboxylation are phosphoenol Pyruvic acid carboxylose which has high affinity for CO2 and capable of assimilation CO2 event at lower concentration, photorespiration is negligible. Photosynthetic rates are higher in C4 than C3 plants for the same amount of stomatal opening. These are said to be drought resistant & they are able to grow better even under moisture stress. C4 plants translate photosynthates rapidly. E.g. Sorghum, Maize, napter grass, sesame etc.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 4

3. Cam plants: (Cassulacean acid metabolism plants) the stomata open at night and large amount of CO2 is fixed as a malice acid which is stored in vacuoles. During day stomata are closed. There is no possibility of CO2 entry. CO2 which is stored as malice acid is broken down & released as CO2. In these plants there is negligible transpiration. C4 & cam plant have high water use efficiency. These are highly drought resistant. E.g. Pineapple, sisal & agave. Classification based on length of photoperiod required for floral initiation: Most plants are influenced by relative length of the day & night, especially for floral initiation, the effect on plant is known as photoperiodism depending on the length of photoperiod required for floral ignition, plants are classified as: 1. Short-day plants: Flower initiation takes plate when days are short less then ten hours. E.g. rice, Jowar, green gram, black gram etc. 2. Long days plants: require long days are more than ten hours for floral ignition. E.g. Wheat, Barley, 3. Day neutral plants: Photoperiod does not have much influence for phase change for these plants. E.g. Cotton, sunflower. The rate of the flowering initiation depends on how short or long is photoperiod. Shorter the days, more rapid initiation of flowering in short days plants. Longer the days more rapid are the initiation of flowering in long days plants.

No-TillageIn this system, no tillage operations are performed between harvest of one crop and planting the next. In most no-till systems, planter-mounted coulters till a narrow seedbed to assist in seed and fertilizer placement. No-till is also referred to as zero-till. Advantages: 1. Maximum erosion control. 2. Soil moisture conservation. 3. Minimum fuel and labor costs. 4. Input and equipment costs are lower than other tillage systems. 5. Soil erosion by wind, water and tillage is greatly reduced. 6. Labor inputs per acre are greatly reduced. Disadvantages :Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 5

1. No incorporation. 2. Increased dependence on herbicides. Weed control is largely dependent on herbicides. 3. Not well suited for poorly drained soils. 4. Initially high residue levels can slow soil warm up. 5. Attachments, such as coulters, must be added to planters and drills. 6. High management level is required. 7. Manure incorporation is difficult. Tillage is essentially eliminated with a no-till system. The crop seed is placed in a narrow strip opened with a coulter or disk seed furrow opener. Most currently available planters can be used in no-till systems with little or no modification. Common options or attachments include coulters, stronger down-pressure springs and weight for penetration. Tilling only a narrow slot in the residuecovered soil achieves excellent erosion control. Shredding standing crop residue prior to planting is not recommended in no-till systems. Performance of planters, drills and cultivators is improved when the residue is standing and attached to the soil, rather than when unattached and lying flat. Although weed control is essential to all systems, the lack of tillage for incorporation with no-till requires pre emergence, surface applied or post emergence herbicides. One or two properly timed applications may be necessary. For later planted crops, such as grain sorghum and soybeans, an early pre plant herbicide application at a one-half or two-thirds rate, near the first week of April when the probability of rainfall for herbicide incorporation and activation is high, has proven successful. This eliminates the need for a burn down herbicide. For full season weed control a second, lighter pre emergence herbicide application at planting time, a post emergence treatment, or crop cultivation may be needed. No-till planting is well suited to many soils. Residue, when uniformly spread, increases water infiltration and reduces soil moisture evaporation. In some poorly drained soils covered with large amounts of residue, the use of no-till may delay soil warming and drying in the early spring, which delays germination and emergence. This condition is rare for normal planting dates. When colder and wetterPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 6

soils are of concern with early planting dates, the use of no-till planter attachments designed to move only residue and not soil away from the row have proven successful. Another option would be the adoption of a ridge system to aid in warming and drying of the row area.No-till farming (also called zero tillage or direct planting or pasturecropping) is a way of growing crops from year to year without disturbing the soil through tillage. No-till is an agricultural technique which can increase the amount of water in the soil and decrease erosion. It may also increase the amount and variety of life in and on the soil but may require increased herbicide usage.

Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 7

Fig.(1): No Tillage (zero Tillage) examples.

Tilth and TillageSoil is the medium in which crops are grown but in its natural state, it is not in an ideal condition to grow them satisfactorily. Surface soil in which seed are to be sown, should not be hard & compact, but soft & friable, so that tender shoots of germinating seeds can push above the soil surface without any difficulty and the young roots penetrate easily into the lower layers of soil in search of food, water & air, Soil should also be free from weeds which otherwise rob the crop of water & nutrients. It should also have sufficient water & air which are very necessary for plant growth. Such ideal condition of soil can be achieved by manipulating the soil properly & bringing it in good filth through a series of mechanical operations like ploughing, clod crushing, dicing, harrowing, leveling, compacting, interculturing etc. by tillage implements. Tillage: Tillage is as old as Agriculture, Primitive man used to disturb the soil for placing seed Jethro Till considered as Father of Tillage Who Written Horse hocing Husbandry book. Tillage of the soil consists of breaking the hard compact surface to a certain depth and other operations that are followed for plant growth. Tillage is the physical manipulation of soil with tools & the tilling of land for the cultivation of crop plants i.e. the working of the surface soil for bringing about conditions favorable for Raising of crop plants. Tillage is the manipulation of soil with tools & implements for loosening the surface crust & bringing about conditions favorable for the germination of seeds and the growth of crops. Soil Tilth: Soil Tilth is the term used to express soil condition resulting from tillage. Hence it is the resultant of the tillage. A soil is said to be in good Tilth when it is soft, friable & properly aerated. The Tilth is the physical condition of the soil brought out by tillage that influences crop emergence, establishment, growth and development. Tilth is a loose, friable, airy, powdery granular &Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 8

crumbly structure of the soil with optimum moisture content suitable for working & germination or sprouting seeds & propagates Soil Tilth is that kind of physical condition of soil when it is loose. Not very powdery but granular & when these granules are felt between fingers they are soft, friable, & crumble easily under pressure, Such soils permit easy infiltration of water & are retentive of moisture for satisfactory growth of plants. Characteristics of good tilth/Measurement of soil tilth: Tilth indicates two properties of soil, viz the size distribution of aggregates and mellowness or friability of soil. Size distribution of soil aggregates: The relative proportion of different sized soil aggregates is known as size distribution of soil aggregates. Higher% of larger aggregates i.e. more than 5 mm are necessary for irrigated agriculture while higher% of smaller aggregates(1-2mm) are desirable for dry land agriculture. Theoretically, the best size of granules or aggregates ranges from 1 to 6 mm. However, it depends on soil, type, soil moisture content (at which ploughing is done) & subsequent cultivation. Mellowness or friability: is that property of soil by which the clods when dry become more crumbly. They do not crumble into dust but remain as stable aggregates of smaller size. A soil with good tilth is quite porous and has fee drainage up to water table. The capillary & non-capillary pores should be in equal proportion so that sufficient amount of water is retained in the soil as well as free air, The soil aggregates would be quite from or stable & would not be easily eroded by water or by wind. Soil tilth: is easy to describe but rather difficult to measure/ Theoretically, best size of granules ranges from 1-6 mm differs with country e.g. England as more than 15mm and Russia 2-3 mm. Besides this, study of pore space, equal distribution of macro & micro pores is good tilth. Ideal soil tilth : An ideal soil tilth is not the same for all types of crops & all types of soils e.g. small seeded crops like bajara, ragi, lucerne, Sesame, mustard require a much finer seedbed, Jowar & cotton require a moderately compact & firm seed bed and not cloddy or loose. Bold seeded crops like gram, maize germinate even in cloddy seedbed.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 9

As regards soil type, a very fine, powdery condition of the surface soil is decidedly bad for a heavy clay soil as it forms a caked surface under rainy condition and all the rain water is then liable to be lost by run-off, taking away also with loamy & lighter soils.

Objectives of TillageObjects of Tillage: These can be summarized in brief as below. 1. To make the soil loose & porous: It enables rain water or irrigation water to enter the soil easily & the danger of loss of soil & water by erosion and run-off, respectively, is reduced. Due to adequate proportion of microspores (capillary), the water will be retained in the soil & not lost by drainage. 2. To aerate the soil: Aeration enables the metabolic processes of the living plants & micro organisms, etc. to continue properly. Due to adequate moisture and air, the desirable chemical & biological activities would go on at a greater speed & result in rapid decomposition of the organic matter and consequently release of plants nutrients to be used by crops. Similarly, the evolution of CO2 gas in this process will result in forming weak carbonic acid in the soil which will make more nutrients available to crops. 3. To have repeated exchange of air / gases: There should be an exchange of air during the growing period of crops. As the supply of O2 from the air that is being constantly utilized in several biological reactions taking place in the soil; should be continuously renewed. At the same time CO2 that is released should be removed & not allowed to accumulate excessively decomposition of org. residues by microorganisms where O2 is utilized & CO2 released. Deficiency or excess of O2 may reduce the rate of reactions. O2 in soil air & atm. Air is more or less same i.e. 20 to 21% CO2 in atmospheric air is about 0.03% & in soil air 0.2 to o.3% which is 8to 10 times more than atmospheric air. It is, therefore, very necessary to often introduce atmospheric air in the soil to keep the concentration of CO2 under by suitable tillage operations. 4. To increase the soil temperature: This can be achieved byPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 10

controlling the air- water content of soil & also by exposing more of the soil to the heat of sun. This helps in acceleration of activities of soil bacteria & other micro organisms. 5. To control weeds: It is the major function of tillage; Weeds rob food & water required by crop & competition results in lowering of crop yield. 6. To remove stubbiest: Tillage helps in removing stubbles of previous crop and other sprouting materials like bulbs, solons etc in making a clean field/seedbed. 7. To destroy insect pests: Insects are either exposed to the suns heat or to birds that would pick them up. Many of the insect-pests remain in dormant condition in the form of pupae in the top soil during off season & when the host crop is again planted, they reappear on the crop. Some may harbor on stubbiest or other eminent of the crop. Grubs & cutworms can be destroyed by tillage. 8. To destroy hard pan: Specially designed implements (Chisel plough) are helpful to break hard pan formed just below the ploughing depth which act as barrier for root growth & drainage of soil. 9. To incorporate organic & other bulky manures: Organic manures should not only be spread but properly incorporated into the soil. Sometimes bacterial cultures or certain soil applied insecticides require to be drilled into the soil for control of pests like white grub. White ants, termites, cut worms e.g. Aldrin. 10. To Invert soil to improve fertility: By occasional deep tillage the upper soil layer rich in org. matter goes down thus plant roots get benefit of rich layer and lower layer which is less fertile comes to top.

Tilth and Tillage- Modern Concepts of TillageModern Concepts of Tillage:Tillage is time consuming, laborious & costly, owing to this new concepts like minimum tillage & zero tillage are introduced.

1. Minimum Tillage: It is aimed at reducing tillage operations tothe minimum necessary for ensuring a good seedbed, rapidPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 11

germination, a satisfactory stand & favorable growing conditions, Tillage can be reduced by: 1) Omitting operations which do not give much benefit when compared to the cost and 2) Combining agricultural operations like seeding & fertilizer application. Advantages: 1) Improve soil condition due to decomposition of plant residues in situ, 2) Higher infiltration caused by decomposition of vegetation present on Soils & channels formed by decomposition of dead roots. 3) Less resistance to root growth due to improved structure. 4) Less soil compaction by reduced movement of heavy tillage vehicles. 5) Less soil erosion compared to conventional tillage. Disadvantages: 1) Less seed germination, 2) More N has to be added as rate of decomposition of organic matter is slow. 3) Nodulation may affect in some legumes. 4) Sowing operations are difficult with ordinary implements.

2. Zero tillage: It is an extreme form of minimum tillage. Primarytillage is completely avoided & secondary tillage is restricted to seedbed preparation in the row zone only. It is followed where: 1) Soils are subjected to wind & water erosion, 2) Timing of tillage operations is too difficult & 3) Requirements of energy & labour for tillage are too high. Advantages: 1) Soils are homogenous in structure with more no. of earth worms. 2) Organic matter content increased due to less mineralization. 3) Surface runoff is reduced due to presence of mulch. Several operations are performed by using only one implement. In these weeds are controlled by spraying of herbicides. Disadvantages: 1) Higher N is too applied due to slower mineralization of org. matter.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 12

2) Large population of perennial weeds appears. 3) Build up of pests is more.

3. Stubble mulch tillage: The soil is protected at all times eitherby growing a crop or by crop residues left on the surface during fallow periods. It is year round system of managing plant residue with implements that undercut residue, loosen the soil and kill weeds. Soil is tilled as often as necessary to control weeds during the interval between two crops. However, it presents the practical problem as the residues left on the surface interfere with seedbed preparation & sowing operations. The traditional tillage & sowing equipment is not suitable under these conditions. Modern methods of tillage are not practiced in Indian condition because: a) Left over residue is a valuable fodder & fuel. b) Limited use of heavy machinery & therefore problem of soil compaction is rare.

4. Peddling: Pudding is ploughing the land with standing water soas to create an impervious layer below the surface to reduce deep percolation losses of water and to provide soft seedbed for planting rice. This followed in rice as the growth and yield are higher when grown under submerged conditions. Maintaining standing water throughout the crop period is not possible without pudding. It aims at destroying soil structure and separates individual soil particles i.e. sand, silt & clay, during operation and settles later. The sand particles reach the bottom, over which silt particles settle & finally clay particles fill the pores thus making impervious layer over the compacted soil. It is done with several implements depending on the availability of equipment and the nature of land such as spade, wetland plough, worn out Dryland plough, mould board plough, wetland puddler, country plough, etc. It consists of ploughing repeatedly in standing water until the soil becomes soft & muddy. Initially, 5-10cm of water is applied depending upon the water status of the soil to bring saturation and above and the first ploughing is carried out after 2-3 days. By this operation, most of the clods are crushed and majority of the weeds are incorporated. Within 3-4 days, another 5cm of water is given & third ploughing is done in both the directions. Planking or leveling board is run to level the field.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 13

5. Conservation tillage: It is disturbing the soil to the minimumextent & leaving crop residues on the soil. It includes minimum & zero tillage which can reduce soil loss up to 99% over conventional tillage. In most cases, it reduces soil by 50% over conventional tillage. Conventional tillage includes ploughing twice or thrice followed by harrowing & planking. It leaves no land unploughes & leaves no residues on the soil.

Preplanting Operations (Operations of seed bed preparation)Plowing:First operation in seed bed preparation used to Air the surface soil to a depth of 15-25 cm (or deeper if possible). Plowing is an art, and the ability to plow land well comes only through practice. Plowing is usually the first step in the preparation of the seedbed. In this operation the soil is loosened, the vegetable material on the surface is turned under and there is a more or less complete inversion of the soil which brings about pulverization. Plowing is one of the most important steps in seedbed preparation, and, if properly done, much labor is saved later on. Advantages of plowing: 1- Preparation of a proper seed bed 2- Killing weeds 3- Stirring the surface soil to be proper for root growth 4- Improving soil aeration 5- Burying previous crop residues to help it decompose faster 6- Allowing water absorbing by the soil (particularly in rain-fed crops) 7- Exposure of soil pest to sun radiation, thus reducing their population.(ex. worms, pupae, larvae...) . How is soil ready to plowing? . 1-Soil is easily pulverized without stitching to your hand. Soil water content should be 50-60 % of field capacity.(Field capacity is the amount of waterPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 14

left in the soil after leaching excess water.) 2-Soil does not stick to the plows. 3-Soil does not dirty the hand when touched. Pan hard Layer (Sub soiling plowing) : Sub soilers are used for plowing below the depth reach by ordinary plowing , it results in increased water infiltration and better crop yield due to destruction of hard pan layers . Its depth range : 70-90 cm .

Fig. 2:SubSoiler Plow Plowing time :The time to plow will vary with the climate, crop and soil condition. The best time to plow the soil is after the prior crop harvested. The land should be plowed and kept prepared for as long a time as possible before the crop is planted. At this time there is no special ruche or other work; organic matter can be turned under given time to decay. In sod lands and heavy soils such as clay loams, earlyPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 15

plowing may be advisable because (1)Plowing buries green or dried material, and (2) improve the structure of the soil. In regions of high winds the loose, open soils, poor in organic matter, are likely later plowing.

Advantages of early Plowing:(1)Allowing previous crop residues to decompose and enrich soil organic content. (2)Exposure of soil pest to sun for longer time. (3)Soil regain of its natural and chemical properties and improving aeration and gases exchange. (4)Allowing more time for the consequent operations.

Advantages of late Plowing:(why plow late?)(1)If soil water content is high have to wait till it dries or plow in a distant spaces to allow quick dry of the soil (particularly if it rained shortly before planting). (2)In case of sandy soil and soils with sharp slopes, plowing is done late to preserve soil from erosion (because weeds and plant residues keep the soil moisture and they should not be plowed until shortly before planting).

Plowing depth :Most farmers prefer shallow plowing to avoid higher costs . However a gradual increase in yield may be expected as plowing depth increases from 10-20cm .Varying plowing depth from year to year may avoid establishing compact subsurface layers benefits of deep.

Advantages of deeper plowing :1. Deeper incorporation of organic matter . 2. Better control of deep rooted and perennial weed . 3. Preventing soil pans formation in sub soil .

Factors affecting depth of plowing:1. Kind of crops to be grown : Deep ( 20-30 cm ) for cotton ,

sugar cane and potatoes , shallow (5-10 cm ) for wheal and barley . 2. Soil type : sandy or clay .Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 16

3. Available machinery tools.

Signs of good plowing :1.The second phase of plowing should be perpendicular (vertical) on the direction of the first phase of plowing. 2.No untilled spots . 3.No growing weed . 4.Fine soil surface without big clods . 5.Constant plowing depth . 6. Straight plowing lines with minimize overlapping . 7.Mixture of manure .

Type of mechanical plows1- Chisel plows. 2- Moldboard plows. 3- Disc Plows. 4- Rotary plows. 5- Subsoiler plows. 1- Chisel plowsStir the surface layer of the soil without changing soil profile. It breaks and pulverize the top soil. Distance between the units is 50 cm. Depth of plowing 10-20 cm. Commonly used in Egypt due to its several advantages. Used in salty and alkaline soils (as it does not change salt distribution in soil profile), soil with high water table and soils in which fertility concentrates in the surface layer only. Require little tractor power. Lower operational costs. Uniform distribution of organic matter. Use curved shanks to penetrate and "stir" the soil without inverting a soil layer. Chisel plows cause less residue disturbance than moldboard plows and are often used in conservation tillage systems.

Fig. 3 : Chisel plowsPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 17

2- Moldboard PlowsVery efficient in fulfilling plowing objectives . It loosen the soil by forcing a triple wedge through it and inverts its surface to incorporate and core plant residues and manure . 15-35 cm plowing depth . The moldboard plow has a large frame that is equipped with a series of "bottoms," each of which consists of a steel coulter to slice through residue followed closely by a steel share that cuts the soil and an attached moldboard that is used to raise and turn over the cut "slice" of soil.

Fig.4: Moldboard plow

3- Disk plowDisk plows usually have three or more individually mounted concave disks that are inclined backward to achieve maximum depth. They are particularly adapted for use in hard, dry soils, shrubby or bushy land, or on rocky land. Disk tillers, also called harrow plows or one-way disk plows, usually consist of a gang of many disks mounted on one axle (see harrow). The disk plow employs round, concave disks of hardened steel, sharpened and sometimes serrated on the edge, with diameters ranging from 20 to 38 inches (50 to 95 centimeters). It reduces friction by making a rolling bottom in place of a sliding one. Its draft is about the same as that of the moldboard plow. The disk plow works to advantage in situations where the moldboard will not. It can be used in loose soils and those too dry and hard for easy penetration by moldboard. It haves organic residues mixed with the soil surface . But it dose not invert the soil surface as well as moldboard 20-40 cm plowing depth .


Fig.5: Disk plow Table.1:Comparision between Mechanical types of plowsCharacters ChiselClay loam, Saline, Sandy

MoldboardHeavy clay, weeds infested

Types of Plows DiskHard dry stony with tough roots residues

RotaryDeep root weed infested

SubsoilerSoil contain pan hard

owing depth

** ** **** ** *

*** **** ** *** ****

**** *** ** **** ****

* * ***** * ***

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Fig.6: Types of Plows


4- Rotary plow-Stir the soil thoroughly leaving a fine texture behind. - Surface plowing. -Several units. -Used in deep-root weed- infested soils. -Required less power than the chisel plow.

Fig.7: Rotary Plow

5- Subsoiler plowSub soiler are used for plowing below the depth reach by ordinary plowing, it results in increased water infiltration and better crop yield due to destruction of hard pan layers. Its depth range 70-90 cm. -Stir the deep hard layers. -Depth plowing is 70-90 cm. -Used on unit. -Used in soils with deep hard layers. -Require relatively high tractor power.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 21

Fig.8:Subsoiler Plow

HarrowingIn agriculture, a harrow (often called a set of harrows in a plurale tantum sense) is an implement for breaking up and smoothing out the surface of the soil. In this way it is distinct in its effect from the plough, which is used for deeper tillage. Harrowing is often carried out on fields to follow the rough finish left by ploughing operations. The purpose of this harrowing is generally to break up clods (lumps of soil) and to provide a finer finish, a good tilth or soil structure that is suitable for seedbed use. Such coarser harrowing may also be used to remove weeds and to cover seed after sowing. Harrows differ from cultivators in that they disturb the whole surface of the soil, such as to prepare a seedbed, instead of disturbing only narrow trails that skirt crop rows (to kill weeds).it is done after plowing to fulfill the following objectives: 1-Fine soil surface with no big clods. 2-Removal of weeds vegetative parts remaining on the soil surface after plowing. 3-Remval of previous crop residues which may interfere with the placement of new crop seeds. 4-Improvement of aeration at the soil surface. 5-mixing of animal manure with soil particles. For harrowing to be carried out efficiently, the following points must be consider: 1-It must be conducted directly after plowing. 2-Oppsite direction to the last plowing phase. 3-Harrowing depth is similar to that was used for plowing to improve sub-surface condition.

Types of Harrows1-

Disk harrow


2345-

Chain harrow Spike tooth harrow Spring tooth harrow Rotary cross harrow.

There are four general types of harrows: disc harrow, tine harrow, chain harrow and chain disk harrows. Harrows were originally drawn by draft animals, such as horses, mules, or oxen, or in some times and places by manual labourers. In modern practice they are almost always tractor-mounted implements, either trailed after the tractor via a drawbar or mounted on the three-point hitch. In cooler climates the most common types are the disc harrow, the chain harrow, the tine harrow or spike harrow and the spring tine harrow. Chain harrows are often used for lighter work such as levelling the tilth or covering seed, while disc harrows are typically used for heavy work, such as following ploughing to break up the sod. In addition, there are various types of power harrow, in which the cultivators are power-driven from the tractor rather than depending on its forward motion. Tine harrows are used to refine seed-bed condition before planting, to remove small weeds in growing crops and to loosen the inter-row soils to allow for water to soak into the subsoil. The fourth is a chain disk harrow. Disk attached to chains are pulled at an angle over the ground. These harrows move rapidly across the surface. The chain and disk rotate to stay clean while breaking up the top surface to about 1 inch (3 cm) deep. A smooth seedbed is prepared for planting with one pass. Chain harrowing may be used on pasture land to spread out dung, and to break up dead material (thatch) in the sward, and similarly in sports-ground maintenance a light chain harrowing is often used to level off the ground after heavy use, to remove and smooth out boot marks and indentations. When used on tilled land in combination with the other two types, chain harrowing rolls the remaining larger clumps of soil to the surface where the weather will break them down and prevent interference with seed germination. Crumbler roller, commonly used to compact soil after it has been loosened by a harrowPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 23

All four harrow types can be used in one pass to prepare the soil for seeding. It is also common to use any combination of two harrows for a variety of tilling processes. Where harrowing provides a very fine tilth, or the soil is very light so that it might easily be windblown, a roller is often added as the last of the set. Harrows may be of several types and weights, depending on the intended purpose. They almost always consist of a rigid frame to which are attached discs, teeth, linked chains or other means of cultivation, but tine and chain harrows are often only supported by a rigid towing-bar at the front of the set. In the southern hemisphere the so-called giant discs are a specialized kind of disc harrows that can stand in for a plough in very rough country where a moldboard plough will not handle the treestumps and rocks, and a disc-plough is too slow (because of its limited number of discs). Giant scalloped-edged discs operate in a set, or frame, that is often weighted with concrete or steel blocks to improve penetration of the cutting edges. This sort of cultivation is normally immediately followed by broadcast fertilization and seeding, rather than drilled or row seeding. They can drawn by horses or tractors. It is not a common practice in Egypt, but in USA it has a widely used. It works (disk harrow) somewhat like the moldboard plow; both turn the soil in furrows. But the disk harrow turns small furrows. It raises the earth and pushes it to one side.

Control of penetration :You can control the depth of which the disk blades penetrate by: I) Using a heavy or light harrow. 2) Adding weights on the harrow 3) Using few or many disks per harrow 4) Exerting hydraulic forces, up or down 5) Using transport and depth regulating wheels 6) Using dull or sharp disk blades 7) Using smaller or layer disks 8) Using cutout or notched disks 9) Adjusting the angle of the disk gangs.


Fig.9:Types of harrows

CompactingIt is commonly conducted after plowing to break large size soil clods and Particles. Also, it is used to cover large seeds after the broadcasting such as faba bean. It helps in the preservation of soil moisture content after plowing. Wooden breaks are pulled by animals of tractor. Also, mechanical compactors may be mounted behind tractor.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 25

Land LevelingTo increase irrigation ease and efficiency the soil surface must be leveled with a slope of 0.5% or less to have a gentle water flow for uniform distribution and minimum erosion.

A-Dry Leveling:By using scraper for leveling dry soil height differences that can be seen by eye (more than 10 cm). The scarper may be carried by animal for small acreage or by using tractors in large farm. Signs for requiring dry leveling: 1-Saltsw appearance on soil surface. 2-Irrigation plant growth in the field. 3-Ununiform water distribution during irrigation. 4-Lower germination percentages. 5-Difficult passage of water through irrigation channels. Required conditions: 1-Maintance of the natural slope from field head to tail. 2-Dry soil and clean surface from vegetative weeds or crop residues. 3-Distribution for removed soil evenly on as large area as possible. 4-Scraper movement in straight lines. 5-Avoid gaps between adjacent lines.\ Disadvantages of dry leveling: 1-Removal of soil fertility from higher to lower spots. 2-Extra costs and time.

Fig.10 : Land dry leveling.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 26

B-Wet Leveling:It means leveling the soil surface in the presence of a thin water layer above it, in order to recognize small height differences(less than 10 cm). Such precise leveling is required for certain crops Egyptian clover and rice. In order to insure proper and high germination and seedling establishment. Disadvantages: 1-Leaching of mineral nutrients. 2-Reduced aeration. 3-Very cost. 4-Low soil fertility. Leveling advantages: 1-higher germination percentages. 2-Uniform growth. 3-Improvement of irrigation efficiency. 4-Higher use of chemical fertilizers.

Fig.11: Filed wet leveling


In both wet and dry land preparation, it is important to properly level the field to promote and maintain a uniform water depth and thus ensure good crop stand and increase water use efficiency.

Land division 1-BorderingIn order to regulate the irrigation and other post management operation the field must be divided into small units(plots) by using Battana. This system used in case of sowing dense crops under traditional irrigation.

Factors affecting the size of the plots:1-Soil type (in heavy soil is much greater than in light soils) 2-Crop kind. 3-Soil topography 4-Soil salinity. Size of the plot of different crops: Wheat, barley and beans may be 410 m; rice and berseem clover 1025m. A-In case of one slope direction Permanent Canalt

Head of field

Slope direction

Plot

Plot Plot Plot

section

section

section

Flat Land

Temporary Canal Tail (end)of field

Main Border

Field Before Bordering

Field Divided Into Sections

section

Field Divided Into Plots


The above sketch gives an example for bordering a wheat field a level land. The field is divided by main borders and temporary canals, made vertical to the permanent irrigation canal. Another borders are made across to these borders and canals. Each temporary irrigated two sides. The width of the border is about 50 - 60 cm. The field canal is formed by making two adjacent borders, and has a width of about 120- 150 cm. Field canals are then being smoothed, and the borders being firmed by the hand hoe "fas". The native bordering implement "Battama" is widely used for making borders and canals.

A-In case of two slope direction Permanent CanalHead of field

Slope direction

Plot

Plot Plot Plot

section

section

section

Flat Land

Temporary Canal Tail (end)of field

Temporary Canal

Second Slope Direction

Field Before Bordering

Field Divided Into Sections

section

Field Divided Into Plots

The above sketch gives an example for bordering a wheat field a level land. The field is divided by temporary canals only made vertical to the permanent irrigation canal. Another cross borders are made across to these canals. Each temporary canalPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 29

irrigate one side only.

2-Ridging and furrowingIt is carried out after plowing and compacting to transform the soil surface from flat to ridges. In order to adjust the distances between the new crop plants depending on spacing needs above and below the soil surface. Also, seeds placement in hills of each row depending upon the growth nature of the new crop.

Advantages of ridging:1- Ridges are warmer than the level, at least on one side. 2- The soil is drier and the loose to of the ridges ensure

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aeration of the soil and prevents cracking of the soil The seeds or seedlings can be protected by planting them on the sheltered sunny side in winter. The crop is more easily irrigated and water can have more regular distribution Easily cultivation (hoeing). Enhance the germination (dryness and warmth of the sunny side) Post planting practices (i.e., replanting, thinning, and weed control, fertilizing and harvesting) can be easier done when crops are grown on ridges. No danger from excess irrigation water as in the case of growing crops on flat land.

After ridging, the field is divided into (ridged plots) by means of field canals and borders, to regulate irrigation. Ridges vary in their distance according to the type of crop. They can have a distance between 50 to 70 cm. For the distance between ridges. It can be done by special modern plows.


Fig.12: Ridges and furrows


Ridging direction:1-Parallel permanent canal. 2-Vertical on slope direction. 3-Parallel the longest side of field if the field is narrow. 4-In case of cotton crop sowing ridging must be from East to West but in corn from North to South. Ridged Plot: Number of ridges surrounded by one temporary canal and one mean border and two separator ridges.Permanent Canal

up Slope direction

down Temporary Canal

Ridged Plots Main Border Cross border (Separator ridge)

The land after plowing , compacting ridged

The land divided into ridged plots by and made temporary canals and main borders and separator ridges


Fig.13: Clean ridges


Seeds and SowingSeed is any material used for planning & propagation whether it is in the form of seed (grain) of food, fodder, fiber or vegetable crop or seedlings, tubers, bulbs, rhizomes, roots, cuttings, grafts or other vegetatively propagated material. Seed is a fertilized ovule consisting of intact embryo, stored food (endosperm) and seed coat which is viable & has got the capacity to germinate.As we say, Reap as you sow, the good quality seed must have following characters: 1. Seed should be genetically pure & should exhibit true morphological & genetical characters of the particular strain (True to type). 2. It should be free from admixture of seeds of other strains of the same crop or other crop, weeds, dirt and inert material. 3. It should have a very high & assured germination percentage and give vigorous seedlings. 4. It should be healthy, well developed & uniform in size. 5. It should be free from any disease bearing organisms i.e. pathogens. 6. It should be dry & not mouldy and should contain 12-14% moisture. Seed is the basic input in the crop production which should be of good quality.

Seed rate: The seed rate per unit area depends on germination ofthe seed, size of the seed, growing habit of the crop, etc. Extremes from the recommended seed rate (i.e. too high or too low) affect the plant population & then yield of crop. E.g. higher seed rate will influence higher plant population/unit area. It results in heavy competition within the crop plants and suppresses the crop growth. Lower seed rate will result lower plant population thereby lowers the yield/unit area. The seed rate is governed by the ultimate stand desired. Most crops are seeded at smaller rates under dry land than under irrigated condition. Seed rate depends on size, germination, growing habit, type of farming, time of sowing, variety, etc.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 34

Sowing of Seed Methods of SowingMethods of Sowing: Is the operation of placing the new crop seeds or vegetative part in soil after or during seed bed preparation. The sowing method is determined by the crop to be sown. There are 6 sowing methods which differ in their merits, demerits and adoption. Those are: 1. Broadcasting 2. Broad or Line sowing 3. Dibbling 4. Transplanting 5. Planting 6. Putting seeds behind the plough. 1. Broadcasting: It is the scattering of seeds by hand all over the prepared field followed by covering with wooden plank or harrow for contact of seed with soil. Crops like wheat, paddy, Sesamum, methi, coriander, etc. are sown by this method. Advantages: 1) Quickest & cheapest method 2) Skilled labour is not uniform. 3) Implement is not required, 4) Followed in moist condition. Disadvantages: 1) Seed requirement is more, 2) Crop stand is not uniform. 3) Result in gappy germination & defective wherever the adequate moisture is not present in the soil. 4) Spacing is not maintained within rows & lines, hence interculturing is difficult. 2.Drilling or Line sowing: It is the dropping of seeds into the soil with the help of implement such as mogha, seed drill, seed-cum-ferti driller or mechanical seed drill and then the seeds are covered by wooden plank or harrow to have contact between seed & soil. Crops like Jowar, wheat Bajara, etc. are sown by this method. Advantages: 1) Seeds are placed at proper & uniform depths, 2) Along the rows, interculturing can be done, 3) Uniform row to row spacing is maintained,Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 35

4) Seed requirement is less than broad casting 5) Sowing is done at proper moisture level. Disadvantages: 1) Require implement for sowing, 2) Wapsa condition is must. 3) Plant to plant (Intra row) spacing is not maintained, 4) Skilled person is required for sowing. 3. Dibbling: It is the placing or dibbling of seeds at cross marks (+) made in the field with the help of maker as per the requirement of the crop in both the directions. It is done manually by dibbler. This method is followed in crops like Groundnut, Castor, and Hy. Cotton, etc. which are having bold size and high value. Advantages: 1) Spacing between rows & plants is maintained, 2) Seeds can be dibbled at desired depth in the moisture zone, 3) Optimum plant population can be maintained, 4) Seed requirement is less than other method, 5) Implement is not required for sowing, 6) An intercrop can be taken in wider spaced crops, 7) Cross wise Intercultivation is possible. Disadvantages: 1) Laborious & time consuming method, 2) Require more labour, hence increase the cost of cultivation, 3) Only high value & bold seeds are sown, 4) Require strict supervision. 4. Transplanting: It is the raising of seedlings on nursery beds and transplanting of seedlings in the laid out field. For this, seedlings are allowed to grow on nursery beds for about 3-5 weeks. Beds are watered one day before the transplanting of nursery to prevent jerk to the roots. The field is irrigated before actual transplanting to get the seedlings established early & quickly which reduce the mortality. Besides the advantages & disadvantages of dibbling method, initial cost of cultivation of crop can be saved but requires due care in the nursery. This method is followed in crops like paddy, fruit, vegetable, crops, tobacco, etc. 5. Planting: It is the placing of vegetative part of crops which are vegetatively propagated in the laid out field. E.g.: Tubers of Potato, mother sets of ginger & turmeric, cuttings of sweet potato & grapes,Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 36

sets of sugarcane. 6.Putting seeds behind the plough: It is dropping of seeds behind the plough in the furrow with the help of manual labour by hand. This method is followed for crops like wal or gram in some areas for better utilization of soil moisture. The seeds are covered by successive furrow opened by the plough. This method is not commonly followed for sowing of the crops. Also, Such method can be classified according to following principles: (A)Land division: 1-Sowing without land division (the condition of rain field farming. 2-With land division :(Section) is commonly used under irrigated farming. (B)Seeds placement methods in soil: 1.Broadcasting. 2.Drilling in narrow rows. 3.Wide rows and hills. 4.Transplanting. (C)Time of irrigation for sown seeds: 1.Dry sowing (before irrigation). 2.Wet sowing (after irrigation). 3.Sowing in water.

Factors affecting the selection of proper sowing methods:1.Seeds and plant size. 2.Crop growth nature. 3.Soil type. 4.Climatic conditions. 5.Sowing date. 6.Weed Population density. 7.Production objectives. 8.Soil Slope.


Sowing methods in Egypt:(A)Dry methods:1.Broadcasting before bordering. 2.Broadcasting after bordering. 3.Drilling in narrow. 4.Ridges and hills. 5.Wide rows and hills.

(1)Broadcasting before bordering:1.Plowing. 2.Harrowing. 3.Compacting. 4.Broadcast the seeds. 5.Compacting again to covering the seeds. 6.bordering into plots. 7.Irrigation.

(2)Broadcasting after bordering::1.Plowing . 2.harrwoing. 3.Compacting. 4.Boerdering. 5.Broadcast the seeds. 6.Irrigation after covering the seeds by hands.

(3)Drilling in Narrow Rows:1.Plowing. \ 2.Harrowing. 3.Compacting. 4.Bordering(land division into strips suitable for dollars width. 5.Sowing by machine. 6.Irrigation.

Why drilling is the proper methods for dry sowing?1-Easily conduct the management operations. 2-Save in seeds. 3-High germination percent. 4-Sowing seeds in the same depth.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 38

5-Save the laborious and time . 6-High Yield. Disadvantages: -Very cost. -Need wide area. (4)Wide Rows and hills: 1.Plowing . 2.harrwoing. 3.Compacting. 4.Boerdering into plots. 5.Sowing in hills in regular distances. 6.Irrigation. Advantages : -It is considered improved method for broadcasting after bordering. Disadvantages : 1.Decrease germination percent. 2.Decrease yield. 3.Difficult to conduct management operation. (5)Ridges and hills : 1.Plowing. 2.Harrowing. 3.Compacting. 4.Ridging and land division into ridges. 5.Conect borders, clean ridges. 6.Sowing in hills at regular distances different between crops. 7.Irrigation. (B)Wet Sowing Methods: 1.Broadcasting : -Soil irrigation; waiting until proper dryness (50-60% F.C.) -Seeds Broadcasting into vertical directions. -Shallow Plowing. -Soil compacting. -Land division into plots by temporary canals and borders. 2.Ridges and hills: -Plowing. -Compacting -Furrowing at the recommended distance for new crop. -Land division into ridged plots by field temporary canals.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 39

- Manual adjustment of ridges shape and straight edges. -Irrigation and waiting until proper dry(50-60% F.C.).Note -Sowing seeds in hills at suitable space on one side or two sides.

Sowing Time, Depth of Sowing, Spacing and Plant PopulationSowing Time: It is the non monetary inputs which greatly influence the crop growth & yield. Therefore, sowing of crop should be done at recommended dates. Any fluctuation in optimum sowing time results in drastic yield reduction. E.g. Wheat.

Spacing and Plant Population: Spacing between the row andwithin the plants decides the plant stand/plant population per/unit area. Optimum plant population results in normal crop growth & thereby yields. One can manipulate the R/R & P/P distance but care should be taken for maintaining the optimum plant population as per the recommendations. A dense population results in competition for nutrients, moisture & light and thereby suppressed growth while less population results in low yield /unit area. Yield of a crop is the result of final plant population which depends on the no. of viable seeds, germination % and survival rates. An establishment of optimum plant population is essential to get maximum yield. Yield/plant decreases gradually as plant population/unit are is increased. However, the yield/unit area is increased due to efficient utilization of growth factors. Optimum plant population depends on plant size, elasticity, foraging area, nature of the plant, capacity to reach optimum leaf area at an early date & seed rate used.

Depth of Sowing: It is also non-monetary input which decidesplant stand in the field. It influences the germination & emergence of seed. Sowing should be done at recommended depth. These vary with the kind of seed and its size. Bigger seeds may be sown at a greater depth while small sized seeds at shallow. Seed should be dropped in the moist zone. Factors affecting sowing depth: 1.Soil Type. 2.Seed size. 3.No.of seeds per hill.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 40

4.Sowing methods. 5.Growth nature of new crop.


Comparison between dry and wet sowing methods Dry method1.Sandy soils (light) 2.Saline soils 3.Soil free weeds 4.Leveled soils 5.In case of late sowing date

Wet method1.Clay loam (heavy soils) 2.Free saline soils(No-Salinity) 3.Infested soil by weeds 4.Unleveled soils. Early sowing date.

1.Soil types preferred :

Advantages:1.Save in seeds 2.Higher germination % 3.Higher emergence seedling 4.Save in time, effort and costs 5.Increase yield

Disadvantages:1Require higher amount of seeds 2.Decrease in germination % 3.Late of emergence seedling 4.Consuning more time, high effort and costs 5.Decrease yield

(C)Planting in presence water: (1)Broadcasting: Used in planting rice and Egyptian Clover)1.Plowing 2.Harrowing 3.Wet leveling. 4.Broadcast the seeds

(2)Transplanting:This method is used in Egypt mainly in planting rice. Using 1/8 of the filed as a nursery and planting rice by the previous method using the seeds needs for faddan. After one month when the rice plants are 15-20 cm above soil surface the seedling distributed all over the whole field after preparing the field as in broadcasting method.


Post Planting operationPlant population density :No. of plants per unit area of land. The optimum density must produce maximum yield thus the recommended level may be vary from one crop to another according to growth nature, space requirements (above &below) soil surface.Yield/area (total yield/unit area)= Individual plant yield No. of plants area

The specific density for each crop could be adjusted by four itms: 1.Sowing method. 2.Seeding rate. 3.Rows &ridges &hills spacing. 4.No. of plants/hill. Factors affecting optimum density: 1.Crop type 2.Sown cultivar. 3.Production purpose. 4.Sowing date. 5.Soil fertility.

Crop Management1.Replanting:It is the operation of repeated sowing in empty spots in the field to reach optimum plant density. It must be conducted as soon as possible after complete seeding emergence by using the same cultivar to avoid maturity variation. Replanting could be avoided if the number of absent spots is not significant (less than 5%), because higher yield by adjacent plants may compensate for such absents.

Reasons for plants absent during germination &seedling stages:1.Irrigation (Excess or shortage). 2.Not fertile soil. 3. Broken seed or seed infected by fungi. 4.Seed bed preparation is not good. 5.Non suitable seeding depth. 6.Infection by diseases or fungi. 7.Birds may picked the seeds. 8.Grelottalba & rates. 9.Soil type: may be saline or calcareous soil.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 43

Replanting methods:1.Wet method: the commonly used in low absent spots (12-24%) by emersion seeds in water for 24 hr. 2.Dry method: more than 24% by sowing of dry seeds then irrigation. 3.Transplanting: Rice.

2.Thining:Due to high Plant density we do it. It is conducted to insure optimum plant density for a given crop shortly after seedling emergence by removal of undesired no. of plants from high density spots to avoid intra specific competition for growth resources. So that remaining plants would grow vigorously and produced their maximum yield. Inter specific competition : competition between plants &weeds Intra specific competition: competition between plants and others. Thinning precautions: 1.Removeweak and broken plants. 2.Early thinning to avoid competition and connection between plants in the hill. 3.In case of common infection in the field must be two thinning .

3.Hoeing (cultivation):It means removal and disturbance of the dry top soil in order to destroy weeds and improved O2 exchange also it provides mechanical support to growing crop plant by accumulation of soil particles around their basis. In Egypt it is conduct by Hoes (manually) or mechanically by cultivators. Some field crops may not need Hoeing (Cultivation), at all if planted by broadcasting such as Rice, Wheat, Egyptian Clover and Barley. At early growth stages (seedling stage) hoeing must shallow; however, deeper hoeing (5-7 cm2) could be used in heavy soil and vegetative growth. One hoeing= 1/2 Irrigation (Because it covering cracks in surface so prevent evaporation of water by sun rays (avoid water loss).


Weeds and Their ControlThere are 3 serious pests of the crop plants which causes loss of yield, i.e. 1. Insect-pests, 2. Diseases, 3. Weeds. The estimated losses in crop yields range from 5% in clean cultivated fields over 70% in neglected fields depending upon the degree of weed infestation. They compete with crop plants for nutrients, water, light and space. The loss of N through weed is as high as 150 kg/ha.

WEED: Any plant not sown in the field by farmer is out of place,called weed. The term, weed used by Jethro Tull for the first time, suggested an useless and harmful plant that persistently grows where it is quite unwanted. According to Robinson: Weeds are that species of plants which grow unwanted or are not useful, often prolific, persistent, interfere with agricultural operations, increase labour cost and reduce the crop yields.

Weed is a plant growing where it is not wanted, unwanted plant, outof place, extremely noxious, useless, and poisonous.

Characteristics of weeds: Weeds are like any other crops plantsin size, form, morphological & physiological characters but possess the following characteristics, on account of which they are considered as enemy of crops by the farmer. 1. The weed seeds germinate early and the seedlings grow faster. They being hardy, compete for light, moisture and nutrients. 2. They flower earlier, run to seed in profusion and mature ahead of the crop. They are difficult to control and it may be even impossible to eradicate some weeds completely. 3. They are non-useful, unwanted & undesirable. 4. They are harmful to crops, cattle and human beings. 5. They can thrive even under adverse conditions of soil, climate, etc. 6. They are prolific and have a very high reproduction capacity. E.g.: A plant of satyanashi (Argemone mexicana) produces over 5000 seeds while a plant of striga produces over half a million seeds.Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 45

7. Viability of weed seeds remains intact, even if they are buried deep in the soil. In some cases, the seeds may remain viable even after passing through the digestive tract of the animals. 8. The seeds may have special structures like wings, spines, hooks, sticky hair, etc. on account of which they can be easily disseminated over long distances. 9. Many weeds like Cynodon dactyl on are vegetatively propagated and spread rapidly all over the field even under adverse conditions

Weeds & Their Control- Classification of WeedsWeeds can be classified in many ways as:

A) Classification based on life cycle: a) Annuals: Weeds complete their life cycle within a year.i) Seasonal weeds: 1. Summer season weeds: Weeds complete their life cycle during summer season. 2. Winter annuals season weeds: Weeds complete their life cycle during winter season. ii. Two seasonal weeds: Weeds complete their life cycle within two seasons

b) Biennials: Weeds require two years for completion of their lifecycle.

c. Perennials: Weeds continue their life cycle for years together. B) Classification based on habitat or place of occurrence:a. Weeds of cropped land: b. Weeds of pastures & grazing lands: c. Weeds along water channels: d. Weeds along roadside: e. Weeds of waste lands: f. Weeds of lawn & orchards: g. Weeds of forest lands: .

C) Classification based on dependence on other hosts:a. Stem parasite: b. Root parasite: c. Independent:Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 46

D) Classification based on soil type:a. Weeds of black soils: b. Weeds on sandy loam soil. c. Weeds of ill drained soil. d. Weeds in tank: It may be submerged, immersed or floating. E.g.: Aquatic weeds like water hyacinth, cattails.

E) Classification based on plant family:a. Graminae. b. Commelinaceae. c. Cyperaceace. d. Amaranthaceac. e. Euphorbiaceae. f. Composite. g. Leguminous. h. Malvaceae. i. Tiliaceae. j. Cruciferae. k. Chenopodiaceae. l. Solanaceae. m. Papaveraceae. n. Portulacaceae. o. Orobanchaeceae. p. Cactaceae.

Weed Control MethodsBroadly classified in two groups:

A)Preventive Measures. B) Curative or Control Measures which includes:i. Mechanical ii.Cropping or Cultural iii.Biological & iv.Chemical

A) Preventive Measures: In this, the weeds are prevented fromits multiplication, introduction & nipped off the buds. It consists of: 1) Use clean seed, 2) Use well decomposed FYM/Compost,Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 47

3) Cut the weeds before seeding, 4) Remove weed growth or keep irrigation & drainage channels clean or free from seeds, 5) Avoid feeding of grain screenings, hay or fodder containing weed seeds without destroying their viability by grinding or cooking, 6) Avoid use of sand or soil from weed infested areas to clean or cultivated areas, 7) Avoid allowing castles to move from weed infested areas to clean or cultivated areas, 8) Clean all the farm implements & machinery properly after their use in infested areas & before using in clean areas, 9) Keep farm fences, roads & bunds clean or free from weeds. 10) Watch seedlings in nurseries carefully so that they do not get mixed with weed seedlings & get carried to the fields.

B) Curative Measures: These measures are followed to removeor to smother the weed growth & further multiplication. It includes: i) Mechanical methods (Physical): It comprises: 1) Hand pulling; 2) Hand weeding; 3) Burning; 4) Flooding; 5) Hoeing; 6) Tillage; 7) Moving; 8) Smothering with non-living material (mulching). Burning of seed bed.

ii) Cropping and competition methods (Cultural): One whoestablish first/early, will suppress other. Therefore, the cultural practices are so managed that the crop plants should establish earlyPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 48

and grow faster ahead of the weeds. It includes: 1) Crop roations: It checks the free growth of weed due to change of crops season to season. 2) Kind of crop: Groundnut covering crops like legumes will smother the weed growth. E.g.: sun hemp, groundnut. 3) Use of fertilizers: Application of optimum doses of fertilizers to crop will help to grow faster. 4) Date & rate of planting or sowing: Sowing of crops at proper time with optimum seed rate will help the crop to cover the ground & will make the weeds deprive of light. iii) Biological methods: It includes the use of living organisms for suppressing or controlling the weeds. Plant, animal or micro organisms may be used for destruction of weeds. These are called as bioagents which feed on only the weeds and not on crop plants. E.g.: Prickly pear or Nagphana weed in South India was controlled by Conchineal insects. (Dactlopius tomentosus). In Australia (Hawaii Islands) several kinds of moths were used to control Lantana Camara which eats the flowers & fruits. This method is very efficient & economical provided right type of predators, parasites or pathogens which even under starvation conditions will not feed upon cultivated crops are found out & introduced. iv) Chemical methods: This is very effective in certain cases and has a great scope provided the chemicals are cheap, efficient & easily available. The chemicals used for weed control & which suppress or destroy the growth of weeds, called as herbicide. These either help in killing the weeds or in inhibiting their growth.E.g.2, 4-D, Atrazine, Glyphosate, etc.

Types of herbicide:i) Selective herbicides are those which kill only weeds without injuring crop plants. ii) Non-selective herbicides are those which kill all kinds of vegetations i.e. weed and crop plant. iii) Contact herbicides kill all the plant parts which may get covered by the chemical by directly killing the plant cells. These chemicals are effective against annuals particularly when they are young but notPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 49

perennials. iv) Translocated/Systemic herbicides are first absorbed in the foliage or through roots and are then translocated to other parts of the plant. Or Kill plants after their absorption by accelerating or retarding the metabolic activities of plants. These are more effective in destroying deep rooted perennials.

Soil sterilents: are non-selective herbicides and have to be appliedinto the soil. They make the soil sterile and incapable of supporting any plant growth. As such any weed seeds or weed seedlings present in the soil are killed. Based on relative time of application to weed emergence the herbicides are classified as: I) Pre-plant applied (Before planting of crop) II) Pre-emergence (Before emergence of weeds) III) Post-emergence (After emergence of weeds) Acid equivalent (a.e.) refers to that part of the formulation that theoretically can be converted into the acid. Active ingredient (a.i.) is that part of the chemical formulation which is directly responsible for the herbicidal effects. Pre and post-emergence treatments to control weeds: Both the terms, Pre and post-emergence treatments are related with time of application of herbicides for control of weeds. Pre-emergence treatment or application of herbicides: Application of herbicides after sowing of crop but before emergence of crop and weeds is called pre-emergence application. It is done from first to fourth day of sowing and only selective herbicides are used. Generally germinating weeds are killed by pre-emergence application and gives competitive advantage of crop. E.g.: Pre-emergence application of Atrazine @ 0.5 to 2.5 kg/ha in sugarcane, Jowar, Alachlor @ 1.5 to 2.5 kg ai/ha in Groundnut, Duiron @ 2.0 kg ai/ha or Oxadiazon @ 1.5 kg ai/ha in cotton. Post-emergence application of herbicides: Application of herbicides after emergence of crop is called post-emergence application. It is generally resorted to when the crop has grown sufficiently to tolerate herbicides and to kill weeds that appear late in the crop. Generally, it is done about 30-40 days after sowing. For example, application of Stam F34 @ 2 kg/ha or MCR 1 kg/ha in paddy 3 weeks after transplanting, 2,4-D @ 0.4 kg/ha in Wheat afterPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 50

4-8 leaf stage, Pendimethalin @ 0.75 to 2.0 kg ai/ha in rice after 3-5 DAT, Isoproturon @ 1.0 kg ai/ha 30 35 days after sowing of Wheat.

IrrigationIt supply the plants crop by its requirements of water. The main objective is to increase water content in soil to an optimum level for crop growth and production.


Fig.14 : Irrigation methods

Irrigation efficiency :The fraction of water delivered during irrigation that ends up as available water for plant up take is measure for irrigation efficiency. Water requirements for crop: Water requirements differ between field crops due to their differences in growth habit, growing season, density, plant purpose . Table2: Water Requirements of Agricultural Crops in Surface Irrigation Methods(5cm depth at each irrigation) Average water requirement Crop Interval (days) (mm)Rice Maize Groundnut Sorghum Sunflower Soybean Greengram Blackgram Gingelly Sugarcane 1250 400 450 400 450 670 250 250 250 2000 4 6-7 7-8 14-15 7-8 6-7 10-12 10-12 15-20 7-8

Table 3: Critical Stages for Irrigation CropsRice Wheat Pulses Peas Berseem Pigeonpea Sorghum Barley Maize

Critical Stages: Initial tillering, flowering : Most critical stage: Crown root initiation, tillering, jointing,. booting, flowering, milk and dough stages, Boot stage; dough stage : Flowering and podding. : Pre bloom stage. : After each cutting. : Flower initiation, pod filling. : Initial seedling, pre flowering, flowering, grain formation. : Boot stage, dough stage : Early vegetative, taselling and silking stage.


ROLE OF WATER FOR GROWTH AND DEVELOPMENT OF CROPS

Water is a constituent of protoplasm Water acts as a solvent. Plants can absorb nutrients when these nutrients are dissolved in water Water is used for transpiration carrier of nutrients from the soil to green plant tissues. They are used for photosynthesis and the end product is also conveyed through water to various plant parts Water forms over 90% of the plant body by green or fresh weight basis. Plants can synthesis food through photosynthesis only in the presence of water in their system. Water helps to maintain the turgidity of cell walls. Water helps in cell enlargement due to turgor pressure and cell division which ultimately increase the growth of plant. Water is essential for the germination of seeds, growth of plant roots, and nutrition and multiplication of soil organism.


Water is essential in hydraulic process in the plant. It helps in the conversion of starch to sugar. Water helps in the transpiration, which is very essential for maintaining the absorption of nutrient from the soil.

Water regulates the temperature and cools the

plant. Water helps in the chemical, physical and biological reaction in soil.

So, water is applied externally, if availability seems limited through soil, not sufficient to meet the requirement due to drought or excess losses. We call the external application of water to the soil to supplement the requirement as `Irrigation'.

FertilizerFertilizer (or fertilizer) is any organic or inorganic material ofnatural or synthetic origin (other than liming materials) that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of cropPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 54

yields are attributable to commercial fertilizer use. Inorganic fertilizer use has also significantly supported global population growth it has been estimated that almost half the people on the Earth are currently fed as a result of synthetic nitrogen fertilizer use. Fertilizers typically provide, in varying proportions: six macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S); seven micronutrients: boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn). The macronutrients are consumed in larger quantities and are present in plant tissue in quantities from 0.15% to 6.0% on a dry matter (0% moisture) basis (DM). Micronutrients are consumed in smaller quantities and are present in plant tissue on the order of parts per million (ppm), ranging from 0.15 to 400 ppm DM, or less than 0.04% DM. Only three other macronutrients are required by all plants: carbon, hydrogen, and oxygen. These nutrients are supplied by water and carbon dioxide. The nitrogen-rich fertilizer ammonium nitrate is also used as an oxidizing agent in improvised explosive devices, sometimes called fertilizer bombs, leading to sale regulations.

Types of Fertilizers:Fertilizer refers to any compound that contains one or more chemical elements, organic or inorganic, natural or synthetic, that is placed on or incorporated into the soil or applied to directly onto plants to achieve normal growth. The main supply sources of plant nutrients include organic manures, plant residues, biological nitrogen fixation and commercial inorganic fertilizers. The type of fertilizers that are most commonly used for crop production in Alberta are chemical fertilizers. Chemical fertilizers refer to commercially manufactured products containing a substantial amount of one or more plant nutrients. The chemical fertilizers can be broadly classified into: nitrogen, phosphorus, and potassium fertilizers. A straight fertilizer contains only one of the nutrients. A compound fertilizer contains two or more nutrients. A complex fertilizer that is formed by mixing ingredients that react chemically, as opposed to a mechanical mixture of two or more fertilizers. A low analysis fertilizer product contains a low percentage of nutrients, usually 30 per cent or less and a high analysis fertilizer contains morePrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 55

than 30 per cent.

Table 4: Percentage of Nutrients in Selected FertilizersAnalysis Nitrogen Fertilizers Urea Ammonium Nitrate-(Granular) Ammonium Sulphate-Urea Ammonium Sulphate Anhydrous Ammonia (gas) Urea-Ammonium Nitrate Solution Phosphate Fertilizers Mono-Ammonium Phosphate Mono-Ammonium Phosphate Ammonium Polyphosphate Solution Nitrogen Phosphates Ammonium Phosphate Sulphate Ammonium Nitrate Phosphate Ammonium Nitrate Phosphate Urea Ammonium Phosphate Urea Ammonium Phosphate Potash Fertilizers Potash Chloride Potassium sulphate Sulphur Fertilizers 46-0-0 34-0-0 34-0-0 21-0-0 82-0-0 28-0-0 12-51-0 11-55-0 10-34-0 16-20-0 23-23-0 27-14-0 27-27-0 34-17-0 0-0-60 0-0-52-12 20-0-0-(24) 0-0-0 0-0-0 12-0-0-(26) Nitrogen Phosphate Potash (N) (P2O5) (K2O) 46 34 34 21 82 28 12 11 10 16 23 27 27 34 0 0 20 0 0 12 0 0 0 0 0 0 51 55 34 20 23 14 27 17 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 60 52 0 0 0 0 Sulphur (S) 0 11 24 0 0 1.5 0 0 14 0 0 0 0 0 12 24 17 90-99 26

Ammonium Sulphate Gypsum (agricultural) Elemental Sulphur* Ammonium Thiosulphate Solution

* Elemental sulphur is suitable for application on perennial forage but is less suitable for annual crops because of slow-release characteristics. If used on annual crops it should be applied in thePrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 56

fallow

year

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allow

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sulphate

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All fertilizers must show the guaranteed nutrient analysis on the label. This states the content of three main nutrients: nitrogen, phosphate (P2O5) (a form of phosphorous) and potash (K2O)(a form of potassium). It is shown by a series of three numbers. For example, if the numbers 10-10-10 appear on a 30 kg bag of fertilizer it means that the bag contains 10 per cent of each raw material (3 kg of nitrogen, 3 kg of phosphate and 3 kg of potash).

METHODS OF FERTILIZER APPLICATIONThe different methods of fertilizer application are as follows:

The fertilization decisionEach producer manages nutrients through answering a few simple questions: Are fertilizers necessary to produce the crop? How much fertilizer is needed if necessary? What fertilizers are available if needed? When is the best time to apply fertilizer? How should the fertilizer be applied?


Fertility management is important. However, variety selection, water management, insects, nematodes, diseases, weed pressure, and climatic conditions also affect crops.

Fertilizer Best Management PracticesBest Management Practices are cost-efficient operation methods that ensure that fertilizers are used effectively with minimal impact on the environment including the good business practices mentioned above. Use realistic yield goals Use average crop yields from the past three to five years, then add 10 percent for a realistic projection of the production potential on your soils, using your production management, in your climate area. Use the most suitable nitrogen fertilizer source, depending upon the crop, application method, and climatic conditions Some fertilizers work better in certain situations due to climate and soil conditions. For example, anhydrous ammonia is lost due to incomplete soil sealing when soils are wet. Price fertilizers on the cost per pound of nutrient This is the best way to compare cost of nitrogen among equivalent sources. Use proper application techniques Use the correct technique for the particular situation. Refer to the specific commodity pages for more particular information. Maintain and calibrate application equipment Improperly maintained and poorly set equipment 'steal' crop input dollars. Make sure owned equipment is properly working and calibrated. Confirm with custom applicators that they have calibrated the equipment. Avoid application to surface waters. Care must be taken to avoid direct application to any surface streams. Time application properly for the crop Nitrogen use efficiency is best when applied close to the time of crop uptake. We hear reports every year of N application to fields for cotton several weeks prior to planting. These increases the probability of N loss from the field, and mayPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 58

necessitate supplemental N fertilizer later in the growing season.

Control soil erosionNutrients move when soil particles move. Using soil conservation keeps soil and nutrients where they can be utilized by growing crops.

Properly control water flowNitrogen movement in the landscape is closely linked to water movement. Slow water down when appropriate by conservation practices, or speed water movement when appropriate. Use cover crops, and maintain crop residue on the soil surface Cover crops reduce the likelihood of N movement in the landscape by 'scavenging' N left in the soil profile after the previous crop. Using the residual N increases cover crop dry matter production, thus enhancing soil quality attributes such as soil organic matter levels and tilth.

What is a fertilizer?A fertilizer is any material, organic or inorganic, natural or synthetic, that supplies plants with the necessary nutrients for plant growth and optimum yield. Organic fertilizers are natural materials of either plant or animal origin, including livestock manure, green manures, crop residues, household waste, compost, and woodland litter. Inorganic (or mineral) fertilizers are fertilizers mined from mineral deposits with little processing (e.g., lime, potash, or phosphate rock), or industrially manufactured through chemical processes (e.g., urea). Inorganic fertilizers vary in appearance depending on the process of manufacture. The particles can be of many different sizes and shapes (crystals, pellets, granules, or dust) and the fertilizer grades can include straight fertilizers (containing one nutrient element only), compound fertilizers (containing two or more nutrients usually combined in a homogeneous mixture by chemical interaction) and fertilizer blends (formed by physically blending mineral fertilizers to obtain desired nutrient ratios).

Specific properties of organic fertilizersOrganic nutrient sources are highly heterogeneous and vary in quality and quantity. The quality aspect is important in determining the nutrient release potential of the organic fertilizer. MicroorganismsPrinciples of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 59

that decompose organic fertilizers use the carbon in such materials as an energy source for growth. Required in even bigger quantities by microorganisms for growth and reproduction is nitrogen (N). Commonly available materials are often particularly low in N content. For organic fertilizers with low N contents (such as cereal straw and most smallholder farmyard manures), microorganisms themselves will consume much of the available N for their own growth. Consequently, insignificant amounts of N will be released for the crop. Thus, on their own, poor quality materials have limited potential to enhance productivity. The effectiveness of such materials can be improved by combining them with mineral N fertilizers such as ammonium-nitrate or urea. Mineral fertilizers may be used more efficiently by crops growing on soils with adequate amounts of soil organic matter supplied by organic fertilizers.

What are the differences between organic and inorganic fertilizers in terms of their use?Organic fertilizers: Soil fertility on smallholder farms is almost entirely dependent on locally available resources. Cattle manure, cereal and legume stover, and woodland litter are the commonly used organic fertilizers, but these are rarely applied in sufficient quantities to impact on crop yields. The use of high quality organic fertilizers is rarely practiced, although through research and extension activities in Africa, some farmers now include legume green manures or legume-based fallows in crop sequences. The main advantage of using organic fertilizers is that, compared to mineral fertilizers, they are usually available on or near the farm at very little or no cost other than labor costs of handling, transportation, or opportunity costs of land used for their production. Inorganic (mineral) fertilizers: Mineral fertilizers need to be applied to crop at least two times within a growing season (split application), either basally at planting or top-dressed during vegetative growth. The amount of inorganic fertilizer used in most smallholder farming systems falls far below standard extension recommendations, due to poor purchasing power, risk aversion due to poor and unreliable rainfall, and lack of significant returns. When available, fertilizer use is not overly labor intensive, thus allowing time for other tasks (or for earning income elsewhere).Principles of Filed Crop Production ( Practical Part).. Dr.Mahmoud El Gohary Ragab Page 60

What are the differences between organic and inorganic fertilizers in terms of application?The method and timing of fertilizer application is an essential component of good farming. For organic materials, decomposition rate and timing of application influence the release of nutrients to the crop. Organic fertilizer application methods include broadcasting, banding, and spot application (or side-dressing). Broadcasting requires less labor and helps to evenly cover the field surface before incorporation into soil through plowing or hand-hoeing. Incorporation generally increases the fertility status of the whole plow layer. If the quantity of organic fertilizer is limited, it may be banded along furrows or spot applied, but the seed needs to be placed away from the fertilizer. Side-dressed organic fertilizers are not likely to have much immediate effect due to delayed nutrient release. Mineral fertilizers can be applied by hand or with application equipment. When hand applied, it is essential to distribute the fertilizers uniformly and at the recommended rates to avoid over- or under-fertilization. Application equipment needs proper adjustment to ensure uniform spreading. Broadcast fertilizer should be incorporated after application to enhance effectiveness or to avoid evaporation losses of N. With banding or spot application, take care that no fertilizer is placed too close to either the seed or the germinating plant, to avoid damage to the seedling or roots.

What are the differences in terms of their effectiveness?Continued use of organic fertilizers results in increased soil organic matter, reduced erosion, better water infiltration and aeration, higher soil biological activity as the materials decompose in soil, and increased yields after the year of application (residual effects). Proper handling of organic fertilizers enhances their quality and effectiveness. For example, with the exception of green manures, there is significant crop response if organic fertilizers are combined with N-based mineral fertilizers or other N-rich organic materials. Mineral fertilizers on the other hand immediately supply nutrients needed by crops. Basal f

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Practices of Field Crop Production

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