MMaatteerriiaall aanndd MMeetthhooddss -...

MMaatteerriiaall aanndd MMeetthhooddss

III MATERIAL AND METHODS

A study entitled ―System based nutrient management for maize and

groundnut cropping sequences‖ was taken up by conducting experiments

in farmer‘s field at Nulugummanahalli, Gauribidnur taluk located in

Eastern Dry Zone of Karnataka and situated at 13°72' North latitude, 77°

35' East longitude with altitude of 882 meters above the mean sea level

during the years 2010-11 and 2011-12. The details of the materials used

and methods adopted during the course of experimentation are described

in this chapter.

3.1 Soil characteristics of the experimental site

Composite soil samples from top 15 cm depth were collected from

the experimental site before sowing and were analyzed for physical and

chemical properties. Soil of the experimental site during first year (2010)

was sandy loam in texture and neutral in reaction (pH 7.34). The electrical

conductivity of soil was 0.27 dSm-1. The organic carbon content was 0.59

per cent. The available nitrogen and phosphorus were medium (319.2

kg ha-1 and 34.9 kg ha-1, respectively) and potassium (604.8 kg ha-1) was

high. During second year (2011), the field experiment was conducted in

separate piece of land belonging to the same farmer and soil of the

experimental site was sandy loam in texture with neutral pH (6.94). The

electrical conductivity of soil was 0.22 dSm-1. The organic carbon content,

available nitrogen and available phosphorus were medium in status with

0.62 per cent, 341 kg ha-1 and 32.6 kg ha-1, respectively. The potassium

(415.5 kg ha-1) was high (Table 3.1).

3.2 Climatic condition

The monthly meteorological data recorded at Gauribidnur taluk,

chikkaballapur district for the period from January, 2010 to April, 2012

regarding normal, actual and deviation from the actual weather

parameters with respect to mean monthly rainfall, mean daily maximum

Table 3.1: Physical and chemical properties of soil in the

experimental sites of different pieces of land during

2010 and 2011 at farmer’s field

Particulars Values Status Methods followed

2010 2011

I. Physical properties

International pipette method (Piper, 1966)

1. Sand (%) 61.0 68.0

2. Silt (%) 28.5 24.5

3. Clay (%) 10.5 7.5

4. Textural class Sandy loam

II. Chemical properties

1. pH (1:2.5) 7.34 6.94 Neutral Potentiometry, using pH meter (Piper, 1966)

2. EC (1:2.5) (dSm-1) 0.27 0.22 Normal Conductometry (Jackson, 1973)

3. Organic carbon (%) 0.59 0.62 Medium Wet oxidation method (Walkely & Black, 1934)

4. Available N (kg ha-1) 319.2 341 Medium Alkaline permanganate method (Subbiah and

Asija, 1956)

5. Available P2O5 (kg ha-1) 34.9 32.6 Medium Olsen s method

(Jackson, 1973)

6. Available K2O (kg ha-1) 604.8 415.5 High

Neutral normal

ammonium acetate method (Jackson, 1973)

Secondary and micronutrients

7. Exchangable Ca (C mol. (P+) kg-1)

11.2 5.2

EDTA titration method (Jackson, 1973)

8. Exchangable Mg

(C mol. (P+) kg-1) 4.1 1.8

EDTA titration method

(Jackson, 1973)

9. Available S (mg kg-1) 13.4 5.5

CaCl2 extractant

Turbidimetry method (Black, 1965)

10. Available B (ppm) 0.14 0.20 Hot water extraction method (Lindsay and Norwell, 1978)

11. Available Zn (ppm) 0.91 0.83 DTPA extractant by AAS method (Lindsay and Norwell, 1978)

and minimum temperature and relative humidity are presented in Tables

3.2 to 3.4.

3.2.1 Normal climatic condition

The normal annual rainfall during 2010 was 688.1 mm. The major

portion of it was received during May to November with maximum rainfall

in the month of September (171.0 mm). The mean daily maximum air

temperature ranged from 26.5 ºC to 34.3 ºC and mean daily minimum air

temperature ranged from 16.5 ºC to 24.0 ºC. The higher mean daily

maximum temperature (34.3 ºC) was observed in the month of April and

lower mean daily minimum temperature was observed in the month of

January (16.5 ºC). The mean monthly relative humidity ranged from 51

per cent in March to 76 per cent in November.

During the year 2011, the normal annual rainfall was 697.9 mm.

The mean daily maximum air temperature was higher in the month of

April (34.5 ºC) and lower in the month of December (26.6 ºC). The mean

daily minimum air temperature was higher in the month of May (24 ºC)

and lower in the month of January (16.5 ºC). The mean monthly relative

humidity was higher in November (76 %) and lower in the month of March

(51 %).

During the year 2012 (from January to April), the normal rainfall

was higher in April month (33.5 mm) with higher mean daily maximum air

temperature and mean daily minimum air temperature (34.5 ºC and 22.8

ºC, respectively). The mean daily maximum air temperature and mean

daily minimum air temperature were lower in the month of January (29.7

ºC and 16.3 ºC, respectively). The higher relative humidity was in the

month of January (62 %) and lower in the month of March (51 %).

3.2.2 Actual climatic conditions

The total rainfall was more in 2010 (1011.7 mm) and almost equal

during 2011 (687.1 mm) as compared to normal rainfall. Only kharif

season crops were benefited from actual rainfall received compared to rabi-

summer crops in both the years. The crop growth period during August

received much higher rainfall (251.4 mm and 190.2 mm, respectively)

compared to other period in both the years.

During the crop growth period of 2010, mean daily maximum air

temperature was higher in the month of October (30.2 ºC) and lower in the

month of November (27.5 ºC). The mean daily minimum temperature

recorded was higher in the month of July (21.6 ºC) and lower in the month

of November (19 ºC). The higher relative humidity was observed in the

month of November (77 %) and lower in the month of October (71 %) (Table

3.2) and depicted in Fig. 3.1.

In the year 2011, higher mean daily maximum temperature was

observed in the month of April and May (34.7 ºC) and lower in the month

of November (28.7 ºC).The mean daily minimum air temperature was

higher in May (23.3 ºC) and lower in January (14.2 ºC). The relative

humidity was less than the normal in most of the months (Table 3.3) and

depicted in Fig. 3.2.

During crop growth period in 2012, higher relative humidity was

recorded in January month (50 %) with lower mean maximum air

temperature (30.5 ºC) and mean minimum air temperature (14.7 ºC) (Table

3.4) and depicted in Fig. 3.2.

3.3 Previous crop in the experimental area

Maize crop was grown before taking up the investigation during the

year 2010 and in the experimental site of 2011, groundnut was the

previous crop.

Table 3.2: Meteorological data indicating monthly normal, actual and deviation for the experimental period

during 2010 at Gauribidnur

Months Rainfall (mm) Relative humidity (%)

Mean daily maximum temperature (ºC)

Mean daily minimum temperature (ºC)

N A D N A D N A D N A D

January 6.8 0.0 -6.8 63 59 -4 29.6 29.8 0.2 16.5 16.7 0.2

February 4.5 0.0 -4.5 58 52 -6 31.0 33.4 2.4 17.8 18.1 0.3

March 5.5 9.0 3.5 51 53 2 34.2 36.1 1.9 19.3 20.1 0.8

April 29.7 106.6 76.9 56 63 7 34.3 37.0 2.7 22.8 23.5 0.7

May 63.4 30.2 -33.2 60 59 -1 34.0 35.0 1.0 24.0 24.1 0.1

June 70.0 40.0 -30.0 69 66 -3 30.8 31.9 1.1 22.3 23.0 0.7

July 92.1 212.0 119.9 73 76 3 29.2 29.1 -0.1 20.2 21.6 1.4

August 85.3 251.4 166.1 74 76 2 28.8 28.9 0.1 21.0 21.5 0.5

September 171.0 155.1 -15.9 74 75 1 29.0 29.4 0.4 20.8 21.5 0.7

October 94.6 101.4 6.8 75 71 -4 28.1 30.2 2.1 18.8 21.2 2.4

November 65.3 104.0 38.7 76 77 1 27.7 27.5 -0.2 18.5 19.0 0.5

December 0.0 2.0 2.0 70 71 1 26.5 27.6 1.1 17.0 16.0 -1.0

Total 688.1 1011.7 323.6 - - - - - - - - -

Note: N: Normal, A: Actual, D: Deviation from normal. Normal values are average of years (Rainfall- 1977 to 2009;

Relative humidity, Maximum temperature and Minimum temperature – 1998 to 2009)







January 6.6 0.0 -6.6 63 60 -3 29.6 30.4 0.8 16.5 14.2 -2.3

February 4.3 8.0 3.7 57 53 -4 31.2 31.1 -0.1 17.8 15.8 -2.0

March 5.6 0.0 -5.6 51 51 0 34.4 34.5 0.1 19.4 17.9 -1.5

April 32.0 83.2 51.2 57 52 -5 34.5 34.7 0.2 22.9 22.5 -0.4

May 62.4 77.6 15.2 60 60 0 34.1 34.7 0.6 24.0 23.3 -0.7

June 69.0 82.4 13.4 69 67 -2 30.9 30.7 -0.2 22.4 21.9 -0.5

July 95.8 50.0 -45.8 73 69 -4 29.2 30.4 1.2 20.3 21.6 1.3

August 90.3 190.2 99.9 74 75 1 28.8 29.7 0.9 21.0 20.4 -0.6

September 170.6 24.9 -145.7 74 70 -4 29.0 29.8 0.8 20.9 20.5 -0.4

October 94.8 120.2 25.4 75 73 -2 28.3 30.4 2.1 19.0 20.4 1.4

November 66.5 38.6 -27.9 76 70 -6 27.7 28.7 1.0 18.5 17.0 -1.5

December 0.1 12.0 11.9 70 68 -2 26.6 28.8 2.2 16.9 14.5 -2.4

Total 697.9 687.1 -10.8 - - - - - - - - -



Fig 3.1: Meteorological data indicating monthly normal and actual for the experimental period during 2010 at Gauribidnur

0

50

100

150

200

250

300

0

5

10

15

20

25

30

35

40

Jan-10 Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rain

fall

(m

m)

an

d R

elati

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mid

ity (

%)

Tem

per

atu

re (

0C

)

Months

Max. Temp. N Max. Temp. A Min. Temp. N Min. Temp. A

RH N RH A Normal RF Actual RF







January 6.4 0.0 -6.4 62 50 -12 29.7 30.5 0.8 16.3 14.7 -1.6

February 4.4 0.0 -4.4 57 39 -18 31.2 32.4 1.2 17.7 17.1 -0.6

March 5.5 0.0 -5.5 51 30 -21 34.4 44.7 10.3 19.3 19.8 0.5

April 33.5 14.6 -18.9 56 32 -24 34.5 42.0 7.5 22.8 24.0 1.2

Total 49.8 14.6 -35.2 - - - - - - - - -



Fig 3.2: Meteorological data indicating monthly normal and actual for the experimental period during 2011 and 2012 at

Gauribidnur

0

20

40

60

80

100

120

140

160

180

200

0

5

10

15

20

25

30

35

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50

Rain

fall

(m

m)

an

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%)

Tem

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0C

)

Months

Max. Temp. N Max. Temp. A Min. Temp. N Min. Temp. A

RH N RH A Normal RF Actual RF

3.4 Experimental details

3.4.1 Experiment-I:

The study entitled ―System based nutrient management for maize–

groundnut and maize-sunflower sequential cropping systems‖ was

conducted with the following details.

The experiment was conducted with maize as kharif crop and during

rabi-summer season, the experimental plots of kharif season were divided

into 2 plots to raise sunflower and groundnut crops and respective

treatments were imposed based on soil test results and soil fertility ratings

of major nutrients after the harvest of kharif maize crop.

Table 3.5: The details of the experiment I

Experimental details Kharif season Rabi –Summer season

Crop Maize Sunflower Groundnut

Variety/Hybrid Dekalb Super

900M Leader 678 TMV-2

Number of treatments 8 8 8

Number of replications 3 3 3

Design RCBD RCBD RCBD

Gross Plot size 6.6 m x 4.8 m 4.8 m x 3.0 m 4.8 m x 3.0 m

Net plot size 5.4 m x 4.2 m 3.6 m x 2.4 m 4.2 m x 2.7 m

Spacing 60 cm x 30 cm 60 cm x 30 cm 30 cm x 15

cm

Recommended dose of fertilizer (N:P:K kg ha-1)

150:75:40 62.5:75:62.5 25:75:38

Season Kharif

(2010 & 2011)

Rabi-Summer

(2011& 2012)

Rabi-Summer

(2011& 2012)

The treatment details of the experiment are as follows;

T1: Rec. NPK as per package of practice

T2: STCR approach for irrigated crop (NPK)

T3: Soil test based NPK recommendation (LMH approach) (STL method)

T4: Soil test based NPK recommendation (± 25 %)

T5: Soil test based NPK recommendation (+ 25 % N, P and K if medium)

T6: Soil test based NPK (NK ± 50% and P ± 25 %)

T7: a) Modified T3 with respect to P (Rec. NK & 100 % P if P is low) +

PSB.

OR

b) Modified T3 with respect to P (Rec. NK & 75 % P if P is medium)

+ PSB

OR

c) Modified T3 with respect to P (Rec. NK & 50 % P if P is high) +

PSB.

T8: SSNM approach for targeted yield of 100 q ha-1 for maize, 37.5 q

ha-1 for sunflower and 25 q ha-1 for groundnut.

3.4.1.1 Design and layout

The experiments were laid out in randomized complete block design

(RCBD). The treatments were replicated thrice. The plan of layout of

experiments is depicted in Fig 3.3 and 3.4 and Plate 3.1 to 3.4.

Legend:

T1: Rec. NPK as per package of practice (150:75:40 kg ha-1)

T2: STCR approach for irrigated maize crop (NPK)




T6: Soil test based NPK (NK ± 50 % and P ± 25 %)

T7: a) Modified T3 with respect to P (Rec. NK & 100 % P if P is low) + PSB

OR

b) Modified T3 with respect to P (Rec. NK & 75 % P if P is medium) + PSB

OR

c) Modified T3 with respect to P (Rec. NK & 50 % P if P is high) + PSB

T8: SSNM approach for targeted yield of 100 q ha-1 of maize

FYM @10 t ha-1 and borax @ 10 kg ha-1 common for all the treatments

Fig. 3.3 Plan of layout of experiment- I in kharif season during 2010 and 2011

T6

T4

T1

T5

T7

Water ch

an

nel

T3

T1

T7

T8

T3

T2

T6

T8

T5

T2

T7

T4

T1

T2

T3

T4

T6

T8

T5

RI RII RIII

6.6 m

4.8 m

N

Groundnut crop

Legend:


T2: STCR approach for irrigated groundnut crop (NPK)






OR

b) Modified T3 with respect to P (Rec. NK & 75 % P if P is medium) +

PSB

OR


T8: SSNM approach for targeted yield of 25 q ha-1 of groundnut


Sunflower crop

Legend:

T1: Rec. NPK as per package of practice (62.5:75:62.5 kg ha-1)

T2: STCR approach for irrigated sunflower crop (NPK)






OR


PSB OR


T8: SSNM approach for targeted yield of 37.5 q ha-1 of sunflower

FYM @ 7.5 t ha-1 and borax @ 10 kg ha-1 common for all the treatments

Fig. 3.4 Plan of layout of experiment- I in rabi-summer season during 2011 and 2012

T6 SF

T4 SF

T1 SF

T5 SF

T7 SF

Wa

ter cha

nn

el

T3 SF

T6

GN

T4

GN

T1

GN

T5

GN

T7

GN

T3

GN

T1 GN

T7 GN

T8 GN

T3 GN

T2 GN

T6 GN

T1 SF

T7 SF

T8 SF

T3 SF

T2 SF

T6 SF

T8

SF

T5

SF

T2

SF

T7

SF

T4

SF

T1

SF

T8 GN

T5 GN

T2 GN

T7 GN

T4 GN

T1 GN

T2 GN

T3 GN

T4 GN

T6 GN

T8 GN

T5 GN

T2 SF

T3 SF

T4 SF

T6 SF

T8 SF

T5 SF

RI RII RIII N

6.6 m

4.8 m

3.0 m

Plate 3.2: General view of kharif maize experiment during 2011

Plate 3.1: General view of kharif maize experiment during 2010

Plate 3.3: General view of rabi-summer groundnut experiment

Plate 3.4: General view of rabi-summer sunflower experiment

3.4.2 Experiment-II:

The study entitled ―System based nutrient management for

groundnut–maize and groundnut-sunflower sequential cropping systems‖

was conducted with the following details.

The experiment was conducted with groundnut as kharif crop and

during rabi-summer season, the experimental plots of kharif season were

divided into 2 plots to raise maize and sunflower crops with respective

treatments were imposed based on the soil test results and soil fertility

ratings of major nutrients after the harvest of kharif groundnut crop.

Table 3.6: The details of the experiment II

Experimental details Kharif season Rabi –summer season

Crop Groundnut Maize Sunflower

Variety/ Hybrid TMV-2 Dekalb Super

900M Leader 678

Number of treatments 8 8 8

Number of replications 3 3 3

Design RCBD RCBD RCBD

Gross Plot size 6.6 m x 4.8 m 4.8 m x 3.0 m 4.8 m x 3.0 m

Net plot size 5.4 m x 4.2 m 3.6 m x 2.4 m 4.2 m x 2.7 m

Spacing 60 cm x 30 cm 60 cm x 30 cm 30 cm x 15 cm

Recommended dose of fertilizer (N:P:K kg ha-1)

25:75:38 150:75:40 62.5:75:62.5

Season Kharif

(2010 & 2011)

Rabi-summer

(2011& 2012)

Rabi-summer

(2011& 2012)

The treatment details of the experiment are as follows;

T1: Rec. NPK as per package of practice

T2: STCR approach for irrigated crop (NPK)

T3: Soil test based NPK recommendation (LMH approach) (STL

method)


T5: Soil test based NPK recommendation (+ 25 % N, P and K if

medium)


T7: a) Modified T3 with respect to P (Rec. NK & 100 % P if P is low) +

PSB

OR


PSB

OR


PSB

T8: SSNM approach for targeted yield of 100 q ha-1 for maize, 37.5 q

ha-1 for sunflower and 25 q ha-1 for groundnut

3.4.2.1 Design and layout

The experiments were laid out in randomized complete block design

(RCBD). The treatments were replicated thrice. The plan of layout of

experiments is depicted in Fig 3.5 and 3.6 and Plate 3.5 to 3.8.

Legend:


T2: STCR approach for irrigated groundnut crop (NPK)






OR

b) Modified T3 with respect to P (Rec. NK & 75 % P if P is medium) + PSB

OR


T8: SSNM approach for targeted yield of 25 q ha-1 of groundnut


Fig. 3.5 Plan of layout of experiment-II in kharif season during 2010 and 2011

T6

T4

T1

T5

T7

Wa

ter cha

nn

el

T3

T1

T7

T8

T3

T2

T6

T8

T5

T2

T7

T4

T1

T2

T3

T4

T6

T8

T5

N

RI RII RIII

6.6 m

4.8 m

Maize crop

Sunflower crop

Legend:


T2: STCR approach for irrigated maize crop (NPK)






OR


PSB OR


PSB T8: SSNM approach for targeted yield of 100 q ha-1 of maize


Legend:

T1: Rec. NPK as per package of practice (62.5:75:62.5 kg ha-1)

T2: STCR approach for irrigated sunflower crop (NPK)






OR


PSB OR


T8: SSNM approach for targeted yield of 37.5 q ha-1 of sunflower

FYM @ 7.5 t ha-1 and borax @ 10 kg ha-1 common for all the treatments

Fig. 3.6 Plan of layout of experiment- II in rabi-summer season during 2011 and 2012

T6 SF

T4 SF

T1 SF

T5 SF

T7 SF

Wa

ter cha

nn

el

T3 SF

T6

M

T4

M

T1

M

T5

M

T7

M

T3

M

T1 M

T7 M

T8 M

T3 M

T2 M

T6 M

T1 SF

T7 SF

T8 SF

T3 SF

T2 SF

T6 SF

T8

SF

T5

SF

T2

SF

T7

SF

T4

SF

T1

SF

T8 M

T5 M

T2 M

T7 M

T4 M

T1 M

T2 M

T3 M

T4 M

T6 M

T8 M

T5 M

T2 SF

T3 SF

T4 SF

T6 SF

T8 SF

T5 SF

3.0 m

RI RII RIII N

6.6 m

4.8 m

Plate 3.5: General view of kharif groundnut experiment during 2010

Plate 3.6: General view of kharif groundnut experiment during 2011

Plate 3.7: General view of rabi-summer maize experiment

Plate 3.8: General view of rabi-summer sunflower experiment

Fertilizer calibration for STCR

NR X 100 X T % CS Fertilizer dose = ------------------ — ------------- X Soil test results

% CF % CF

Total nutrient uptake (kg ha-1) NR = ----------------------------------------- Grain yield (q ha-1)

Total nutrient uptake in control (kg ha-1) CS = --------------------------------------------------

Soil test value in control

Total nutrient uptake in treated plot – Soil test value X CS

CF = ------------------------------------------------------------------------------ Fertilizer dose

Where,

NR = Nutrient requirement per quintal of grain

CS = Per cent contribution from available soil nutrients

CF = Per cent contribution from the applied fertilizer nutrients

T = Target yield (q ha-1)

Standardized STCR equations for different crops in Eastern dry zone

A. Maize

FN = 3.41 T – 0.08 SN (KMnO4 - N)

FP2O5 = 1.94 T – 0.41 SP2O5 (Bray‘s S P2O5)

F K2O = 2.28 T – 0.072 SK2O (Amm. Acetate - K2O)

T= 100 q ha-1

SN, SP2O5 and SK2O= Initial available nitrogen, phosphorus and

potassium, respectively.

B. Groundnut

FN = 6.39 T – 0.48 SN (KMnO4- N)

FP2O5= 15.20 T – 10.20 SP2O5 (Bray‘s S P2O5)

F K2O= 8.68 T – 0.80 SK2O (Amm. Acetate- K2O)

T= 25 q ha-1



C. Sunflower

FN = 14.42 T – 1.76 SN (KMnO4- N)

FP2O5 = 10.94 T – 7.39 SP2O5 (Bray‘s S P2O5)

F K2O = 6.86 T – 0.91 SK2O (Amm. Acetate- K2O)

T= 37.5 q ha-1



In general, the STCR upper recommendations limit up to 150 % and

lower recommendations limit up to 50 % of the state general

recommendations.

Criteria for deciding SSNM levels

If soil nutrient rating is medium - Apply exactly removal quantity

If soil nutrient rating is low - Apply 30 % more

If soil nutrient rating is high - Apply 30 % less

Example: Maize

Yield Target: 10 t ha-1

Nutrient removal at 10 t ha-1: N: 26.3 X 10 = 263.0 kg ha-1

P2O5: 13.9 X 10 = 139.0 kg ha-1

K2O: 32.8 X 10 = 328.0 kg ha-1

In case of maize example:

Suppose soil test results of the field: 220:30:285 N, P2O5, K2O kg ha-1

Rates according to the soil test: Low, Medium and High (N, P and K,

respectively).

Nutrient requirement considering soil supply factor:

Nitrogen is low hence N: 263.0 X 130/100 = 299.0 kg ha-1

P is medium in status hence the dose goes as such

P2O5: 139.0 kg ha-1

K is high hence K2O: 328.0 X 70/ 100 = 229.6 kg ha-1

For micronutrients

Since there is no low, medium and high fertility classification in the

soil testing programme, nutrient efficiency factor could be considered for

calculating doses for the soils falling below critical or above critical limits.

No need to apply if micronutrients in soil are more than the critical limits.

Table 3.7: Soil fertility ratings for major and secondary nutrients in

Karnataka

Sl. No. Nutrient

Soil test ratings (kg ha-1)

Low Medium High

1 Available ‗N‘ <280 280-560 >560

2 Available ‗P2O5‘ <22.9 22.9-56.3 >56.3

3 Available ‗K2O‘ <141 141-336 >336

4 Available ‗S‘ <10 ppm 10-20 ppm >20 ppm

Tandon (2005)

Table 3.8: Critical limits of micronutrients in soil (DTPA extractable)

Tandon (2005)

Sl. No. Nutrient element Critical level in soil

1 DTPA- Zn < 0.60 ppm

2 DTPA- Fe < 2.5 ppm

3 DTPA- Mn < 1.0 ppm

4 DTPA- Cu < 0.2 ppm

5 Hot water- B < 0.5 ppm

6 Amm.ox.-Mo < 0.2 ppm

Table 3.9: Changes in the NPK dose on the basis of fertility ratings in

LMH approach (STL method)

RDF

(kg ha-1)

Addition to be made in RDF at low fertility rating (kg ha-1)

Deductions to be made in

RDF at high fertility rating (kg ha-1)

Nitrogen

< 50 No change No change

51-100 + 12.5 -12.5

101-175 +25.0 -25.0

176-250 +37.5 -37.5

251-325 +50.0 -50.0

Phosphorus

<25 No change No change

26-75 + 12.5 -12.5

76-125 +25.0 -25.0

Potassium

<25 No change No change

26-50 + 12.5 -12.5

No changes in recommended dose of fertilizer (RDF) at medium fertility ratings

3.5 Salient features of hybrids/variety used in the experiment

3.5.1 Maize crop

The maize hybrid used in the investigation was Dekalb Super-900M.

It is modified single cross hybrid produced and marketed by M/s

Monsanto India Ltd. The hybrid matures in 115 to 120 days and gives

superior yield of 90 to 95 q ha-1 with large cylindrical cobs, more rows and

more grain per row.

3.5.2 Sunflower crop

Leader – 678 was the hybrid from M/s Kavery seed company Ltd.

used in the investigation. The hybrid matures in 105-110 days with plant

height of 190 to 220 cm, head diameter 24 to 28 cm. The oil content

ranges from 37-40 per cent.

3.5.3 Groundnut crop

TMV-2 is a Spanish bunch type variety derived by mass selection

from Gudiyattan bunch, released in the year 1940 at Tindivanam

(Tamilnadu). The duration of the variety is about 110 to 120 days. The

yield ranges from 15 to 20 q ha-1.

3.6 Cultural operations

3.6.1 Land preparation

The land was ploughed with tractor drawn mould board plough

followed by harrowing and levelling to bring the soil to fine tilth. Layout

was made according to the experimental design with small bunds around

each plot and replication to avoid movement of water and nutrients from

one plot to another.

3.6.2 Manures and fertilizers application

Based on the soil test results and soil fertility (NPK) ratings, the

fertilizers were applied for all the crops (Appendix I to III). Total quantity of

phosphorus and potassium were applied as basal dose for all the crops.

However, nitrogen was applied in 3 split doses for maize as basal dose (50

%) and remaining 25 per cent at 30 and 60 days after sowing (DAS),

respectively and in 2 splits (50 % each) as basal dose and at 30 days after

sowing for sunflower. For groundnut crop, along with phosphorus and

potash, total quantity of nitrogen and gypsum at 500 kg ha-1 were applied

as basal dose. The nutrients were applied in the form of urea, single super

phosphate and muriate of potash. The fertilizer was band placed at 5 cm

away from the seed line and mixed thoroughly in soil. The FYM at 10 t ha-1

(for maize and groundnut) and 7.5 t ha-1 (for sunflower) was applied

commonly for all the treatments. The NPK content in FYM was 0.5, 0.2 and

0.2 per cent, respectively and available NPK from applied FYM was

calculated on the basis of 40 per cent for present crop and 30 per cent for

the succeeding crop. Since boron status in the soil was below critical level,

borax at 10 kg ha-1 was applied commonly to all the treatments. The

phosphate solubilising bacteria (PSB) was applied along with FYM in

treatment T7 based on phosphorus status in the soil.

3.6.3 Sowing

Recommended seed rate of 15, 110 and 5 kg ha-1, respectively for

maize, groundnut and sunflower crops were used for sowing. Sowing was

done using dibbling method in all the crops by maintaining recommended

spacing (Table 3.5). Dates of sowing for different crops in different seasons

were depicted in Table 3.10.

3.7 After care

3.7.1 Gap filling and thinning

After 15 days of sowing, thinning and gap filling was done manually

in all the crops to maintain optimum plant population.

3.7.2 Irrigation schedule

Irrigation was given in 6-7 days interval depending on the weather

conditions to keep the soil moist for all the crops. Irrigation was with held

10 days before the crop attained maturity.

3.7.3 Inter cultivation and weed control

Pre emergent herbicides were applied after one or two days of sowing

and one hand weeding at 40 DAS was done for effective weed control.

Earthing up was done after 30 DAS in all the crops.

Table 3.10: Date of sowing and harvest of experimental crops

Crops Date of sowing Date of harvesting

2010 2011 2012 2010 2011 2012

Maize based sequence

Kharif maize 6th July 19th July — 2nd November 10th November —

Rabi-summer groundnut — 4th January 4th January — 22nd April 20th April

Rabi-summer sunflower — 4th January 3rd January 24th April 18th April

Groundnut based sequence

Kharif groundnut 6th July 19th July — 25th October 8th November —

Rabi-summer maize — 3rd January 2nd January — 25th April 20th April

Rabi-summer sunflower — 4th January 3rd January — 24th April 18th April

3.7.4 Plant protection measures

During the experimental period, kharif maize was meagrely affected

by downy mildew disease. Hence, spraying of Ridomyl-MZ (Mancozeb +

Metalaxyl) was done to control the disease. In groundnut, tikka disease

was controlled by the application of carbendezim.

3.7.5 Harvesting and threshing

All the crops under study were harvested manually at physiological

maturity stage (Table 3.10). The plants from the net plot area were

harvested in each treatment separately and after complete drying; the

weight of the pods in groundnut, grains in maize and seeds in sunflower

from each net plot area was recorded and converted to hectare. Similarly,

the total haulm yield, stover yield and stalk yield were calculated on

hectare basis for groundnut, maize and sunflower, respectively.

3.8 Collection of experimental observations and sampling procedures

The details of the observations recorded, methods followed and

intervals of observation in different crops are indicated in Table 3.11.

Table 3.11: Details of observations recorded in different crops

Observation Method followed Interval

1.Maize: Growth parameters

Plant height

(cm)

Height of the primary shoot was measured from the ground level to the base of the youngest fully opened leaf until ear head

emergence. After which plant height was measured from the base of the plant to the

tip of the longest leaf and expressed in centimeters.

30, 60, 90

DAS and at harvest

Number of leaves plant -1

Total number of green leaves on five randomly selected plants in each treatment was counted and expressed as the average

number of green leaves per plant.

30, 60, 90

DAS and at harvest

Leaf area (cm2)

per plant

Length of fully opened leaf lamina was

measured from the base to the tip. Leaf breadth was taken at the widest point of the leaf lamina. The product of leaf length and

leaf breadth was multiplied by the factor 0.747 (Stickler et al., 1961).

30, 60, 90

DAS and at harvest

Total dry matter production

(g plant -1)

Oven dry weight (drying at 70 ºC to a constant weight) of plants at different growth stages represents the total dry matter

production (g plant-1).

30, 60, 90

DAS and at harvest

Yield parameters:

Cob length (cm)

The length from peduncle to tip of the cob was taken and expressed in centimeter.

At harvest

Cob weight

ear-1 (g)

The dried five cobs were threshed and the mean weight of grains was taken as the cob

weight.

At harvest

Number of

rows cob-1

The number of rows per cob was counted and

mean number was recorded

At

harvest

100 seed weight (g)

Hundred seeds from each treatment were

counted randomly, weighed and expressed in grams

At harvest

Grain yield

(q ha-1)

At harvest, plants from each net plot were

harvested and cobs were separated, sun dried, threshed, cleaned and weighed. Grain

yield per hectare was worked out from the grain yield per net plot and expressed in quintal per hectare

At

harvest

Stover yield

(q ha-1)

Stalk yield of maize was recorded after complete sun drying of stalks from each net

plot and converted in to quintal on hectare basis.

At

harvest

Harvest index

(HI)

Grain yield (q ha-1) Harvest Index (HI) = ----------------------------- Biological yield (q ha-1)

At

harvest

2.Groundnut: Growth parameters

Plant height (cm)

The plant height of five randomly selected tagged plants was measured. The measurement was made from base of the

plant to the tip of the main stem.

30, 60, 90 DAS and at

harvest

Number of branches per

plant

Number of branches was counted from five

randomly selected plants and the average was worked out.

30, 60,

90 DAS and at harvest

Number of leaves per plant

Number of leaves produced by each of randomly selected five plants was recorded

and mean of these five plants was taken.

30, 60, 90 DAS

and at harvest

Leaf area (cm2) plant-1

The green leaves collected from five plants were passed through a leaf area meter (Model LI-3100 from LICOR Co., Nebraska).

30, 60, 90 DAS and at

harvest

Total dry

matter production

(g plant -1)

Oven dry weight (drying at 70 ºC to a constant

weight) of plants at different growth stages represents the total dry matter production (g

plant-1).

30, 60,

90 DAS and at

harvest

Yield parameters

Number of

pods per plant

The total number of filled pods was counted from five randomly selected plants and the average was recorded.

At

harvest

Weight of pod

per plant (g)

The pod weight obtained from five randomly selected plants was sun dried to a constant

weight and weighed and then average was taken.

At

harvest

Shelling percentage

Shelling percentage was calculated using the formula, Weight of kernels (g)

Shelling % = -------------------------------x 100 Weight of pods (g)

At harvest

Kernel yield

per

plant (g)

The kernel weight obtained from five

randomly selected plants was recorded and average was taken as kernel yield per plant.

At harvest

100 kernel weight (g)

Hundred kernels obtained from shelled pods

were mixed thoroughly and hundred seeds were counted from each net plot yield and the

weight was recorded.

At harvest

Pod yield

(q ha-1)

Groundnut plants in net plot area were

harvested separately and total dried biomass yield from net plot area was recorded. Pods were separated, cleaned and weighed. Later

the pod yield of net plot area was computed on hectare basis and expressed in quintal per ha.

At harvest

Haulm yield

(q ha-1)

The dry haulm yield from each net plot at harvest was recorded after separating the

pods and complete sun drying for a period of one week and haulm yield was worked out

per hectare.

At harvest

Kernel yield

(q ha-1)

After shelling of groundnut pods from each net plot area kernels were weighed. Later the

kernel yield of net plot area was computed on hectare basis and expressed in quintal per

ha.

At

harvest

Harvest index (HI)

Pod yield (q ha-1)

Harvest Index (HI) = ---------------------------- Biological yield (q ha-1)

At harvest

3. Sunflower: Growth parameters

Plant height

(cm)

Height from the base of the plant to the tip of the main shoot until head initiation and from

base of the plant to the head base after head initiation.

30, 60, 90 DAS

and at harvest

Number of

leaves plant -1

Number of fully opened green leaves on main stem of a plant.

30, 60, 90 DAS

and at harvest

Leaf area (cm2) plant-1

The green leaves collected from five plants

were passed through a leaf area meter (Model LI-3100 from LICOR Co., Nebraska).

30, 60,

90 DAS and at

harvest

Total dry

matter production

(g plant -1)

Oven dry weight (drying at 70 ⁰C to a

constant weight) of plants at different growth

stages represents the total dry matter production (g plant-1).

30, 60,

90 DAS and at harvest

Yield parameters

Head diameter

(cm)

Diameter of head was recorded in the

diagonal direction at maturity.

At

harvest

Number of

seeds per head

Sum of total of filled and unfilled seeds head -

1 was recorded.

At

harvest

Chaffiness percentage

Number of unfilled seeds per capitulum

------------------------------------------------ X100 Total number of seeds per capitulum

At harvest

1000 seed weight (g)

Weight of random seeds selected from the seed lot obtained from each net plot was recorded

At

harvest

Seed weight

(g plant -1)

Total weight of seeds obtained from the whole plant was recorded

At harvest

Seed yield

(q ha-1)

Net plot area was harvested separately and total dried biomass yield from net plot area

was recorded. After threshing, seeds were separated, cleaned and weighed. Later the seed yield per net plot area was computed on

hectare basis and expressed in q ha -1.

At harvest

Stalk yield

(q ha-1)

The dry stalk yield from each net plot area

was recorded after complete sun drying for a period of one week and stalk yield was worked out per hectare and expressed in

q ha -1.

At

harvest

Harvest index (HI)

Seed yield (q ha-1)

Harvest Index (HI) = ---------------------------- Biological yield (q ha-1)

At harvest

3.10 Quality parameters of sunflower and groundnut seeds

3.10.1 Oil content (%)

The oil content was estimated by Nuclear Magnetic Resonance (NMR)

spectrometer by using a standard reference sample.

3.10.2 Groundnut oil yield (kg ha-1)

Oil yield per hectare was worked out on the basis of kernel oil

content and kernel yield of groundnut.

Oil per cent

Oil yield (kg ha-1) = ---------------------X Kernel yield (kg ha-1) 100

3.10.3 Sunflower oil yield (kg ha-1)

Oil yield per hectare was worked out on the basis of seed oil content

and seed yield of sunflower.

Oil per cent Oil yield (kg ha-1) = ---------------------X Seed yield (kg ha-1)

100

3.11 Chemical analysis of plant and soil sample

The plant samples used for recording dry matter production at

harvest were used for analyzing nutrients present in the plant. After

recording the dry weight from each treatment, the samples were powdered

in a micro willey mill. The samples were analyzed for different nutrients

content (N, P2O5 and K2O) in maize, groundnut and sunflower plant parts.

3.11.1 Nitrogen uptake by crop

Nitrogen content of stover/haulm/ stalk and grains/kernels/seeds

was estimated by Kjeldahl method as outlined by Piper (1966) and

expressed in percentage. Nitrogen uptake (kg ha-1) by crop was calculated

for each treatment separately using the following formula.

Nitrogen concentration (%) Nitrogen uptake (kg ha-1)= ——————————— X Biomass (kg ha-1)

100

The sum of uptake by stover/haulm/stalk and grains/

kernels/seeds was considered as the total uptake by the respective crop.

3.11.2 Phosphorus uptake by crop

The phosphorus content of stover/haulm/stalk and grains/ kernels/

seeds was determined by vanadomolybdate method (Piper, 1966) and

absorbance of the solution was recorded at 430 nm using

spectrophotometer and then computed to total uptake by crop as

explained in 3.11.1.

3.11.3 Potassium uptake by crop

Potassium content in plant sample (Stover/haulm/stalk and

grains/kernels/seeds separately) was determined by flame photometer

method (Piper, 1966) and expressed in kg ha-1 as explained in 3.11.1.

Plant analysis

Nitrogen content (%) Kjeldahl digestion and distillation method (Piper, 1966)

At harvest Phosphorus (P2O5) content (%)

Diacid digestion and vanadomolybdate method (Piper,1966)

Potassium (K2O) content (%)

Diacid digestion and flame photometer method (Piper, 1966)

Soil analysis

Soil pH, EC, organic

carbon, available major nutrients,

secondary nutrients and micronutrients

( Zn and B)

The composite soil samples from 0 to 15

cm depth was collected from each treatment at harvest and were air dried

in shade then powdered and passed through 2 mm sieve and analysed for pH, EC, organic carbon, available major

nutrients, secondary nutrients and micronutrients ( Zn and B) as detailed in Table 3.1

Before

sowing and after harvest of

the crop

3.12 Balance of nitrogen, phosphorus and potassium status in soil

In both the years, balance of nitrogen, phosphorus and potassium

was worked out by considering the initial soil available N, P2O5 and K2O.

To this amount, nutrients added through fertilizers and manures were

added. By subtracting the crop uptake from this sum, the expected

balance of nutrients was arrived. Net gain or loss of nutrients was worked

out by subtracting expected balance from actual balance determined.

3.13 Enumeration of microbial population

The soil samples were collected from the rhizosphere of the plants at

harvest of rabi- summer crops. The soil samples collected were placed in a

polyethylene bag and brought to laboratory and stored in refrigerator at

5 ºC until used for analysis. The enumeration of total bacteria, fungi and

actinomycetes in the soil samples was carried out by following the

standard serial dilution plate count technique outlined by Jenkinson and

Powlson (1976). The media‘s like Soil Extract Agar for bacteria, Martin‘s

Rose Bengal streptomycin sulphates Agar for fungi and Kuster‘s agar for

actinomycetes were used. The petriplates were incubated at 30 ºC for three

to six days and population was counted and expressed as CFU g-1 of soil.

3.14 Cost of cultivation

The cost of inputs, labour charges and prevailing market rates of

farm produce were taken into consideration for working out the cost of

cultivation, gross and net returns per hectare. The net returns were

calculated by deducting cost of cultivation from gross returns. The details

to cost of cultivation are given in Appendix XXII. Benefit – cost ratio was

worked out as follows:

Gross return (` ha-1)

Benefit: cost ratio=-------------------------------------------- Cost of cultivation (` ha-1)

3.15 Statistical analysis and interpretation of data

The analysis and interpretation of the data were done using the

Fisher‘s method of analysis and variance technique as given by Panse and

Sukhatme (1967). The level of significance used in ‗F‘ and ‗t‘ test was 5 %

probability and wherever ‗F‘ test was found significant, the ‗t‘ test was

performed to estimate critical differences among various treatments.

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