Pros and cons of grazing cover crops

transcript

Pros and Cons of Grazing Cover CropsTim Reinbott and Rob KallenbachUniversity of MO

Cover crop Options-Cereals to Brassicas

Cereals

Cereal rye and wheat best if spring cover is required

Spring Oats make good autumn growth but won’t overwinter

Vegetative growth excellent quality feed

Cereal Rye and Other Cereals Rapid Growth During late April and May

Forage Production and Quality of Cereals

Ohio State Univ. Fact Sheet AGF-026-00 David Samples and R. Mark Sule

Carryover of Herbicides On Cover Crops-Kevin Bradley, MU Plant Sciences

Weather is a huge factor. A lot of carryover in 2013, little in 2014 or 2015.

Planting In Fall: Drilling or Overseeding

Timing? Corn About 50% Green, Soybean 75% leaves are Yellow

Overseeding Cereal Rye

Wheat & Cereal Rye Quality

Dec Jan Feb Mar Apr May Jun0

45WheatRye

Crude Protein in the 20-30 range in the fall and spring

Nutritive value of Oat Forage

Stage Yield CP TDNt/a --------- % ---------

Vegetative 0.6 24 72Boot 1.0 22 70Heading 1.4 18 66Milk 2.1 15 62Late Dough

3.2 11 53

Livestock Gains on Wheat and rye

ADG Total Gainlb/d lb/a

Wheat 1.8 180Cereal Rye 1.6 336

Rye produces more than wheat

Dec-01 Jan-01 Feb-01 Mar-01

WheatRye

Use before mid-Jan if fall seeded Strip grazing improves utilization Few varieties with known forage

potential

With All Cereals When Should Grazing Begin?

Grazing should start when forage reaches 8 inches

When Should Grazing Stop?

Livestock should be rotated when forage ht. is less than 3 inches

Regrowth much slower when over grazed

Small Grain Recommendations

Seeded in mid-August for most autumn feed Oats planted at 80 to 100 lb./acre Wheat and cereal rye can be planted at same time but at 100 to

130 lb/acre 50 to 75 lb./acre N at planting Do not graze to a height of less than 3 inches Yields of 1.5 to 3.0 tons/acre common

Annual Ryegrass

Easily established Rapid fall growth Retains green tissue nearly all

winter Remains vegetative into early

Annual Ryegrass Establishment

Annual Ryegrass Ready for Grazing

Grazing often can begin 60 days after planting

Rotational grazing a must for best utilization

Graze no shorter than 3” to encourage regrowth

Overseeding Annual Ryegrass

Grazing Management-8 inch and 3 inch Management

Annual Ryegrass Stockpiles Well

Annual Ryegrass Quality

Nov Dec Jan Feb Mar Apr May Jun0

Animal Gains on Annual Ryegrass

Grazing Days ADG Total

Gaind lb/d lb/a

Year 1 95 1.8 511Year 2 83 1.5 314

Winter Kill-Some Varieties

Annual Ryegrass Recommendations

Plant a winter hardy cultivar in late-August at 25 to 30 lb./acre-Marshall and Bounty as examples,

Apply 50 lb./acre of N at planting Apply a additional 50 lb./acre of N in late Feb. Begin grazing when grass reaches 8 to 10 inches Leave a 3 to 4 inch stubble for regrowth –

especially in winter If reseeding is desired, remove livestock in mid-

Soybean Herbicides Affect Cover Crop Growth

Many Herbicides Affect Fall Growth-May Want to Consider A Post Emergence Approach

Brassica Forages

Brassicas; Advantages

Rapid growth; capable of producing 3 tons/acre

Handle heat fairly well Continue to grow after killing

frosts Both above and below

ground portions can be grazed

Brassicas

Seeds are small 200,000 per lb

Existing sod, weeds, etc. compete severely

A weak seedling for first 21 days or so.

Brassicas

Strip grazing offers best utilization

Watch for bloat Offer some dry

roughage for stock

Brassica Forage Quality

Nov Dec Jan Feb Mar Apr

Brassicas: Recommendations

Plant from mid-April though mid August at 2 to 4 lb./acre Plant 60 days prior to feed need Control competition for first month after seeding Apply 75 lb./acre of N at planting Do not be fed alone in the diet (bloat and other problems)

In New Zealand Winter Grazing on Feeder Beets and Kale.

Let’s Combine Brassicas and Cereal Crops

Covercrop Legumes

Legumes

Nodules-Symbiotic Relationship Between the Plant and the Bacteria. Atmospheric Nitrogen is Fixed by the Bacteria For Use by the Plant.

How Do You Know A Nodule Is Fixing Nitrogen?

Important to Inoculate

Each Species of Legume has a Different Species of Bacteria

You must match them together.

Legumes-In the fall do not produce much biomass

Develop a rosette but little autumn/winter growth

Fine for cover but not much feed to stock

Excellent quality

Hairy Vetch-in Mid May90% of its growth 2 weeks before flower

Early May Late May

Hairy Vetch Growth Over Time

Adapted from Gallagher, Penn State2007 Hairy Vetch Corn Yield-0 N

Time lbs/acre %N N lbs/acreEarly (May 4) 1,400 3.82 55 113Middle (May 15) 4,300 4.43 190 132Late (May 31) 6,600 4.15 274 140

2008Early (May 1) 3,204 2.49 80 92Middle (May 14) 4,005 2.92 117 121Late (May 29) 4,361 4.55 197 79

Legumes

~90% of growth from early March to mid-May

Yields of 1 to 2 tons/acre******Growth in spring often late enough to interfere with cropping operations

Mean Forage Nutritional AnalysisFrom November-June

Species Crude Protein ADF NDF

Arrowleaf clover 24.9 ab 21.5 bc 26.0 cd Field Pea 23.2 b

21.4 bc 30.2 c Cereal Rye 19.1 c 25.1 a

46.4 a Ryegrass 19.1 c

24.7 ab 41.8 b Hairy Vetch 26.4 a 19.7 c

25.1 d

Summer Cover Crops-Sorghums and Millets

Forage Quality of Sorghum and Corn

Strip Killing Sorghum Sudan Into Tall Fescue

Reinbott and Blevins, 1995

Grazing and Haying Restrictions Soybean Herbicides Old Soil Applied Chemistries Such as Dual, Treflan, Prowl-No Restrictions Newer Soil Applied Chemistries-Depends some only 14 days others

never Most Post Emergence Herbicides-Do Not Graze-Basagran the Exception Roundup (Glyphosate)-8 weeks Liberty-Do Not Graze

Corn Herbicide Grazing Restrictions

Dual, Prowl and others no restrictions Atrazine- after 21 days 2,4-D-after 7 days Roundup-8 weeks Liberty-60 days forage 70 days fodder

Questions?ReinbottT@Missouri.edu

Pros and cons of grazing cover crops

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