Cover Residues and Green Manures

Topic #2062

Mr. ChristensenOntario Corn Producers Association http://www.ontariocorn.org/ocpmag/magh701pg8.htm

Definitions

• Cover Crops—Crops that are destroyed while still green and growing to improve the soil.

• Crop Residues—That portion of the crop plant remaining in the field after harvest.

Why Use Cover Crops?

• Nitrogen Management—Cover crops can enhance N production and/or reduce leaching.

Legumes (clovers, cowpea and hairy vetch) provide nitrogen for future crops.

Grass and non-legume broadleaf covers recycle excess nitrogen act as slow-release fertilizer.

Why Use Cover Crops?

• Erosion Control—Cover crops can be used to reduce wind and water erosion.

• Improving Soil Quality—Cover crops enhance soil structure while increasing soil biota activity. (reduce soil compaction, increase--water percolation and retention, and organic mater, improve soil aggregation, infiltration and bulk density.

Why Use Cover Crops?

• Weed Suppression—Cover crops can shade and interfere with weed germination (rye--allelochemicals).

• Insect Management—Cover crops can play a role in biological insect control (increased survival of Trichogramma wasp survival)

• Pastures—Cover crops can be used as forage crops and feed sources.

Hairy vetch

Cereal Rye

Alfalfa

Oilseed Radish

Ontario Corn Producers Association http://www.ontariocorn.org/ocpmag/magh701pg8.htm

Perdue University www.agry.purdue.edu/ext/forages/publications/Legumes/alfalfa.html

Michigan State University—Extension Bulletin E2884 Cover Crop Choices for Michigan

Cover Crop Establishment• Overseeding—seeding a cover crop

between the rows of a growing crop. (ex. Crimson clover into established corn)

Michigan State University—Extension Bulletin E2884 Cover Crop Choices for Michigan

Cover Crop Establishment• Frost seeding—seeding a cover crop into

an established crop in the later winter or early spring. (Ex. Red clover into wheat or rye in march)

Michigan State University—Extension Bulletin E2884 Cover Crop Choices for Michigan

Crimson clover in wheat

Cover Crop Establishment• Drilling and Planting—Planting a cover

crop into crop residue following harvest. (ex buckwheat following peas, rye or hairy vetch following soybeans or corn)

• Aerial or highboy seeding—allows seeding before harvest.

Michigan State University—Extension Bulletin E2884 Cover Crop Choices for Michigan

Management of Cover Crops

• Cultural—cover crop dies during the winter (oats, cowpea, oilseed radish, sorghum, Berseem clover)

• Mechanical—Moldboard plowed or reduced tillage systems. Watch growth to prevent using up soil moisture, most notably in rye.

Cover Crop Establishment

• Chemical—Cover crops can be controlled by herbicides if timed correctly.

Michigan State University—Extension Bulletin E2884 Cover Crop Choices for Michigan

Burned down hairy vetch in no-till pumpkins

Cover Crop and Crop Residue Problems

• Can slow soil warming

• Can provide a place for pests to over-winter

• Cover crops cost money to establish and manage.

www.painnetworks.com/pages/05/050958.html