Cover crops

Sustainable Agriculture

Submitted by:K. Soujanya

What is cover crop ?• A cover crop is any crop grown to provide soil

cover.It may or may not be incorporated.

• Cover crops are grown primarily to prevent soil erosion by wind and water.

• When cover crops are planted to reduce nutrient

leaching following a main crop, they are often termed "catch crops."

Abstract

Cover crops could be considered the backbone of any annual cropping system that seeks to be sustainable.

Brief description is provided for winter cover crops, summer green manures, living mulches, catch crops, and some forage crops.

To impart a sense of the importance of these practices in sustainable farming,.

Stripcropping with Cover Crops, Lancaster County, Pennsylvania.Photo courtesy of USDA NRCS.

Principal Uses of Cover Crops and Green Manures

Winter Cover Crop

Summer Green Manure Crop

Living MulchCatch CropForage Crop

Benefits of Cover Crops and Green Manures

Organic Matter and Soil StructureNitrogen ProductionSoil Microbial ActivityNutrient EnhancementRooting Action

Contd’

Weed SuppressionSoil and Water Conservation.

Limitations of Cover Crops

Cover Crops in RotationPest Management Benefits o

f Cover Crops

The soil moisture is maintained optimally and soil organic matter is maintained which increases the soil productivity.

Rooting Action Fibrous action

makes the soil loosen and the micro and macro pores are maintained in ratio

Soil and Water Conservation inVegetation Management to Create a Cover Crop Mulch

•During the dry periods of the year, cover crops help reduce dust, improving air quality.

•This also helps to reduce the problem of mite infestations, which intensify under dusty conditions.

Pest Management Benefits of Cover Crops

PROVIDE HABITAT FOR BENEFICIAL - PREDATOR, PARASITOID INSECTS & ARACHNIDS (SPIDERS & MITES):

Since pest management strategies in organic growing emphasize reliance on nature and the use of “soft” chemicals.

It is important that beneficial arthropods are abundant and in close proximity to the crop to control harmful insects and mites.

Winter Cover Crop

A winter cover crop is planted in late summer or fall to provide soil cover during the winter.

Often a legume is chosen for the added benefit of nitrogen fixation.

In northern states, the plant selected needs to possess enough cold tolerance to survive hard winters.

Summer Green Manure Crop

A summer green manure occupies the land for a portion of the summer growing season.

These warm-season cover crops can be used to fill a niche in crop rotations, to improve the conditions of poor soils, or to prepare land for a perennial crop.

Legumes such as cowpeas, soybeans

Percent nitrogen in legume tops and roots. 

Crop Tops Roots

  %N %N

Soybeans 93 7

Vetch 89 11

Cowpeas 84 16

Red Clover 68 32

Alfalfa 58 42

Forage Crop

Short-rotation forage crops function also as cover crops when they occupy land for pasturage or haying.

Examples include legume sods of alfalfa, sweet clover.

Catch CropA catch crop is a cover crop established after harvesting the main crop and is used primarily to reduce nutrient leaching from the soil profile.

For example, planting cereal rye following corn harvest helps to scavenge residual nitrogen, thus reducing the possibility of groundwater contamination.

Vegetation Management to Create a Cover Crop Mulch

In conservation tillage systems- we use herbicides.

Non-chemical methods include propane flamers, mowing and mechanical tillage.

Figure is a homemade roller to kill cover crops.

From USDA Farmer's Bulletin No. 2279

Limitations of Cover Crops

Results seen only in longterm.

For the immediate growing season, seed and establishment costs need to be weighed against reduced nitrogen fertilizer requirements and the effect on cash crop yields.