Details

Cat­e­gory: Ben­e­fits of Cover cropping

SOIL FER­TIL­ITY

Increase Crop Production

One of the pri­mary uses of cover crops is to increase soil fer­til­ity. These types of cover crops are referred to as “green manure.”

They are used to man­age a range of soil macronu­tri­ents and micronu­tri­ents. Of the var­i­ous nutri­ents, the impact that cover crops have on nitro­gen man­age­ment has received the most atten­tion from researchers and farm­ers, because nitro­gen is often the most lim­it­ing nutri­ent in crop production.

Often, green manure crops are grown for a spe­cific period, and then plowed under before reach­ing full matu­rity in order to improve soil fer­til­ity and quality.

Green manure crops are com­monly legumes. Legume cover crops are typ­i­cally high in nitro­gen and can often pro­vide the required quan­tity of nitro­gen for increased crop pro­duc­tion. This
qual­ity of cover crops is called fer­til­izer replace­ment value.

SOIL QUAL­ITY
Add Vital Organic Matter

Cover crops can also improve soil qual­ity by increas­ing soil organic mat­ter lev­els through the input of cover crop bio­mass over time. Increased organic mat­ter enhances soil struc­ture, as well as the water and nutri­ent hold­ing and buffer­ing capac­ity of soil.

Soil qual­ity is man­aged to pro­duce opti­mum cir­cum­stances for crops to flour­ish. The prin­ci­pal fac­tors of soil qual­ity are soil sali­na­tion, pH, microor­gan­ism bal­ance and the pre­ven­tion of soil con­t­a­m­i­na­tion.

WEED SUP­PRES­SION
Crowd Out Competition

Thick cover crop stands often com­pete well with weeds dur­ing the cover crop growth period, and can pre­vent most ger­mi­nated weed seeds from com­plet­ing their life cycle and repro­duc­ing. If the cover crop is left on the soil sur­face rather than incor­po­rate­d­into the soil as a green manure after its growth is ter­mi­nated, it can form a nearly impen­e­tra­ble mat. This dras­ti­cally reduces light trans­mit­tance to weed seeds, which in many cases reduces weed seed ger­mi­na­tion rates.

In a recent study released by the Agri­cul­tural Research Ser­vice (ARS) sci­en­tists exam­ined how rye seed­ing rates and plant­ing pat­terns affected cover crop pro­duc­tion. The results show that plant­ing more pounds per acre of rye increased the cover crop’s pro­duc­tion as well as decreased the amount of weeds. The same was true when sci­en­tists tested seed­ing rates on legumes and oats; a higher den­sity of seeds planted per acre decreased the amount of weeds and increased the yield of legume and oat production.

REDUCE RUNOFF

Stop Soil Ero­sion And Bet­ter Uti­lize Water

By reduc­ing soil ero­sion, cover crops often also reduce both the rate and quan­tity of water that drains off the field. Cover crop bio­mass acts as a phys­i­cal bar­rier between rain­fall and the soil
sur­face, allow­ing rain­drops to steadily trickle down through the soil pro­file. In addi­tion increas­ing the bio­mass of the soil helps to retain this moisture.

Just before cover crops are killed they con­tain a large amount of mois­ture. When the cover crop is incor­po­rated into the soil, or left on the soil sur­face, it often increases soil mois­ture. On farms
where water for crop pro­duc­tion is in short sup­ply, cover crops can be used as a mulch to con­serve water by shad­ing and cool­ing the soil sur­face. This reduces evap­o­ra­tion of soil moisture.

NUTRI­ENT RECY­CLING
Uti­lize Lost Nutri­ents Buried Deep In The Soil

Cover Crops are an ideal way to re-​capture lost nutri­ents. Nutri­ents are often car­ried down the soil pro­file never to be uti­lized. Cover crops can tap into those lost nutri­ents and bring them tothe suf­fer. Choose species with long root systems.