There are numerous reasons why cover crops are helping farmers all around the world to achieve better yields and fight weeds without any adverse impact on our ecosystem but we will cover the 10 most common. Farmers are not just chasing direct yield increases but also increases in soil fertility and improve soil structure besides reducing off farm environmental effects. They also promote biodiversity and the agro-ecosystem. If you have not considered using cover crops on your farm we have 10 reasons that may change your mind.
1 Improves Soil Fertility
Legume crops have the ability to fix nitrogen for the subsequent crop. It is a common practice among organic growers to include such crop to produce nitrogen for the rest of the crop rotation. Some cover crops are known for their ability to make more phosphorus available to other crops. Deep rooted cover crops bring nutrients up from deep in the soil profile.
2 Reduce Soil Erosion
Bare soil is easily washed away by rain. Cover crops tight canopy protects the soil from drying and scouring effects of wind and harsh impact of heavy rain. The loosened soil structure as a result of cover crop allows rapid absorption of rain and prevents runoff.
3 Organic Matter
Cover crops add organic matter to the soil. However the amount of organic matter they contribute depends on the cover crop species selected and the condition under which they are grown. While looking at organic matter return, it is important to consider climatic differences and how cover crop has been incorporated into the crop rotation as well. Cover crops help in maintaining organic matter. If no effort is made to maintain organic matter in the soil while continuing cropping, the level of organic matter in the soil will continue dropping.
4 Checks Nutrient Loss
Cover crops that take up nitrogen help to reduce nitrogen loss due to leaching. Indirectly it also helps to reduce the potential of contamination by nitrates in shallow aquifers. When cover crop is killed, nutrients held in the plant tissues return to the soil and are used by the following crop.
5 Fights Pest
Not all cover crop species are host for all pests. That means certain cover crops are non host for certain pests. Some cover crops even release toxic material to fight targeted pest. There are many common examples of cover crops that fight nematode population. One such example is marigold that restricts nematode’s reproduction.
6 Controls Weed growth
Many people believe actively pulling weeds will eliminate future weed from plaguing their garden. What they don’t seem to understand is that there is an endless supply of dormant weed seeds waiting to germinate. Cover crops play the most effective role of limiting the weeds by presenting tough competition for resources for them. Cover crops limit the sunlight that reaches weeds by rapidly creating a canopy cover and preventing weed from either germinating or surviving.
7 Improves Soil Structure
Cover crops enhances soil structure and increase soil biota activity. They also reduce soil compaction by making it porous. This enhances water percolation and retention. The dense root masses of the cover crops loosen soil structure as they decompose.
8 Emergency Forages
Cover crops can be grazed by ruminant animals during early spring before row crops are planted. They can also be used as a forage crop and feed source.
9 Soil Moisture
Organic matter contributed by cover crops acts like a sponge in the soil. They hold rain water and gradually release them to plant roots.
10 Cost Benefit
There are many cover crops to choose from to suit specific situation. They are much cheaper compared to vegetable seeds or seedlings. The other biggest benefit is their low maintenance. Majority of the variety can be planed and left alone.
While there are enough reasons why cover crops should be an integral part of overall sustainable agricultural farm strategy, it requires proactive and timely management for several reasons. Cover crops grow vigorously and if they are left as is in the spring, they will exhaust water needed for the subsequent crops. They will also serve as an alternate host or refuge for insect pest and disease. Residues from dead cover crop in the spring can delay soil warming and subsequent seed bed preparation. However these issues can be appropriately handled with timely management and the understanding of plant growth habits that are used as cover crops.