“Let it grow” – the Cover Crop Challenge
by Emily Carey
On average, seven tons of soil per acre is lost each year to soil erosion, Jim Hyde, Connecticut state agronomist with USDA-NRCS, estimated. When valuing the soil components, nutritional value and future crop potential, that seven tons/acre loss is estimated to cost a minimum of $40/acre, and other studies estimate the loss to cost hundreds of dollars per acre. If your soil is not covered, you are losing money and giving away the soil you are expecting to grow crops.
While that may be a frightening reality, there is an easy solution: cover crops. Cover crops have visual beneficial impacts on soil health and crop yields. The RUSLE2 model estimated that in well-covered, good-infiltrating soil that has no-till corn planted, there is a one ton/acre loss in soil. Conversely, if the soil is permanently covered, in good infiltrating soil under grass, there will only be a 0.1 ton/acre loss.
While limiting soil erosion is a huge benefit that comes with planting cover crops, there are more benefits that were discussed during the August webinar on the “Cover Crop Challenge: Let it Grow,” hosted by the Connecticut Resource Conservation and Development (RC&D).
“We’ve been watching the farms and how their using their cover crops under the belief that it’s fantastic that the cover crops are being used but there is still so much more potential,” Hyde said. This desire to educate farmers about all the potential and the benefits led the CT RC&D, USDA-NRCS and CT Northwest Conservation District (NWCD) to develop the cover crop challenge.
The Cover Crop Challenge is an initiative designed to encourage CT farmers to utilize cover crops on their fields. The NWCD website said, “The goal of the Cover Crop Challenge: ‘Let It Grow’ is to introduce producers new to cover crops or expand existing cover crop users’ perspectives to grow crops to their full vegetative state. This will promote realization of the greater potential for soil health, nutrient capture and cycling and soil erosion prevention … This project will challenge producers to consider their cover crops similar to a cash crop, to better realize the monetary value, agronomic value and ecological benefit of growing cover crops to their full vegetative state.”
In addition to reduced soil erosion, Hyde explained other benefits that come with using cover crops. One that he touched upon was less compaction. If cover crops are allowed to grow through their full shoot length and root fill, it can be estimated that there is going to be a lot less compaction.
Additionally, the further the cover crop grows, the higher the nutrient levels become. Fuller roots improve organic matter in the soil, and nutrients come down from the shoot where they are captured, retained and cycled within the root zone, making them available for future crops.
Going back to the root structure and organic matter, Hyde discussed how cover crops help to improve moisture management. The root structures and organic matter help move water up or down to get either to or away from the crop when needed. Organic matter also stores water which helps to improve the soil structure and improve the moisture management through the soil profile.
Improving weed control and an improved soil biology that comes from having more diversity in the predatory and beneficial insects and pests both above and below the ground are some other benefits that come with having cover crops. Although data are still being collected, it has been found that since cover crops were planted on fields, there has been 4% – 10% yield increases.
However beneficial it is to incorporate cover crops in a full growth crop rotation, it does come with some challenges, such as timing, equipment, creating a new system, costs, and scouting bug and disease pressures.
There are many things to keep in mind before participating in the challenge of growing cover crops. Hyde recommended starting small with just planting a small area and using one to two bags of cover crop seed per acre.
The Cover Crop Challenge includes free soil health and soil nutrient tests from Cornell and UConn as well as provides free cover crop seeds to farmers who signed up to participate in the challenge.
Rod Porter, regional sales representative for King’s AgriSeeds, joined the webinar to discuss the variety of cover crops that are available for producers to utilize.
There are both single species and multi-species mixes available. Porter included in his presentation that it is important that whatever species are being used complement each other instead of compete. Species like winter cereal rye and pea-oat mix are the species that are being used in the challenge. Both of these cover crops bring their own sets of benefits that make them useful to producers.
Vince LaFontan, executive director of Flanders Nature Center and co-owner of Mountain View Farm, was also included in the webinar to discuss the successes his farm has had planting cover crops. Mountain View Farm in Kent, CT, has been farmed upon since the late 1700s and is a certified organic vegetable farm. After receiving a grant, the farm began to utilize cover crops on a regular basis to gain the most out of them. Of the 40 acres the farm has, only three are in active cultivation, with rotational planting being used.
After trying a number of cover crops, the LaFontans have narrowed it down to using two species. Winter rye is the farm’s staple and is planted after the cash crop is harvested, and hairy vetch is the other species used. Both of these species have benefited the farm and how the cash crop has grown in the soil after the cover crop was planted.
For more information on the Cover Crop Challenge, visit nwcd.org/cover-crop-challenge.