Thoughts on Cover Crops by Jim Tate

Hanover – Caroline Soil and Water Conservation District

Recently I have had a couple of people tell me that we do not do a very good job of distributing information regarding cost share and in particular Cover Crops.
We send out mailings. We produce a newsletter four times per year, we have a web site and more recently a blog. We participate in producer meetings every year. We attend extension events and field days, often on the program. We have e-mail addresses and we have telephones. We have not yet taken up billboards but funding is tight.

Thus I am writing this article and intend to distribute it to all for whom I have an E-mail Address, post to our district blog and possibly submit to our next newsletter; but we just sent out a newsletter so it may be a while before it shows up there. We will provide the information in any venue we can find.

Cover Crops are a priority of the Chesapeake Bay powers that be. Significant research has shown that properly grown cover crops are an excellent method for reducing soil loss and uptake of excess nutrients, particularly nitrogen. To be significantly grown the cover crops have to be planted in a timely fashion and allowed to achieve some growth and root development prior to the onset of cold weather. As a result, for several years, cover crops have been, and continue to be, a priority for the Virginia Agricultural Cost Share program.

Cover Crops are a very popular practice in our district and annually the signup increases, which increases the competition for the funding.

There are actually four cover crop practices. Below are links to the Ag BMP manual specification for each practice.

All cover crops have nutrient management language in them and the cover crops need to be reflected in the participants nutrient management plan. I will discuss each one briefly.

SL-8 Specialty Cropland Cover Crop
http://webdat.dcr.virginia.gov/agbmpman/SL-8.pdf

The Sl-8 is designed as a cover crop for land that is used for production of specialty crops. These are things like vegetables and tobacco.

This cover crop has a flat rate payment which is currently $35.00 per acre. It is the least restrictive of the cover crops allowing more options of what can be planted and the cover can be planted in winter or summer as needed but must remain in place for a minimum of ninety days.

SL-8B Small Grain Cover Crop for Nutrient Management and Residue Management http://webdat.dcr.virginia.gov/agbmpman/SL-8B.pdf

The SL-8B is the most popular cover crop. This is in part due to its higher payment level which was instituted to do what it did, which was encourage more participation in cover crops.

It is also the most complicated and has the most restrictions. I will try to simplify as much as possible.

It has Planting dates and it has two payment rates associated with early and late planting. The planting dates are broken down further by climatic zones of the state. Here in Hanover and Caroline we are in the coastal plain and our early planting date is October 25th and the regular planting date is November 15th. Cover crops may not be killed down or tilled until March 15th.

These dates are a constant source of inquiry and suggestion. The dates are not arbitrary. They were created by Va Tech based on climatic data and frost zones and timing. The State Ag BMP committee is annually besieged with requests to change these dates for producer driven reasons. The dates are not cast in stone; but they are cast in research driven data. The dates as well as the cover crop specifications are open to new verifiable peer reviewed data.

There is a premium paid for planting before the early planting date.

There is an additional premium paid for using rye as the cover crop.

There are reasons for both of these factors. Rye has been demonstrated to be a superior scavenger of nitrogen which reduces leaching loses to the water table and it sequesters and recycles the nitrogen back to the soil in an organic state which is more environmentally friendly.

The early payment is to encourage early plant establishment to facilitate nitrogen scavenging in the fall before leaching occurs. Once the nitrogen is leached out then scavenging and recycling is a mute point.

Early fall cover crops are primarily for nitrogen scavenging and are intended to go behind corn or other crops where there is a chance of residual chemical nitrogen.

This is not to negate or minimize the benefits of later planted cover crops as soil conservation tools or biomass and soil building tools and these benefits are real; but if the crop is late planted, the at risk nitrogen will have a greater probability of being gone in surface runoff with fall rains or having moved down the soil profile and leached to the groundwater.

We have had several producers offer this year that they have been unable to get their cover crops planted in a timely fashion behind their beans because the beans were slow to ripen or because the ground was too wet to harvest beans.

While a cover crop at any time or behind any crop has benefits to the soil, the SL-8B early payment was designed to go behind high nitrogen fertilized crops which have the probability of residual nitrogen.

Additionally this year NRCS presented an additional payment for aerial seeding of cover crops into standing crops such as beans. This practice will probably be extended by NRCS if it is accepted by producers and shows some success.

We often have request for new species of cover crops under the SL-8B. There are valid reasons for the requests. However the Chesapeake Bay Water Quality Model gives points to each state for specific criteria related to water quality. The model has been somewhat inflexible in accepting new cover species again due to a lack of peer reviewed data.

Having said that:

There is no prohibition against adding other species to a small grain cover crop. To clarify: If you plant, for example, a rye cover crop drilled at 2 bushels per acre, there is no reason you can not add crimson clover or forage radishes or hairy vetch or other plant species to your cover mix. No, the program will not increase payment for the other species but the early payment rates are lucrative now and producers have the freedom to include other species for production benefit.

WQ-4 Legume Cover Crop
http://webdat.dcr.virginia.gov/agbmpman/WQ-4.pdf

This leads directly to the Legume cover crop, WQ-4 . The purpose of this practice is to encourage the use of organic nitrogen and the reduction of chemical nitrogen on subsequent grain crops.

The practice currently pays a flat rate of $35.00 per acre. There are some planting dates but they vary by species of legume cover. The cover crop can be planted by a variety of methods but the grain crop following is intended to be no tilled into the cover crop residue. The producer has to certify the reduction in chemical nitrogen application due to use of this cost share practice.

Grazing is not allowed with this WQ-4 cover crop practice. This is a very nice and underused practice that has a lot of benefit for producers.

SL-8H Harvestable Cover Crop
http://webdat.dcr.virginia.gov/agbmpman/SL-8H.pdf

The SL-8H is the harvestable cover crop. This practice was developed in recent years along with the no residue no till (SL-15B) as practices that could be used by double crop forage producers to incentivize reducing tillage and keeping a living cover on the silage land. It includes fall and winter nutrient application restrictions as do all of the cover crops. No Nutrients of any type may be applied before March 1st. However, where animals are a part of the producers operation, and subject to conditions in the specification, animal manures may be applied in accordance with a nutrient management plan.

There is a flat rate per acre payment of $25.00. This practice is not designed for cash grain production. There is a 300 acre limit per producer for this practice.

All planting dates are the same as the early dates for the regular cash grain cover crop and there are no late dates. There are no additional premiums in this practice.

Kill dates for all cover crop practices are not before March 15th. The exception is the WQ-4 which is multi season applicable and must be maintained a minimum of 90 days from establishment.