We applied a burn-down herbicide application on May 8 to terminate the cover crops and control other weeds. On May 9 we planted a group 2.7 soybean. This included planting with a drill into standing cereal rye, wheat and annual ryegrass. This has become a fairly standard practice among experienced cover croppers. Sometimes the cover crops are controlled after planting with an early post application. The standing cover crops do not usually created a problem planting into – you just need to make sure your planter is set up correctly. As the cover decomposes it creates a mulch layer which can be a big help keeping soils cooler and retaining moisture during hot, dry years.
Keep in mind that with corn you can have a problem with a high carbon to nitrogen ratio creating a deficiency situation early in the growing season, particularly with cereal rye, but this is not an issue with soybeans.
Early May was a very dry period for this part of Indiana. I took some pictures on May 25 (not included). The beans were up but barely and I was a little worried about complete termination. We received some rain last week, about 1.5″, and things changed completely with good elimination of the cover crops and what looks like a nice stand of soybeans.
Hopefully with the shorter season beans and an early May planting we’ll be able to get our fall covers in place in a more timely manner than we’ve been able to do the last 2 years. For the start of the growing season things look very good.
We had a great day March 30 for our Cover Crops Workshop and Field Day. We had 32 in attendance, 24 farmers and while we had to work around thunderstorms we did find a window where we could go out and look over the plots – unfortunately the soil pits had filled up with water from the rains.
The morning program included a presentation from Corey Lacey. Corey is a Purdue University graduate student working with Dr, Shalamar Armstrong on whether nitrogen taken up and stored in cover crops is available the following crop year. Research is ongoing with this but the ultimate answer is, “some is available but it will take more research to determine exactly how much.” Hopefully at some point there will be enough research where this impact can be determined more precisely. We also discussed termination, herbicide carryover, and how this can impact cover crop selection.
As there was a morning window when it wasn’t raining, we took advantage of the situation to head out to the plots. NRCS Soil Scientist Mike Wigginton discussed what he found at the plots and in the soil pits with attendees.
The pits had filled up with water from a combination of water infiltration (it’s been a wet spring here) and rain the night before so these pictures are from the day before when we dug the pits. I’m focusing on root depth because while top growth is nice to look at and offers some benefits, beneath the soil surface is where things are really happening. It may be difficult to see the roots themselves in the pictures so look for the golf tees. Keep in mind that cover crop roots:
Increase water holding capacity and infiltration by forming channels
Provide a pathway for crop roots to travel, allowing more access to water during dry periods
Provide habitat for soil microbes
Through decomposition improve soil organic matter and increase nutrient availability
Help break up soil compaction layers
In the case of legumes provide nitrogen fixation
The cereal rye plot had some good spring growth going on and there were very few weeds present. Mike found roots to 32 inches deep, down to the glacial till layer. As you can see from the picture, the pit started to fill with water running right above that dense till layer as soon as it was dug.
The second strip was planted to barley, rape and hairy vetch. The growth wasn’t quite as lush as the cereal rye strip but it was coming. Mike found living roots in the soil pit down to 26 inches, right above the glacial till layer.
The final strip with spring growth was planted to annual ryegrass, hairy vetch, crimson clover and rape. The rape and vetch were just getting going, the clover was coming in well but was still fairly small and the annual ryegrass had a lot of growth. Mike found a lot of roots in this pit, down to 36″.
One of the interesting “finds” was that even though short, crimson clover had already started nodulation meaning it was starting to add nitrogen to the soil. I have no idea if this will be a significant amount for the corn we’ll be planting but it will be something to look for this fall during harvest (as I type this we are planning to terminate on April 17 if the weather holds).
We always plant one strip to oats and tillage radish because this is a great mix for farmers just getting started with cover crops. Oats and radish both winter kill so it takes away any termination concerns. While you lose some benefit because of no spring growth, it still provides quite a bit. We did not dig deep pits for this or our “check” strip with no cover crops as we would not have found living roots. Keep in mind that last fall we planted the strips on October 18, well past the recommended September 15 date for both of these, based on the Midwest Cover Crops Council Selector Tool. The oats and radish did come up last fall but were pretty small. However even with this situation, the weed population was significantly less than in the straight no-till plots. The main weeds we found were dandelion, chickweed and purple deadnettle. Evidently, even though we planted later than recommended, the cover crops inhibited the germination of the winter annual weeds.
While we are not arguing that planting cover crops means you can do without weed control the next year (is anyone arguing this?) since purple deadnettle is a host for soybean cyst nematode (SCN), this mix, even planted late, may provide an advantage when planted ahead of soybeans.
While our plots are for demonstration and education, not research, I did find myself thinking it may be worth doing some weed counts in the future.
Following the plot tour we had a farmer panel featuring Zach Cain, a Montgomery County farmer, Clint Orr, a Clinton County farmers and Justin Mohler, who farms in Boone and Clinton counties. We had a good discussion. Much of it was on specifics such as planting equipment and setup, mixes that did and didn’t work, termination issues – really the nitty-gritty of cover crops.
This was a good day. I hope everyone learned a lot. On the evaluations several farmers said they intended to start planting cover crops and others mentioned new mixes they would try. Thank you to Boone County Farm Bureau for sponsoring lunch and, as always, to the many farmers, agribusinesses, lenders, etc., who have assisted with this project. I look forward to our next field day, sometime this fall.
Our next Cover Crops Field Day Will be held Thursday, March 30 from 8:30 a.m. to around 3:15 p.m. The program will be held in the Annex Building at the Boone County 4-H Fairgrounds, 1300 E 100 S, Lebanon, IN.
Speakers for the day include Mike Wigginton from the Natural Resources Conservation Service, Corey Lacey from Purdue Agronomy, Brian Daggy from Boone County SWCD, Curt Emanuel from Boone County Extension and a farmer panel featuring Bruce Guernsey, Zach King and Clint Orr. Topics will include a discussion of the financial benefits of cover crop, species selection, herbicide management, how cover crops can impact available soil nitrogen, and touring cover crop plots to discuss production systems and impacts on soil health.
The program has been approved as a Private Applicator Recertification Program (PARP). Lunch, sponsored by the Boone County Farm Bureau, will be provided. There is no cost except for a $10 fee for those seeking pesticide credit. Pre-registration is requested to help with meal planning. To register call the Boone County SWCD at 765-482-6355, ext, 134 or e-mail Sheryl Vaughn at the SWCD. Much of the program will take place outside at the field plots so participants should dress accordingly.
The principle behind Nitrogen scavenging is pretty simple. Each growing season, some nutrients remain in the soil after the crop is harvested. In the case of most nutrients, we don’t worry much about them, so long as the soil stays in the field. They will be available for future growing seasons. Nitrogen (N) is different. It is not stable in soil so any excess N will usually be lost. This loss may occur in several ways. Some will be lost into the atmosphere through a process known as volatalization while some may be leached out of the soil or be carried off the soil surface as runoff by water.
Someone may look at the previous paragraph and say, “Shouldn’t farmers just use less nitrogen?” While there are certainly people who over-fertilize (but not many – fertilizer is expensive and farmers are no fonder than anyone else about spending money on something which does them no good), for the vast majority of farmers, the answer to that question is no. Farmers should plan to have a little nitrogen left over. It’s too fine a line to try to fertilize so the crop uses exactly the amount applied. All it takes is one rainfall event or some very hot, humid weather, and the crop runs out of N at the end of the growing season. The end of the growing season is when the plant sets its sights on reproducing – forming seed. By running out of N at this point, grain yields may be severely reduced. Corn ears may abort kernels, or they may add less starch to kernels, resulting in something known as low test weight, which will cause a dockage in the price farmers receive. Farmers should plan to have a little N left over; the financial risks of running short are too great.
When we plant cover crops, particularly those considered nitrogen scavengers – which all five fall, 2015 treatments are – those cover crops use the available N for their own growth. Instead of being lost, N remains in the field. Next spring as that cover crop is terminated, nitrogen remains available for the farmer to use in the next growing season.
In order to illustrate exactly how this works, we will need to do some math. The relevant information is that we applied 233.1 pounds of nitrogen per acre before planting the corn crop this May. That is enough N to grow 220 bushels of corn, which we were told is the yield potential of this field (our plot has very good, fertile soil). For those of you not in Central Indiana, this was a bad growing season. June and July had record amounts of rain. Waterlogged root systems are not efficient at transporting nutrients into the plant and producing high yielding corn. Our harvest for this plot was 150 bushels of corn per acre and we feel pretty good about that yield; many farm fields in this area did far worse.
When we subtract 175 from 233.1 we are left with 58.1 pounds of N remaining in the soil. The reality is that this year there probably isn’t quite that much. Due to the extreme wetness, some of this probably leached away. But much will remain. Instead of losing it either into the air or through future rainfall events this coming fall and winter, our remaining nitrogen will be taken up by our cover crops. This keeps it in the field where it will be available when we plant soybeans next spring. And while soybeans are a legume and produce their own nitrogen, they don’t start the nitrogen-fixation process until plants are several weeks old. Soybeans still use nitrogen to get started and what’s available will help in crop establishment.
There are many other cover crop benefits besides N-scavenging. However our crop situation this year, where yields are below expectations, provides a nice example of how cover crops can improve the environment by reducing the amount of nitrogen which finds its way into rivers and streams or the atmosphere. These cover crops may also help our financial situation by reducing the amount of fertilizer we need to use next spring. Double bonus!
Curt Emanuel, Extension Educator, Purdue Extension – Boone County
On Tuesday, September 29 we planted three of the five cover crop “treatments” we’ll be incorporating into the project. Those treatments are:
Annual Ryegrass-Oats-Crimson Clover
Tillage (Oilseed) Radish-Oats
Late-planted (about November 1) Cereal Rye
Rain interrupted us before we could get the Radish-Oats mix planted and we’ll be planting some cereal rye later. Hopefully we’ll get the oats and radish in the ground by the end of this week. We performed no tillage and made no herbicide applications before planting. All of the cover crops are planted in 40′ strips and we did a replication (planted each treatment in two areas of the field). I’ll load a map in the near future.
This will make for an interesting educational opportunity. It’s pretty late to be planting radish so we may not get much top growth but it may surprise people when we dig pits next spring to see how much root growth went on underground. It really is amazing to see plots where very little vegetation came up where they have root systems two or three feet deep. It’s a nice example of how much good these cover crops may be doing even when we don’t see evidence of it from the surface.
EDIT: Oats and radish were planted by Brian on October 1, 2015.
Curt Emanuel, Extension Educator, Purdue Extension – Boone County
This blog is to discuss the progress of an exciting project taking place in Boone County Indiana. In early 2015 the Boone County Commissioners graciously granted the Boone County Conservation Partnership control of approximately ten acres of county-owned farmland as an educational and demonstration area designed to encourage the adoption of environmentally friendly farming practices by demonstrating their practical use in a field situation. Through this blog, members of the partnership will detail the management of the area, provide regular updates on progress and discuss lessons learned through this experience. The actual area to be farmed is a touch less than 10 acres but this seemed a better blog title than The 9.8 Acres.
The initial focus of the project will be on cover crops although other conservation practices, such as No-till, will be utilized. We will be planting strips of various cover crop varieties, monitoring their performance, and using the site to hold field days and other educational events to help farmers make informed decisions regarding this practice.
This blog will serve two purposes and the tone of posts may vary significantly depending on the intended audience. We hope to inform the general public about the basic principles behind cover crops; their benefits, their negatives (we love cover crops but there are downsides as there are with any farming practice!), and some of the complications that occur any time a farmer adopts a new system. Other posts will be designed for farmers and will include fairly technical information including items such as stalk and soil nitrate testing, compaction, chemicals and fertilizers used, yield data, specific observations relative to the establishment of cover crops, InField Advantage results, and so on.
The four organizations that compose the Boone County Conservation Partnership are:
Several local farmers have agreed to assist us by serving on an advisory committee to provide local input and technical expertise. Each of these farmers is progressive, supports environmental conservation (as do the majority of farmers) and has experience growing cover crops. These farmers are:
Project leaders are Brian Daggy, Boone County SWCD Resource Conservationist and Curt Emanuel, Purdue Extension – Boone County Extension Educator. Contact either of us for additional information or if you are interested in being a sponsor. Contact information is: