The wet spring of 2010 gives me reason to be optimistic that the rye cover crops in my highly erodible land (HEL) soybean ground will return multiple benefits. Foremost will be the ability to grow excess moisture out of the soil, providing storage in a saturated soil profile for any rainfall received and minimizing the chances of an erosion event due to saturated conditions.
Low areas that usually have the wettest conditions and highest potential for planting problems will be more trafficable and have less potential for sidewall compaction problems. These areas established better last fall because of the good soils and moisture availability. They will be ahead of the hillsides in growth.
This may allow me to get into fields a day or two earlier as well. That could be critical in a spring that looks likely to have a start to planting.
The late planting and slow start of the rye growth due to a cool, damp and cloudy fall will provide a lesson in how much cover you actually need from a cover crop. Only Mother Nature knows at this point how much growth we’ll get in the next 3 weeks.
In the spring of 2007, we had a 6-inch rain event in the Battle Creek watershed that flooded the town of Battle Creek, causing millions of dollars of damage. One of my rye cover-cropped HEL soybean fields that lays at the top of the watershed sustained very little damage due to the extra protection. I was out planting that hillside a few days after the storm.
A neighbor called me up on my cell phone to ask how it was working and if he should go try it on his ground. I told him you just have to check the soil conditions, reminding him that I was working in a different environment than he was.
The growing rye cover crop will also sequester nitrogen that may otherwise move out of the soil profile in the event of heavy spring rains. Nutrients cycled and carbon produced in the form of plant tissue that will break down and release carbon dioxide through the growing season are a main benefit, also. I have a feeling this “greenhouse benefit” may be one of the more overlooked benefits of cover crops.
As I indicated in my earlier post, there were a lot of 240- to 260-bushels hits on the yield monitor during harvest. After reviewing my yield maps, I can confirm that most of those spikes were in areas where the cover crop established the best.
I also took some soil samples in early May and sent them to the USDA-ARS in Mandan, N.D., where they were examined under a microscope. I have some nice pictures of my very own Vascular Arbuscular Mycorrhizae (VAM) growing in my rye roots. These populations are present in the green rye cover crop at planting time in the spring and expand rapidly into the growing corn plant roots that follow.
The microscopic hyphae from the fungal mycorrhizae colonize the corn plant roots and increase net root mass volume from 10,000 to 100,000 times. Increased phosphorous uptake and the ability to remove moisture from the soil below the wilting point are some of the main benefits of the VAM.
At this time, I consider the erosion control benefits to be the most important. Any soil not lost to erosion counts toward soil building. If I am going to drop $500 per acre into land costs and inputs, I have no problem investing $30 per acre in erosion control.
Excess soil moisture grown out of the soil helps reduce that erosion. Flow areas stay more stable and sheet and rill erosion is minimized so I can make my first trip to the field either a burndown or a planting.
Yield increases due to a healthier and more biologically active soil are the gravy of the system. When you take care of your soil health, it will take care of you in return.