The million dollar question. How do you build your soil’s organic matter when you are spending all summer cutting off all the crop biomass in the form of hay or silage? That has been on my mind lately as I think about the upcoming 2014 season. As farmers, we all know that we are always looking to improve our practices and to build soil health, while maintaining profitability, yet if we don’t have the season to get a cover crop to grow through the winter, than how do we maintain or build our organic matter in the soil when we are shipping it off in bales?
I am in a soil science class at OSU and the teacher is constantly preaching “add organic matter!” but doing this economically is difficult especially when growing high volume, low profit hay crops. I have used a seed pea crop to help replenish the OM we are removing from our already sandy soils.
We have had great luck with growing peas for seed, and there is quite a bit of stubble that can be worked back in the ground or no-tilled into. This method is great because seed prices are pretty good right now, as well as the nitrogen credit from the fixation of the peas themselves. Data from the universities say that peas can fix around 150 units of N in one year, which is about $100/acre value. The straw decomposes quickly to make fall tillage work easy, however my crop was not ready to combine until September due to some late summer rains.
Peas yield around 3,000 lbs/acre and the going price is around $.24/lb. The inputs are modest, however PH needs to be close to 6. They combine easily, we use a soybean head so we can lay the sickle down on the ground to help cut the vines since they form a mat on the ground. We put crop lifters on the rock guards that help peel away the material off the ground and it feeds very well.
We have followed peas with fall triticale with great success. The triticale will be off the following June, which gives you time to get your alfalfa planted in late summer, or to squeeze in a double crop of Sorgum or other warm season crop to take advantage of the summer heat.
I will have 80 acres in seed peas to harvest this fall, and I will welcome the added organic material as well as the N fixation to help my following fall triticale crop in 2015.