By Reagen Tibbs
Crop producers in central Illinois have a wide range of management decisions to make throughout the year. This leads to a series of often difficult decisions to make before, during, and after the growing season. What type of tillage is needed? How much fertilizer should be applied? When is the desired planting date, population, and row spacing? When should an herbicide or fungicide be applied? All these decisions require adequate time and understanding of the pros and cons. As harvest is beginning across central Illinois and the rest of the Midwest, one decision that may loom at the forefront of a producer’s mind is cover crops.
The benefits of adopting cover crops have been widely explored and explained for some time. They offer a wide range of benefits, including (but not limited to): protecting soil from erosion, controlling weed pressure, holding moisture in the soil, locking soil nutrients (such as nitrogen) into the soil, and building organic matter. Certain species of cover crops are better at some of these than others, so the decision as to what cover crop to plant and how much to plant is an important one. Two recent studies attempt to answer these questions by not only exploring the benefits of different cover crops, but also how various characteristics affect the cash crop that follows. These studies highlight how proper cover crop management can help producers maximize the benefits cover crops provide.
More Time Means More Biomass
To help get the full benefits of some cover crop species, biomass is the most significant factor. Simply put, the more biomass, the better a cover crop can help control weeds, lock nutrients and moisture into the soil, and protect the soil from erosion. However, terminating cover crops at the right time to plant the following cash crop is another important consideration. So, when should cover crops be seeded, and when should they be terminated in order to maximize biomass while also not interfering with cash crops? An article published in Agrosystems, Geosciences, and Environment examined how planting and termination timing influences biomass production in different cover crops.
Across two trial years in Nebraska, researchers planted four different cover crops: wheat, winter rye, triticale, and canola. With each cover crop, the researchers studied the difference in biomass between two different seeding/termination periods: seeding in early October and termination in mid-April, and seeding in mid-September and termination in early May. The seeding rates for each cover crop was 103 kg/ha (91.89 lbs./acre) for wheat, 68 kg/ha (60.67 lbs./acre) for rye, 93 kg/ha (82.97 lbs./acre) for triticale, and 9 kg/ha (8.03 lbs./acre) for canola.
Source : illinois.edu