High-quality soybeans rely on a balanced system consisting of soil, environmental factors and decisions made by the farmer.
Dr. Mark Shankle, research professor at Mississippi State University stationed at the Pontotoc Ridge-Flatwoods Branch Experiment Station, and Dr. William Kingery, agronomy and soil ecology professor at Mississippi State University in the Department of Plant and Soil Sciences, focus on just that through their research. Their research evaluates the effect cover cropping systems have on dryland soybeans through plant vigor, growth and yield. Each researcher plays a vital role in the study. Shankle oversees most of the groundwork and soybean production, while Kingery analyzes soil samples in the lab at MSU.
This study has completed its second year of testing management systems with different types of fertilizer, cover crops and planting dates for production of dryland soybean in a no-tillage environment. While the scientists are seeing some promising results with this year’s outcomes, the study will need multiple years of data to establish which system provides the best long-term effects.
This study is using an early planting date and a late planting date, which are about a month apart. Because this factor of soybean production is so dependent on weather conditions, Shankle plants as early as he is permitted and then waits three to four weeks to plant again. In 2019, those dates were April 30 and May 23.
Other studies have proven, and this study will validate, that planting earlier is better under normal spring weather conditions. An early planting date allows soybean plants to reach maturity prior to late-season stresses such as drought, disease and pests.
Soil fertility is an important factor in soybean production and must be monitored from year to year. Careful management of soil fertility helps soybeans reach full yield potential.
The fertilizers used in this study include:
· No fertilizer
· Fertilizer based on soil test recommendations
· Poultry litter applied at a rate similar to soil test recommendations
This study has completed two growing seasons and soybean production systems that included poultry litter as a fertilizer source resulted in the highest yields.
Farmers must be cautious when choosing cover crop species. The benefits of using a cover crop must be justifiable for the input costs. Also, some species do not winter well and may die before the soil can reap the benefits. The Natural Resources Conservation Service has an online survey for farmers to answer questions about soil on their farm and receive a recommendation for cover crops to use.
Cover crops used for this research include:
· Cereal rye
· Hairy vetch
· NRCS prescribed mix — cereal rye and mustard
· Native vegetation
Soybeans are grown in a dry-land no-till environment for this study. Without irrigation, soil moisture needs to be conserved year-round through conscious management decisions. Leveraging no-till practices helps the soil retain the moisture it has accumulated.
Preliminary results for this study consist of yield values for each system, but complete results will include soil microbial analyses. Soybeans require and attract microbes which allow the soybean plants to fix nitrogen in the soil. With several years of data, Shankle and Kingery hope to identify systems to sustainably produce high-yielding soybeans on dryland farms in Mississippi.
More information can be found here.