Soil aggregate stability and erosion resistance in response to integration of cover crops and poultry litter in a no-till rainfed soybean cropping system

Soil aggregate stability plays a crucial role in influencing erodibility and soil health. This study explored the integration of cover crops and poultry litter effects on soil aggregate stability and erosion resistance in a no-till rainfed agriculture system. A five-year field experiment was conducted in an Atwood silt loam soil near Pontotoc, Mississippi in which no-till soybean was grown every year following five winter cover crops and three fertilization treatments. The cover crop treatments included native vegetation (control), cereal rye, winter wheat, hairy vetch, and a mix of mustard plus cereal rye and the fertilizer treatments included no fertilizer (control), recommended inorganic fertilizers, and poultry litter in a split-plot design. Soil aggregate stability indicators were measured at the conclusion of the study. The results showed that aggregates in the 0.25–0.053 mm fraction were the most prevalent among all treatments while the 2–1 mm fraction represented the smallest proportion. The highest soil aggregate stability index of 60.2 % was observed under cereal rye and the highest mean weight diameter of 1.6 mm was observed under mustard plus cereal rye. The mustard plus cereal rye also displayed the lowest soil erodibility factor K. Among the fertilizer sources, poultry litter resulted in the highest values of soil aggregate stability index, mean weight diameter, mean weight specific surface area, and fractal dimension. Random forest modeling and path analysis identified mean weight specific surface area, fractal dimension, and mean weight diameter as the dominant predictors of soil erodibility factor K. The results overall highlight that integrating cereal rye with or without mustard along with poultry litter can enhance soil aggregate stability and this enhancement may contribute to increased soil erosion resistance in rainfed cropping systems.