A cover crop and no-tillage system for enhancing soil health by increasing soil organic matter in soybean cultivation

No-tillage systems and cover cropping can improve soil organic carbon (SOC), which enhances soil health and sustainability. However, the interaction between tillage systems and cover crops in Andisols is still unclear and requires further investigation. This study examined the relationship between tillage systems and cover crop management and their effect on SOC and soil health. This study was conducted from October 2017 to October 2019 at the Center for International Field Agriculture Research and Education, Ibaraki University, Japan. The field experiment design was split-plot, with the first main factor was being tillage (no-tillage; no-till, moldboard plow; plow, and rotary cultivator; cultivator), and the second factor was being winter cover crop (fallow, hairy vetch, and rye). The measurement indicators included SOC, total N, C/N ratio, available P, exchangeable bases (K, Ca, Mg, Na), cation exchange capacity, melanic index, bulk density, soil penetration resistance, soil particle size distribution (sand, silt, and clay) and substrate-induced respiration. The results showed that no-tillage systems and cover crop management can improve SOC, total N, available P, exchangeable K-Mg, CEC, bulk density, soil penetration resistance, and substrate-induced respiration that serve as soil health indicators under soybean cultivation. A comprehensive evaluation using Z-score, a formula for calculate the value of certain variables that we observe with a specific treatment factor and compare it with the average value of certain variables in all treatments, for SOC, several soil characteristics, crop productivity, and biomass input, the highest score was reached under no-till and rye management. The combination of no-till and rye cover crops appears to be a good technique for increasing SOC and soil health in Andisols. The melanic index values were greater than 1.70, indicating that the soil was a fulvic Andisols with a low degree of humification. This suggests that no-till with rye system can enhance SOC and soil health.

Automated summary

This study found that no-tillage systems and cover crop management can improve soil organic carbon, total nitrogen, available phosphorus, exchangeable potassium-magnesium, bulk density, soil penetration resistance, and substrate-induced respiration which serve as indicators of soil health. The combination of no-till and rye cover crops appears to be a promising technique for enhancing SOC and soil health in Andisols. The melanic index values suggest that the soil is fulvic Andisols with low degree of humification, indicating that the no-till with rye system can enhance SOC and soil health.