Modeling Soil Health Indicators to Assess the Effectiveness of Sustainable Soil Management on Mediterranean Arable Land

Considering future tasks in soil health, resource management, and environmental protection, farmers are challenged to develop sustainable strategies for managing soil and land resources. In this study, the long-term sustainability of two fertilization strategies-current, with synthetic fertilizers (SYN) vs. conservative, with organic sources of nitrogen (organic amendments plus green manure with a legume, CONS)-was assessed in a processing tomato/durum wheat rotation. The EPIC model was used, validated with field data, and then run to simulate the management for 30 years under three current and future climates. Yield, soil organic carbon (SOC) stock change, nitrogen use efficiency (NUE), water use efficiency (WUE), and nitrate leaching were considered sustainability indicators. Under all of the future climate scenarios, tomato yield increased with CONS, remaining almost stable with SYN. Wheat yield increased both with CONS and SYN; however, the average yield with CONS was considerably lower than with SYN. NUE and nitrate leaching followed the same trend, both decreasing with CONS, while WUE was higher with CONS compared to SYN. The effect of CONS on SOC was always positive. Thus, the alternative N fertilization strategy proposed can be a favorable option for maintaining soil health and sustainable crop production.