Enhancing soil quality and grain yields through fertilization strategies in integrated crop-livestock system under no-till in Brazilian Cerrado

The study aimed to evaluate the effects of P and K fertilization strategies with and without N-fertilization on soil quality and crop yields in integrated crop-livestock system (ICLS) in the Brazilian Cerrado. The treatments included various fertilization strategies, such as applying P and K during either the cropping phase (conventional fertilization) or the pasture phase (system fertilization), with or without N-fertilization during the pasture phase. Soil samples were collected two years after the experiment was initiated from the 0–10 cm layer, and soybean yields were determined at the end of the crop cycle. Soil carbon (C) stocks remained largely unaffected by the different fertilization strategies. However, soil nitrogen (N) stocks, as well as C and N within the microbial biomass, were lower when conventional fertilization and 0 kg ha⁻¹ of N were used in pastures compared to other treatments. Enzyme activity also decreased with conventional fertilization and 0 kg ha⁻¹ of N in pastures. Scores for Nutrient Cycling and Nutrient Storage were higher with 100 kg ha⁻¹ compared to 0 kg ha⁻¹ of N in the case of conventional fertilization, marking an increase of 22% and 18% for Nutrient Cycling and Nutrient Storage, respectively. For soil function associated with Nutrient Supply, there was no difference between the treatments. Within the 0 kg ha⁻¹ of N group, system fertilization was 12% and 24% higher compared to conventional fertilization. The soil quality index (SQI_FERTBIO) was higher with 100 kg ha⁻¹ (0.83) compared to 0 kg ha⁻¹ of N (0.77), showing an 8% increase. Soybean yield was 3% higher with system fertilization and 7% higher with 100 kg ha⁻¹ of N, compared to conventional fertilization with 0 kg ha⁻¹ of N. In conclusion, even in the short term, adopting a system fertilization strategy and applying N-fertilization in pastures benefits soybean yields in ICLS under no-till.