Dados do Trabalho

Título

FERTILIZATION STRATEGIES FOR INTEGRATED CROP-LIVESTOCK SYSTEM TO IMPROVE SOIL QUALITY IN THE BRAZILIAN CERRADO

Resumo

System fertilization in integrated crop-livestock systems (ICLS) has been an alternative for sustainable intensification, ensuring higher production and gains in soil quality. Our study aimed to evaluate the short-term effect of different P and K fertilization strategies, with or without N fertilization on pasture, on soil quality and crop yield in ICLS in the Brazilian Cerrado. The treatments involved fertilization strategies, applying P and K in the cropping phase (conventional fertilization) or pasture phase (system fertilization); and without or with N-fertilization on pasture phase. Soil was sampled in January 2021, two years after the experiment was established in the 0−10 cm layer, and soybean yield was determined at the end of the crop cycle. The soil quality index (SQIFERTBIO) was determined from chemical (FERT) and biological (BIO) indicators in an average with equalized weights of three soil functions and respective indicators: (F1) nutrient cycling (based on the activities of the soil enzymes β-glucosidase and arylsulfatase), (F2) nutrient storage (soil organic carbon and cation exchange capacity) and (F3) nutrient supply (Ca, Mg, K, P, pH, H + Al, Al, sum of cations, and cation saturation). The F1 score was higher with 100 kg ha−1 of N (0.20) compared to 0 kg ha−1 of N (0.34) by 70% within conventional fertilization. Also, within the 0 kg ha−1 of N, system fertilization (0.33) was 65% higher compared to conventional fertilization (0.20). The soil functions F1, F2 and F3 had a positive relationship with soybean yield, R2 = 0.24, 0.24 and 0.27, respectively. SQIFERTBIO was higher with 100 kg ha−1 of N (0.55), compared to 0 kg ha−1 of N (0.43) by 28%. However, SQIFERTBIO had a closer relationship with soybean yield, with R2 = 0.82. N-fertilization in the pasture promotes greater SQIFERBIO. SQIFERBIO is closely related to soybean yield, so we should promote management practices that improve soil functions to promote soil health.

Palavras-chave

soil quality index; soil functions; soil health; soil enzymes.