Resumo

BAEZ PEREZ, Aurelio et al. Effect of conservation agriculture practices on some chemical properties of Vertisols. Rev. Mex. Cienc. Agríc [online]. 2017, vol.8, n.4, pp.759-772. ISSN 2007-0934.  https://doi.org/10.29312/remexca.v8i4.5.

El Bajío is an important agricultural area of México and among its soils, the Vérticos have greater potential for agriculture, but the physical-chemical deterioration caused by intensive farming practices has had an impact on its fertility and profitability for grains production. Conservation agriculture practices (CAPs) are a viable option to reverse this problem. The objective of this paper was to evaluate pH, organic matter (MOS), organic carbon accumulation rate (COS), and P-extractable Olsen in five Vertisols: four from Michoacán and one from Guanajuato, with four to eight cycles of continuous cultivation with CAP. Five agronomic practices were evaluated: (1) grass-grass rotation, all crop residues and sewage use; (2) rotating grass-legume-grass, all crop residues and sewage use; (3) same as 2, but with dam water; (4) grass-grass rotation, 30% crop residues and use of dam water; and (5) grass-grass rotation, all crop residues and well water use. The pH was alkaline before the CAP implementation, and decreased to slightly alkaline as a function of the culture time, mainly in the stratum of 0-5 cm. The MOS increased between 1.5 and 2%, after eight continuous CAP cycles. The COS accumulation rate varied between 1.5 and 7 t ha-1 year-1. The accumulation of P-Olsen showed a low correlation with the MOS content (r= 0.44). The highest concentration of P-Olsen was found in the 0-5 cm stratum (up to 47 ppm). CAPs improved the chemical characteristics of the Vertisols evaluated in this study.

Palavras-chave : conservation agriculture; soil organic carbon.