Chemical Attributes and Carbon Stratification Rates at Intercropping Corn and Palisade Grasses in No Tillage Systems

Abstract

In integrated crop-livestock systems (ICLS), grain crop and pasture development may affect the soil organic carbon stocks and chemical soil fertility and help to renew degraded pastures, increasing land use efficiency and endeavor income. Our objectives were to evaluate changes in the soil chemical properties, carbon stock in soil and carbon stratification rates of a typical Acrudox soil, with or without ICLS, liming and fertilization. The systems studied integrated with maize were: (i) Urochloa brizantha cv. Marandu (ICLS-Ub-Mar), (ii) U. brizantha cv. Piatã (ICLS-Ub-Pia) and (iii) U. ruziziensis ICLS-Ur) and (iv) U. brizantha cv. Marandu (untreated control-UC) single without maize intercropped. Experiment was performed at the Institute of Animal Science in the municipality of Nova Odessa, São Paulo State (Brazil) using a randomized blocks experimental design. ICLS increased the C stocks and CSR that are good quality indicators of the sustainability of an agricultural system. Higher values of CSR 1.7 were found in the integrated crop-livestock systems with maize and ICLS-Ur. On the other hand, without integrated-crop-livestock and no liming, no fertilization pasture of Marandu palisade grass showed the lowest and above critical CSR=0.7. It is interesting to highlight that the liming and fertilization in crops can influence the soil chemical properties and improve the soil fertility (reduce high acidity, aluminium saturation, increase exchangeable bases and C stocks) and it promotes the higher forage accumulation and maize grains or silage.