Enhancing surface liming rate on a no-till cropping system in an oxisol of Southern Brazilian.

Abstract

The aim of the experiment is to evaluate the physical and chemical effects caused on the properties of red latosol containing high levels of organic matter in the aftermath of 40 months after surface liming and the effects on yield components of no-till maize. The experiment was conducted in an area of 1000 m 2 split into 40 plots of 25 m 2 , and the experimental design adopted was randomized complete blocks with five treatments and four replications. The treatments consisted of five rates of lime: 0, 2.5, 5, 12.5 and 30 ton.ha-1 (1 SMP pH 5.5). After 40 months of experiment installation, soil samples were taken in a total of four sub samples per plot, that were properly homogenized at different depths (0 to 5, 5 to 10 and 10 to 20 cm) and evaluated on chemical parameters (pH, H+Al, Ca, Mg, Al saturation and bases); on physical parameters (resistance to penetration and soil water infiltration) and on maize crop parameters (yield, height of insertion of first cob and plant?s height). It was observed that equal and above 1 SMP to pH 5.5 ameliorated soil pH in the layers up to 20 cm after 40 months of application, interfering in the levels of Al+H, Ca, Mg, saturation of bases and saturation of aluminum. However, significant effects on soil pH were observed in a depth up to 10 cm. The application of different surface liming rates did not interfere on penetration resistance or soil water infiltration capacity. The effects on soil chemical properties with the rate of 1 SMP to pH 5.5 resulted in higher maize grain yield. Key words: Chemical correction, soil physics, maize, acidity