Guilherme Filgueiras Soares
Abstract:
The use of gypsum with the aim of increase the root growth in depht it is necessary to, because liming in no tillage system, limits the corrective effect the superficial layer. Therefore, the greater root development with gypsum, may increase the absorption of phosphorus efficiency by plants the higher soil volume explored. The objective of this study was to evaluate the effect of gypsum associated with phosphate fertilization, in the soybean and second crop corn cultures development and yield, under no tillage system. The experiment was carried out in Federal University of Goiás, Jataí Regional, with 15 treatments established in a split plot randomized block design, in a 5x3 factorial scheme, with four replications. The first factor corresponded to gypsum rates (0, 1, 2, 4 and 8 Mg ha-1) and the second factor corresponded phosphorus rates (0, 50 and 100% of recommended rate for soybean crop). In soybean was evaluated chlorophyll content, leaf area index, dry matter, leaf chemical analyses, final plant population, number of pods, mass of thousand grains and grain yield. For corn was evaluated chlorophyll content, leaf area index, dry matter of plants, plant height, height of the first ear, stem diameter, leaf chemical analyses, final plant population, number of ears, average length of ear, number of lines and grains in each ear, mass of thousand grains and grain yield. The gypsum provides increases in soybean chlorophyll content. The gypsum application provides increases in Ca and S content leaf and decrease in Mg and K contents in soybean and corn crops. The disbalance N/K relation in corn leaves, provided by increasing gypsum rates, reduces the leaf area in corn culture. The gypsum don´t interfere in soybean and corn second crop yield in first year after application. Ten months gypsum application increases the P, Ca and S contents in all soil profile and decrease the Mg and K contents
