Potencial uso de resíduos orgânicos agroindustriais nas culturas do arroz e brachiaria

Abstract

The objective was to evaluate the growth and productivity of rice grains under bovine urine in soil, leaf and acid sorghum doses, in soil applications with monitoring of nutritional contents and electrical conductivity. The study was conducted in the two experimental farms of the Federal University of Lavras. The cultivar used was the BRSMG Esmeralda, in all the trials, with density of 80 seeds linear meter. In the first and second experiments, four doses of bovine urine (0, 5, 10 and 20 v / v%) were used in two applications via soil and two foliar route with a volume of 4000 L / ha-1 in each application in the two years. In the third experiment, 7 doses (0, 5, 10, 20, 50, 100 and 150 m3 / ha-1) were divided into two applications via soil. No cover fertilizer was applied in any experiment. Plant productivity and growth were determined by leaf area, plant height, chlorophyll index, disease severity and weight of 1000 grains. In the treatments with milk acid serum, the contents of K, Na, SB, T, pH, electrical conductivity, exchangeable sodium percentage and sodium adsorption ratio were monitored in the soil at 0 to 20 cm depth. There is an effect of urine doses for application via soil to leaf area. It was observed that there was interaction with the treatments of bovine urine applied via foliar with the agricultural years for chlorophyll index and productivity. For the remaining characters, there was a lack of response in all treatments and residues used. This lack of results is related to the low nitrogen content present in the bovine urine sample, and for phosphorus and potassium contents in the soil, these are above the critical level limiting the increase of productivity. For the results of the milk acid whey experiment the absence of results may be associated with the area fertility levels and soil compaction, reducing serum infiltration, limiting growth and yield. The increase in serum doses increased the electrical conductivity and exchangeable sodium percentage by 1.75 and 7.75 in relation to the control, but did not provoke the process of sodification and salinization of the soil, even though the serum had a potential for sodification with based on the results of the sodium adsorption ratio. It was concluded that bovine urine and whey were not efficient in growth and grain yield of rice culture. Higher doses of whey present potential for soil sodification.