Integração Lavoura – Pecuária associada à calagem favorece a microbiologia em solo arenoso

Abstract

In the western region of São Paulo, the great problem with degraded pastures and sandy soils has been minimized with the implantation of systems that integrate crops and livestock. The objective of the present work was to evaluate biometric and biochemical changes in soybean crop and the impacts caused by soil microbiology in response to different management practices in a crop - livestock integration system in its third year of implementation. For this, soil samples were collected from an area under an integration system and different soil management, in its third experimental year, which is located at the Experimental Farm of UNOESTE, in the municipality of Presidente Bernardes - SP. Vessels with a capacity of 5 kg were filled with soil and afterwards the sowing of soybean cultivar RIBER 6813 RR was carried out. The pots with the plants were arranged in the vegetation of the University of the West - UNOESTE, in Presidente Prudente - SP, under periodic irrigation and controlled conditions of temperature and humidity for 60 days.The experimental design was completely randomized in a double factorial system (2x5) with six replications. The treatments consisted of scarification of the soil and different fertilizations: T0 = Control (fertilization only of soybean planting); T1 = Liming; T2 = Liming + Gypsum; T3 = Liming + Gypsum + NPK; and T4 = Liming + Gypsum + NPK + Micronutrients. Microbiological analyzes of the soil (carbon and microbial nitrogen, basal respiration and enzymatic activity (dehydrogenase)) were also carried out. Biochemical analyzes of the plants (MDA, total phenols and peroxidase), soya growth and nodulation were also performed. The results were submitted to the Tukey test at the 5% probability level. Soil scarification and fertilization with micronutrients provided, in the third experimental year, a reduction in microbiological indicators in the soil, after its effectiveness in the production system. The system of production without scarification with liming only, at the beginning of the implantation, increased the microbial biomass and maintained the microbial quotient in values suitable for sustainable agricultural systems. The secondary metabolism in soybean indicated that, in the third experimental year, there was an increase in the compounds related to the defense of the plants in the management with less chemical and physical interventions of the soil.