Desempenho de cultivares de soja em latossolos amarelos distróficos e plintossolos pétricos concrecionários

Abstract

In Brazil, soy stands out for being cultivated throughout the national territory. In Tocantins, Oxisols, Neosols Quartzarenics and Plinthosols are the predominant soil classes, with the latter presenting strong limitations to the use of machines, mainly due to the excessive amount of gravel, despite this undesirable characteristic, cultivation is not an obstacle. However, there is a shortage of studies and consolidated information regarding recommendations and management in this soil. Thus, the objective is to evaluate the agronomic performance of soybeans and identify possible associations with soil attributes. The research was carried out in Porto Nacional in a rainfed no-tillage system in the 2020/21 season, being installed in a randomized block design with four treatments (soybean cultivars) and four replications in two different areas: concretionary Petric Plinthosols (FFc) and Dystrophic Yellow Oxisols (Lad). The management was carried out according to the farm, the harvest was carried out when the soybean reached full maturity. Data were analyzed using descriptive statistics, analysis of variance and multivariate analysis using the principal component analysis (PCA) method. Cultivar 81I81RSF was highlighted in morphometric characters and showed excellent productivity. Cultivar NS7901 showed good results for productive traits (number of stems, number of pods, final plant population and productivity). Cultivars 8473RSF, 81I81RSF and NS7901 had good oil content. The chemical and granulometric attributes of the soils revealed that both soil classes are clayey, the FFc has the highest concentrations of nutrients and the Lad is more acidic, with that the chemical characters differentiate the studied soils. The physico- hydric ones revealed that the Plinthosol presented lower humidity during the soybean cycle and the soils have identical behavior in relation to the biological attributes. Thus, it is concluded that soybean traits were not affected by soil classes, but by cultivars. Nutrient contents in leaf tissues suffered interference from both factors. It is important to emphasize that the soils are different, but this did not affect the grain yield when the climatic conditions are similar. The chemical attributes show that the soils are different. While the physical-hydric ones point out that the Oxisol has a higher available water content and higher gravimetric humidity during the harvest. Biological attributes demonstrate balance of the microbial community with management adopted in different soils.