Atributos químicos do solo e teores de nutrientes em grãos de milho e soja após aplicação de remineralizador associado a plantas de cobertura e cama de frango

Abstract

The objective of this research was to evaluate the application of soil remineralizer associated with cover crop consortium and chicken litter on soil chemical properties, on the nutritional contents of corn and soybean grains and to determine which treatments promoted the greatest contribution to soil alteration through principal component analysis (PCA). The experimental design was randomized blocks in a split-strip scheme with two additional factors and four replicates. The primary strips were three cover crop consortium: black oat + forage turnip (mix 1); white lupine + forage pea (mix 2); oat + turnip + lupine + pea (mix 3). The secondary strips were the presence and absence of chicken litter (6 Mg ha-1). The sub-strips were the presence and absence of soil remineralizer (8 Mg ha-1). The additional factors were: absolute control and control with NPK fertilization. The chemical characteristics of the soil (pH, H+Al, P, K, Ca, Mg, V% and CEC) were evaluated at 6, 12, 18 and 24 months after the beginning of the experiment in the 0.00-0.10 and 0.10-0.20 m layers. Nutritional evaluation of corn and soybean grains (P, K, Ca and Mg) was also performed. The association of the remineralizer with chicken litter and with the consortia was efficient in improving and maintaining the chemical conditions of the soil at adequate levels, in addition to reducing the time required for the remineralizer to react; among the consortia used, oats + turnip provided the greatest effect in the association with the remineralizer and chicken litter; the use of the remineralizer, chicken litter and the oat + turnip consortium provided pH, H+Al, V%, CEC, P, K, Ca and Mg values similar to those verified in the control with NPK fertilization, demonstrating that soil fertility management with these alternative sources was as efficient as conventional chemical fertilization. The use of the remineralizer promoted higher P and Mg contents in corn grains and Ca and Mg in soybeans; the association of the remineralizer with chicken litter or with the oat + turnip consortium resulted in higher P contents in soybeans; The association of the remineralizer with chicken litter provided a higher K content in soybean grain. The principal component analysis indicated that among the soil chemical attributes evaluated, those that best explained the variability of the treatments used were pH, H+Al, Ca, Mg, V% and P. P was more related to the treatments that associated the remineralizer with chicken litter and with the consortia. pH, Ca, Mg and V% presented behavior contrary to that observed for H+Al, and the influence of these attributes did not follow a pattern as the evaluation period increased, also varying among the different treatments.