Absorption of nutrients and chemical reconditioning of red latosol by cover plants cultivated in Amazon environment

Abstract

Maintaining the balance of the system using cover crops is a promising alternative for the Amazon region. In this context, the present study aimed to evaluate the absorption of nutrients by cover crops and the reconditioning of soil chemical attributes after management with different cover crops. The experiment was conducted in the experimental area of the Federal Institute of Education, Science and Technology of Rondonia, Colorado do Oeste Campus, in the municipality of Colorado do Oeste, RO, Brazil. The experimental design used was completely randomized, arranged in a 7x4 factorial scheme, consisting of seven species of cover crops (Crotalaria spectabilis, Crotalaria breviflora, Crotalaria ochroleuca, Mucuna aterrima, Mucuna pruriens, Dolichos lablab and Canavalia ensiformis) and four sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm), with four replicates. The results concluded that the cultivation of Crotalaria spectabilis, Crotalaria ochroleuca and Crotalaria breviflora provided higher dry matter yield. The species Dolichos lablab stood out in the accumulation of nitrogen, phosphorus, calcium and sulfur in the leaves at full flowering. The contents of organic matter, total carbon, C/N ratio, N-total, P, K, Ca2+ and Mg2+ of the soil were higher at the depth of 0-10 cm with a decrease in subsurface layers. The species Dolichos lablab and Mucuna pruriens are efficient in terms of supplying organic matter, organic carbon, C/N ratio, N-total, phosphorus, calcium and Ca/Mg ratio of the soil, promoting a direct impact on the fertility of its surface layers up to 10 cm deep. Cultivation of Crotalaria breviflora and Crotalaria spectabilis caused variation in soil exchangeable bases, being directly correlated with the values of pH, SB and CEC