Biological Attributes of the Soil with Intercaled Crops and Oil Palm (Elaeis guineensis Jacq.): Sustainable Management in the Amazon

Abstract

Aims: In the Brazilian Amazon, the practices and use of agroforestry systems (SAF) are increasingly used, the proper management of them helps to improve soil properties and also to prevent their degradation. In this context, the objective of this work was to evaluate the biological attributes of the soil in the oil palm cultivation systems with intercropping. Study Design: The experimental design used was completely randomized with four repetitions and six treatments: Oil palm (Elaeis guineense Jacq.) interspersed with pineapple (OPi), bean (OBe), banana (OBa), yucca (OYu) and Brachiaria humidicola (OPa), as well as adjacent area only with Brachiaria humidicola as a witness (Pa). The Tukey test was used at a level of 5% probability in samples analyzed at a depth of 0-0.0 m, to compare the means of the variables evaluated. Place and Duration of Study: The experimental area is located of São João da Baliza, vicinal 26, km 12, with geographic coordinates of reference 00º.51'13.3''N and 60º00'19.8''W, the altitude of 100 msnm and, distant to 352 km from the capital Boa Vista, state of Roraima realized in 2016. Results: The TOC presented values between 4.70 and 9.45 g kg-1, being the highest values found in the interim systems OYu, Pa, OBa, highlighting the intermediate system OPi that presented the lowest levels. The highest basal respiration values ​​of the soil (RBS) (23.50 mg C-CO2 kg-1 soil h-1) and carbon from microbial biomass (C-BMS) (116.0 mg C microbiano kg-1 soil) were verified in the pasture system. Likewise, for the urease and acid phosphatase activity, the grass system stands out as a control with values of (148.42 g NH4+ g-1 soil 2 h-1) y (230 μg de p-nitrofenol g-1 soil h-1) followed by palm with grass and yucca systems. However, the β-glucosidase activity (51.22 μg p-nitrofenol g-1 h-1) it was positively influenced by the oil palm system with yucca. On the other hand, the system interspersed with pineapple showed a higher metabolic coefficient (qCO2) (0.36 mg C-CO2 g-1 C-BMS h-1). It can be concluded that the pasture system (Pa) is presented as a more stable environment, followed by interspersed systems of oil palm with grass (OPa) and yucca (OYu).