Implantação e avaliação de um sistema agroflorestal para recuperação de pastagem degradada no bioma Cerrado

Abstract

The aim of this research is to present a agroforestry system (AFS) focused on improving the thermal quality of the environment and balancing the carbon budget. In the first manuscript, aimed to describe the costs, implementation and dynamics of changes in the thermal environment of an AFS in a degraded pasture of Urochloa decumbens in tropical environment. To do this, an AFS was planted in two rows 3 m apart in an isolated area 6 m wide and 90 m long. The rows were covered with cattle manure, fermented corn silage waste, composted calf bedding and NPK 08-28-16 formulation (250 g.m linear-1). The rows were planted with Eucalyptus grandis, Musa spp. AAB, Morus nigra, Manihot esculenta Crantz, Tithonia diversifolia and Dipteryx alata. The implementation cost was BRL 4312.28 (US$ 763.33), which was mainly comprised of the mechanized preparation of the area (29.90%) and labor (21.11%). Compared to the degraded pasture, there was a reduction in the temperature and humidity index (THI), black globe humid index (BGHI) and radiant thermal load (RTL) during the dry season within the AFS. The agroforestry model enable a low investment cost for the formation of natural shading and a reduction in heat stress factors from 16 months of implementation. In the second manuscript, aimed to develop a DPSIR tool for a degraded Urochloa decumbens pasture in the Cerrado biome and propose the implementation of a low-tech AFS as a mitigating action against carbon loss. A biodiverse AFS was developed in a degraded Urochloa decumbens pasture and, 36 years after its implementation, a DPSIR tool was developed for pasture degradation in the Cerrado, suggesting the use of the AFS as a response to the impacts generated by the process, highlighting the accumulation of carbon in the production system. It was observed that the Eucalyptus spp. plants in the SAF generated a stock of 4.567 Mg of C after 36 months of implementation. The DPSIR tool for pasture degradation processes in the Cerrado, which presents it as a multifactorial condition capable of generating risks to the environmental, economic and social sustainability of livestock production systems, but which allows the SAF to be adopted as a response to the environmental impacts generated. It is concluded that the low-tech AFS made it possible to partially mitigate the impacts caused by a degraded tropical pasture in the Cerrado biome.