Agroforestry systems with Khaya ivorensis provide improved tree growth and economic benefits to rural producers

Abstract

Agroforestry systems such as Taungya are sustainable alternatives for the recovery of degraded areas and profitability with commercial plantations, providing improvements in soil physical, chemical, and biological properties. In this context, African mahogany (Khaya ivorensis A. Chev)  emerges as an important forest species in Brazil, with the potential for intercropping. The objective of this study was to evaluate the growth and economic return from the Taungya system compared to K. ivorensis monoculture in a degraded area in the humid tropics. Three planting systems were studied: T1, monoculture (K. ivorensis); T2, K. ivorensis + 1st cycle with Zea mays + 2nd cycle with Manihot esculenta; T3, K. ivorensis + 1st cycle with Vigna unguiculata + 2nd cycle with Zea mays. The survival, growth, and relative increments in plant height and stem diameter were determined for the three management systems. Productivity of the agricultural crops was quantified, and bacteriological analyses of the soil and economic systems were performed. The Taungya system with bean and corn crops provided greater growth of K. ivorensis, in addition to a greater density of total bacteria in the soil and provided a higher level of soil conditioning. In these systems, the cultivation and sale of agricultural crops can amortize the total cost of planting and maintenance of plantations with forest species, especially if family labor is considered. However, the completion of additional agricultural cycles may further amortize these investments.

Abstract
Agroforestry systems such as Taungya are sustainable alternatives for the recovery of degraded areas and profitability with commercial plantations, providing improvements in soil physical, chemical, and biological properties. In this context, African mahogany (Khaya ivorensis A. Chev)  emerges as an important forest species in Brazil, with the potential for intercropping. The objective of this study was to evaluate the growth and economic return from the Taungya system compared to K. ivorensis monoculture in a degraded area in the humid tropics. Three planting systems were studied: T1, monoculture (K. ivorensis); T2, K. ivorensis + 1st cycle with Zea mays + 2nd cycle with Manihot esculenta; T3, K. ivorensis + 1st cycle with Vigna unguiculata + 2nd cycle with Zea mays. The survival, growth, and relative increments in plant height and stem diameter were determined for the three management systems. Productivity of the agricultural crops was quantified, and bacteriological analyses of the soil and economic systems were performed. The Taungya system with bean and corn crops provided greater growth of K. ivorensis, in addition to a greater density of total bacteria in the soil and provided a higher level of soil conditioning. In these systems, the cultivation and sale of agricultural crops can amortize the total cost of planting and maintenance of plantations with forest species, especially if family labor is considered. However, the completion of additional agricultural cycles may further amortize these investments.