The adoption of planted fallow largely depends on the cost and feasibility of using the technology; easy, inexpensive and simple fallow establishment methods are known to greatly enhance adoption. It was the objective of this study to assess the effects of weeding regime on the establishment of Calliandra calothyrsus and Inga edulis on degraded acid soils in southern Cameroon. A combination of the two fallow species and two weeding regimes, weeding or not weeding, were compared to a natural fallow. The trial was conducted in two sites of different base saturation levels with four replications. The results indicate that differences between the two species and the two weeding regimes were statistically significant (p 005) on both sites for all measured tree growth parameters, as well as the residual effects on subsequent maize grain yield. Presence of weeds reduced stem diameter and height of C. calothyrsus and I. edulis at the early stage of their establishment. Weeding doubled the leaf biomass of both species. The highest woodmass was produced by Inga in plots with weeding treatment, with 48 t/ha of dry material. Tree fallow improved the yield of succeeding crops by twofold over the natural grass fallow. Weeding treatment improved maize yield, from 1.9t/ha to 2.8 t/ha after Calliandra fallow, and from 2.22 t/ha to 3.0 t/ha after Inga fallow. The significant effects of weeding treatments implies that fallow-improving tree species should be planted in relay intercropping for trees to benefit from the weeding of crops, thus reducing the labour spent on fallow establishment.
Tag: inga
Agroforestry in acid soils of the humid tropics
The majority of the soils in the humid tropics are acidic and infertile. Agroforestry systems are the most appropriate forms of sustainable, productive management of soils in the humid tropics because perennial woody vegetation can recycle nutrients, maintain soil organic matter, and protect the soil from surface erosion and runoff. This chapter evaluates three agroforestry systems that are helpful to overcome these constraints to production—namely, alley cropping systems; managed leguminous fallows to accelerate the restoration of soil fertility and reduce the duration of the fallow period; and fruit tree-annual crop sequential cropping systems. These technologies represent a range of agroforestry options, the suitability of which will vary with the relative availabilities of land, labor, and capital. Alley cropping may contribute to the maintenance of soil fertility under annual cropping by improved nutrient cycling, but the system’s total labor and possibly capital requirements are likely to be greater than those with shifting cultivation. Hence, the system seems appropriate for situations of limited land availability. In contrast, managed fallows might reduce the duration of the fallow period and improve productivity per unit time by accelerating weed suppression and nutrient accumulation in the fallow biomass. This system requires relatively small quantities of labor and capital, but like most fallow-based systems, it requires moderate to high land availability. Finally, cultivation of fruit trees can help alleviate labor and capital constraints by spreading labor over periods of low demand and by providing additional income through the sale of fruits and other products.