Screening of Seven Plant Species for Short‐Term Improved Fallows in the Humid Forest Zone of Cameroon

Abstract

Seven short‐fallow plant species were evaluated for their aboveground biomass production, nutrient accumulation, and weed suppression potential in Nkolbisson, Cameroon. The fallow species included Arachis pintoi, Vigna radiata, Desmodium intortum, Centrosema pubescens, Indigofera hirsutus, Indigofera spicata, and Pueraria phaseoloides. The experimental design was a randomized complete block with four replications and seven treatments (fallow species). Twelve months after planting, highly significant differences (p < 0.01) were observed among fallow species for phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) concentrations, respectively, in plant tissue. Similarly, highly significant differences (p  =  0.0013) occurred among fallow species for aboveground biomass production, which ranged between 3.12 t ha⁻¹ (I. spicata) and 9.16 t ha⁻¹ (A. pintoi). Potassium only showed highly significant differences among plant species for nutrient accumulation (p  =  0.0001). However, A. pintoi, C. pubescens, I. hirsutus, and P. phaseoloides yielded substantial amounts of recycled N (>100 kg ha⁻¹ year⁻¹) that can benefit the subsequent crop. For small‐scale producers, these species are likely to supply adequate nitrogen for cereal crops. A total of 26 weed species belonging to 15 botanical families were encountered in the various plots. Weed dry weight differed significantly (p  =  0.02) among the fallow plots and ranged from 0.12 t ha⁻¹ (in P. phaseoloides plots) to 2.32 t ha⁻¹ (in A. pintoi plots). Results of this study suggest that there are a wide range of plant species that could be used in improved fallow technologies aimed at improving nutrient‐degraded soils and suppressing weeds.

Keywords:

• Biomass production
• Cameroon
• improved fallow
• nutrient cycling
• weed control

ACKNOWLEDGMENTS

Laboratory analyses of soil and plant samples were made possible by financial assistance from the African Development Bank.