Resource acquisition of mixed species fallows - Competition or complementarity?

Abstract

This paper presents the results of studies conducted in Kenya during 1998-99 using Sesbania sesban, Macroptilium atropurpureum and Crotalaria grahamiana to test whether: mixed species fallows are more productive due to an increased nitrogen resource capture efficiency; competition for below-ground resources in mixed species induces deeper rooting patterns in mixed species fallows; competition for below-ground resources in mixed species is increased due to their complementary root activity patterns; and whether increased competition for soil mineral nitrogen in mixed species results in increased nitrogen fixation in mixed fallows. A simplified model of below-ground resource capture and complementarity in mixed species fallow systems is presented