Light and water use in maize (zea mays)-pigeonpea (cajanus cajans) intercrop under semi-arid conditions of Kenya

Abstract

Intercropping cereals and legumes is a better way of utilising resources such as light, water and nitrogen. Understanding of how efficiently these resources are utilised in maize-pigeonpea intercrop system is important to achieve higher productivity. A study was conducted at Jomo Kenyatta University of Agriculture and Technology between October 2001 and June 2002 to determine light and water use in maize-pigeonpea intercrop system. The experiment was laid out as a randomized complete block design (RCBD) replicated 4 times. Treatments included two pigeon pea maturity types; two long duration (erect - ICEAP 00053 and semierect - ICEAP 00040) and one medium duration (ICEAP 00557) type intercropped with maize (Katumani) or sole crop. Data on canopy light interception and soil water content changes were determined using sunfleck ceptometer and neutron probe respectively. Results showed that maize intercepted more light than pigeonpea early in the season (0-70 DAP) because the former has a fast initial growth rate than the later thereby minimizing competition for light. Similarly there was spatial and temporal variation in water use. In conclusion temporal complimentarily in maize-pigeonpea intercrop reduced competition for light between the two crops hence maize yields were unaffected. Temporal differences in root growth ensured full use of water during the growing season. Similarly, spatial use of water below the ground could be better by a combination of shallow and deep rooting components in an intercrop system.