LIGHT INTERCEPTION AND USE EFFICIENCY DIFFER WITH MAIZE PLANT DENSITY IN MAIZE-PEANUT INTERCROPPING

Abstract

Intercropping increases crop yields by optimizing light interception and/or use efficiency. Although intercropping combinations and metrics have beenreported, the effects of plant density on light use are not well documented.Here, we examined the light interception and use efficiency in maize-peanutintercropping with different maize plant densities in two row configurations insemiarid dryland agriculture over a two-year period. The field experimentcomprised four cropping systems, i.e., monocropped maize, monocroppedpeanut, maize-peanut intercropping with two rows of maize and four rows ofpeanut, intercropping with four rows of maize and four rows of peanut, andthree maize plant densities (3.0, 4.5 and 6.0 plants m–1 row) in bothmonocropped and intercropping maize. The mean total light interception inintercropping across years and densities was 779 MJ$m–2, 5.5% higher than inmonocropped peanut (737 MJ$m–2) and 7.6% lower than in monocropped maize (843 MJ$m–2). Increasing maize density increased light interception inmonocropped maize but did not affect the total light interception in theintercrops. Across years the LUE of maize was 2.9 g$MJ–1 and was not affectedby cropping system but increased with maize plant density. The LUE of peanutwas enhanced in intercropping, especially in a wetter year. The yield advantageof maize-peanut intercropping resulted mainly from the LUE of peanut. Theseresults will help to optimize agronomic management and system design andprovide evidence for system level light use efficiency in intercropping