Growth analysis of component crops in a maize-soybean intercropping system as affected by time of planting and spatial arrangement

摘要

Two field trials were conducted in 2007 and 2008 to determine the appropriate sequence of planting and spatial arrangement for the maize-soybean intercropping system for optimum growth. The experimental design was a randomized complete block design with three replicates. Treatments consisted of combinations of five relative times of planting either maize or soybean and two spatial arrangements of soybean (alternate or double rows). One sole crop each of maize and soybean was added for comparison. Results of the growth analysis indicated that maize planted simultaneously with soybean or before soybean recorded significantly higher values of leaf area index (LAI), crop growth rate (CGR) and net assimilation rate (NAR). Spatial arrangement did not influence these parameters in maize. Interaction between time of planting and spatial arrangement was however significant. LAI and CGR for maize increased with time while NAR declined. For the soybean crop, soybean planted on the same day with maize or planted before maize recorded significant LAI, CGR and NAR values. Soybean planted in double arrangement with maize recorded significant higher growth than soybean planted in alternate row arrangement with maize.