Effect of Alley Cropping Microclimate on Wheat Productivity and Leave Decomposition in a Semi-Desert Region of Northern Sudan

Abstract

The study was conducted at Hudieba Research Station (Lat. 17.°57′N, 33.°8′E, 300 Km, on a loamy sand soil of the semi-desert region of northern Sudan during 2013 -2015 to examine the effect of alley-cropping system using three N-fixing trees (Leucaena leucocephala, Sesbania sesban and Sesbania Formosa) on climatic factors, soil fertility, and to examine the effects of incorporating tree leaves on soil on wheat grain yield in alley cropping system compared to control. The seedlings of the three trees were transplanted in the field in 2011 to establish alleycropping system (8-m wide alleys and 2-m inter rows), the performance of the tree species was assessed as the microclimatic factor and their effect on water use efficiency. Wheat was sown in November two months after incorporating tree leaves earlier in September in RCBD with three replicates and then evaluated for yield and yield components compared to control. Results indicated that the three trees differed in their ability to modify the microclimate with regard to solar irradiance, Formosa being the suitable one. Alleycropping system using Formosa and Sesban trees had good potential in improving water use efficiency compared to Leucaena and control. Nitrogen contents in tree alleys soil much higher in the depth from 0-60cm (309.3, 280.8 and 240.4ppm) for Formosa, Sesban and Leuceana respectively than in control (172.2ppm). Nitrogen content was increased in alley cropping system and in control after incorporating Formosa, Sesban and Leucaena leaves, respectively. Whereas Formosa and Sesban gave higher wheat grain yield (2810, 2513 kg/ha), Leucaena showed the lowest (632 kg/ha) as compared to the control (1759, 1912 and 1776 kg/ha) after incorporating Formosa, Sesban and Leucaena leaves, respectively. It could be concluded that Formosa was a suitable for alleycropping system for the purpose of modifying microclimate and improving crop productivity in semi-desert areas of Northern Sudan. Also All leaves examined in this study were good sources of N for high tress soils which are low in this element.