Production Potential of Agricultural Crops under Different Spacings of Melia Composita Based Agroforestry System in Semi-Arid Region

Abstract

Spacing is one of the most critical management practices in agroforestry systems as it determines the spatial arrangement of trees and their interaction with intercrops. Appropriate spacing ensures optimal light distribution, reduces competition, and improves system productivity. An experiment was conducted to evaluate the effect of different spacings of Melia composita on the performance of agricultural crops (wheat, barley and mustard) under agroforestry system. Six-month-old seedlings were transplanted in March 2019 at two spacings (4×3 m and 5×3 m). During the Rabi season (2020-21), wheat (WH-1105), barley (BH-393), and mustard (RH-30) were grown in the interspaces of Melia composita. Tree growth at the time of sowing of agricultural crops indicated good establishment, with height ranging from 6.63-6.71 m, diameter at breast height from 11.29-12.27 cm, and basal diameter from 14.46-15.74 cm. Crop growth and physiological traits showed significant variation under different spacings of Melia composita. In wheat, plant height, chlorophyll content, photosynthesis, transpiration, and stomatal conductance were significantly affected. Grain yield of wheat was 5.06 t ha-1 under sole cropping, with yield reductions of 31.22% and 26.09% under 4×3 m and 5×3 m spacing, respectively. Barley exhibited similar trends, with grain yield reductions of 27.85% and 23.09%, while mustard recorded reductions of 32% and 26% under the respective spacings over control. The benefit-cost ratio ranged from 1.10 to 1.59 in wheat, 0.92 to 0.97 in barley, and 1.24 to 1.84 in mustard, with higher values under sole cropping. Overall, wider spacing (5×3 m) proved more favorable for crop performance and economic returns than closer spacing (4×3 m).