Biomass evaluation of pasture in hot arid Rajasthan

Ground vegetation cover, trees/bushes density and biomass yield of pasture in hot arid region of Rajasthan during October and March were assessed. Dry matter (DM) yield of ground cover was higher during March than October month. Acid detergent fibre (ADF) and cellulose contents were higher during October and crude protein (CP) content was similar during October and March months. In the subsequent study, DM availability, leaf: stem ratio and composition of pastures with high grass cover and low density of trees and bushes were evaluated during monsoon and autumn seasons. Plant density in the ground cover decreased from 8.0/m² during monsoon to 3.6/m² during autumn season while DM yield was similar (68.3 and 61.9 g/m²). The DM content decreased from 82.2% during autumn to 61.6% during monsoon. Leaf: stem ratio decreased from 0.93 during monsoon to 0.42 during autumn. The CP content of the pasture decreased from 12.2% during monsoon to 7.2% during autumn. The ADF and cellulose contents in leaf and stem increased from monsoon to autumn. Copper, Zn, Fe and Mn contents were higher in leaves than stem. Copper content increased with plant maturity from monsoon to autumn. The results suggested that the yield of biomass decreased during autumn in arid region and required supplementation of fodder to livestock.