Litter production and litter dynamics in different agroforestry systems in the arid western region of India

Abstract

Litterfall production, decomposition and nutrient release was investigated for three prominent agroforestry tree species, Prosopis cineraria, Tecomella undulata and Hardwickia binata, grown in the arid western region of India. The highest litterfall was recorded for H. binata (9.44 Mg ha−l y−1) followed by P. cineraria (8.94 Mg ha−l y−1) and T. undulata (3.74 Mg ha−l y−1). It took 15, 12 and 9 months for decomposition of 90% of the litter of H. binata, P. cineraria and T. undulata, respectively. Regression analysis showed that rainfall and air temperature had significant impacts on the decomposition process. Soil moisture and soil microbial biomass carbon showed high correlations (R2 > 0.70, p < 0.01) with litter decay. The rate of release of N (kN = 0.0014, surface (0–15 cm); kN = 0.0015, sub-surface (15–30 cm)) and K (kK = 0.0041, surface; kK = 0.0047, sub-surface) was highest from P. cineraria, whereas release rates of P were statistically equivalent for all species. N release from the decomposing litter increased initially, but then decreased as decomposition progressed. Concentrations of P, K and Mg in the litter decreased throughout the decomposition, with some fluctuations in P and Mg for P. cineraria and H. binata at the later stage. Ca release did not follow any specific trend. P. cineraria, with considerable amounts of litterfall, the highest nutrient inputs to the soil and the most rapid release of nutrients during the decomposition, was concluded to facilitate greater fertility build-up of the soil compared with the other two species.