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

Abstract

Litterfall production, decomposition and nutrient release was investigated in three prominent agroforestry tree species, Prosopis cineraria, Tecomella undulata and Hardwickia binata, grown in an arid region. 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 impact on the decomposition process. Soil moisture and soil microbial biomass carbon also 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 fastest from P. cineraria, whereas the 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 in P. cineraria and H. binata at the later stage. Ca release did not follow any specific trend. P. cineraria, with a considerable amount of litterfall, added more nutrients to the soil and had a faster release of nutrients during the decomposition and can thus facilitate greater fertility build-up in the soil, compared with the other two species.