Soil biology in traditional agroforestry systems of the Indian desert

Abstract

Traditional arid and semi-arid agroforestry systems serve as models for the 'protective-productive' rehabilitation strategies of agrarians. The nature of the organic materials present and their decomposition governs nutrient availability in soil systems. Indian desert vegetation has various non-fodder plants in and around farms that can well be used, along with diverse microbes, for improving soil biological fertility. The higher percentage loss of non-fodder plant litter, and the comparatively high phosphorus mineralisation offer the possibility of improving the biological characteristics of arid soils. Prosopis cineraria-based systems govern soil microbes according to their soil organic matter content. Enzyme activities and their dynamics with respect to litter amendment have been comparatively wellstudied for desert soils. Changes in microflora due to addition of Acacia leucophloea (AL) and Prosopis juliflora (PJ) litter in wetting-drying cycles in microcosm experiments revealed that a higher proportion of litter enhanced population levels of cellulolytic fungi, with a further rise following rewetting. However, populations of lipolytic fungi, proteolytic bacteria and actinomycetes were higher during the initial periods of decomposition. The results indicate a strong relationship between lipolytic fungi and sugar fungi, lignolytic fungi, actinomycetes, and proteolytic bacteria. Bacteria and actinomycetes play a synergistic role during decomposition of desert soils.