Structural diversity and nutrient recycling potentials of three selected agroforestry homegardens in southern Kerala
Abstract
Homegardens in Kerala mimic forest ecosystems on account of the tree components included and are agroforestry systems that integrate different agricultural crops and enterprises as per the needs and interests of the farm family. Analysis of the structural diversity and nutrient recycling potentials of three agroforestry homegardens in southern Kerala revealed multi-tier cropping patterns with cropping intensities ranging from 177.18 to 187.04%. Two of the homegardens included livestock components adding to the nutritional security of the family. Diversity indices were in the order 0.92, 1.53 and 0.86. The quantum of litter fall varied with the tree canopies and species, amounting to 473.6, 425.37 and 345.11 kg adding 7.02, 7.517 and 5.165 kg NPK annually in the three homegardens. Maximum nutrient additions were recorded for nitrogen and potassium and least for phosphorus.
Keywords
Download Options
Introduction
Agroforestry systems offer immense potential for sustainable agriculture as the tree based systems are rich in biodiversity and organic matter production that can be suitably recycled in the system. Trees are characterized by a continuous litterfall, the quantity varying with age, species, canopy spread and season. Litter contributes significantly to the nutrient pool of the agroforestry system. In Kerala, homestead agroforestry predominates among the agroforestry systems practiced in the state. These systems refer to the intimate associations of multipurpose trees and shrubs with annual and perennial crops and invariably livestock, within the compounds of individual houses, with the whole tree- crop- animal unit being managed by family labour (Ferenandes and Nair, 1986). The present study explored the diversity of three selected agroforestry homegardens in Thiruvananthapuram, southern Kerala and the nutrient accretions via litter fall from the perennial components.
Conclusion
The study provides an insight to the diversity and nutrient recycling potentials of agroforestry homegardens in southern Kerala. The homegardens studied represented multi- storied tree based systems with high cropping intensities, however, the diversity and evenness indices worked out were low. The tree species add substantial amounts of litter and nutrients contributing to the soil fertility status and thus sustaining the soil productivity in the tree crop systems. The litter accrued considerable amount of nutrients with nitrogen and potassium accretions being comparatively more than that of phosphorus. The total amount of nutrients added depended on the quantity of the litter produced and its nutrient contents.
