Resource integration and productivity of understorey tuber crops in an agroforestry home garden of southern Kerala
Sheeba Rebecca Isaac1 and Janova Varghese2
1) FSRS Sadanandapuram, Kottarakkara, Kerala, India.
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Agroforestry gardens are characterized by the high organic matter production insitu especially in the form of litter from the perennial components included in the system. Preliminary data collection on use of litter revealed major fraction of the respondents to burn them at frequent intervals. Recycling and use of litter as organic sources in crop production have little been exploited and in this background the investigation on the use of leaf litter as nutrient source in tuber crops was taken up in a selected agroforestry homegarden of Southern Kerala, India. Quantification of the litter biomass in the garden revealed an annual production of 352 kg. Litter composted using earthworms and enriched with biofertilisers formed the nitrogen source for the tuber crops (Cassava, Arrow root, Tannia, Taro and Amorphophallus) raised as intercrops. Laboratory investigations on the allelopathic effects of seven tree species litter did not reveal significant negative allelopathic effects on the sprouting of the tuber setts. The field experiment on the use of composted litter as nitrogen source (50 per cent RDN substitution) was laid out in randomized block design with four replications during March to November 2013 and results revealed positive responses to litter compost especially in Tannia, Taro, Arrow root and Amorphophallus. The percent reduction cassava yields compared to 100 per cent chemical use were highest. Maximum yields and profits were realised in Amorphophallus, 32.38t ha-1 and 3.03 respectively) Taking into account the economics and benefits accrued with the organic recycling, composting of litter and use as a viable nutrient source can be safely recommended for tuber cultivation in agroforestry systems