Integrated recycling of on-farm agri-horticultural wastes through vermiculture as an approach to organic intensification of Ethiopian horticulture possibilities

The potential horticultural zones of Ethiopia falling in the Great Rift Valley ecosystem the runs from North-east to almost South-west bisecting the country into Western and Eastern highland plateau is reported to be under considerable ecological pressure. The semi-humid, humid and per-humid zones in this ecosystem totally covering about 21.5 percent of the country have ideal physical consitions for the production of both annual as well as perennial crop. The predominant soil orders of these zones are represented by inceptisols, alfisols and oxisols which are vulnerable to soil erosion and loss of soil fertility. Further, their high P-fixing capacities due to excesses of Fe and Al render them strongly P-deficient and leaching of bases leading to deficiencies of Ca, Mg and Mo, which may severely limit horticultural crop productivity, Biorecycling could play a vital role in the replenishment of bases and improve soil physical conditions if proper management practices are excercised. In such a context, nutrient recycling assumes great significance, emphasis however, needs to be placed on natural resource maintenance, use of organic composts and manures in view of their synergistic aspect of sustainable soil management. One of the most viable and practical approaches to organic intensification in horticultural production systems could be integrated recycling of horticultural wastes through vermiculture. The two steps method at the first instance employs chopping/shredding of wastes like banana pseudostem/Leaves, arecanut husk/sheath/ leaf, coconut coir pith/husk, straw and stalks of field crops, coffee cherry husk ideally 1-2 cm across and treated with fresh cow dung shurry (w percent of wieght basis) with or without Pleurotus spawn (0.01 percent on wight basis)/ Pleurotus spent waste (0.1 percent on weight basis). The material in small heaps with moisture adjusted to 30-40 percent, left for pre-decomposition in the field for about 25-30 days with turnings and moisture adjustments at fortnightly intervals. The second step invlves mixing of pre-decomposed organic wastes, dry leaves, green matter (leaves of Erythrina, Glyricidia etc,) and cowdung slurry at 4:1:1: 1 by volume and laid out in vermibeds of size 3x1x1m layer by layer with one kilo of mixed African Earth worm species comprising of Eudrilus, Eugeniae, Perionyx excavatus and Eisenia fetida distributed uniformly in the beds. Moisture of the beds is regulated at about 40 percent with provision of good aeration by giving turnings at 10-15 days intervals with infusion of fresh cowdung slurry at each turning. It takes 30-45 days at this step, for the formation of vermicompost. The present paper discusses the methodology of integrated recycling of agri-horticultural wastes indetail, evaluating the process vis-a-vis conventional procedures of compost making nutrient content of vermicompost, efficiency of the process and the effect of vermicompost use in citrus nurseries, omamental plants like rose etc.