The intensive crop production systems rely heavily on inorganic fertilisers, which exert a strong influence on the cost of production. There exists the possibility for reducing the cost of production with the use of local, potential sources of organic wastes like the poultry litter. With the reduced availability of the conventional source of organic fertiliser, (namely farmyard manure), farmers are resorting to the use of poultry litter. However; the quality of the poultry litter or manure used is highly heterogeneous and it is important to assess its nutrient contents in view of using it as a partial substitute for inorganic fertilisers. the storage and disposal of poultry litter is a potential source of environmental pollution. The objectives of this study were firstly to assess the fertiliser value of poultry waste ( litter and manure ) in foodcrop production and secondly to investigate how poultry waste can be disposed so that it does not affect the environment. The project consists of three components namely the determination of the nutrient qualities of poultry waste(both litter and manure), the composting of such waste and field trials to assess the fertiliser value of poultry composts. All three activities were undertaken. Results indicate that poultry waste is alkaline in nature with pH varying from 8.5 in litter to 8.8 in manure. Poultry waste can thus contribute significantly towards improving the quality of the highly acidic leached soils found in the uplands of Mauritius. Poultry manure (9 175 ppm and 26.8 rneq % respectively) is richer than litter (7 017 ppm and 20.8 meq %) in available P and K, but both represent good sources of Kand P. Poultry manure contained less organic matter (31.6 % as opposed to 43.9 %) and was slightly richer in total N ( 2.6 % ). The C:N ratio of poultry waste, ranged from 7:1 to 12:1, and indicates that N will be readily available to the plant. Composting of poultry waste with other carbon rich materials can be considered in a composting process. The pile method was found to be effective for composting poultry waste. When poultry waste was composted in heaps above ground, maturity of the compost was reached after 8 to IO weeks with litter and about twice as Jong i.e. 18 to 20 weeks in the case of manure. Composting lowered pH to near neutrality and decreased organic matter content probably owing to oxidation of carbon by microorganisms. Composting also brought about an increase in available P and K but the trends in changes in total N and in C:N ratio were less perceptible. Poultry compost, be it manure or litter, is slightly alkaline in nature (average pH: 7.65) and could thus prove to be a valuable resource for improving acidic soils in the superhumid areas of the country. Field trials were carried out to assess the fertiliser value of composted poultry manure and litter. Results indicate that when manure was used at the rate of SOt/ha in cabbage the amount of mineral fertilisers can be reduced by two-thirds the level usually recommended i.e. 60 kg N, 80 kg 1'205 and I 00 kg K20 per hectare. However, results were not consistent with lettuce and cauliflower.
The Objectives were:
(i) to replace partly if not totally the amount of inorganic fertilisers used in fooclcrops production by poultry wastes.
(ii) to dispose poultry waste usefully so that it does not affect the environment.