Impact of livestock production systems on the nutrient content of bio slurry in Kapchorwa district

Abstract

This study was conducted in Kapchorwa District with the objective of determining the nutrient concentration of bio-slurry under three livestock production systems namely; zero grazing, semi-zero grazing and free grazing. Survey questionnaire administered to obtain information on the family size, bio-slurry storage, management and livestock production systems. Laboratory analyses were also done on bio slurry obtained from outlet tank and storage pits to determine the nutrient content. Eighteen (18) households were surveyed while collecting the bio-slurry samples from each household. Nine (9) households in triplicates practicing the three-production system were purposely selected for collection of outlet tank Bio-slurry samples and 0.5 litres of mixed composite samples were obtained. Similarly, other Nine (9) households were selected and storage pit bio-slurry samples collected making eighteen (18) composite samples for laboratory analysis. The results from this study indicated that; Total nitrogen of both outlet tank and storage pit slurry under zero grazing was highest (0.67% and 0.66) % respectively, mean value of available P for both outlet tank and storage pit slurry per livestock production systems significantly decreased (p<0.001). Zero grazing system had the highest average K (32.9 Cmol/kg) followed by semi zero grazing (14.37 Cmol/kg) and free grazing with least average K (9.74Cmol/kg). Mean slurry pH for zero grazing was significantly higher (9.07) than that of semi-zero grazing (8.4) and free grazing (8.0). However, the pH result of outlet tank slurry was higher than that of storage pit slurry in all the three livestock production systems. The study shows that livestock production systems have a significant impact on the nutrient concentration of Bio-slurry. Nutrient concentrations tend to differ from one livestock production system to another. The loss of nutrients from bio slurry during storage should be prevented by ensuring that the storage capacity of bio slurry pits and storage containers is sufficient to prevent overflow. The storage pit should be covered to minimize N losses and preferably made of an impermeable barrier to avert Leaching of bio-slurry.