INFLUENCE OF ANIMAL MANURES ON DEHYDROGENASE ACTIVITIES AND MICROBIAL POPULATION IN TROPICAL SOIL OF SOUTHEASTERN NIGERIA

This study assessed the usefulness of poultry and swine manures in the improvement of soil properties, microbial counts and dehydrogenase activities. A randomized complete block design was applied with three replicates consisting of poultry and swine manures as treatments applied at the rate (30 t ha−1) on each of the two experimental plots. Soil samples obtained from depths 0-15 cm and 15-30 cm at week 0, 2, 4, 6, 8, 10 and 12 for dehydrogenase and microbial densities using standard procedures. The pH (H20) slightly increased from 4.08 to 5.60 following manure application. At 0-15 cm soil, poultry manure increased pH by 25% soil while swine manure increases by 21%. Potential dehydrogenase recorded highest amount of production 7.09 Mg g-1 at 6 weeks of decomposition treated with swine manure at 15-30 cm soil depth. Bacterial counts increased from 1.27 x104 Cfu g-1 to 6.00 x107 Cfu g-1 in soil treated with poultry manure whereas soil amended with swine manure increased from 1.50 x104 Cfu g-1 to 7.10 x107 Cfu g-1. The results revealed that swine manure enhanced dehydrogenase production and microbial diversities than poultry manure.