The Impact of Land Use Types and Acidity Indices on Soil Humic Fractions Quantities at Umudike, Tropical Rainforest, Nigeria

Natural humic fractions deposited in the soil are most times sources of industrial humic substances use for crop production. However, the quantities of the humic substances, which are components of soil organic matter, are affected by lots of factors and processes, including land- use. The effects of different land- use and soil acidi0ty indices on the quantity of soil humic fractions at Umudike, Abia State were studied. To assess these effects, soils samples were collected from a depth of 0-10cm from primary forest land, mixed cropping farm, grassland, pig waste dumpsite cow dung dumpsite, poultry droppings dumpsite and goat dung dumpsite within Umudike area of Abia State, Nigeria. Humic acid, fulvic acid, humin, particle size distribution, pH, exchangeable acidity and organic matter were determined using standard laboratory procedures. Also, relationships be- tween the selected soil acidity indices and humic fractions were estimated. The result showed that goat dung dumpsite had significantly (P<0.05) highest mean values of 0.15% and 0.24% for humic acid and humin, respectively. Pig waste and poultry droppings dumpsites had pH values of 6.3 and 6.2, respectively. Soil exchangeable acidity correlated positively (P<0.05) with fulvic acid having a coefficient of determination (R) value of 0.0770. The results obtained showed that goat dung dumpsite might serve as a potential natural mining site for artifi- cial humic acid and humin; also acidity indices affect humic fractions in the soi