Improving the soil available phosphorus and exchangeable calcium of three parent materials of the smallholder farmers using amendments in Abia State, Southeastern Nigeria

Enhancing the soil properties of the smallholder farmers’ farm will increase the soil productivity potentials, boost crop production and empower the farmers economically. It is upon this framework that this incubation study was set up at the Soil Science and Meteorology Laboratory of Michael Okpara University of Agriculture Umudike. The aim was to ascertain the effect of amendments on soil available phosphorus and exchangeable calcium of three parent materials namely; Sandstone, Shale and Alluvium in Abia State. The treatments comprised of seven amendments namely: Control (no amendment), Biochar, Ash, Lime, Biochar + Poultry Manure, Ash + Poultry Manure and Lime + Poultry Manure. They were applied at a sole rate of 1.43g to 100g of the soil and the ton equivalent was 2t/ha. The treatments were replicated three times in a Completely Randomized Design. The incubation study lasted for twelve weeks and available phosphorus alongside exchangeable calcium was determined at two weeks intervals. Experimental soil baseline showed that the soils had low available Phosphors with the following values; Shale 7.20 mg kg-1, Sandstone 10.11 mg kg-1 and Alluvium 9.06 mg kg-1. In Sandstone, Biochar + PM significantly (p<0.05) increased the available Phosphorus at 2, 4, 6, 8 and 10 weeks of incubation with 34.70, 25.45, 26.85, 21.65 and 19.40 mg kg-1 respectively. The highest value of exchangeable calcium was recorded at the 10th week of incubation for Shale with a value of 12.38 comlkg-1. On the average Biochar + PM increased available phosphorus and also the exchangeable calcium. Further field investigation is recommended.