Effect of organic amendment on properties and nutrient loss ofsoils of selected parent material

Abstract

Soils of Southeastern Nigeria like those of other humid tropical countries are prone toleaching due to high rainfall resulting in low fertility, nutrient status, and crop yield.Evaluating the effects of selected organic amendments on retention of nutrients in soils is ofmajor concern and formed the purpose of the study. Soil samples were collected from AsuRiver Group, (ARG), Bende Ameki Group (BAG), Coastal Plain Sand (CPS) and FalsebeddedSand Stone (FBS) which were the four respective parent materials studied. Three replicates of10 kg of prepared samples from each parent material were bagged and thereafter appliedwith 10 tons ha-1 each of poultry (PD) and goat droppings (PD, GD). The thoroughly mixedcombinations laid in a completely randomized design (CRD) were allowed to blend for threemonths after which, samples were collected from each bag and analyzed. The remainingamended soils were subjected to a rainfall simulation which enabled the collection ofsediment yield which was also analyzed to determine the nutrients in them. Generated soildata were analyzed with analyses of variance (ANOVA). Means were separated using the leastsignificant difference (LSD) at 5% probability level. The result showed that soil organiccarbon increased from 15.80 – 17.70, 6.90 - 14.20, 7.10 – 13.90 and 11.39 - 17.50 gkg-1 inARG, BAG, CPS and FBS respectively before and after amendment and later decreased to 10.8,11.30, 6.70, and 8.30 g kg-1 in the sediment yield following simulation. Similarly, there weresignificant losses of about 23.52, 60.85; 60.00 and 47.20 % of total nitrogen to detached soilsin the respective lithologies. Total nitrogen and available phosphorus losses in the soilsfollowed the order: CPS > FBS > BAG > ARG and FBS > CPS > BAG > ARG respectively.