The study assessed the soil qualities of five land use types; Oil palm plantation, Nursery site, Forest (Teak), Citrus orchard and Arable Crop land in Kabba College of Agriculture using selected biological indicators which include, Organic Carbon (OC), Total Nitrogen (TN), Microbial Biomass Carbon (MBC) and Microbial Biomass Nitrogen (MBN). An area of 40 m x 30 m that is representative of each land use was selected, sampled and analyzed following standard procedures for laboratory analysis. The highest values of OC (18.41 g/kg) and TN (7.95 g/kg) were obtained at the nursery site followed by Oil Palm (OC - 14.12 g/kg; TN - 6.56 g/kg), the lowest values were obtained at the Arable Crops site (OC - 10.53 g/kg; TN - 5.20 g/kg). The MBC values ranged from 307 – 498 mg/kg across the land use studied. The MBN values obtained in this study ranged between 16.93 - 34.41 mg/kg. The MBC/MBN ratios obtained in this study were relatively high and in the following order Forest land (26.5 mg/kg) > Oil Palm Plantation (21.3 mg/kg) > Citrus orchard (19.5 mg/kg) > Nursery site (15.9 mg/kg) > Arable Crops land (12.2 mg/kg) respectively indicating the predominance of fungi in these soils. It is recommended that sustainable practices that will encourage replenishment of C and N into the soil should be adopted in the study area.

Field experiment was conducted to study the effects of crop residues in combination with NPK fertilizer (NPKF) on soil chemical properties and growth performance of white seed melon at Ile-Oluji, Ondo State Nigeria. The experiment involved applications of cocoa bean husk (CBH), cocoa pod husk (CPH), cocoa pod waste (CPW), kola pod husk (KPH), Tithonia diversifolia (weed much (WM) in combination with NPK 15:15:15 Fertilizer to produce twelve treatments at 4 t ha-1 CBH + 200 kg ha-1 NPKF, 4 t ha-1 CBH + 100 kg ha-1 NPKF, 4 t ha-1 CPH + 200 kg ha-1 NPKF, 4 t ha-1 CPH + 100 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 100 kg ha-1 NPKF, 4 t ha-1 KPH + 200 kg ha-1 NPKF, 4 t ha-1 KPH + 100 kg ha-1 NPKF, 2 t ha-1 WM + 200 kg ha-1 NPKF, 2 t ha-1 WM + 100 kg ha-1 NPKF, 300 kg ha-1 NPKF and control, all the amendments tested significantly improved soil chemical properties and growth performance of white seed melon relative to control. Three cocoa plants residues in combination with NPKF at reduced rates 4 t ha CBH + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF and 4 t ha-1 CPH + 200 kg ha-1 NPKF respectively significantly (p < 0.05) improved soil pH, organic matter (OM), available P, exchangeable k, Ca and Mg, Na, Fe, Al and ECEC among the amendments tested. All treatments increased number of leaf, branches and vine length of white seed melon compared to control. 4 t ha-1 CBH + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF, 4 t ha-1 CPH + 200 kg ha-1 NPKF, had highest value of crop branches.