Cover crop biomass and organic manure applications for improved soil physico-chemical properties and tomato yield in a continuous-cropped arable land.

Abstract

The growing global population and limited land resources have made farmers to rely heavily on continuous cropping, which in turn has negatively impacted soil quality and crop productivity. This study, conducted at location is southwest Nigeria, aimed to restore a continuous-cropped arable land. The study assessed the effectiveness of cover crop biomass and organic manure application on soil physical quality and tomato yield through six treatments in two experiments involving groundnut planting and tomato cultivation. The treatments consisted of piggery manure and groundnut residues (PG+G); poultry manure and groundnut residues (PM+G); groundnut residues only (G only); poultry manure only (PM only); piggery manure only (PM only) and control (no manure). Disturbed and undisturbed soil samples were collected, before the experiment and after the harvest of both groundnut and tomato, from the soil depth 0-40 cm, at 10 cm increments. The results showed that organic amendments significantly (p < 0.05) increased soil organic matter by 11-38 % in the 0-10 cm surface layer and 15-36 % in the 10-20 cm subsurface layer while it reduced in the control. The pH increased, soil bulk density decreased by 14-27% (0-10 cm) and 3-27% (10-20 cm), soil water content increased by 12-118% (0-10 cm) and 4-30% (10-20 cm) while the soil saturated hydraulic conductivity improved by 17-218% (0-10 cm). Poultry manure gave the highest tomato yield components: ≈ 224 fruits, ≈ 45 mm fruit diameter, and 15.8 ton/ha yield, all significantly (p < 0.05) better than the control and other treatments. These findings showed that cover crops biomass cum organic manure could restore the soil physical quality of continuous-cropped arable lands and significantly optimize crop yield.