Effects of soil amendments on selected soil physical properties and okra (Abelmoschus esculentus L. Moench) yield in Southwest Nigeria

A two-year study was conducted during in the wet season of 2021 and 2022 at the Teaching and Research Farm, Ejigbo Campus, Ejigbo, Osun State, Nigeria to evaluate the effects of soil amendment on moisture content, soil strength and okra yield. The study included the following treatments: (i) slashing with cutlass, (ii) manually spraying with glyphosate, and (iii) conventional tillage. The moisture content in soil was determined gravimetrically. The soil strength of 1.65 and 1.98 MPa were recorded for amended (AM) and non-amended (NA) treatment plots respectively, which resulted in 16.7% decrease in soil strength when compared with NA experimental plots. The mean soil strength during the first cropping season in 2021 (1.59 MPa) was significantly higher than in the second cropping season in 2022 (1.30 MPa), resulting in an 18.2% reduction in average soil strength between 0–30 cm soil depth. AM plots achieved the highest yield, significantly exceeding the yield of treatment plots where weeds were sprayed with herbicide (SPO, 0.15 tons/ha) and those where vegetation was slashed with a cutlass (SLO, 0.13 tons/ha) without amendment – by 867% and 1015%, respectively, at the 0.05 probability level. Soil amendments generally enhance soil physical conditions, creating a more favorable environment for plant growth compared to non-amended soil. Keywords: conventional tillage, soil strength, spraying, land preparation, soil amendment