The impact of soil amendments on the moisture content, soil strength, and yield of okra on a loamy sand soil in southwest Nigeria

Abstract

The consequences of improper tillage and soil management are reflected through the decrease in soil health and reduction in crop yield. The objective of this study was to provide information about appropriate tillage practices and soil amendments that can not only improve the soil quality but also lead to optimal okra production in a sustainable way. A two-year study was conducted in the wet season of 2021 and 2022 at the Teaching and Research Farm, Ejigbo Campus, Ejigbo, Osun State, Nigeria. Three options for land preparation were involved, including the following treatments: i. slashing with the aid of cutlass, ii. spraying manually with glyphosate, and iii. conventional tillage. Three different types of nutrient management packages were applied. The moisture content in the soil was determined gravimetrically and soil penetration was measured by pushing a stainless-steel cone-tipped penetrometer (12.8-mm diameter, 30◦ cone) into the soil at a steady rate. The soil strength means of 1.65 and 1.98 MPa were recorded for an amended plot (AM) and non-amended (NA) treatment plots respectively, resulting in 16.7% decrease in soil strength when compared with NA experimental plots. Also, the mean soil strength in the first cropping season for the twelve treatments in 2021 (1.59 MPa) was significantly greater than that in the second cropping season of 2022 (1.30 MPa). This resulted in 18.2% reduction in average soil strength in the second cropping season between 0 to 30 cm soil depths. TRP (1.45 tons/ha) on one of the AM plots had the highest yield and was significantly greater than SPO (0.15 tons/ha) and SLO (0.13 tons/ha) on the NA plots by 867 and 1015% respectively at the 0.05 probability level. In comparison to a non-amended soil environment, soil amendment frequently results in healthier physical properties of soil that support a more favourable soil environment for plant growth.