Lime and Vermicompost Application to Acid Soils and Their Effects on Maize Yield and Yield Components in Lalo Asabi District, West Wollega Zone, Oromia, Ethiopia

Abstract

Soil acidity is one of the major yield-limiting factors for crop production worldwide, particularly on highly weathered and leached tropical soils. Different reports have indicated that there is significant soil acidity coverage in Ethiopia. In particularly, in the western part of the country, soil acidity is a well-known problem limiting crop production and productivity. As part of the solution to such a problem in soils, the combined application of lime and VC on maize has not been investigated in the area, in which maize was one of the potential cereal crops in the area. A field experiment was conducted at Lalo Asabi district in western Wollega during the 2020 cropping season to evaluate the responses of maize to the combined application of lime and vermicompost (VC). The experimental treatments were five rates of lime (CaCO3) (0, 25, 50, 75, and 100% of lime requirement (LR)) and three levels of vermicompost (0, 2.5, and 5 t ha-1). The treatments were arranged in factorial combinations in a randomized complete block design with three replications. One composite surface soil samples from a depth of (0-15 cm) was collected from the experimental field before the commencement of the experiment. Maize yield and yield components were measured following standard procedures. The yield components and yield results revealed the main effects of lime and VC showed a significant effect (p<0.05) on the number of days to 50% tasseling and silking, ear height, number of cobs per plant, number of grains per cob, thousand grain weight, above ground biomass, and harvest index of maize. However, days to 90% physiological maturity, plant height, cob length and grain yield of maize were significantly affected (p<0.05) by lime and VC interactions. Even though both were statistically equal, the combined application of lime at 100% LR + 5 t VC ha-1 yielded the highest grain yield (7.99 t ha-1) followed by the combined application of lime at 75% LR + 2.5 t VC ha-1 whereas the lowest grain yield (2.97 t ha-1) from control plots. The results of economic analysis indicated that the combination of lime at 75% LR + 2.5 t VC ha-1 showed a marginal rate of return of 2322.74%, with the highest net benefit of 49980 Ethiopian Birr compared to other treatments. This study indicates combined use of lime and VC could ameliorate the adverse effect of soil acidity, and application of 75% LR + 2.5 t VC ha1 enhances grain yield and produces the highest net benefit of maize grown on acidic soil of the Lalo Asabi district.