Effects of Lime and NPSB Fertilizer Rates on Yield Attributes and Yield of Wheat, and Soil Properties in Harbagona District of Sidama Region, Ethiopia

Abstract

Wheat is a crucial global cereal crop, particularly vital for Ethiopian highlanders. However, its production is often influenced by various environmental factors, notably soil acidity. This field experiment was carried out in Harbagona, Sidama Region of Ethiopia, during the main cropping season of 2022, aimed to evaluate the effects of combined lime and NPSB fertilizer applications on wheat yield and soil properties. The experiment was designed in a randomized complete block with ten factorial combinations involving five rates of NPSB fertilizer (0, 50, 100, 150, and 200 kg ha^-1) and two lime levels (with and without) replicated thrice. Results showed that combining lime with NPSB fertilizer significantly increased wheat grain and biomass yields, with the highest yields achieved at 150 kg ha^-1 NPSB application rate. Furthermore, the integrated application of lime and NPSB improved soil pH, reduced exchangeable acidity, and increased cation exchange capacity, thereby enhanced nutrient availability. Economic analysis revealed that lime integrated with 100 kg ha^-1 NPSB fertilizer provided the highest net benefit and marginal rate of return. Additionally, lime application extended days to heading, but accelerated days to maturity, while NPSB fertilization reduced both heading and maturity durations. Moreover, the combined application of lime and NPSB fertilizer enhanced various yield attributes of wheat, including tiller count, plant height, spike length, seed weight, and harvest index. In conclusion, the application of 100–150 kg ha^-1 NPSB fertilizer combined with lime not only enhanced soil properties, but also optimized yield and economic benefits. These findings emphasize the importance of nutrient management and soil amelioration practices in optimizing wheat yield and soil health in acidic soil conditions.