The Effect of Phosphorus Fertilizer Sources and Lime on Acidic Soil Properties of Mollic Rhodic Nitisol in Welmera District, Central Ethiopia

Abstract

The soil acidity problem is intensified by improper utilization of synthetic fertilizers in addition to other naturally existing causes; thus, it is important to consider effects on soil health beyond seasonal crop productivity. Most widely used sources of soluble phosphate fertilizers cannot perform effectively on acidic soil due to its fixation. Field experiments were conducted on the acidic nitisols of Welmera District in two locations to determine the effects of using lime and different phosphorus fertilizer sources on the soil acidity attributes and nutrient use efficiency of barley crops. Treatments include a factorial combination of 4 different phosphate fertilizer sources (PARP, MOHP, NPSB, and NAFAKA) with 2 application rates (34.5 kg P2O5 ha−1 and 69 kg P2O5 ha−1) and 2 lime application rates computed from soil exchangeable acidity result 404.25 kg·ha−1 and 563.9 kg·ha−1 for on-station and on-farm sites, respectively, with no lime application (1/4th of LR and 0 lime). Partially acidulated rock phosphate as a phosphorus fertilizer significantly improves soil acidity attributes such as exchangeable acidity, present acid saturation, and plant available phosphorus, and also another soil nutrient status is significantly affected by using different phosphorus sources with the lime application. Application of PARP phosphate sources significantly improves soil exchangeable acidity and present acid saturation by 42% and 41%, respectively, over the commonly used NPSB standard sources of phosphorus fertilizer. Using lime with alternative phosphate sources also contributes to more effective nutrient use efficiency and barely yields improvements with a productive acid soil amendment option. Maintaining soil health by using those integrated approaches improves the efficient utilization of scarce unrenewable resources on sustainable bases.