Nutrient uptake and yield response of wheat (Triticum spp.) to different fertiliser applications in Ethiopia

Abstract

In northern Ethiopia, the persistently low crop yield is often attributed to inadequate soil fertility and inappropriate fertiliser recommendations. This study employed the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model for site-specific fertiliser recommendations to enhance wheat (Triticum spp.) yield. The objectives included quantifying soil nitrogen (N), phosphorus (P) and potassium (K) supplies, modelling observed and simulated yields, and validating the QUEFTS model. The experimental trials encompassed four treatments: (T1) model-based fertilisation; (T2) blended fertilisation; (T3) farmer-developed fertilisation; (T4) control, stratified across three different farm income groups. Soil information from the experimental plots was analysed and utilised as model inputs to estimate soil nutrient supplies. Yield and agronomic data were recorded, and nutrient uptake was analysed. Model performance was evaluated using metrics including root mean square error, coefficient of determination, index of agreement, and percent bias. Results indicated an N:P:K soil supply ratio of 7.5:1:7.8 in the experimental fields. The highest grain yield (5 886 kg ha−1) was observed in QUEFTS-based fertilisation, representing a significant (p < 0.05) increase in yield. Statistical analyses confirmed a promising level of accuracy of the model predictions. Therefore, the QUEFTS model could be a valuable tool to assist farmers in adjusting fertiliser application based on crop requirements and economic considerations.