RESPONSE OF WHEAT (Triticum aestivum L.) TO PHOSPHORUS AND POTASSIUM FERTILIZERS RATES AT KECHI, SOUTH WEST ETHIOPIA

Abstract

Wheat is the most significant cereal and staple crop. However, the primary obstacles to output and productivity are the depletion of soil nutrients and the improper application of fertilizers. Therefore, this experiment was conducted at Kechi, South West Ethiopia, to evaluate the growth and yield response of wheat to phosphorus and potassium fertilizer application rates during the 2023 main cropping season. The experiment comprised 12 treatment combinations with four rates of phosphorus (P) (0, 10, 20, and 30 kg/ha) and three rates of potassium (K) (0, 30, and 60 kg/ha) in the form of triple superphosphate (TSP) and murate of potash (KCl), respectively. The experiment was laid out as a randomized complete block design (RCBD) in a factorial arrangement and replicated three times per treatment. Data were collected on crop phenology, growth, yield, and yield components. The collected data were analyzed using statistical analysis software version 9.2.The outcome showed that the primary effects of potassium and phosphorus had a considerable effect on the harvest index and the number of productive tillers. The interaction effect of phosphorus and potassium had a substantial effect on the following parameters: days to heading, days to physiological maturity, plant height, and total tiller number, number of grains per spike, thousand seed weight, aboveground biomass, grain yield, and straw yield. Furthermore, 20 kg/ha P and 30 kg/ha K fertilizer application rates provided the maximum grain production (4350 kg/ha). The economic analysis also indicates that a net benefit of 229,815 ETB/ha and a marginal rate of return of 1783.1% were achieved from 20 kg/ha P and 30 kg/ha K combination. As a result, this combination can be suggested to raise wheat's grain production. However, since this experiment was conducted in a single season and at one site, repeating over seasons and locations will be required to come up with a plausible recommendation.