Response of the Newly Released Shaga Rice Variety to Nitrogen and Phosphorus Fertilizer Rates in Vertisols of Fogera and Achefer Plain, North Western Ethiopia

Abstract

An experiment was conducted at Fogera and Achefer in the year 2020/21 and 2021/22 cropping seasons. Treatments were comprised of factorial combinations of five N levels (0, 92, 184, 276 and 368 kg ha<sup>-1</sup>) and four P<sub>2</sub>O<sub>5</sub> levels (0, 23, 46 & 92 kg ha<sup>-1</sup>) replicated three times in RCB Design. The objective of the experiment was to determine economically optimum rates of nitrogen and phosphorus fertilizer on yield and yield components of shaga rice variety. Data were collected on plant height, panicle length, number of tillers, number of fertile panicles, thousand seeds weight, grain yield, straw yield, and harvest index. All collected data were subjected to analysis of variance. Economic analysis was also done for yield. The combined analysis of the two years result showed that very highly (P<0.001) significant effect on plant height, number of total tillers per row meter length. And number of fertile panicles per row meter length, grain yield, and straw yield. most of yield component parameters and highly significantly affecting number of filled grain per panicle and number of tillers per row meter length. The highest grain yield (4.76 and 6.56 t ha<sup>-1</sup>) was obtained at 184-46 N- P<sub>2</sub>O<sub>5</sub> kg ha<sup>-1</sup> in Fogera and Achefer, respectively. The economic analysis has exhibited that the combined application of 184-46 N- P<sub>2</sub>O<sub>5</sub> kg ha<sup>-1</sup> is the most profitable treatment, with a mean net benefit of 74430.00- and 115994.00-Birr ha<sup>-1</sup> for Fogera and Achefer, respectively. Therefore, it can be concluded that application of nitrogen and phosphorous fertilizers at rates of 184-46 N- P<sub>2</sub>O<sub>5</sub> kg ha<sup>-1</sup> is the best recommended rate for rainfed lowland shaga rice variety in Fogera and Achefer plains and other similar agroecology.