This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso C...This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso Central Rift Valley of Ethiopia. Trails were conducted at six experimental sites, sorghum yield response to N and P fertilizers application and economically optimum rates of nitrogen (EONR) and phosphorus (EOPR) were evaluated on a vertisols within the semi-arid Miesso districts west Hararge zone of Oromia region. The nutrient rates in 2014 cropping season four levels of Nitrogen (N) alone, these levels with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> Phosphorus (P) and without N, 69 kg<span style="white-space:nowrap;">·</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> N with three levels of P treatments including the zero control were evaluated. In 2015, cropping season similar rates of N alone, the same rate N with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> P, 92 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> N with three rates of P including the zero control were evaluated. The treatments were arranged in a randomized complete block with three replications in factorial design. Nutrient responses of sorghum were determined using asymptotic quadratic plateau functions. The significantly highest nitrogen rate was 46 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> alone in 2014 season, which gave grain yield of 2.56 Mg<span style="white-space:nowrap;">·ha<sup>−1</sup></span><sup> </sup>with a maximum yield advantage of 43%. P rates in both seasons and combined (sites + seasons) were not significantly influenced sorghum yield. Nitrogen agronomic and partial factor productivity peaked at 23 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> but declined with increasing N rate. The EONR combined (sites + seasons) were 37, 45, 52 and 60 <span styl展开更多
Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer ...Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly展开更多
文摘This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso Central Rift Valley of Ethiopia. Trails were conducted at six experimental sites, sorghum yield response to N and P fertilizers application and economically optimum rates of nitrogen (EONR) and phosphorus (EOPR) were evaluated on a vertisols within the semi-arid Miesso districts west Hararge zone of Oromia region. The nutrient rates in 2014 cropping season four levels of Nitrogen (N) alone, these levels with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> Phosphorus (P) and without N, 69 kg<span style="white-space:nowrap;">·</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> N with three levels of P treatments including the zero control were evaluated. In 2015, cropping season similar rates of N alone, the same rate N with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> P, 92 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> N with three rates of P including the zero control were evaluated. The treatments were arranged in a randomized complete block with three replications in factorial design. Nutrient responses of sorghum were determined using asymptotic quadratic plateau functions. The significantly highest nitrogen rate was 46 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> alone in 2014 season, which gave grain yield of 2.56 Mg<span style="white-space:nowrap;">·ha<sup>−1</sup></span><sup> </sup>with a maximum yield advantage of 43%. P rates in both seasons and combined (sites + seasons) were not significantly influenced sorghum yield. Nitrogen agronomic and partial factor productivity peaked at 23 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> but declined with increasing N rate. The EONR combined (sites + seasons) were 37, 45, 52 and 60 <span styl
文摘Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly
