Yimer Tigist, Abera Girma, Beyene Sheleme, Paulus Ravensbergen Arie Pieter, Ukato Amrachu, Rasche Frank
School of Plant and Horticultural Science, College of Agriculture, Hawassa University, Hawassa, Ethiopia.
Plant Production Systems Group, Wageningen University and Research, Wageningen, the Netherlands.
Heliyon. 2024 Jul 2;10(13):e33926. doi: 10.1016/j.heliyon.2024.e33926. eCollection 2024 Jul 15.
Maize ( L.) is an important food crop in Ethiopia, but productivity is low mainly due to low soil fertility and suboptimal fertilization. Therefore, this study aims to determine the yield, nutrient use efficiency and economic feasibility of maize production under various fertilizer applications and test the suitability of the Quantitative Evaluation of the Fertility in Tropical Soils (QUEFTS) model for predicting maize yield response to fertilization in Sidama region, southern Ethiopia. On-farm experiments were conducted at six sites (Site 1-6) of Sidama region, southern Ethiopia during the 2019 growing season. The experiments were laid out in a randomized complete block design (RCBD) with three replications. The experiment was a nutrient omission trial with seven treatments: control, two full NPK treatments and four nutrient omission treatments with contrasting N and P rates. Omitting N resulted in 5-28 % yield loss and omitting P resulted in 4-44 % yield loss compared to the lower rate of full NPK treatment across all study sites. Whereas omitting K resulted in 21 % yield loss only at sites 2 and 3. An increase in maize yield was mainly associated with an increase in both nutrient uptake and nutrient use efficiency of NPK. The results showed the need to revise blanket recommendations since the highest mean grain yields and net economic returns with acceptable marginal rates of return were obtained with NPK application or higher levels of NP (N2P2 treatment). In addition, the present QUEFTS model validation study revealed the good fit between QUEFTS model predicted maize grain yields (6.3 t ha) to the average actual yields (7.4 t ha) and this was also confirmed by small average values of RMSE = 1.5 t ha and PBIAS = 6.9 %. Thus, the model can be a promising option for development of site specific fertilizer recommendations under smallholder farming systems in the region.
玉米（L.）是埃塞俄比亚的一种重要粮食作物，但产量较低，主要原因是土壤肥力低和施肥不合理。因此，本研究旨在确定不同施肥条件下玉米生产的产量、养分利用效率和经济可行性，并测试热带土壤肥力定量评价（QUEFTS）模型对埃塞俄比亚南部锡达马地区玉米施肥产量响应的预测适用性。2019年生长季，在埃塞俄比亚南部锡达马地区的6个地点（地点1 - 6）进行了田间试验。试验采用随机完全区组设计（RCBD），重复3次。该试验为养分缺失试验，有7种处理：对照、两种全量氮磷钾处理和四种不同氮磷比例的养分缺失处理。与所有研究地点较低施肥量的全量氮磷钾处理相比，不施氮导致产量损失5 - 28%，不施磷导致产量损失4 - 44%。而不施钾仅在地点2和3导致21%的产量损失。玉米产量的增加主要与氮磷钾养分吸收和养分利用效率的提高有关。结果表明，由于施用氮磷钾或更高水平的氮磷（N2P2处理）获得了最高的平均籽粒产量和净经济回报以及可接受的边际回报率，因此需要修订通用施肥建议。此外，目前的QUEFTS模型验证研究表明，QUEFTS模型预测的玉米籽粒产量（6.3吨/公顷）与平均实际产量（7.4吨/公顷）拟合良好，RMSE = 1.5吨/公顷和PBIAS = 6.9%的小平均值也证实了这一点。因此，该模型对于该地区小农户种植系统下制定特定地点的肥料推荐可能是一个有前景的选择。
