Polyacrylamide (PAM) mitigates soil nutrient depletion and increases nutrient utilization; however, the effect of PAM combined with other amendments have not been tested much under field condition. The objective of our study was, therefore, to identify the best combination of amendments that can improve soil nitrogen (N) and phosphorus (P) balances while maximizing utilization efficiency and profitability under teff cultivation. A field experiment was carried out for 2 years in the midland agroecology of Ethiopia. A total of 24 experimental plots were designed using RCBD with three replications. The treatments were PAM (40 kg ha⁻¹), biochar (B = 8 t ha⁻¹), lime (L = 4 t ha⁻¹), gypsum (G = 5 t ha⁻¹), PAM+B, PAM+L, PAM+G, and a control. N and P inflows from atmospheric deposition, biological fixation, and fertilizers; and outflows by water erosion, leaching, gaseous emissions, and harvested products were monitored in all plots via NUTrient MONitoring approach. Results showed that all the applied soil amendments improved nutrient balances (8–134%) compared with the control. Of the measured outflows, harvested products (43–60%) and water erosion (14–31%) were the major contributors to N depletion, followed by leaching (15–23%) and gaseous emissions (11–13%). Among the soil amendments, PAM+L appreciably reduced P loss from water erosion (61%); and N losses from erosion, leaching, and emissions by 55, 10, and 3%, respectively; and increased N use efficiency by 31% compared with the control. Moreover, PAM+L provided a net benefit much higher compared with others. Thus, application of PAM+L would be an effective strategy for sustainable agriculture, especially in acidic and degraded dryland areas.

中文翻译：

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聚丙烯酰胺和其他土壤改良剂的双重好处：在埃塞俄比亚中部农业生态系统中缓解土壤养分枯竭和提高使用效率

聚丙烯酰胺 (PAM) 可减轻土壤养分消耗并提高养分利用率；然而，PAM 与其他修正相结合的效果尚未在现场条件下进行过多测试。因此，我们研究的目的是确定可以改善土壤氮 (N) 和磷 (P) 平衡的最佳改良组合，同时最大限度地提高苔麸种植下的利用效率和盈利能力。在埃塞俄比亚中部生态农业进行了为期 2 年的田间试验。使用 RCBD 设计了总共 24 个实验小区，三个重复。处理是 PAM (40 kg ha ^-1 )、生物炭 (B = 8 t ha ^-1 )、石灰 (L = 4 t ha ^-1 )、石膏 (G = 5 t ha ^-1)、PAM+B、PAM+L、PAM+G 和一个对照。来自大气沉降、生物固定和肥料的 N 和 P 流入；通过营养监测方法在所有地块中监测水侵蚀、浸出、气体排放和收获产品的流出量。结果表明，与对照相比，所有应用的土壤改良剂都改善了养分平衡（8-134%）。在测量的流出量中，收获产品（43-60%）和水侵蚀（14-31%）是氮消耗的主要贡献者，其次是浸出（15-23%）和气体排放（11-13%）。在土壤改良剂中，PAM+L 显着减少了水蚀造成的磷损失（61%）；侵蚀、浸出和排放造成的氮损失分别降低 55%、10% 和 3%；与对照相比，氮的利用效率提高了 31%。而且，与其他相比，PAM+L 提供了更高的净收益。因此，PAM+L 的应用将是可持续农业的有效策略，尤其是在酸性和退化的旱地地区。