Cross‐linked polymer hydrogels, polyacrylamide co‐polymer (XPAM) or polyacrylate (XPAA) offer potential solutions for soil degradation, declines in soil resilience, and poor productivity in marginal soils. However, little is known about their long‐term effect on soil nutrient availability. This 9‐yr, irrigated, outdoor, cropped pot study evaluated a single, one‐time addition of XPAM or XPAA at 0.25 or 0.5% dry wt. (5.6 or 11.2 Mg ha^–1) in a degraded (artificially eroded) soil. Controls included an unamended degraded soil and an unamended, non‐degraded soil (i.e., topsoil). We measured nutrients in soil and leachate water each year, and in the first 5 yr, crop yields and nutrient uptake. Both hydrogels increased average soil pH and electrical conductivity (EC), soil extractable K, Na, and total organic carbon (TOC), and decreased soil extractable Mg relative to the control. Unlike XPAM, XPAA produced a greater increase in soil extractable K, increased extractable Fe, Zn, Mn, and Cu, increased Olsen P, and decreased total inorganic carbon (TIC). Neither hydrogel affected crop yields but XPAA increased K and Zn and decreased Mg and Na uptake in crops compared to controls. Relative to the control, both hydrogels decreased cumulative Ca, Mg, and S leaching mass losses and increased mean EC of leachate. Unlike XPAM, XPAA increased cumulative leaching mass losses of K, P, NO₃–N, and NH₄–N relative to the control. The hydrogels’ soil effects persisted for ≥7 yr, differing as a function of the quantity of included counterions and the stability of the gel structure after soil placement.

中文翻译：

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交联聚合物可提高退化土壤对养分的吸收

交联的聚合物水凝胶，聚丙烯酰胺共聚物（XPAM）或聚丙烯酸酯（XPAA）为土壤退化，土壤弹性下降和边缘土壤生产力差提供了潜在的解决方案。但是，对其对土壤养分有效性的长期影响知之甚少。这项为期9年的灌溉户外盆栽研究评估了一次或一次添加干重为0.25或0.5％的XPAM或XPAA。（5.6或11.2 Mg ha ^–1）在退化的（人工侵蚀的）土壤中。对照包括未改良的退化土壤和未改良的未退化土壤（即表土）。我们每年测量土壤和渗滤液水中的养分，在最初的5年中，测量作物的产量和养分吸收。两种水凝胶均提高了土壤平均pH和电导率（EC），土壤可提取的K，Na和总有机碳（TOC），并且相对于对照而言，土壤可提取的Mg降低。与XPAM不同，XPAA的土壤可提取钾含量增加更多，可提取铁，锌，锰和铜的含量增加，奥尔森磷增加，总无机碳（TIC）减少。与对照相比，水凝胶都不会影响作物的产量，但是XPAA可以增加作物中的钾和锌，减少镁和钠的吸收。相对于对照，两种水凝胶均降低了累积的Ca，Mg，和S浸出质量损失和渗滤液平均EC的增加。与XPAM不同，XPAA增加了K，P，NO的累积浸出质量损失₃ -N和NH ₄ -N相对于对照。水凝胶对土壤的影响持续≥7年，这取决于所含抗衡离子的数量和土壤放置后凝胶结构的稳定性。