Dept. Soil, Water, and Climate, University of Minnesota, St. Paul, MN, 55108, USA.
Dept. Soil, Water, and Climate, University of Minnesota, St. Paul, MN, 55108, USA.
Environ Pollut. 2021 Sep 1;284:117124. doi: 10.1016/j.envpol.2021.117124. Epub 2021 Apr 20.
Potato (Solanum tuberosum L.) production in irrigated coarse-textured soils requires intensive nitrogen (N) fertilization which may increase reactive N losses. Biological soil additives including N-fixing microbes (NFM) have been promoted as a means to increase crop N use efficiency, though few field studies have evaluated their effects, and none have examined the combined use of NFM with microbial inhibitors. A 2-year study (2018-19) in an irrigated loamy sand quantified the effects of the urease inhibitor NBPT, the nitrification inhibitor DMPSA, NFM, and the additive combinations DMPSA + NBPT and DMPSA + NFM on potato performance and growing season nitrous oxide (NO) emissions and nitrate (NO) leaching. All treatments, except a zero-N control, received diammonium phosphate at 45 kg N ha and split applied urea at 280 kg N ha. Compared with urea alone, DMPSA + NBPT reduced NO leaching and NO emissions by 25% and 62%, respectively, and increased crop N uptake by 19% in one year, although none of the additive treatments increased tuber yields. The DMPSA and DMPSA + NBPT treatments had greater soil ammonium concentration, and all DMPSA-containing treatments consistently reduced NO emissions, compared to urea-only. Use of NBPT by itself reduced NO leaching by 21% across growing seasons and NO emissions by 37% in 2018 relative to urea-only. In contrast to the inhibitors, NFM by itself increased NO by 23% in 2019; however, co-applying DMPSA with NFM reduced NO emissions by ≥ 50% compared to urea alone. These results demonstrate that DMPSA can mitigate NO emissions in potato production systems and that DMPSA + NBPT can reduce both NO and NO losses and increase the N supply for crop uptake. This is the first study to show that combining a nitrification inhibitor with NFM can result in decreased NO emissions in contrast to unintended increases in NO emissions that can occur when NFM is applied by itself.
在灌溉粗质地土壤中种植马铃薯需要大量施用氮肥（N），这可能会增加活性氮的损失。生物土壤添加剂，包括固氮微生物（NFM），已被推广为提高作物氮利用效率的一种手段，尽管很少有田间研究评估它们的效果，也没有研究过 NFM 与微生物抑制剂的联合使用。在一项为期两年的灌溉壤土砂质土研究（2018-19 年）中，定量了脲酶抑制剂 NBPT、硝化抑制剂 DMPSA、NFM 以及添加剂组合 DMPSA+NBPT 和 DMPSA+NFM 对马铃薯生长和生长季氧化亚氮（NO）排放和硝酸盐（NO）淋失的影响。除了零氮对照外，所有处理均施用过磷酸铵 45 kg N ha-1，并分两次施尿素 280 kg N ha-1。与单独施用尿素相比，DMPSA+NBPT 分别减少了 25%和 62%的 NO 淋失和排放，并增加了 19%的作物氮吸收，尽管添加剂处理都没有增加块茎产量。DMPSA 和 DMPSA+NBPT 处理的土壤铵浓度较高，与单独施用尿素相比，所有含有 DMPSA 的处理均能持续减少 NO 排放。NBPT 单独使用可减少 21%的氮素淋失，减少 37%的氮素排放2018 年与单独施用尿素相比。与抑制剂相反，NFM 单独使用可使 2019 年 NO 增加 23%；然而，与单独施用尿素相比，与 DMPSA 共同施用 NFM 可减少≥50%的 NO 排放。这些结果表明，DMPSA 可以减轻马铃薯生产系统中的 NO 排放，DMPSA+NBPT 可以减少 NO 和 NO 损失，并增加作物吸收的氮供应。这是第一项表明，与单独施用 NFM 时可能导致的意外增加的 NO 排放相反，将硝化抑制剂与 NFM 结合使用可以减少 NO 排放的研究。
