ETSI Agronómica, Alimentaria y de Biosistemas (ETSIAAB), Universidad Politécnica de Madrid (UPM), Ciudad Universitaria, 28040 Madrid, Spain.
School of Environment, Natural Resources and Geography, Bangor University, Bangor, Gwynedd LL57 2UW, UK.
Sci Total Environ. 2018 May 15;624:1202-1212. doi: 10.1016/j.scitotenv.2017.12.250. Epub 2017 Dec 27.
Nitrification inhibitors (NIs) such as dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) provide an opportunity to reduce losses of reactive nitrogen (Nr) from agricultural ecosystems. To understand the fate and efficacy of these two inhibitors, laboratory-scale experiments were conducted with C-labelled DCD and DMPP to determine the relative rates of mineralization, recovery in soil extracts and sorption in two agricultural soils with contrasting pH and organic matter content. Concurrently, the net production of soil ammonium and nitrate in soil were determined. Two months after NI addition to soil, significantly greater mineralization of C-DMPP (15.3%) was observed, relative to that of C-DCD (10.7%), and the mineralization of both NIs increased with temperature, regardless of NI and soil type. However, the mineralization of NIs did not appear to have a major influence on their inhibitory effect (as shown by the low mineralization rates and the divergent average half-lives for mineralization and nitrification, which were 454 and 37days, respectively). The nitrification inhibition efficacy of DMPP was more dependent on soil type than that of DCD, although the efficacy of both inhibitors was lower in the more alkaline, low-organic matter soil. Although a greater proportion of DMPP becomes unavailable, possibly due to physico-chemical sorption to soil or microbial immobilization, our results demonstrate the potential of DMPP to achieve higher inhibition rates than DCD in grassland soils. Greater consideration of the interactions between NI type, soil and temperature is required to provide robust and cost-effective advice to farmers on NI use.
硝化抑制剂（NIs），如双氰胺（DCD）和 3,4-二甲基吡唑磷酸盐（DMPP），为减少农业生态系统中活性氮（Nr）的损失提供了机会。为了了解这两种抑制剂的命运和效果，我们进行了实验室规模的实验，用 C 标记的 DCD 和 DMPP 来确定在两种具有不同 pH 值和有机质含量的农业土壤中，这两种抑制剂的相对矿化率、土壤提取物中的回收率以及吸附率。同时，还测定了土壤中铵盐和硝酸盐的净生成量。添加 NI 到土壤后两个月，C-DMPP 的矿化率（15.3%）明显高于 C-DCD（10.7%），并且无论 NI 和土壤类型如何，两种 NI 的矿化率都随温度升高而增加。然而，NI 的矿化似乎对其抑制效果没有重大影响（从低矿化率和矿化与硝化的平均半衰期的差异可以看出，矿化和硝化的半衰期分别为 454 和 37 天）。DMPP 的硝化抑制效果比 DCD 更依赖于土壤类型，尽管在碱性和低有机质土壤中，两种抑制剂的效果都较低。尽管可能由于土壤或微生物固定化等物理化学吸附作用，DMPP 有更大比例变得不可用，但我们的结果表明，DMPP 有可能在草地土壤中比 DCD 实现更高的抑制率。需要更充分地考虑 NI 类型、土壤和温度之间的相互作用，以便为农民提供关于 NI 使用的可靠且具有成本效益的建议。
