CAJ | 학술논문

为比较硝化抑制剂双氰胺、硫代硫酸钾对土壤氮的硝化抑制效果，明确其对土壤氮转化作用效应，采用室内培养试验方法，研究了双氰胺、硫代硫酸钾及其配施对土壤矿质氮动态变化、硝化作用及氮回收率的影响。结果表明，单施氮肥土壤硝化作用活跃，77.7%的化肥氮以铵态氮形式从矿质氮库消失，其中56.6%的氮形成硝态氮。氮肥配施双氰胺、硫代硫酸钾分别显著降低矿质氮库铵态氮消失量74.1%（P<0.01）和16.6%（P<0.05），同时配施双氰胺和硫代硫酸钾处理铵态氮出现增加现象。氮肥配施双氰胺及同时配施2种抑制剂均不同程度地抑制氮的硝化作用，抑制率分别为35.5%～98.7%和82.2%～103.5%，硝化作用延滞时间均在20 d以上。氮肥配施硫代硫酸钾的硝化抑制率为1.6%～62.6%，硝化作用延滞时间为10 d。双氰胺硝化抑制效应优于硫代硫酸钾，且2种抑制剂同时配施作用效果优于其单独施用。施用硫代硫酸钾可促进土壤NO2--N积累，双氰胺可抑制NO2--N生成。氮肥配施双氰胺及同时配施两种抑制剂处理显著增加土壤矿质氮含量、降低其他去向氮含量同时显著提高土壤矿质氮回收率14.7%（P<0.05）和12.0%（P<0.05）。总体上，抑制剂双氰胺在铵态氮转化、硝化作用抑制及提高矿质氮回收率等方面作用效果均优于硫代硫酸钾，硫代硫酸钾与双氰胺配施在硝化抑制作用方面具有协同效应。该研究结果可为双氰胺、硫代硫酸钾在农田氮素面源污染控制中的应用提供科学依据，但对2种抑制剂硝化抑制特性的全面了解，尚需在田间试验条件下进行进一步的研究和验证。
위비교초화억제제쌍청알、류대류산갑대토양담적초화억제효과，명학기대토양담전화작용효응，채용실내배양시험방법，연구료쌍청알、류대류산갑급기배시대토양광질담동태변화、초화작용급담회수솔적영향。결과표명，단시담비토양초화작용활약，77.7%적화비담이안태담형식종광질담고소실，기중56.6%적담형성초태담。담비배시쌍청알、류대류산갑분별현저강저광질담고안태담소실량74.1%（P<0.01）화16.6%（P<0.05），동시배시쌍청알화류대류산갑처리안태담출현증가현상。담비배시쌍청알급동시배시2충억제제균불동정도지억제담적초화작용，억제솔분별위35.5%～98.7%화82.2%～103.5%，초화작용연체시간균재20 d이상。담비배시류대류산갑적초화억제솔위1.6%～62.6%，초화작용연체시간위10 d。쌍청알초화억제효응우우류대류산갑，차2충억제제동시배시작용효과우우기단독시용。시용류대류산갑가촉진토양NO2--N적루，쌍청알가억제NO2--N생성。담비배시쌍청알급동시배시량충억제제처리현저증가토양광질담함량、강저기타거향담함량동시현저제고토양광질담회수솔14.7%（P<0.05）화12.0%（P<0.05）。총체상，억제제쌍청알재안태담전화、초화작용억제급제고광질담회수솔등방면작용효과균우우류대류산갑，류대류산갑여쌍청알배시재초화억제작용방면구유협동효응。해연구결과가위쌍청알、류대류산갑재농전담소면원오염공제중적응용제공과학의거，단대2충억제제초화억제특성적전면료해，상수재전간시험조건하진행진일보적연구화험증。
Nitrification inhibitor has been proved to be effective in retarding nitrification process of nitrogen in the soil. Application of nitrification inhibitors to the field is considered to be a major method in controlling nonpoint pollution induced by nitrogen fertilizer in agricultural production. Dicyandiamide and thiosulfate are two types of nitrification inhibitors widely used throughout the world. A large number of studies have been carried out on dicyandiamide and thiosulfate focusing on their inhibitory effects. Till now, very limited information is available on the comparative effects of dicyandiamide and thiosulfate on transformations of nitrogen in the soil. The aim of this experiment was to investigate the effects of nitrification inhibitor dicyandiamide, potassium thiosulfate and their combination on the changes of mineral nitrogen, nitrification process and nitrogen recovery in the soil. A forty-day incubation experiment was conducted under the laboratory conditions (20℃). The experiment included unfertilized control, soil appended with urea nitrogen of 200 mg/kg alone, soil appended with urea nitrogen and dicyandiamide of 40 mg/kg, soil appended with urea nitrogen and potassium thiosulfate of 64 mg/kg, and soil appended with urea nitrogen and two inhibitors. Soil moisture in different treatments remained 60 percent of field water capacity. During the experimental period, soil samples were collected dynamically and the contents of mineral nitrogen such as nitrate nitrogen, ammonium nitrogen and nitrite nitrogen were analyzed. The result showed that an active nitrification process was found in the soil appended with nitrogen without nitrification inhibitors, where 77.7 percent of NH4+-N in applied nitrogen disappeared from the mineral nitrogen pool during the whole incubation period of 40 d. It was estimated that 56.6 percent of applied nitrogen was accumulated as NO3--N. Addition of nitrification inhibitors dicyandiamide and potassium thiosulfate resulted in a decrease in the extent of NH4+-N disappearance by 74.1 percent and 16.6 percent, respectively. However, addition of dicyandiamide and potassium thiosulfatecaused the increase in soil NH4+-N concentration. The nitrification process of nitrogen was inhibited in the soil appended with dicyandiamide and dicyandiamide combined with potassium thiosulfate, and the inhibition rates from 35.5 percent to 98.7 percent and from 82.2 percent to 103.5 percent were recorded, respectively. The delay of nitrification process was more than 20 days in two treatments. The nitrification rate in the soil appended with potassium thiosulfate was from 1.6 percent to 62.6 percent and the delay of nitrification process was 10 days. It was indicated that dicyandiamide induced a more pronounced inhibition on nitrogen nitrification as compared to potassium thiosulfate. Furthermore, a more efficient inhibition was observed for addition of dicyandiamide combined with potassium thiosulfate than that of dicyandiamide or potassium thiosulfate alone. It was also observed that potassium thiosulfate increased the accumulation of NO2--N in the soil while dicyandiamide suppressed the production of NO2--N. Nitrification inhibitor dicyandiamide or dicyandiamide combined with potassium thiosulfate increased the concentration of mineral nitrogen significantly while decreased the concentration of nitrogen unaccounted. Application of dicyandiamide, dicyandiamide combined with potassium thiosulfate increased the nitrogen recovery by 14.7 percent and 12 percent, respectively, compared with that in the treatment receiving nitrogen fertilizer alone. In summary, dicyandiamide proved superior to potassium thiosulfate in maintaining NH4+-N, inhibiting nitrification process and enhancing nitrogen recovery. A synergistic effect was also observed for the combined application of dicyandiamide and potassium thiosulfate. Results in this study are expected to provide scientific basis for practical application of two nitrification inhibitors. The inhibitory effect of dicyandiamide and potassium thiosulfate depends on soil temperature, moisture, microbial activity and other factors, and field experiment needs to be conducted to test the inhibitive characteristics of dicyandiamide and potassium thiosulfate on the nitrification.