不同硝化抑制剂组合对铵态氮在黑土和褐土中转化的影响

【目的】添加硝化抑制剂和氮肥增效剂是提高氮肥利用率的有效方法。研究不同硝化抑制剂和氮肥增效剂组合对不同性质土壤中铵态氮转化特征的影响，为科学合理选择抑制剂提供理论依据。【方法】供试生化抑制剂包括2-氯-6 (三氯甲基) -吡啶 (Nitrapyrin，CP)、3,4-二甲基吡唑磷酸盐 (DMPP)、1-甲氨甲酰-3-甲基吡唑 (CMP)、3-甲基吡唑 (MP)、2-氨基-4-氯-6-甲基嘧啶 (AM)、N-guard、二氰二胺 (DCD)。供试土壤为黑土和褐土，以氯化铵为氮肥，按照常用量添加各生化抑制剂制备稳定性肥料，用于室内恒温、恒湿土壤培养试验。试验设不施肥 (CK)、氯化铵 (N)、N + CP、N + CP + AM、N + CP + DCD、N + CP + N-guard、N + CP + DMPP、N + CP + CMP、N + CP + MP等9个处理。在培养第1、4、7、11、15、22、30、45、60、75、90、105、120天取土样，测定土壤含水量、土壤NH₄+-N和NO₃–-N含量，并计算硝化抑制率。【结果】在黑土和褐土两种类型土壤中，铵态氮转化特征具有显著差异，在弱酸性黑土中硝化反应速率显著低于碱性褐土。在黑土中，不同硝化抑制剂组合N + CP、N + CP + N-guard、N + CP + DMPP、N + CP + DCD、N + CP + CMP、N + CP + AM、N + CP + MP都表现出较好的硝化抑制效果，可以维持黑土中较高的铵态氮含量超过4个月以上。其中N + CP、N + CP + DCD、N + CP + N-guard处理在120天时，其硝化抑制率为37%～40%。而N + CP + AM、N + CP + MP、N + CP + DMPP为32%～36%，N + CP + CMP为26%。在褐土中，N + CP + DCD组合硝化抑制效果最大，在培养120天，其硝化抑制率为20%；其次是N + CP、N + CP + AM，其硝化抑制率在培养第105天时分别为23%、12%，在培养第90天时分别为63%、60%；N + CP + N-guard、N + CP + DMPP、N + CP + MP、N + CP + CMP在培养第75天时硝化抑制率分别为43%、42%、37%、35%，有效硝化抑制作用时间可维持75天左右。【结论】在黑土和褐土2种不同类型土壤中施用氯化铵氮肥，应添加专一硝化抑制剂或组合制成高效稳定性铵态氮肥。在湿润地区pH较低的酸性土壤上，例如黑土，适宜的硝化抑制剂较多，其中N + CP或N + CP + N-guard、N + CP + DCD组合的硝化抑制效果显著且持续时间长。在干旱半干旱的碱性土壤上，例如褐土，N + CP + DCD组合的硝化抑制效果和持续时间优于其他组合，可用于褐土上施用的高效稳定性氯化铵氮肥的生产。

Effects of different nitrification inhibitor combinations on the transformation of ammonium nitrogen in black soil and cinnamon soil

【Objectives】Adding nitrification inhibitors and nitrogenous fertilizer synergist is an effective way to improve the utilization rate of nitrogenous fertilizer. The effects of different nitrification inhibitors and nitrogenous fertilizer synergist on the transformation of ammonium nitrogen in soil with different properties were studied for the choice of available inhibitors in different soils.【Methods】The tested biochemical inhibitors included 2-chloro-6 (trichloromethyl) -pyridine (CP), 3, 4-dimethyl-pyrazole phosphate (DMPP), 1-methoxyl-3-methylpyrazole (CMP), 3-methylpyrazole (MP), 2-amino-4-chloro-6-methylpyrimidine (AM), N-guard, dicyandiamide (DCD). The tested soils were black soil and cinnamon soil, and ammonium chloride was used as nitrogen fertilizer. The stable fertilizer was prepared by adding above mentioned individual or several biochemical inhibitors according to the usual dosage. A indoor culture experiment was conducted at constant temperature. The contents of NH₄+-N and NO₃–-N in soil were measured at 1, 4, 7, 11, 15, 22, 30, 45, 60, 75, 90, 105, 120 days since the beginning of culture experiment, and the inhibition rates of nitrification were calculated.【Results】In the black soil and the cinnamon soil, the transformation characteristics of ammonium nitrogen were significantly different, and the nitrification rate in the weakly acidic black soil was significantly lower than that in the alkaline cinnamon soil. In black soil, nitrification inhibitor treatments of N+CP, N+CP+N-guard, N+CP+DMPP, N+CP+DCD, N+CP+CMP, N+CP+AM and N+CP+MP all showed good inhibition effect, which could maintain high NH₄+-N content in black soil for more than 120 days. At the 120 days, the nitrification inhibition rates of N+CP, N+CP+DCD and N+CP+N-guard were 37%–40%, while those of N+CP+AM, N+CP+MP, N+CP+DMPP were 32%–36% and that of N+CP+CMP was 26%. In the cinnamon soil, the N+CP+DCD combination had the most effective nitrification inhibition. At 120 days of cultivation, the nitrification inhibition rate was 20%. The nitrification inhibition rates of N+CP and N+CP+AM were 23% and 12% respectively at the 105 days, 63% and 60% respectively at the 90th day. The nitrification inhibition rates of N+CP+N-guard, N+CP+DMPP, N+CP+MP, and N+CP+CMP were 43%, 42%, 37% and 35% respectively at the 75th day of culture, and the effective nitrification inhibition time could last for about 75 days.【Conclusions】Specific nitrification inhibitors or combinations should be added to make efficient and stable ammonium nitrogen fertilizer when using ammonium chloride as nitrogen fertilizer in soils with different pH values. The nitrification inhibitor CP alone or CP+N-guard and CP+DCD combination perform significant and long inhibition on the transformation of ammonia nitrogen in acidic black soil. The CP+DCD combination works well on arid and semi-arid alkaline cinnamon soil.