不同水氮条件下双氰胺对设施番茄生长发育和土壤氮素淋失的影响

Effects of Dicyandiamide on Tomato Growth and Nitrogen Leaching from Soil in Intensive Greenhouse Under Different Irrigation and Nitrogen Managements

采用田间小区试验法研究不同水氮条件下硝化抑制剂双氰胺(DCD)对设施番茄生长发育和土壤氮素淋失的影响。结果表明:在优化水氮处理条件下,配施DCD能显著抑制土壤NH4+-N含量的降低,提高氮素利用率;同时降低土壤硝态氮含量,从而减少氮淋失。与传统水氮处理相比,优化水氮配施DCD(W2N2+DCD、W2N3+DCD和W2N4+DCD)可使设施番茄施用氮素的平均利用率由13.84%提高到22.45%;可使表层(0-10cm)土壤的NO3--N淋失量降低49.34%～55.54%,0-30cm土层NO3--N含量降低35.21%～64.88%;平均减少30-120cm土层NO3--N淋失量61.08%～72.00%。同时,优化水氮配施DCD的调控措施还能够显著降低番茄体内硝酸盐含量,改善番茄果实品质,可使番茄果实硝酸盐含量降低51.94%～62.82%,且对番茄产量影响不大。综合评价,与传统水氮处理相比,优化水氮配施DCD处理W2N2+DCD在番茄生长期内减少施氮量59.02%,节约灌溉用水29.80%,能够使土壤0-10cm土壤NO3--N累积量减少54.01%,且在初果期、盛果期、末果期和拉秧期0-120cm剖面中NO3--N累积量分别降低58.32%,72.80%,63.23%和52.60%,并将氮素利用率提高到25.49%,番茄果实硝酸盐含量也降低59.81%,较好地实现了经济和环境效益双赢。

Effects of a nitrification inhibitor, dicyandiamide （DCD） on the tomato growth and nitrogen leaching from soil in intensive greenhouse under different irrigation and nitrogen managements were studied by using a field experiment. The results showed that the combination of recommended nitrogen and irrigation with the addition of DCD could significantly inhibit the decrease of the NH＋ --N contents in the soil, and reduce nitrogen loss as NO3--N. Comparing with the traditional management of nitrogen and irrigation, the combination of recommended nitrogen and irrigation with the addition of DCD（W2N2q-DCD, W2N3 q-DCD and W2N4q-DCD） could improve the average utilization efficiency of nitrogen from 13.84% to 22.45%. In addition, the average NO3- --N content in the top soil depth（0--10 cm） was decreased by 49.34%-55.54%, the NO3--N contents in the 0--30 cm and 30--120 cm soil profiles were also reduced by 35.21%-64.88% and 61.08%- 72.00%, respectively. Meanwhile, the combination of recommended nitrogen and irrigation with the addition of DCD could also significantly decrease the NO3--N contents in tomato fruit, and improve the quality of tomato fruit. The NO3--N content in tomato fruit was decreased by 51.94%-62.82%, but the yield of tomato were not significantly affected by the combination of recommended nitrogen and irrigation with the addition of DCD. During the tomato growth, the nitrogen input and amount of irrigation in W2N2＋ DCD treatment were decreased by 59.02% and 29.80% in comparison with the traditional management of nitrogen and irrigation. However, comparing with the traditional management of nitrogen and irrigation, W2N2＋DCD could reduce the NO3--N accumulation in the top soil depth（0--10 cm） by 54.01%, and reduce the NO3--N accumulation in the 0--120 cm soil profiles by 58.32%, 72.80%, 63. 23% and 52. 6% during the early, middle, late fruit stage and after-harvest stage, respectively. Furthermore, the utilization efficiency of nitrogen was improved to 25.49%, and the NO3--N content in tomato fruit was decreased by 59.81%. Overall, these results suggested that the W2N2＋DCD could offer the best economic benefit and environmental benefit.