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2012~2013年在宁夏引黄灌区露地花椰菜-大白菜轮作体系下,采用田间小区定位试验研究了不同有机无机配合施氮对蔬菜经济产量、氮素吸收利用和土壤无机氮残留的影响,并提出了两种露地蔬菜合理的氮肥投入阈值。结果表明,相对于对照(N0)处理,有机无机配施能显著提高露地蔬菜经济产量,但过量增施氮肥会造成露地花椰菜和大白菜减产。合理地有机无机配施显著提高露地蔬菜对氮素的吸收利用。2012和2013年花椰菜当季氮肥利用率分别为13.3%~26.3%和26.6%~51.8%,大白菜分别为22.3%~51.6%和34.2%~64.4%。同一个蔬菜季内,0~100 cm土壤无机氮累积量随着化肥氮用量增加而增加。综合考虑露地蔬菜经济产量、氮素平衡和土壤无机氮残留状况,花椰菜和大白菜的氮肥投入阈值范围分别为[309.0,425.0]和[223.9,392.6],0~100 cm土体无机氮残留区间分别为[155.4,227.9]和[160.6,229.7]。因此,在氮肥投入阈值范围内,可以实现露地蔬菜增产和环境风险降低的双赢目标。
2012 ~ 2013 Under the cauliflower-Chinese cabbage rotation system in the irrigated area of Yellow River in Ningxia, the effects of different organic and inorganic nitrogen fertilizers on the economic yield, nitrogen uptake and utilization of soil inorganic nitrogen and soil inorganic nitrogen residue were studied using field plot test Two kinds of open-field vegetables reasonable nitrogen input threshold. The results showed that compared with the control (N0) treatment, organic and inorganic combination could significantly increase the economic yield of open-field vegetables, but excessive nitrogen addition could reduce the yield of broccoli and Chinese cabbage. Reasonably organic and inorganic combination significantly improve the uptake of nitrogen in vegetables. The nitrogen utilization rates of cauliflower in 2012 and 2013 were 13.3% -26.3% and 26.6% -51.8%, respectively, and those of Chinese cabbage were 22.3% -51.6% and 34.2% -64.4% respectively. In the same vegetable season, the accumulation of inorganic nitrogen in 0 ~ 100 cm soil increased with the increase of fertilizer nitrogen. Taking into account the economic yield of open-field vegetables, nitrogen balance and soil inorganic nitrogen residues, the input thresholds of nitrogen fertilizer for broccoli and Chinese cabbage were [309.0,425.0] and [223.9,392.6], respectively. The residual inorganic nitrogen in 0-100 cm soil Respectively [155.4,227.9] and [160.6,229.7]. Therefore, it is possible to achieve a win-win goal of increasing the yield of open-field vegetables and reducing the environmental risk within the threshold of nitrogen fertilizer input.