• 关键词：控释掺混肥  脲酶  氮转化功能基因  硝酸盐淋溶

• 基金项目：国家水体污染控制与治理科技重大专项（No.2017ZX07102-001）

• 张雪莲
• 北京市土肥工作站，北京 100029

• 王学霞
• 北京市农林科学院植物营养与资源研究所，北京 100097

• 金强
• 北京市土肥工作站，北京 100029

• 杜晓玉
• 北京市土肥工作站，北京 100029

• 刘自飞
• 北京市土肥工作站，北京 100029

• 张梦佳
• 北京市土肥工作站，北京 100029

• 赵青春
• 北京市土肥工作站，北京 100029

• 廖洪
• 北京市土肥工作站，北京 100029

• 于跃跃
• 北京市土肥工作站，北京 100029

• 刘彬
• 北京市土肥工作站，北京 100029

• 张新刚
• 北京市土肥工作站，北京 100029

• 崔同华
• 平谷区农业技术推广站，北京 101200

• 张海伶
• 平谷区农业技术推广站，北京 101200

• 文方芳
• 北京市土肥工作站，北京 100029

• 摘要：以西蓝花为对象，研究了露地菜田不同施肥方式下土壤氮转化酶、氮转化功能基因及氮吸收量的差异，监测了西蓝花生育期内不同时期0~100 cm土壤硝态氮含量动态变化.结果表明：①施氮处理（CF、CU80%和CU60%）土壤脲酶活性是缺氮处理（PK）的1.78~3.11倍，差异显著（p＜0.05），并且其AOA、AOB、nirS、nirK和nosZ丰度分别较PK处理分别增加了26.35%~50.98%、57.69%~126.73%、50.76%~120.79%、31.41%~118.07%和39.45%~282.95%.减氮20%控释掺混肥一次性底施处理（CU80%和CU60%）与传统底追结合施肥处理（CF）之间的脲酶活性和氮转化功能基因丰度均无显著差异（p>0.05）.②不同施肥处理植株全氮含量和吸氮量无显著差异（p>0.05）.③与CF处理相比，CU80%处理提高了0~20 cm土壤硝态氮供应，其含量是CF处理的1.97~15.22倍.④试验开始后第31 d，施肥、灌溉和降雨导致试验地块40~60 cm和60~80 cm土壤硝态氮平均含量分别增加到种植前的3.37倍和7.33倍，且80~100 cm土壤硝态氮含量高达23.22 mg·kg^-1.西蓝花采收后，试验区各土层硝态氮平均含量均降到8 mg·kg^-1以下，表明西蓝花种植期间发生了明显的硝酸盐淋溶.⑤追肥、灌溉和降雨导致CF处理40~60、60~80和80~100 cm土壤硝态氮含量分别增加到55.98、51.69和36.04 mg·kg^-1，而CU80%处理相应土层的硝态氮含量分别仅为CF处理的5.91%、18.61%和26.69%.综上结果表明，减氮20%控释掺混肥一次性底施（CU80%）在满足土壤氮转化、耕层氮供应和作物吸氮的前提下，有效削减了硝态氮淋溶，显著降低了农田面源污染.

• Abstract：In this manuscript， the variation of soil urease activity， nitrogen transformation functional genes abundance and nitrogen uptake in broccoli， as well as the dynamic changes of nitrate concentration in 0~100 cm soils were studied during the growth period of broccoli in open vegetable field under different fertilization treatments. The results revealed that：①Soil urease activity under nitrogen applying treatments （CF、CU80% and CU60%） were 1.78~3.11 times higher than that in the treatment without nitrogen （PK）. The differences were significant （p<0.05）. The AOA， AOB， nirS， nirK and nosZ gene abundances separately increased by 26.35%~50.98%， 57.69%~126.73%， 50.76%~120.79%， 31.41%~118.07% and 39.45%~282.95% compared with PK treatment. Soil urease activity and nitrogen transformation functional genes did not show any significant differences between controlled release blended fertilizer with 20% rate reduction of N one-time applying treatment （CU80% and CU60%） and traditional base fertilizer combined with topdressing treatment （CF） （p>0.05）. ② The total nitrogen content in plant and nitrogen uptake content by plant showed no difference under different fertilization treatments （p>0.05）. ③Compared with CF， CU80% enhanced the nitrate supply in 0~20 cm soils， in which the nitrate concentration was 1.97~15.22 times of that in CF treatment. ④On the 31^st day after planting， due to fertilization， irrigation and precipitation， the average nitrate concentration in soil at depth of 40~60 cm and 60~80 cm in experiment area were individually increased to about 3.37 and 7.33 times of the concentration before planting and the nitrate concentration in soil at depth of 80~100 cm was 23.22 mg·kg^-1. However， the average soil nitrate concentration decreased to lower than 8 mg·kg^-1 in all different depths after harvest， indicating that obvious nitrate leaching occurred during the planting of broccoli.⑤Topdressing， irrigation and precipitation increased the soil nitrate concentrations at depth of 40~60 cm， 60~80 cm and 80~100 cm， which separately increased to 55.98 mg·kg^-1， 51.69 mg·kg^-1 and 36.04 mg·kg^-1 in CF treatment， while the nitrate concentrations at corresponding soil depths under CU80% treatment were 5.91%， 18.61% and 26.69% of that under CF treatment. These results revealed that controlled release blended fertilizer with 20% rate reduction of N one-time applying treatment （CU80%） could not only maintain soil nitrogen transformation， nitrogen supply and plant uptake， but also significantly reduce the nitrate leaching and farmland non-point pollution.

• Key words：controlled release blended fertilizer  urease  nitrogen transformation functional gene  nitrate leaching

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