露地种植大白菜的氮肥效应与氮素损失研究  

Nitrogen use efficiency and N losses from Chinese cabbage grown in an open field

作　　者：曹兵[1] 贺发云[2] 徐秋明[1] 蔡贵信[2] 

机构地区：[1]北京市农林科学院植物营养与资源研究所,北京100097 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008

出　　处：《植物营养与肥料学报》2007年第6期1116-1122,共7页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(40171048);北京市科技新星项目(2005B37)资助

摘　　要：采用田间小区和微区试验，研究了施用化学氮肥在露地大白菜上的氮肥效应和氮素损失。氮素总损失用^15N示踪法测定，氨挥发用通气密闭室法测定，反硝化损失用乙炔抑制-原状土柱培养法测定，不加乙炔测定N2O排放。结果表明，施用化学氮肥增产显著，用差值法计算得到的氮肥利用率在25．3％～47．2％之间，相应的示踪法氮肥利用率为18．1％～24．6％。化学氮肥显著增加了氨挥发、反硝化和N2O排放等气态氮损失；其中氨挥发占施氮量的0．97％～17．1％，反硝化占4．33％～8．55％，N2O排放在1．09％～1．63％之间变化。大白菜收获时9．2％～10．9％的标记尿素被淋洗到40cm以下土层。试验期间尿素的氮素总损失达41．1％～48．1％，以表观淋洗损失最为严重，其次是氨挥发，而反硝化损失最低。与普通尿素相比，包衣尿素明显降低了氨挥发。Understanding of N-cycling in the soil-plant-atmosphere system is a prerequisite to maximize nitrogen use efficiency （NUE） and to develop optimized nitrogen budget for crop production. However, information on direct measurement and evaluation of N loss via ammonia volatilization, nitrate leaching, denitrification and NUE in vegetable fields is scarce. The aim of this study was to quantify the effects of N fertilization on fate of nitrogen and Chinese cabbage （ Brassica chinensis L. ） growth. Field plot and ^15N microplot experiments were conducted to investigate N use efficiency （NUE）, N fate and losses of chemical N fertilizers applied to an open field planted with Chinese cabbage. Total nitrogen loss, ammonia volatilization, denitrification loss and nitrous oxide emission were measured by labeled ^15N technique, enclosure method, and acetylene inhibition-soil core incubation technique, respectively. Results showed that application of chemical N fertilizers significantly increased Chinese cabbage yield. NUE of the N fertilizers by difference method ranged from 25.3 % to 47.2 %, and the corresponding figure by trace method was in the range of 18.1% - 24.6 %. Application of chemical N fertilizer markedly increased gaseous nitrogen losses including ammonia volatilization （0.97 % - 17.1% of applied N）, denitrification losses （4.33% - 8.55% of applied N）, and N2O emissions （1.09% - 1.63% of applied N）. At harvest 9.2% - 10.9% of labeled urea was leached below 40 cm soil layer. Total N loss of urea ranged from 41.1% to 48.1% during Chinese. cabbage growing season. It seems that apparent N leaching was the most important pathway of N losses, followed by ammonia volatilization, with denitrification being a minor pathway. Coated urea effectively reduced ammonia volatilization.

关 键 词：大白菜 氮肥效应 氮素损失 包衣尿素 

分 类 号：S634.1[农业科学—蔬菜学]