中文摘要：

运用大型原状土柱在田间条件下比较了水稻基肥干耕施（干施）与湿耙施（湿施）对氮素损失与水稻氮素吸收的影响，试验设尿素干施、湿施与对照3个处理，同步测定了施肥后小区的氨挥发、淋洗以及水稻的吸氮量。结果表明：（1）干施法氨挥发显著低于湿施法，模拟试验分别为40．1与68．8kghm^-2，占施氮量的13．4％与22．9％，2004年的大田试验分别为19．2与26．2kghm^-2，占施氮量的7．7％与10．4％；（2）而干施法的总氮（TN）淋洗量显著大于湿施法，分别为14．3与4．6kghm^-2，占施氮量的4．8％与1．5％，氮的淋洗以NO3--N为主，占总量的73．7％～97．3％，两者的NH4＋-N淋洗量差别很小；（3）与湿施法相比，于施法净减少氮肥损失19．0kghm^-2，水稻吸氮量增加15．1kghm^-2，氮肥利用率提高了5个百分点，产量略有提高，而土壤含氮量没有显著变化。因此，水稻基肥尿素干深施法是一项值得推广的施肥方法。

英文摘要：

An experiment using monolith lysimeter was conducted to compare dry deep-placement of urea （DPU） in plowed paddy field before permanent flood with wet broadcast of urea （WBU） on puddled paddy field in effect on fertilizer N loss and rice N uptake at the Jiangsu-Changshu National Agroecological Experiment Station （31°33＇ N, 123038, E）. The experiment was designed to have three treatments, i.e. deep-placement, broadcast and CK （no urea applied） , and ammonia volatilization, N leaching and rice N uptake were measured during the rice growing season. Results show that NH3 volatilization flux from DPU was significantly lower than from WBU, being 40. 1 and 68.8 kg hm^ -2, or 13.4% and 22.9% , respectively, of the fertilizer N used in the lysimeter in 2007, and 19.2 and 26.2 kg hm^-2, or 7.7% and 10.4% , respectively, for DPU and WBU in field trial in 2004. Leaching of total N （TN） in DPU was markedly higher than in WBU, being 14.3 and 4.6 kg hm -2, or 4.8% and 1.5% of the fertilizer-N applied, respectively. Nitrogen was leached away mainly in the form of NO3- -N in the rice-growing season, accounted for 73.7 %-97.3% of the total N leaching. But NH4-N leaching did not show much difference between DPU and WBU. Compared with WBU, DPU reduced net N loss by 19.0 kg hm -2 and increased rice N uptake by 15.2 kg hm-2 and plant apparent recovery of fertilizer-N by 5% , i. e. 34% in WBU and 39% in DPU. DPU raised crop yield slightly over WBU, but did not affect much soil N content. The results indicate that the DPU method is superior to the common practice of broadcasting urea into flooded paddy field and is worth extrapolating.