Abstract: Effects of single application depth of nitrogen on summer maize yield, nitrogen accumulation and fertilizer use efficiency were studied in Taihe and Dongzhi counties of Anhui province, so as to probe the suitable depth for single fertilizer application in summer maize and to provide reference for precise single fertilization in mechanization of summer maize. Seven treatments of hole application were included in the present field experiment, CK, depth of 6 cm (D6), 9 cm (D9), 9 cm and 12 cm \[D(9+12)\], 12 cm (D12), 12 cm and 15 cm \[D(12+15)\], and 15 cm (D15). Except CK treatment, the doses of N, P2O5 and K2O were 180 kg/hm2, 135 kg/hm2 and 180 kg/hm2 in all fertilization treatments respectively. The results showed that in all treatments, maize yields in Taihe were 1.3~1.5 times of those in Dongzhi under the same fertilizer application. In both Taihe and Dongzhi experimental spots, maize yield of D12 urea application was increased than that of D6 and D15 treatments by 12.6% and 6.7%, respectively. The nitrogen accumulation in maize plant was the highest in D12 treatment, and in Dongzhi it was significantly higher than that of D6 and D15 treatments. The depth of urea application could significantly affect nitrogen use ratios in agronomy and apparent. The results in both Taihe and Dongzhi experimental spots indicated that the nitrogen apparent recovery in D12 treatment was increased than that of D6 and D15 treatments by 9.6% and 10.5%, respectively. The suitable depth for urea single application in Anhui province is about 12 cm in summer maize.

Key words: summer maize, urea, single application of fertilizer, application depth, nitrogen use efficiency

摘要： 在安徽省太和县（TH）和东至县（DZ）研究了氮肥一次穴施深度对夏玉米产量、养分积累量以及氮肥利用率的影响，以探讨夏玉米一次施肥的适宜深度，为夏玉米机械化精准一次施肥提供依据。试验设对照（CK）、深6 cm（D6）、深9 cm（D9）、深9 cm+12 cm\[D(9+12)\]、深12 cm（D12）、深12 cm+15 cm\[D(12+15)\]、深15 cm（D15）一次穴施7个处理，肥料养分施用量为N 180 kg/hm2、P2O5 135 kg/hm2、K2O 180 kg/hm2。太和和东至点不同深度穴施尿素处理下夏玉米的产量结果表明，同等施氮条件下太和的产量为东至的1.3～1.5倍；两个试验点尿素12 cm深施（D12）比6 cm深施（D6）和15 cm深施（D15）夏玉米产量分别增加12.6%和67%。植株氮素积累量均以D12处理为最高，并且东至点D12处理玉米植株氮素积累量显著高于D6和D15处理。施肥深度对氮肥农学利用率和表观利用率有显著影响，两个试验点的结果表明12 cm深施氮肥表观利用率比6 cm和15 cm深施分别提高9.6%和10.4%。安徽夏玉米尿素一次施用的适宜深度为12 cm左右。

关键词: 夏玉米, 尿素, 一次性施肥, 施肥深度, 氮肥利用率