不同施氮运筹对夏玉米产量、净收益及氮肥利用率的影响

氮肥管理是农业可持续发展面临的重大挑战。在测土提出合理施肥量OPT(N 210,P2O590,K2O60kg/hm2)的前提下,在襄汾县通过田间试验研究了5种氮肥运筹方式对夏玉米产量、净收益及氮肥利用率的影响,结果表明,与对照(OPT-N)相比,不同氮肥运筹均明显提高夏玉米产量、净收益,提高玉米籽粒和秸秆的含氮量及玉米的吸氮量;OPT3处理可以获得10 102 kg/hm2的产量,较不施氮肥增产23.4%,每千克纯氮可以生产9.1 kg的籽粒,净收益可达15 319元/hm2,较对照增收19.3%,同时肥料利用率可达47.0%,是最适宜的氮肥运筹方式;OPT1也可获得较高的产量和净收益,分别为9 897 kg/hm2和14971元/hm2,氮肥的农学效率为8.2 kg,产量较对照增产20.9%,净收益较对照增收16.6%,但氮肥的利用率相对较低,为38.6%,也是可以接受的氮肥运筹方式。该研究成果可为山西省夏玉米生产提供理论支撑和实践指导。

Effect of Nitrogen Fertilization Distribution on Summer Maize Yield,Net return and Nitrogen Use Efficiency

Nitrogen management remains one of the most challenging tasks forsustainable agriculture.Based on soil analysis and fertilizerrecommendation OPT（N 210,P2O5 90,K2O60 kg/hm^2）,field experiment was conducted in a randomized design with six treatments and three replicates to study the influence of the distribution of nitrogen application on summer maize yield,net re-turn,and agronomic efficiency of nitrogen application as well as nitrogen use efficiency.The results showed that the distribution of nitrogen application had a significant effect on summermaize yield,net return,the nitrogen content of grain and stalk as well as ni-trogen uptake.The treatment of OPT3（1/2 N applied at V 5-6 stage and 1/2 N as topdressing at jointing stage of maize growth） produced the highest yield and net return by 10 102 kg/hm^2 and 15 319 yuan/hm^2,respectively.Comparing with the treatment of without nitrogen application（OPT-N）,yield and net return increased by 23.4%and 19.3%,respectively.At mean time,agronomic efficiency of nitrogen and nitrogen use efficiency were 9.1 kg and 47.0%,respectively.This indicated that OPT3 was optimum mannerof nitrogen distribution.The treatment of OPT1（N applied at jointing stage of maize growth）helped produce betteryield（9 897 kg/hm^2）and net return（14 971yuan/hm^2）.Compared with OPT-N,yield and net return increased by 20.9%and 16.6%,re-spectively.But nitrogen agronomic efficiency（8.2 kg）and nitrogen use efficiency（38.6%）were lowerthan OPT3.OPT1 also was an option manner.These results will provide theoretic and practice guide forrational fertilization of summer maize in southern region of Shanxi province.