控释掺混肥对春玉米产量、光合特性及氮肥利用率的影响

Effects of Different Mixing Rates of Controlled-Release Urea and Common Urea on Grain Yield and Nitrogen Use Efficiency of Spring Maize

通过田间试验,研究相同氮肥用量条件下,不同比例包膜控释尿素(100%、75%、60%、45%、30%)与普通尿素混合施用对春玉米叶片SPAD值、光合速率、产量、经济效益及氮肥利用率的影响。结果表明,随着控释氮肥施用比例的增加玉米叶片SPAD值、光合速率、籽粒产量、生物产量及肥料利用率均呈现先增加后降低的趋势。与100%普通尿素一次性基施相比,45%~75%CRU与普通尿素配比的处理在灌浆期仍保持较高净光合速率(Pn),玉米增产幅度及效益较高;各配比处理平均增加氮肥农学效率3.6 kg kg-1~6.5 kg kg-1,增加氮肥利用率3.1%~14.9%。其中哈尔滨地区以60%CRU处理玉米产量效益最高,增产13.2%,增效1554元hm-2,双城地区以75%CRU处理玉米产量效益最高,增产12.9%,增效1402元hm-2。控释氮肥与普通尿素以一定比例配施能够增加穗位叶的叶绿素浓度和净光合作用速率,延缓玉米叶片的衰老,增加0~30 cm土壤硝态氮含量,降低30~60 cm和60~90 cm及0~90 cm土层土壤硝态氮残留量。在黑龙江省早春冷凉的气候条件下,玉米生产不宜施用100%控释尿素,应将控释尿素比例控制在45%~75%,以达到高产高效、降低环境污染的目的。

The effects of different mixing rates(100%, 75%, 60%, 45% and 30%) of controlled-released urea(CRU)and urea(U) with the equality of nitrogen fertilization for each treatment on SPAD value, photosynthetic efficiency,grain yield, economic profits and nitrogen use efficiency of spring maize were studied through field experiments.Results were as follows: With the increase of proportion of CRU, SPAD value, photosynthetic efficiency, grain yield,biological yield and nitrogen use efficiency were increased firstly and then gradually decreased. Compared with 100%U as basic fertilizer treatment(100% BU), the higher photosynthetic efficiency in 45% ~ 75% CRU+U treatments could be maintained during grain filling period, meanwhile, the grain yield and economic profits were higher; The increase of agriculture N efficiency was 3.6 kg kg-1~ 6.5 kg kg-1, and nitrogen use efficiency was 3.1% ~ 14.9%.Applying CRU with a mixing ratio of 60% was most beneficial to increase the yield and economical profits of spring maize in Harbin, with an increase of grain yield and economic profits by 13.2% and 1554 yuan hm-2, respectively;Moreover, the ratio of CRU in Shuangcheng was 75%, with an increase of grain yield and economic profits by 12.9%and 1402 yuan/ha, respectively. Appropriate mixing rate of CRU and U could improve SPAD value and photosynthetic efficiency, slow down the ageing process of maize leaves, increase the nitrate nitrogen contents in 0 ~ 30 cm soil layer,and decrease the nitrate nitrogen contents in 30 ~ 60 cm, 60 ~ 90 cm and 0 ~ 90 cm soil layers. To achieve high yield and high efficiency and decrease environmental pollution, the rate of 100% CRU was irrational. While the mixing rate of 45% CRU to 75 % CRU should be the appropriate range on the cold climate conditions of maize seedling stage in Heilongjiang Province.