不同缓/控释尿素对小麦生长及氮素利用的影响

[目的]通过大田试验筛选山东省适宜于小麦生长的缓/控释尿素,并初步研究其氮素高效利用的机制.[方法]选用的肥料产品有4种,包括树脂包膜尿素(PCU)、多肽尿素(PPU)、脲甲醛尿素(UF)和本实验室制备的树脂包膜与脲酶抑制剂结合型控释尿素(CHQ),以普通尿素和不施氮肥为对照,分别在山东潍坊和泰安进行田间试验,供试小麦...

Effects of different slow/controlled release urea on wheat growth and nitrogen utilization

  【Objectives】   This study compared the effects of slow/controlled release urea products on wheat growth and nitrogen use efficiency in Shandong Province. The aim was to provide a reference for choosing suitable urea products in wheat production.   【Methods】   Field experiments were conducted in Tai’an and Weifang cities, representing two the main winter wheat production areas in Shandong Province. We used ‘Jimai 22’ as wheat test cultivar to investigate the effects of four slow/controlled release urea products: resin-coated urea (PCU), peptide urea (PPU), urea-formaldehyde urea (UF), and self-made resin coating combined with urease inhibitor to control the release of urea (CHQ), and common urea and no fertilizer as controls. One time of application was used for the four slow/controlled release urea products, and twice of applications was used for the control urea with ratio of 1∶1 for basal and topdressing. We investigated the plant height, tillering traits, dry matter accumulation and transportation, yield and yield components, and nitrogen use efficiency of wheat. The soil available nitrogen content and urease activity were measured at wintering, greening, jointing, flowering, and mature stages.   【Results】   All the slow/controlled release urea treatments reduced the soil urease activity in wintering stage of wheat growth, slowed down the hydrolysis of urea, and reduced soil available nitrogen content. At the maturity stage in Weifang, only CHQ had higher soil available N content than urea control, while in Tai’an, all the slow/controlled release urea treatments had higher soil available N than urea control. The soil available N content in CHQ treatment in Tai’an and Weifang increased by 81.86% and 6.20% than the control, respectively. Compared with the control in Tai’an, all four slow/controlled releases of urea treatments promoted wheat growth, dry matter transport before flowering, and dry matter production after flowering, thereby benefiting population construction and yield formation and enhancing N absorption and utilization. The wheat yield in CHQ treatment in Tai’an (6966.67 kg/hm2) and Weifang (10342.22 kg/hm2) (P < 0.05) were increased by 38.69% and 11.07%, respectively, and N production efficiency (18.83 kg/kg and 26.72 kg/kg) increased by 38.66% and 11.06%, respectively, compared to the urea control. The yield and N production efficiency in Weifang was higher than in those Tai’an, but the increase rate in CHQ treatment was opposite.   【Conclusions】   Slow/controlled release urea products have different wheat production efficiencies in Shandong Province. In high fertility loam soil of Weifang, the urea product that could control the release and hydrolysis of nitrogen product in the soil (CHQ) was effective, while in low fertility sandy soil of Tai'an, all the four slow/controlled release urea could maintain a high nitrogen supply in the later stage of wheat growth, and N fertilization efficiency outweighs that in control. Therefore, urea product with resin coating and urease inhibitor is recommended for improving wheat production in Shandong Province.