叶龄调控下水肥耦合对寒地水稻生物学特征及水肥利用效率的影响

【目的】旨在通过优化水稻生育进程的水肥供给来促进水稻的生长发育。【方法】大田试验于2016—2017年在黑龙江省八五二农场进行,以垦稻24 (主茎叶片数为12) 为材料,采用2种灌溉模式和2种施肥模式的正交试验设计：叶龄灌溉模式 (LI) 与常规灌溉模式 (RI),叶龄调控侧深施肥模式 (SF) 与常规施肥模式 (RF)。【结果】LI+SF模式对水稻形态特征、光合特性、水肥利用效率及产量具有显著影响(P<0.05)。与RI+RF相比,LI+SF模式使叶面积指数、单株不定根数、总根长、总根表面积及总体积显著提高了21.2%、22.7%、20.8%、45.2%和17.8%,灌浆期水稻光合速率、净光合速率、叶绿素含量及气孔导度显著提高了17.4%、18.4%、26.8%和40.1%,水稻结实率、千粒重和理论产量显著提高了6.3%、2.4%和28.2%,实收产量平均增加5.2%,纯收入增加13.2%,氮肥农学利用率、籽粒吸氮量、产谷利用效率、氮肥偏生产力及氮收获指数被显著提高了11.1%、6.9%、5.8%、13.6%和8.0%。LI模式可以节约灌溉水用量1 000 t/hm²。RI+SF对水稻植株形态、光合特性、生物学产量和水肥利用率具有一定的促进作用,实收产量平均增加2.3%,没有充分发挥水肥耦合作用。【结论】LI+SF模式为本研究最佳的精准灌溉施肥模式,也是适合在我国北方推广的寒地水稻节水、节肥、丰产技术模式。

Effects of Irrigation and Fertilization Coupling on Biological Characteristics,Water and Nitrogen Use Efficiencies of Rice in Cold Regions Under Leaf Age Regulation

【Objective】The objective is to improve the growth and development of rice by optimizing water and fertilizer supply in rice growing duration.【Method】A field experiment of fertilization and irrigation under leaf age regulation was conducted in 2016 and 2017 at 852 Farm in Heilongjiang Province. Rice variety Kendao 24 was used as material under two irrigation modes (leaf age irrigation mode, LI; conventional irrigation mode, RI) and two fertilization modes (leaf age regulation side deep fertilization mode, SF; conventional fertilization mode, RF).【Result】Rice morphological traits, photosynthetic characteristics, water and fertilizer use efficiency and grain yield were significantly affected by LI+SF (P< 0.05). Compared with RI + RF, LI+SF significantly increased leaf area index, adventitious root number per plant, total root length, total root surface area and total root volume by 21.2%, 22.7%, 20.8%, 45.2% and 17.8%, respectively. Photosynthetic rate, net photosynthetic rate, chlorophyll contents and stomatal conductance were significantly increased by 17.4%, 18.4%, 26.8% and 40.1%, respectively. Seed setting rate, 1000-grain weight and theoretical yield were significantly increased by 6.3%, 2.4% and 28.2%, respectively. Average yield was increased by 5.2%, and net income was increased by 13.21%. Agronomic efficiency of nitrogen fertilizer, grain nitrogen uptake, grain yield and utilization efficiency, partial productivity of nitrogen fertilizer and nitrogen harvest index were significantly increased by 11.1%, 6.9%, 5.8%, 13.6% and 8.0%, respectively. In addition, 1 000 t/hm² irrigation water can be saved by LI mode. RI+SF mode can exert a positive influence on plant morphology, photosynthetic characteristics, biological yield and water and fertilizer use efficiency. The average yield was increased by 2.3%. However, the coupling effect of water and fertilizer was not fully exerted.【Conclusion】LI + SF mode is the best precise irrigation and fertilization mode in this study, and it is also suitable to be popularized as a water-saving, fertilizer saving and high-yield technology for rice in the cold area of northern China.