井水增温灌溉对寒地水稻生物学特征及水肥利用效率的影响

为解决井水灌溉温度低导致北方寒地水稻水肥利用效率差和产量低的问题,以"垦稻24"(主茎叶片数11叶)为材料,于2015—2016年在黑龙江省八五二农场进行井水增温灌溉大田试验。结果表明,提高井水灌溉温度对寒地水稻植株形态特征、光合特性、产量及水肥利用效率均产生了显著的影响。与井水常温灌溉模式相比,井水增温灌溉模式明显促进了水稻植株的生长与根系的下扎,分别使水稻叶面积指数、单株不定根数、根系总根长、总表面积及总体积提高了14.7%、14.5%、11.6%、33.1%、17.0%;井水增温灌溉模式显著增强了齐穗期的光合作用,分别使水稻光合速率和净光合速率提高19.5%和22.2%;提高了水稻的产量和纯收入,使穗粒数和理论产量增加11.1%、25.6%,实收产量增加4.8%,平均年纯收入达6 749.6元/hm~2,增收13.98%;同时井水增温灌溉模式显著提高了水稻的水肥利用效率,使水分利用率、氮肥农学利用率、籽粒吸收氮量、产谷利用效率及氮收获指数分别提高了8.5%、5.4%、9.2%、4.9%、3.8%。而井水直灌模式造成水稻秧苗发生冷水害问题,导致水稻发育迟缓,显著抑制了水稻形态特征、光合特性、产量及水肥利用效率。井水增温灌溉为本研究的最佳增温灌溉模式,也是适合在我国北方推广的水稻节水节肥丰产技术措施。

Effects of warming well water irrigation on the biological characteristics of rice in cold regions and its water and fertilizer use efficiencies

To solve the problems of low water and fertilizer use efficiency and low yield of rice caused by cold well water irrigation in northern cold regions, warming well water irrigation field experiments were conducted in 2015 and 2016 at 852 Farm in Heilongjiang Province. Rice variety "Kendao24" was used as study material. The results indicated that increasing the temperature of well water irrigation had a significant effect on rice plant morphology, photosynthetic characteristics, yield, and water and fertilizer utilization efficiency. Compared with normal temperature well water irrigation mode, the warming well water irrigation mode significantly promoted the growth of rice plants and the roots grow downward. The leaf area index, the number of adventitious roots, the total root length, the total surface area and the total volume of the rice increased by 14.7%, 14.5%, 11.6%, 33.1% and 17.0%, respectively. The warming well water irrigation mode also significantly enhanced photosynthesis at full heading stage of rice and increased photosynthetic rate and net photosynthetic rate of rice by 19.5% and 22.2%, respectively. And the number of grains per spike, theoretical yield and the actual yield increased by 11.1%, 25.6% and 4.8%, respectively. The average annual pure income reached 6 749.6 yuan/hm² and increased by 13.98%. At the same time, the warming well water irrigation mode significantly improved the water and fertilizer utilization efficiency and saved the production cost. The water use efficiency, nitrogen fertilizer use efficiency, seeds absorption nitrogen, grain yield and nitrogen harvest index increased by 8.5%, 5.4%, 9.2%, 4.9% and 3.8%, respectively. The direct irrigation mode caused the cold water damage to the rice seedlings, which led to the delay of rice development and significantly inhibited rice morphological characteristics, photosynthetic characteristics, yield, and water and fertilizer use efficiency. In conclusion, the warming well water irrigation mode is the optimized irrigation mode in this study, and it is also one of the technical measures for rice water saving, fertilizer saving, high yield and suitable for promotion in northern China.