玉米密植引起的低氮干旱胁迫形成机制与调控途径研究

The efficient way of high yield corn production is to increase the planting density. Corn production reached a high yield of 1000 kg / 667m2 for the abundant resources of light and temperature in the Yellow Irrigation area of Ningxia. However, the increased planting density intensified the competition among plants of the high density, leaded to problems of the low nitrogen and drought stress of soil and eventually the production instability, less cost-effective, hard to further enhance the production, and poor repetion of high yield. Therefore, field trials should be conducted to research the corn water and nitrogen stress problems after increasing the density by setting different water, nitrogen processing under conditions of high-density and high-yield in Ningxia. Different water and nitrogen treatment of leaf area changes in canopy structure, material accumulation and allocation, root development and nitrogen accumulation and distribution, yield components factors and other physiological and ecological indicators under the conditions of corn growth and development process will be analyzed. To prove high-density planting patterns in Ningxia special ecological environment, especially, to reveald high-density yield in corn water, nitrogen adjustment mechanism and pathways of water stress, nitrogen system regulatory, while provide a theoretical basis. It would be helpful to improve the single corn yield potential in a large area, achieve high yield and efficiency, and it was great significance to promote the healthy development of regional corn industry of Ningxia.

增加种植密度是玉米高产的有效途径，宁夏引/扬黄灌区利用丰富的光温资源，玉米生产多点次大面积创造了1000公斤/667m2的高产水平，但在高产创建中发现，增密后加剧了高群体下植株间的竞争，往往引起土壤低氮、干旱胁迫，造成产量不稳、效益不高、进一步提高产量的难度增大、高产技术的重演性差等突出问题。因此，针对玉米增密后引起的水、氮胁迫问题，通过在宁夏高产玉米区设置高密度条件下的不同水、氮处理试验，综合分析不同水、氮处理条件下玉米生长发育进程、叶面积变化、冠层结构、物质积累与分配、根系发育、氮素积累与分配以及产量构成因子等生理生态指标，探明宁夏特殊生态环境下高密度种植模式，特别是高密高产条件下玉米水、氮胁迫调节机制及其水、氮系统调控途径，为宁夏玉米高产提供理论依据，对大面积提高宁夏玉米单产水平、实现高产高效，促进区域玉米产业健康发展具有重要意义。

项目针对玉米增密后引起的水、氮胁迫问题，开展了密植玉米群体密度及库源特征研究，确立了宁夏高产玉米适宜种植密度及产生水氮胁迫的高密度种植范围；通过在宁夏高产玉米区研究了密植玉米水、氮胁迫变化规律及对生长发育和产量的影响，通过分析密植玉米不同水、氮处理条件下玉米生长发育进程、叶面积变化、物质积累与分配以及产量构成因子等生理生态指标变化，探明宁夏特殊生态环境下高密度种植模式；通过不同时期灌溉、施肥试验、品种试验，比较研究密植玉米灌溉调节、氮肥施用调节的水氮调控技术途径。提出了减轻和消除低氮干旱主要胁迫的密植高产水氮最佳耦合栽培技术途径，并通过大田生产加以验证，完善了宁夏玉米密植高产栽培技术；发表研究论文6篇，参编专著4部，培养科技骨干3名，稳定了玉米栽培研发团队，促进了宁夏玉米栽培学科的发展；项目相关栽培理论与技术研究结果指导了宁夏玉米高产高效生产示范创建，研究成果支撑了 “宁夏玉米增产增效综合技术集成与示范推广”获得2016年全国农牧渔业丰收奖二等奖等6项科研奖励。研究成果为宁夏玉米高产栽培提供了技术与理论支撑，对大面积提高宁夏玉米单产水平、实现高产高效，促进区域玉米产业健康发展具有重要意义。