| The maize yield potential in irrigation districts of Inner Mongolia plain is highest in China, where the newsreel of super high yield spring maize was refurbished continually. At present, there were two main questions that limited yield promoting. First, the replaying of high yield newsreel in small area into large area was difficult, and the yield promoting was more and more diffcult; second, the illogicality between the shortage of water resource and low WUE in high yield potential regions limited yield promoting. The key of these tow questions was that the mechanism of super-high yield of maize and method of improving WUE were not clear. This research took the yield potential mining and the water use efficiency promoting as the final goal, and the structural and functional properties of canopy and root of super high yield spring maize was researched under different yield level, different density and different water saving agronomic measure. Based on it, and combined the yield properties analysis of super high yield colonies, the super-high yield mechanism and the way of yield potential mining were revealed, and the coordinate technical way of super-high yield and water resource saving was explored. The main result was expouned below.1. The essential of yield promoting of super high yield spring maize was the result of increasing of TGN unit area which was at the bottom of density increasing. There were two ways to increase TGN. One was to increase EN unit area; the other was to increase GN by adapting floribunda type maize and raising floret pregnancy rate. Correlation analysis showed that MNAR had indirect effect on yield by effecting GN. So promoting individual photosynthetic productivity by optimizing population structure was an important way to excavate yield potential. The MLAI value of safe super-high yield population was about 5 by quantitative analysis. The main way to promoting yield for middle and large ear cultivars should be to maintain suitable density, control vegetable growth and intensify the management in anthesis maturity period, so as to reduce growth redundance and promote harvest index and grain weight. Yield promotion of middle and small ear cultivars should depend on densitifacation, but the density should be less than 90000 ears per hectare, so optimizing population structure, enhancing water and fertilizer management, promoting seed-setting rate and stabilizing 1000 kernals weight were very vital in production.2. The structural and functional characteristics of root and canopy of super high yield spring maize mainly represented below. The population canopy LAI increased, plant profile was relative compact, leaf angle and leaf area of top leaves decreased, but leaf area of bottom leaves increased, so optimaizing the light distribution when intercepted more PAR.The Pn and LWUE of ear position leaves and top leaves of super high yield maize promoted remarkably while that of bottom leaves was not fall. The root biomass reduced a little but population biomass increased obviously. Root biomass, total vigor and active absorption area had relative centralized for transverse distribution and the distribution ratio in deep soil layer in vertical direction increased. The population source enlarged significantly but sink had become limited factor of increasing higher yield for super high yield maize. So construct a stable source, enlarging sink and coordinating the relationship of source and sink had become vital ways to excavate yield potential in population structure, furthermore, increasing the photosynthetic rate of top leaves and stabilizing that of bottom leaves was an important way for functional yiled mining.3. With the density increased of super high yield spring maize, the senescense of bottom leaves especially in anaphase accelerated and the photosynthetic properties and photochemical efficiency reduced, the LAD ratio after flowering reduced. All above block material accumulation and yield enhance after flowering stage. But the super high yield maize could regulate and compensated automatically for the adverse effect by increasing density. For example, the increasing of canopy LAI above ear could compensate the reduction of individual LAI. The individual plant could make the leaf at better light interception position by regulating the angle and bending of middle and top leaves automatically. Leaf angle above ear of super high yield maize was less than 20°, leaf angle of ear was between 25°and 35°, and leaf angle below ear was about 35°. Root dry matter, total vigor and active absorption area had centralized lateral distribution with the increase of density and the rate increased with the increase of soil depth. Root and canopy relationship analysis showed that the more centralized the larger of deep root rate. So the way of increasing yield and WUE was the increase of top leaf LAI.4. Covering film between furrows ameliorated the PAR distribution in canopy below ear through adjust the top leaves and middle leaves, meanwhile, promoted the protective enzyme system activity and the antioxidant capacity of leaves so as to delay leaf senescence. Biomass, vigor and active absorption area of root system were promoted under covering film between furrows, furthermore, the root distribution amount in wide row was increased then the absorption range was enlarged, and the distribution ratio of root biomass and root total active absorption area increased. Covering film between furrows increased canopy LAI in anaphase through promoted the canopy LAI above ear, therefore, the ratio of LAD and dry matter accumulation after flowering increased, meanwhile, the grain sink increased obviously, so the source-sink ratio was harmony. The yield increasing effect of covering film between furrows started in the abreast period of vegetable growth and reproductive growth, and mainly represented in anaphase. Covering film between furrows made a suitable water condition for root through water horizontal movement, and promoted water use efficiency through promoted the use efficiency of rainfall and soil water.5. Super compensate effect was incarnated obviously in canopy and root growth which was under regulated deficit irrigation treatments. Leaf area, protective enzyme system activity, photosynthetic rate and leaf water use efficiency was increased remarkably, and leaf senescence delayed obviously after rewatering in different deficit irrigation treatments. the top leaves had the super compensate effect in photosynthesis and the bottom leaves had the super compensate effect in water use efficiency, furthermore, the contribution of non-leaf organs such as bract and leaf sheath to yield was outstanding under regulated deficit irrigation. Regulated deficit irrigation promoted the dry matter, vigor and active absorption area of root remarkably, and the root function in top soil and deep soil all had the super compensate effect after rewatering. In the condition of covering film between furrows, regulated deficit irrigation could reduced water consumption and water consuming intensity remarkably, and promoted water use efficiency of super high yield spring maize. The comprehensive farming of covering film between furrows and regulated deficit irrigation could reached the goal of high yield and high water resource efficiency which promote maize yield by 15% to 30%, and promote water use efficiency above 20%.
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