Effects Of Potassium Management On Yield，Quality And Relative Physiological Characteristics Of High Yield Summer Maize (Zea Mays L.)

From2010to2012, the field experiments were carried out at State Key Laboratory ofCrop Biology/College of Agronomy, Shandong Agricultural University. The field and soilcolumn experiments were carried out in this research. Two cultivars of summer maize （Zeamays L.）, Denghai661（DH661） and Zhengdan958（ZD958） were used for experimentalmaterials, and six levels of potassium application rates were designed. It was explored that theeffects of potassium application rate and time on the yield, quality and relative physiologicalcharacteristics of high yield summer maize and cleared the appropriate amount of potassiumapplication. The main results and conclusions were as follows.1Grain YieldThe results showed that the grain yield was increased at the first, and then graduallydecreased with the increment of the K2O application rates. Simulated by a quadratic curve, thegrain yield of DH661reached its maximum under K fertilizer application rate of K184kg·ha^-1, and the ZD958was under the rate of K2O201kg·ha^-1. In conclusion, under this fieldexperiment conditions, the most optimal K fertilizer rate was180kg·ha^-1K2O.2Grain QualitiesK applied could increase the grain amylose content, amylopectin and total starch contentaffect not significant; however potassium applied could reduced grain crude fat content.DH661and ZD958two varieties of the total protein, albumin, globulin, gliadin and glutencontent with potassium increased, indicating that the potassium was conducive to theimprovement of two varieties of corn protein and component.3Potassium Accumulations and Distribution The population potassium absorption of plant showed high response （p<0.05） to Kapplication in various stages especially before flowering. The individual potassium absorptionof plant was unimodal function and the peak emerged20days after flowering. The value ofpotassium in stem was the most in kinds of organs. The proportion in stem was54.04%⁶2.32%for DH661and51.14%⁶3.33%for ZD958at maturity. Agronomicefficiency of K and K recovery efficiency were increased at the first, and then graduallydecreased with the increment of the K application rates. As applied K increased, partial factorproductivity from the applied K was reduced significantly. K was absorbed mainly before thespinning stage, and K in seed came from nutritive organ mostly.4Relative Physiological Characteristics of Summer MaizeApplied K could increase the leaf area index and chloroplast pigments content. Bleedingsap increased at the first, and then gradually decreased with the increment of K applicationrate. Applied K could enhance rind penetrometer resistance by17.9%,25.57%in maximumfor DH661and ZD958. But the increase in different internodes was different. The increasedvascular bundles especially the small vascular bundles, per unit area of crease rection ofinternode, was the key reason to improve stalk puncture strength.One-time sowing fertilization was not conducive to root growth before the jointing stage,but increased the fertility late dry weight of roots. K applied promotes shallow root volumegrowth, increased by31.60%and19.93%at male tetrad stage, respectively. Instead ofpotassium root length increased to improve the supply of potassium. Potassium root dryweight was significantly higher than the deep soil; applying potassium fertilizer raised agreater proportion of root dry weight at maturity.