Study On Characteristies Of Root System Growth And Relationship Between Root And Upland Parts Of Maize

The experiment was carried out with the PVC tube plant and field plant, through different density treatments , study on the characteristis of different layer of root, the space distribution dry weight of root ,the relationship between root and upland parts of maize. The results are summarized as below:Long ,weight ,volume ,surface area and active absorption area of root in maize, all of them performanced single peak curve while growth period. The peak value appeared 12th days after Spinning stage, after this along with growing process growth speed of them slow decline. When maturing stage all indexes still keep roseum value. From sowing to 23 days, density effect them minuteness, thereafter with density increasing all indexes raducing. The higher layers of root, the greater the influence. Different layer root had different time of growth and function, value and time of peak existed difference, showing with growth and decline process. The higher Levels of root, the later of occurrence time and the bigger of value of peak.Below of difference density treatments, dry weight of root in 0-100cm soil layer following single peak curve, peak value occurs in the filing stage. Falling rate of peak value was the highest in high density. Apeak distribution of root system in maize along soil profile as following: In flare opening stage peak value of dry weight of root in 0-20cm, dry weight of root reduced quickly with the increasing soil layer thickness. After flare opening stage apeak distribution of dry weight root in soil was Negative Index curve. Difference of apeak distribution of dry weight of root in different density treatments.The root shoot ratio was increased gradually during maize growth process, Tendency of root - shoot ratio was displayed slow-fast-slow regular pattern. The root shoot ratio was achieved maximum in seedling stage, the speed of root shoot ratio change slowly . Between shooting and flare opening period , the speed of root shoot ratio descended quickly. After flare opening stage the speed of root shoot ratio descended smooth out. In maturing stage the speed of root shoot ratio achieved minimum. Root system and plant growth responds to enlargement of population isochronous, all of them reduced with enlargement of population, root reduced especially. Root surface area and leaf area have isochronism also, both of them interrestriction and interpromomtion. Root was closely related to yield, after spinning stage root weight was positively related to the maize yield, in filing stage root weight was notability positively related to the maize yield.