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Corn varieties spatial and temporal distribution of the roots in the soil and its relationship with changes in soil nutrients (NPK) to compare different eras, the characteristics of plant growth and nutrient uptake, and nutrient differences in the body's circulation and distribution, selected of the last century, five since decades on behalf of, in the large scale production of six different decades maize varieties (white horse teeth, the Queen, the 2nd single, Tang anti No. 5 of ND108 and Zhengdan, 958) for the material in the field, the same density and same fertilization. The results show that, compared with the early corn varieties, modern varieties developmental process slower, longer growth period, leaf area, leaf senescence is slow. Large bell, the different eras of maize varieties plants dry weight, no significant differences in the content of nitrogen and phosphorus; However, the large bell after a period, a significant increase in the growth rate of modern varieties, plant dry weight, nitrogen and phosphorus accumulation rate significantly higher than the early varieties; tested varieties of dry matter, nitrogen and phosphorus accumulation throughout the growth period after silking, plant dry weight increase is about equal to the grain yield, photosynthetic products that grain yield and silking accumulation related. And dry matter, nitrogen and phosphorus accumulation law, the potassium content of the maize varieties in different years large bell stage there are significant differences in the performance of the fifties of the last century varieties lt; the late seventies varieties lt; modern varieties. Corn on potassium absorption mainly completed before silking, silking stage after the the potassium accumulation rate decreased. Nitrogen, phosphorus and potassium in grain from vegetative organs to transfer the amount of the majority, especially from the leaves of the transfer. Most of the corn root distribution in the 0-30 cm soil layer, 30 cm below the soil in the root system greatly reduce the nineties of the last century, and modern varieties of root length density greater than the early varieties. The corn root size was negatively correlated with the nitrogen content in the soil. Greater root length density and soil nitrogen depletion is more, especially in the corn vertically below the stem. Depletion of soil phosphorus and potassium and nitrogen: modern corn varieties P uptake was significantly higher than the early varieties, but compared to the depletion of soil available phosphorus and early varieties no significant decrease in the surface soil available phosphorus content in the harvest period even higher than the silking stage; corn genotypes in different age distribution in the soil had no significant effect on soil potassium consumption. In summary, the leaf area of ??modern corn varieties, the growth period after silking longer, slower leaf senescence accumulate more NPK, conducive to grain filling, to form a high-yielding. Modern corn varieties total root length and root density greater consumption of nitrogen in the soil. Potassium Accumulation Accumulation of dry matter, nitrogen and phosphorus. The grain yield from dry matter accumulation after flowering, grain NPK and then transferred from vegetative organs.
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