Root Characteristics of Super High-Yield Spring Maize

Abstract

Using cultivar Jinshan 27 as test material and high-yield maize cultivar as the control, we analyzed the root characteristics of super high-yield maize. The results showed that the percentage of roots in deep soil was higher, the biggest roots width tended to be deeper, the number of root per plant in deep soil layer increased for super high-yield maize, and the difference of root parameters enlarged with the increase of the soil depth compared with the control. The root dry weight was first up then down in the growing process, and the maximum value appeared at silking stage and showed extremely difference from the control. The percentage of root weight at 0–20 cm soil layer was lower obviously than the control, and that at the soil layer over 40 cm was more than the control at every growing stage. Ratio of shoot/root was close to the control at early growth stage, and lower than the contrast at later growing stage. Changes of root vigor showed a single apex curve in growing and the peak value appeared at silking stage. Root vigor at every growing stage changed as a single apex curve with the increase of soil depth under super high-yield cultivation, but root vigor of the control changed greatly in different growing stages. The activities of SODPOD of root system per soil layer were higher than the control at silking and milking stages in super high-yield maize, but MDA content was lower than the contrast. The root growing condition and nutrient supply were improved by deep ploughing, optimizing fertilization and high planting density, which not only improve the deep root growing, but also keep root a higher physiological activity, providing a basis for production of super high-yield maize.