Characteristics of dry matter and nutrients accumulation and transformation of super-high yield spring maize

Dry matter and N, P and K nutrient accumulations and transformations of super-high yield maize were studied. The maize cultivar, Jinshan 27, was grown under super-high-yield cultivation (SHY) and normal high-yield cultivation (CK) condition in 2009 and 2010. The results show that dry matter accumulation amount per hectare of the super-high-yield cultivation is significantly higher than that of the normal cultivation, especially after the silking. The dry matter accumulation rates of the super-high-yield cultivation after the silking are higher than those of the normal cultivation, which are increased by 4.5% in 2009 and by 3.2% in 2010. The contribution rates of dry matter accumulation to the production under the normal high-yield cultivation are increased by 8.5% in 2009 and by 3.9% in 2010. The dry matter transfer rates of vegetative organs of super-high yield cultivation spring maize are 15.1% in 2009 and 14.9% in 2010, and the contribution rates of trans-shipment to production are 16.6% in 2009 and 18.5% in 2010, which ensure the coordination of source-sink relationship. The N, P and K accumulation rates after silking and their contributions to grain under the super-high-yield cultivation are significantly higher than those under the normal high-yield cultivation, and the N contribution rates are increased by 30.0% in 2009 and 16.3% in2010, the P contribution rates are increased by 10.8% in 2009 and 6.0% in2010 and the K contribution rates are increased by 7.9% in 2009 and 8.2% in2010. The translocation rates of N and P of stemsheath under the super-high-yield cultivation are higher than those under the normal cultivation, while the translocation rates N and K of leaves are contrary. Among them, the transfer N rates of leaves are 41.0% in 2009 and 42.9% in 2010, and the contribution rates to grain nitrogen under the super-high-yield cultivation are lower than those under the normal high-yield cultivation, which make the leaves of maize maintain a high photosynthetic capacity in the late growth stage.