Characteristics of dry matter and nutrient accumulation and translocation 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 translocation 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 translocation 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% in 2010,the P contribution rates are increased by 10.8% in 2009 and 6.0% in 2010 and the K contribution rates are increased by 7.9% in 2009 and 8.2% in 2010.The translocation rates of N and P of stem-sheath under the super-high-yield cultivation are higher than those under the normal cultivation,while the translocation rates of N and K of leaves are contrary.Among them,the translocation 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.