Abstract: To explore the response of different spring maize species and soil moisture to the planting density,and the relationships among these factors,yield and lodging rate in the Loess Plateau rainfall area,Zhengdan 958 and Jindan 86 were selected as research materials in the program,which were of special lodging resistance.Five kinds of planting density (52 500,60 000,67 500,75 000,82 500 plants/ha) were set in the field experiment,corn agronomic traits,the property of anti-lodging mechanism,and the variation of soil humidity individually were analyzed,then further revealed their correlation with yield and lodging rate ways.The results indicated that with the increased of population density,for the Zhengdan 958,the plant height and ear height increased first and then decreased,but the coefficient of ear height changed smooth,for the Jindan 86,the plant height,ear height and the coefficient of ear height increased gradually.The agronomic traits and mechanics properties of base third internode increased at the beginning and then decreased,the species of Zhengdan 958 reached the highest value at the 75 000 plants/ha,and there were significant difference on the internode of diameter among five planting densities.The species of Jindan 86 reached the highest value at the 60 000 plants/ha,and there were significant difference under the 67 500,75 000,82 500 plants/ha.With the increased of population density,the soil moisture from the soil suface to 200 cm depth increased first then decreased during the jointing stage and silking stage,and Zhengdan 958 and Jindan 86 reached the highest values at the 75 000, 60 000 plants/ha accordingly, the soil moisture decreased then increased from the pustulation period to mature period.The correlation analysis results showed in the jointing period,trumpet period and silk period,there were positive correlation between the soil moisture and internode diameter,dry weight of internode and the biomass of per unit of stem length,the biomass of per unit of stem length and the strength of stem puncture and flexural property,there were positive correlation among the strength of stem puncture,flexural property,biomass of internode,biomass of per unit of stem length and yield,by contrast,these index were negative correlation with lodging rate.The yield and water use efficiency of Zhengdan 958 and Jindan 86 reached to the highest value at the 75 000,60 000 plants/ha,respectively,and the yield increased from 7.67% to 25.74%,from 20.36% to 29.63%, respectively.The water use efficiency enhanced from 6.45% to 17.71% and from 14.14% to 20.38% for Zhengdan 958 and Jindan 86,respectively,the highest lodging rate appeared under 75 000 plants/ha and Zhengdan 958 was lower.We can choose rational planting density according to the maize species,then integrate the stem growth and soil water use efficiency,which will be useful to decrease the lodging rate and raise yield.

Key words: Maize, Density, Stem, Agronomic traits and mechanism, Soil moisture, Yield, Anti-lodging rate

CLC Number: 

• S513.01