Effect Of Climate Conditions On Growth And Grain Yield Of Maize In North China Plain

Due to water resources serious shortage in North China plain, the winter wheat and summer maize cropping system consumed too large water and the status quo of unsustainable development. By reducing winter wheat planting area, with winter wheat-summer maize and spring maize cropping system instead of winter wheat and summer maize cropping system. Water consumption reduced but the new problems is grain yield declines. This study focus on grain yield increase in maize season, final realize the grain yield decrease was not significant in three harvests in two years with four harvests in two years, but water consumption significantly reduced.3years field experiment were conducted in Wuqiao experimental station of Hebei province, two maize varieties were used, there are6sowing dates in2009, there are3sowing dates in2010and2012. To research the sowing date change on birth process, population structure, source-sink relationship and yield formation. By improving the ecological conditions achieve stable yield of corn. The main results were as follows:Total growth period showed a trend of shortening with the delayed sowing date. Mainly shorten period in planting to jointing stage. ZD958and ZND4have no obvious difference. The most important factor is Tmax(r=0.87**), followed is daily range of temperature (r=0.70**), followed is mean temperature (r=0.65*).3years experiment results showed that different sowing date has certain influence of agronomic traits in maize plant, with the sowing date delaying the plant height, ear high increased, stem diameter between the interannual have different performance. In general, spring maize and summer maize plant height and ear height have significant difference. Canopy light transmittance increased with the increase of leaf area index shows the tendency of decrease. Bottom light transmittance in2009showed a trend of decrease after the first increase, ear layer of light transmittance and the underlying performance similar to that in2010and2012and2009.Source properties of maize have different performance with delayed sowing date. In general, the leaf area index (LAI) increased first then decreased with delayed sowing date in2009, LAI increased in2010and2012. The group photosynthetic potential firstly increased then decreased with delayed sowing date. From silking stage to mid grouting SPAD values of different levels of head rise upper and lower level decline trend. Population growth rate (CGR) CGR have not obvious rule. Before and after silking dry matter weight have decrease trend along with the sowing date delaying in2009, but it has reverse trend in2010. Sink properties of maize have different performance with delayed sowing date. Kernels per spike performance is2009>2012>2010. It has not significant difference following sowing date change. Thousand kernel weigh has not similar performance. It decreased follow sowing date postpone in2009, but it increased in2010. Kernel/leaf ratio decreased follow sowing date postpone.As the growth period advance, each organ total nitrogen concentration is on the decline, Total nitrogen content of leaf and stem sheath is on the decline, bracts and cob increased first then decreased, total nitrogen content of grain is on the rise. Along with the growth period, the concentration of total sugar of leaf increase first then decrease. Sheaths and grain showed a trend of increase, bracts and cob showed a trend of increase. Total sugar content of leaf and bract-cob increase first then decrease, sheaths and grain showed a trend of increase. Silking stage with the sowing date delaying each organ C/N showed a trend of decrease. Mature period with the sowing date delaying leaf and stem sheath showed a trend of increase first then decrease, bract-cob and grain showed a trend of increase.Grain yield have differences in3years. Thousand kernel weigh is the most important factors to grain yield, followed kernels per spike, harvest ears has less effect on grain yield. From various periods in dry matter weight and yield of correlation analysis showed that the12-leaf period to silking period have the most closely relationship. Effective accumulated temperature, sunshine hours and rainfall in the whole stages was significant positive correlation with grain yield. Water use efficiency (WUE) of overall performance is2009>2010>2012. Water consumption is decreased obviously of three harvests in two years with two harvests in one year.