Effect of soil moisture on growth and yield of winter wheat

Based on soil moisture at different growth stages,root density,plant height,leaf area and yield data from field experiments at Gucheng agro-meteorological field experimental station of Chinese Academy of Meteorological Sciences during 2011 to 2013 for winter wheat,effects of different soil moisture on growth and yield were analyzed. The results indicate that soil relative humidity greater than 50% in 0-50 cm soil layer is favorable for winter wheat during 2011 to 2012 at Gucheng station. Root system of winter wheat is not dense and yield of winter wheat are not high when soil moisture in 0-80 cm soil layer is less than 50% during 2012 to 2013,even soil moisture in80-120 cm soil layer is between 55%-88%. Root system is the densest when soil moisture in 0-80 cm soil layer reaches 55% to 70%,which results in better growth of winter wheat and a good yield. Root system of winter wheat is in the worst condition when relative humidity in 0-120 cm soil layer is less than 55% while it is in the best condition when relative humidity in 0-120 cm soil layer is greater than 80%. Thus,yield of the former is the lowest,but the yield of latter is not highest. The yield under a condition that the soil moisture in 0-80 cm soil layer ranges55% to 70% is better instead.