Abstract: The soil relative moisture characteristics of Liaoning in seeding period and the relationships between soil relative moisture and soil property, crop varieties and meteorological factors were studied. Statistical methods were adopted including correlation analysis, regression analysis, factor analysis and interpolation analysis. Data collection covered the soil parameters and the daily value of conventional meteorological factors from 49 weather stations in Liaoning from March to May, 2004-2013, soil moisture data from agrometeorological experimental stations in western Liaoning in May, 2004-2010 and regional soil parameters of Liaoning. The relative soil moisture of Liaoning in spring increased by 1.6% per year on average, and it was usually higher in the southeast than in the northwest. In most parts of the province, the soil waterholding capacity was 20%-25%. Crop tillage would reduce soil relative moisture by 5.6%-36.4%. Among the meteorological factors, soil relative moisture in previous period had the greatest impact on soil relative moisture (r=0.48), and vapor pressure had the least (r=-0.08). Soil relative moisture was influenced by soil property, cultivated crop varieties and various meteorological factors, which we should take full account in soil moisture forecast during seeding time in spring.

Key words:  , dry matter distribution., nitrogen application rate, canopy, wheat, photosynthetic active radiation interception