Effect Of Soil Moisture For Main Crops Emergence And Seedling Formation Security In The Cold And Arid Regions Of North China

Drought is the main environmental factor that affects crop growth, especially in aridand semi-arid regions. Each period from seed to harvest of crop by drought stress canaffect the yield and quality,particularly the role of seedling, the higher rate of germinationand seedling are the foundation of stable and high yield of crop. In order to protect cropemergence safely and form seedling securitily,we studied the effects on safe emergence ofdifferent soil moisture for corn, red kidney beans, oats, flax and millet; the effects on sugarbeet transplanting survival and yield and quality of different supplementary water capacity;the effects on potato emergence and yield of different supplementary water capacity,through setting different soil moisture and different supplementary water capacity, inmeadow chestnut and chestnut farmland.The main research results are as follows:1.Soil moisture affects crop emergence rate significantly. The five kinds of crop havea threshold requirement for safety emergence of soil moisture, that is the critical soilmoisture of emergence safety, the crop emergence will occur rising significantly afterreaching the value water, and that interval is the jump interval of crop emergence.2.Identified the sensitival soil moisture interval of five crops emergence securityly. weobtained the sensitival soil moisture interval based on the jumped soil moisture through thecluster analysis for the two year results. In the meadow chestnut farmland, corn, red kidneybean, flax, oats and millet are7.90%-9.25%,7.90%-9.25%,9.61%-12.02%,9.31%-12.02%,9.61%-13.21%; in the chestnut farmland, they are4.83%-5.62%,4.83%-5.62%,4.83%-12.36%,6.16%-7.21%,5.34%-6.27%.3.Identified the soil moisture threshold for crop emergence safety. Soil moistureinfluenced emergence rate and emergence progress. The processes of five crops’semergence profile to soil moisture demonstrated three kinds of types.that is jump,ascending and S-cueve. When the soil moisture contents was higher,emergence progesspresented fast jump type; When the soil moisture contents was lower, emergence progesspresented slow ascending type; When the soil moisture was between of them, emergenceprogess presented S type. According to emergence progress si S curve and obtaining strongseedling, we get the soil moisture critical value, In the meadow chestnut farmland, cornand millet are10.87%, red kidney bean, oats and falx are9.61%; and in the chestnut farmland, corn, red kidney bean, flax and mille are6.16%, oats is6.26%.4.Identified the lower limit of supplementary water capacity for sugar beettransplanting into seedlings. The type and yield of supplementary water affect sugar beettransplant survival and quality, underground supplementary water is beneficial forsupplying water for sugarbeet seedlings directly and effective water retention. In thefarmland of meadow chestnut soil in the Cold and Arid Regions of North China, thesupplementary water amount of sugarbeet transplanting is100-150ml/plant, and it is150-200ml/plant in the farmland of chestnut soil, and with a yield increase of68.78%-81.82%, and a sugar yield increase of65.57%-81.82%compared with the yieldwithout water supplement.5.Identified the lower limit of supplementary water capacity for potato. Supplyingwater or not have no significant effect for potato emergence, but it can affect the yieldsignificantly. Useing underground supplementary water type to sow potato, in the meadowchestnut farmland, the water capacity is200ml/plant; and in the chestnut farmland that is100-200ml/plant, the economic yield can increase31.72%and19.74%-35.25%comparedwith the yield without water supplement.