| No tillage for winter wheat has been conducted in North China. A successive 2-years field experiment in winter wheat growing periods was carried out in Luancheng Experimental Station of CAS in 2003-2005. In the study, taking conventional tillage (CT)and rotary tillage(RT) as check, the dynamics of soil temperature and soil moisture under no-tillage (NT) was measured continuously. Soil physical properties were systemically studied in this paper, effects of No tillage on the growth of winter wheat, the yield and water utilization of winter wheat were also analyzed. The main results included:1. Soil properties such as bulk density, water retentiveness and thermal conductivity under NT was higher than that of CT and RT. Two years experiment showed that soil bulk density under NT was the highest and almost kept consistent in all the layers. The soil bulk density of ridge under NT for 2.5cm layer was 0.13 g cm-3, 0.12 g cm-3and 0.12 g cm-3 higher than that of t under CT, RT and the furrow of NT after sowing in 2003. While the ridge soil bulk density of NT was 0.04 g cm-3,0.02 g cm-3and 0.02 g cm-3 higher than that of CT, RT and the furrow of NT before seeding in 2004. For the water retentive, under 300 cm soil matrix suction of ridge under NT was 11.23%, 24.78% and 4.18% higher than under earth furrow of NT, CT and RT in 0~5cm plough layer. The soil thermal conductivity for the ridge of NT was 0.22, 0.25 and 0.3 W·m-1·C-1 higher than under earth furrow of NT, CT and RT.2. Soil temperature under NT for the winter wheat field show different trends in different growth duration. From sowing stage to hibernation stage and from re-green stage to jointing stage, the soil temperature showed "low-temperature", while during hibernation stage; the soil temperature exhibited a "high temperature" under NT. Before hibernation, soil temperature of NT was lowest, and CT was highest in a day; the average daily soil temperature of plough layer under NT was 0.62℃ and 0.38 ℃ lower than that of under CT and RT, respectively; soil cumulative temperature under NT was 5.2℃ and 3.3℃ less than under CT and RT. The "low temperature phenomenon" of NT from re-green stage to jointing stage was also pronounced, and the maximal and minimum temperature under NT was lower than under that of CT and RT. The daily average soil temperature of plough layer under NT was 0.77℃ and 0.72℃ lower than under CT and RT; soil cumulative temperature under NT was 19℃ and 14.9℃ less than CT and RT. During hibernation stage, soil temperature of winter wheat field under NT showed "high temperature phenomenon. During a day, the temperature of all layers from 2.5cm to 80cm, maximal and minimal temperature, daily average temperature and cumulative temperature during hibernation stage under NT was highest, CT was lowest. The high temperature phenomenon of plough layer under NT was not obvious, at the 80cm depth, and the average soil temperature under NT for twoyears was 0.53℃ and 0.24 ℃ higher than that of CT and RT. The daily average minimal temperature for two years under NT was 0.23 ℃ and 0.17℃ higher than that of CT and RT.3. Soil moisture under NT was higher than that of CT and RT, and the soil could save more irrigation water under NT due to better water retention. During winter wheat seedling stage, the soil moisture of all layers for 180cm soil profile under NT was highest, RT was lower, and CT was lowest. The difference of soil moisture was more pronounced at the plough layer, and the difference reduced gradually with the incensement of depth. Water consumption under NT was least, and CT was most. For the 180cm soil profile, the soil under NT could save water of 22.5mm and 15.5mm than that of CT and RT.4. With no tillage, winter wheat showed relatively later emergence and tillering, lower rate of emergence and tillering, which had affected on the growth and development of winter wheat. The winter wheat under NT emerged 3 days later than that of CT and RT, and had lower rate of emergence. The average basic seedlings of winter wheat under NT for two...
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