Characteristics Of Soil Temperature And Soil Water Under Different Tillage Patterns And Effect On Crop Growth In North China Plain

Aimming at the actuality and the existent problems on conservation tillage technology in the aeras where had winter wheat and summer maize two crops a year in North China Plain, using the conventional cross tillage as the CK and using the winter wheat and summer maize's growth trends, soil temperature and soil moisture which were successively and dynamicly measured as the stresses, this paper studied the influences on winter wheat planting and seeding under conservation tillage conditions, the characteristic of soil water and soil temperature and the influence on growth and development of winter wheat and summer maize by the numbers and analysed the yield in Luancheng Experimental Station of CAS in 2004-2005.The main results were as follows:1.The low seeding emergence had a direct connection with maize stalk or root stubble under conservation tillage conditions.The studies sorted the reasons which affected the wheat seeding to sowing too shallow.sowing too deep,physical obstacles by maize stalks,seed moldiness and deficiency or unevenness of soil water and defmituded the key factors and priority sequence which affected wheat seeding under different tillage.At the same time,the studies investigated the relationship of the amount of the wheat seeding and the amount of the stalk returned to the field under the sowing conditions when the stalk still standing on the field or the stalk was crushed. Finally the paper got the formulas which can calculate the best amount of the stalk returned to the field on the condition of the amount of the seeding required to the field.The formulas were y=402.67x^-0.7192 and y=509.4x^-1.0597.2.The winter wheat soil temperature had the two domino offects of descenting and increaseing temperature under the conservation tillage conditions.In the time from seeding to living through the winter and from returning green to lifting the nodes,the winter wheat soil temperature represented obvious descenting temperature domino offect under no-tillage conditions.In the time of living through the winter the winter wheat soil temperature represented increaseing temperature domino offect under no-tillage conditions.In the entire growth time the soil temperature had the same changing trend with the outside air temperature under every tillage conditions.Seeing the relationship between soil temperature and soil depth,after returning green the soiltemperature reduced gradually along with the soil depth increaseing under different tillage conditions.3.The conservatation tillage winter wheat paddock have protects water function, the average water content of top layer of soil is higher than traditional tillage. When the water content in the field is reduced, the difference to strengthen in different tillage patterents;when the water content in the field rises(whether precipitation pour water), the difference to minish in different tillage patterents. It is the highest all the time in soil water content that two kinds no-tillage. On every level of top layer, the level soil of 20-30cm is relatively high in water content.4.After winter wheat returning green,the growth time of the two no-tillage modes postponed and the biggest different value can be 11 days.The plant highness > the leaf area> the tilling ratio et al under the two no-tillage conditions were all obvious lower than the values under conventional tillage conditions.Under different tillage conditions,the yields of the two conventional tillage didn't have the obvious difference(P=0.01) and were all obvious higher than other three tillage.Other three tillage were obvious different from each other and the yield of no-tillage with the stalk standing was lowest.The yields of the no-tillage with the stalk standing> rotary tillage^ no-tillage with the stalk crushed were lowed 3646.91kg/ hm2,2954.16 kg/ hm2,2029.62 kg/ hm2 and reduced 44.9% > 36.4% ^ 25% of the outputs compared with the conventional tillage conditions.Through the comparison of the yield character,kenong9204 and shijiazhuang8 were suit to plant under conservation tillage conditions.5.Under conservation tillage conditions when there were former crops,the summer maize field soil didn't represent obvious descenting temperature actions and this could have relationship with the seeding on the ridge in the field.The average temperature of every treatment existed a certain difference before the middle of August when the air temperature was high.After the maize groouting,the difference was little among every treatment.And the soil day average temperature of every treatment had the same changing trend with the air temperature changing.The soil temperature of different layers had the same changing trend and the soil temperature decreased gradually along with the increasing of the soil depth under different tillage conditions when there were former crops.6.Under conservation tillage conditions the stalk of former crops covering had a certain function of keeping water and the amount of containing water of different soil system was higher than conventional tillage conditions.In 0-10cm soil layers the quality water amount of ever system had an obvious difference and the rotary tillage in the entire growth time had the highest water amount and the no-tillage with stalk standing or crushed had a lower water amount.The soil quailty water amount under conventional tillage with former crops was relatively low and it was lowest compared with the CK.In10-20cm soil layers or deeper layers the difference of every system was little and the changing trend was the same with the change in growth time.7. In early growth time the growth rate was fasU the coefficient of the leaf area was big and the accumulation of the dry matter was much and in the evening growth time these were to the same gradually under conservation tillage conditions.Seeing from the yield,under the rotary tillage with former crops and two no-tillage conditions,the yield of summer maize increased 1186.95kg/hm2> 1565.7kg/hm2N 1413.9kg/hm2 and the yield increased 14.3%> 18.9%> 17% compared with the CK.The yield under the conventional tillage with the stalk returning to the field increased a little but not obviously.No matter under what tillage conditions,the yields of the compact variety zhengdan958 and jundan20 were obvious higher than the three others and the difference of the unknit variety and middle variety was little.Under rotatry tillage conditions,the summer maize yield of the compact variety zhengdan958 increased along with increaseing of the planting density.When the density achieve to a certain degree,the yield didn't increase but decreased slowly.The formula drawed from the planting density and the yield is y=-149.17x2+1180.9x+8165.9, R2=0.9465.8. The annual economic benefits of the two kinds of traditional tillages were highest. The second was the crushing stalk and no-tillage.The economic benefits of the rotary tillage and the having stalk and no-tillage were lowest.Integrated economic benefits and ecological benefits,crushing stalk and no-tillage could become the conservation tillage which could be energetically extended.