Effect Of Mulching On Soil Temperature And Yield Of Winter Wheat In Arid Region

There was a series of problems just as water dicifit,unstable temperature and lower production of yield on winter wheat in northwest semiarid rainfed area.Mulching could adjust and stabilize soil temperature,collect rainwater and keep moisture,improve water use efficiency,which was the key to improve yield of wheat and keep the sustainable development of agriculture.The text researched the influence on soil temperature and the yield of winter wheat under different mulching methods and materials.The experiment included the whole plastic film mulching(PM)and 4 kinds of bundled straw covering.The field was divided into covering belt and planting belt by bundled straw covering.The covering belt width were all 50 cm.The planting width was 35 cm,50 cm,70 cm,85 cm in turns.In planting belt planted 3 lines-seeding(SM3),4 lines-seeding(SM4),5 lines-seeding(SM5),6 lines-seeding(SM6),Bundled straw mulching 3 lines-seeding,and bundled straw mulching 4 lines-seeding had three cover materials — the new corn stalk(N),old corn stalk(O)and wheat straw(W),The cover material of bundled straw mulching 5 lines-seeding and bundled straw mulching 6 lines-seeding were the new corn stalk and non-mulching with row-seeding as control(CK),The main research results were as follows:1.Mulching has different effect on winter wheat yield.The yield of bundled straw covering was reduced with the increase of planting belt width and planting rows.The bundled straw mulching 3 lines-seeding(SM3),4 lines-seeding(SM4)increased by 69.1%,41.3% than CK control.The bundled straw mulching 5 lines-seeding(SM5),6 lines-seeding(SM6)were no significant with CK.The whole plastic film mulching(PM)improved by 61.3% than CK,but its no significant with SM3 and SM4.The spike numbers and the kernel numbers were the main factors for the yield change of winter wheat.The coefficient of variation CV(16.1%)of Spike numbers and kernel numbers were 15.7% and 16.1%.TKW(Thousand Kernel Weight)(CV = 8.5%)was more stable.The Spike numbers of bundled straw covering was reduced with the increase of planting belt width and planting rows.The Spike numbers of SM3 and SM4 were increased by 20.2%?13.4% than CK.SM6 was reduced by 17.9% than CK.SM5 was no significant with CK.PM was reduced by 15.2% than CK.In general,mulching could increase kernel numbers,which were increased by 20.4%-37.4% under bundled straw covering than CK.PM increased kernel numbers 63.9% than CK.2.Mulching was benefit for vegetative growth,Which could promote the amount of dry matter transfer befor flowering and accumulation after flowering of mian stem of winter wheat.The plant height and dry matter accumulation per plant were affected under mulching treatments indifferent degrees.Plant height of SM3,SM4 were significantly higher than CK16.8%,18.6%.The plant height and dry matter accumulation per plant of PM were significantly higher than CK 27.1% and 78.4%.The amount of dry matter transfer befor flowering and its transfer efficiency of mulching were increased by 0.17-0.26 g and 4.31-7.37 percentage points than CK.Dry matter accumulation after flowering of mulching was increased by 0.15-0.38 g than CK.Finally,the harvest index of main stem of mulching was improved 5.6-9.1 percentage points than CK.3.Mulching has different effect on mean soil temperature of 0-25 cm soil layer during whole growth period.SM3 and SM4 could significantly reduce the soil temperature.SM3 and SM4 respectively lower 1.78? and 2.27? than CK.There were no significant differences among SM5,SM6,PM with CK.The bundled straw covering approximately showed the cooling effect at different growth stages.Cooling rate increased with growth process.SM3 and SM4 showed the cooling effect in 0-25 cm at every growth period.SM5 and SM6 showed the cooling effect,except jointing stage showed the warming effect.Upper soil layer,in addition to the SM6(0-10 cm)has a warming effect,SM3,SM4,SM5 in various soil reduced temperature than CK,and sublayer(15-25 cm)was greater than the upper(0-10 cm)in the cooling extent.There was no significant between PM and CK on the mean soil temperature at the different growth stages and the different soil layers.Specifically,the covering played the role of the warming and cooling,compared the time and space dynamic of soil temperature.The proportion of the cooling point times accounted measuring point times of mulching,respectively were SM3 = SM4(92.5%)> SM6(85.0%)> SM5(82.5%)> PM(70.0%).The cooling effect on soil average daily temperature of the bundled straw mulching eventually led to the growth duration of bundled straw mulching delayed nearly 8-16 d than CK,and the growth duration of whole plastic film mulching advanced 6 d than CK.The daily variation of soil temperature risen with the soil layer in the morning,noon and evening,in contrast.The daily variation range of soil temperature showed: late growing periods(flowering-maturity)> earlier growing periods(wintering-flowering),and the upper(0-15 cm)> the lower(15-25 cm).Covering showed cooling effect in the morning,nooning and evening,and its cooling range were nooning > evening > morning.The difference in treatments was characterized by the largest in the evening followed by noon,the smallest in the morning.4.There was no significant difference on yield,spike numbers and kernel of different covering materials.But there was a obvious difference on TKW(Thousand Kernel Weight).SM3 was significantly higher 5.9%than SM4.SM3-N was the highest,SM4-O was the lowest,differ by 10.8%.The difference of soil temperature 0-25 cm from flowering to maturity under bundled straw covering measures was wheat straw(21.24?)> old corn straw(21.13?)> new corn straw(20.26?),SM3(21.10?)> SM4(20.66?),SM4-N was the lowest,SM3-O was the highest,the differ was 1.77?.The coefficient of variation CV(16.1%)of soil temperature from flowering to maturity under covering measures: new corn straw(12.55%)> old corn straw(11.49%)> wheat straw(10.45%).SM3(11.40%)was similar to SM4(11.45%).So soil temperature fluctuation was relatively slow under wheat straw mulching,and new corn straw mulching was more intense.Appropriate bundled straw mulching could effectively decrease temperature and reduce steam,which could promote wheat growth,and has a similar effect to increase yield with whole plastic film mulching.The straw of mulching could return to the field after crushing and decomposing,which could combine utilizing land with maintaining.Considering from the aspects of environmental protection and sustainable development,the bundled straw mulching was more suitable for popularization and application in the northwest rainfed area in china.