Effects Of Different Film Mulching And Water Treatments On Growth And Yield Of Winter Wheat

The main factors restricting the development of agricultural production In China's northwest arid and semi-arid regions are the lack of rainfall and low temperature.Meanwhile,in order to effectively solve the problem of mulch residue in agricultural production,the field experiment were conducted by ridge-furrow planting of winter wheat “xiaoyan22”,ordinary transparent film,degradable film and black film mulch on ridge,irrigating20 mm,40mm,60 mm in the jointing stage,research the effect of different felm mulch and water treatments on the plant nitrogen accumulation and translocation,plant growth,water use efficiency and soil hydrothermal regimes,evaluate the yield and explore the best water mode and covering mode that suitable for winter wheat growth.After a year of research and analysis finally get the following conclusion:(1)The plastic film mulching can conserve soil moisture,After the reqing period,winter wheat was growing rapidly,soil water consumption was serious,and soil water storage of mulch was significantly higher than that of control treatment.After the reqing period,winter wheat was growing rapidly,soil water consumption was serious,and soil water storage of mulch was significantly higher than that of control treatment After grouting stage,because the canopy coverage increases,the evaporation decreases,the water retention of the film is reduced,and the difference in soil water storage between covering treatment and control treatment is reduced.The soil moisture retention performance of different mulching films is different,the results showed that the water retention capacity of black film was the best,ordinary film was the second,and degraded film had a little poor water retention capacity due to the later degradation.(2)Plastic film mulching can reduce the soil temperature change amplitude during the growth period of shallow soil,and has a certain warming effect in the lower temperature season,and can reduce the highest surface temperature in the higher temperature season,so as to provide a more suitable soil temperature environment for the growth of winter wheat.Plastic film mulching can effectively improve the soil temperature before heading,especially the shallow soil temperature,the warming effect of ordinary film and degradable film is better than that of black film,after heading,because of the dense growth of crops,the surface light of field is reduced,and the warming effect is not significant.The comprehensiveanalysis showed that the effect of common membrane and degradable membrane on soil warming was good and no significant difference,and the effect of black membrane on soil warming was not obvious because of poor light transmittance.(3)On the whole,the plant height of wheat under the interaction of film mulching and irrigation was much higher than that under the control treatment.When the coverage was the same,the plant height increased with the increase of supplementary irrigation,but the plant height difference between high water treatment and middle water treatment was smaller and smaller with the advance of growth period.There was no significant difference in plant height between ordinary film and degradable film during growth period,black film was beneficial to plant height growth in late growth period compared with transparent film.The effect of different mulching films on leaf area was not obvious before jointing stage.the leaf area of different mulching films was black film > common film > degradable film under the same irrigation level in later growth stage.The effect of water content on leaf area was greater after supplementary irrigation,and the larger the amount of supplementary irrigation,the larger the leaf area value was.Film mulching and irrigation are important factors affecting the quality of dry matter,the same performance is that the larger the amount of supplementary irrigation,the greater the dry matter quality of single plant,but with the advancement of the growth process,the difference between high water treatment and medium water treatment gradually decreased.After flowering,the difference of dry matter quality of different mulching treatments began to be obvious,which showed as black film > common film > degraded film.Plastic film mulching was helpful to chlorophyll synthesis,but different plastic film mulching had no obvious effect on chlorophyll synthesis.Medium water treatment is more suitable for chlorophyll synthesis,which can not only provide enough water but also increase photosynthetic yield and delay the aging process of winter wheat,and high water treatment can accelerate the decomposition of chlorophyll.The daily variation of photosynthetic rate showed "unimodal trend" and reached its maximum at 10:00 am.The daily variation of transpiration rate and stomatal conductance showed "double peak trend",which reached maximum at 10:00 and 14:00 respectively.The influence of irrigation factors on photosynthesis was greater than that of mulching factor,in different water treatment,middle water treatment is the best.(4)Water can promote the accumulation of nitrogen in winter wheat plants before flowering,and the nitrogen content in each nutrient organ in the blooming period is shown as the higher the amount of nitrogen,the higher the concentration of nitrogen.The amount of nitrogen in the black film in different membranes is higher than the normal membrane and thebiodegradable membrane,which could be due to the fact that the soil under the black film is more favorable to the accumulation of nitrogen.The nitrogen content of the grains in different irrigation levels in the mature stage showed that medium water treatment > high water treatment > low water treatment,it is indicated that the nitrogen transfer is not the more water the better.Different organs have different transport capacity,transfer rate and contribution rate to grain nitrogen,and the contribution rate of nitrogen transport of different nutritive organs under different treatments is leaf > stem sheath > glume shell.The greater the amount of supplementation in the flowering period,the more nitrogen accumulation in each nutrient organ,However,the transport rate of nitrogen and the contribution rate of nitrogen to the grain will not increase with the increase of the irrigation water.Too much or insufficient irrigation will hinder the transfer of nitrogen to the grain,and the medium water treatment in the same mulch will improve the efficiency of nitrogen transport.Compared with ordinary film and degradation membrane,black film treatment has higher nitrogen transfer volume and higher contribution rate to grain.(5)The intercropping of mulch and irrigation can significantly increase the number of panicles,grain weight and grain number in winter wheat,thus increasing wheat yield.In addition to the control,the number of panicles in each treatment was not significant,and there were significant differences in the number of 1000-grain weight and spike grain number,resulting in different yield.The yield of medium water and high water treatment is significantly higher than that of low water treatment.There is no significant difference between medium water treatment and high water treatment.The yield of different mulch is shown as black film > common film > degradation film,but there is no significant difference between ordinary film and degradation film.Under the same water level,water use efficiency under different mulching film is shown as black film > common film > degradation film,under the same plastic film mulching,water use efficiency under different levels of irrigation is shown as medium water treatment > low water treatment >high water treatment.The ultimate goal of water-saving agriculture is to save water and increase production.The comprehensive analysis concludes that the combination of black film cover and medium water treatment can effectively improve the water use efficiency and increase crop yield,the use of a degradable film in place of black film coverage may also be considered in terms of environmental protection.