| Ridging covered the planting of crops in the ditch is currently one of the planting patterns in dry regions. It can reduce soil moisture evaporation, keep moisture, improve the effect of crop water use efficiency, so the crops can achieve optimal product quality. Winter wheat "xiaoyan22" were used as material in this test, plastic film mulch, semi-permeable membrane, bare land under the condition of different water and nitrogen coupling process, tracking observation of winter wheat plants and the change of the underground soil in field and pot in different growing phases, research the effect of different ridging covered and different water and nitrogen coupling on water use efficiency and plant growth in each period, evaluate the yield and explore the best water and nitrogen coupling mode and covering mode that suitable for winter wheat growth. Provide the reference data to improve the quality and yield of winter wheat. It also provides the basis for exploring section water fertilizer production in the future. By October2012to June2013, experimental research and analysis finally get the following conclusion:(1) In the0to25cm soil layer, ridging covering can improve the soil temperature, and ridging cover plastic insulation effect is better than semi permeable membrane, in the five different in the depth of the analysis, ground temperature from high to low were:ridging covering mulch>ridging covering semi permeable membrane> bare land. This shows ridging covering mulch will prevent direct exchange between soil temperature and atmosphere, prevent soil temperature loss, mulching film has good heat preservation, it can also provide suitable environment for the growth of winter wheat.(2)Riding covering mulch and ridging covering semi permeable membrane has good keeping moisture characteristics from the green period to postulation period, in every stage soil moisture content presented:ridging covering semi permeable membrane>ridging covering mulch>bare land. That means semi permeable membrane keep moisture performance better than mulch. And by the late, especially mature, difference of soil moisture content between ridging covering mulch and bare land is very small, This is because the actual trial ridging covering most of the mulch are damaged, the mulch itself quality of material is thin, can be damaged burst easily, plus rain wind and other environmental impact, accelerated the weathering rate; Semi-permeable membrane is thicker than others, not easily damaged, it can save a long time to guarantee the characteristics of its ability to keep moisture, from beginning to end ridging semi-permeable membrane cover soil moisture content is higher than other processing.(3) Comprehensive plant height, chlorophyll, leaf area and dry matter, in consideration of the growth of winter wheat and water and nitrogen coupling efficiency of resources, in the field of winter wheat, adopt water and nitrogen treatment (W2N2), that irrigation water is60mm, nitrogen application rate is120kg/hm2. Winter wheat in pot under the condition of water and nitrogen treatment(W3’N2’), plant height, leaf area, chlorophyll, dry matter production and achieves the maximum value, so that irrigation water is75%-85%of field capacity, nitrogen application rate is0.2g/kg will best for winter wheat plants grow.(4) Ridging covering and nitrogen and water coupling interaction, when the water and nitrogen coupling were same, growth index ridging covering semi permeable membrane treatment is higher than the ridging covering mulch; When covering and irrigation water phase at the same time, the index increases with the increase of nitrogen application rate first increases and then decreases.120kg/hm2is the critical value, and more than this value the indexes will decrease. When riding covering and nitrogen application at the same time, the indexes of water demand is different.(5) Chlorophyll, transpiration rate, stomata conductance of these physiological indexes achieve the highest under the ridging covering semi permeable membrane under water and nitrogen treatment (W2N2). Net photosynthetic rate affected by nitrogen, it reach maximum in ridging covering semi permeable membrane and under the condition of middle water; Yield achieve the highest under ridging covering semi permeable membrane as well as water and nitrogen treatment (W2N2),it was reached10.981t.hm-2.It suggested that ridging covering semi permeable membrane as well as water and nitrogen treatment (W2N2) is beneficial to the accumulation of yield. It can produce good economic benefit. |
