Preliminary Study On The Synthesis Effects Of Water And Fertilizer In Saline Soil

With the shortage of water resources becoming serious,the recognition of water-saving agriculture importance (Agriculture of China's total water consumption accounts for more than 70%) further enhance,but now the focus is more targeted at the key projects of irrigation district and the water-saving technology,such as the transformation and auxiliary hardware of field projects. The water-saving technologies in field are researched and concerned relatively weak,especially in the water deficit conditions,how to utilize the synthesis effects of water and fertilizer,increase the efficient utilization of soil water in saline soil,which are researched unprofound,the mechanism unclear,can't adapt the time requirements of agricultural water-saving. In saline areas,crop production potential can't be made full use,apart from the effects of salt stress;The most fundamental reason is the disharmony of water and nutrients. Based on the current situation the shortage of water resources and soil salinization in irrigation district,took salt-tolerant crops of sunflower as the subject investigated to research the synthesis effects of water and fertilizer in saline soil,some preliminary results as follows:(1) Analysis the synthesis effects of water and fertilizer on the growth and development of sunflower under different soil salinity with the method of factor analysis,draw the appropriate application of P about is 256 kg/hm~2 before seeding in light and moderately saline soil,above or below this value has no significant effect.(2) Analysis the crop dry matter accumulation in salt stress,obtained mildly saline soils,sunflower N fertilizer 225 kg/hm~2,irrigation 104.7 mm circumstances in flowering,the crop dry matter accumulation is largest,reachs 327.2 kg/hm~2·d;moderate soil salinity N fertilizer384 kg/hm~2,irrigation 62.6 mm circumstances,the largest amount of dry matter accumulation is 179.5 kg/hm~2·d.(3) Analysis the diurnal variation of leaf water potential of sunflower in different salinity soil,the general performance of leaf water potential is highest in the morning and at night when the weather was fine,the afternoon around 3:00 p.m. at the lowest,in the daytime,the leaf water potential of sunflower moderately saline soil was lower than slightly saline soils in the morning around 8:00 the biggest difference is 1.5 MPa;This difference is small at night,between 0.08~0.28 MPa;indicate that salt stress decreased leaf water potential.(4) Analysis of the leaf water potential and environmental factors in the synergistic relation,establishe the mathematical model of the leaf water potential,net radiation,leaf temperature,and atmospheric water potential.(5) Analysis of the diurnal variation of the leaf water potential and soil matric potential,the leaf water potential and matric potential has a positive relationship,within the same day the relationship of leaf water potential and soil matric potential is different in the early,middle and late.(6) On the basis of the field experiment,apply BP artificial neural network simulation to predict the sunflower water-fertilizer-salt-production model,training the network by changing hidden nodes,through a series of training and adjustment,final reach the artificial neural network model of hidden nodes for seven,the topological structure of 4:7:1, the model has higher precision.