| The Songliao Plain began supporting the construction of drip irrigation works relying on the national project in recent years. However, in view of the typical region and climate conditions, the research are less on application. The idear of water-fertilizer saving and agricultural production affect soil environment be lacked. The effect of drip irrigation under mulch film to crop soil system is still to be perfect. Based on the shortcoming, by setting two conditions of soil fertility with Mulching and bare land cultivation treatment and water nitrogen two factors and three levels combination treatment. Study on the effect of film mulching and water and nitrogen on coupling on maize drip irrigation to seek suitable cultivation measures and water and nitrogen application rate.Provide a theoretical basis for the combination of film mulching cultivation measures and integration of water and fertilizer engineering technology, the main conclusions are as follows:1-Film can increase the germination rate and improve the effective number of trees which contribute to grain yield, enhanced leaf photosynthetic capacity and good soil fertility increase the effect of film. Better soil fertility film can significantly increase the accumulation of NPK of grain and steam leaf reached 8.2～19.8% and 3.9-9.1%, lowland force covered only significantly increased the grain nitrogen and the accumulation leaf potassium. Film can increased the harvest index of NPK reached 0.2-1.7%. Film and increased soil fertility can enhance the rate of leaf transpiration, soil water which reservoir down by film was consumed by crop, the total water consumption ET was closely to bare ground, while the low soil fertility level, the bare ground> film exceed 6.89%. Film, fertility can increase production is 10.8～14.2、19～22.7% and partial productivity of NPK is 4.3～26.9、7.6-40kg/kg, and there have promoting interaction between two factors, can improve the utilize efficiency of water reached 17～18.4% and 10.8～12.1%, but there have no promote interaction.2、Film increase the decomposition of organic matter, weakening the soil’s organic fertility and improving the content of topsoil available nitrogen is 2.13-12.0 mg/kg, available phosphorus is 0.54-2.08mg/kg and potassium is 8.47-31.Omg/kg on growth period 0～20cm.Bcause of the film’s closure, the solution of water and fertilizer’s loss was reduced, Film can optimize the local soil and water environment and increase available nutrients, good soil fertility can expand the film’s effects. At the beginning of Heading Stage, the film on 20-60cm’s efficiency of soil nutrient availability is less than its effect of increase maize’s absorption of soil nutrients, and bare land> film. The 0～20cm’s availability of soil nutrient come from the amount of increasing residual-based, while the affect is not significantly or reduce residual nutrient on 20-100cm.3、Film can reduce the consumption of 0-20cm soil water after irrigation, after irrigation, water volume of 1～3d was consumed on the drip irrigation, the plant of drip tape which from 17.5cm and 35cm, and the film side where lower than the bare land 3.6,2.63.1.04mm respectively, effect of surface soil water’s storage:drip tape>plant location>film side. The soil water consumption of bare land’s drip irrigation and plant’s 0～20cm which decreased compared 1d～3d after irrigation 3d～5d and 5d～7d, the rate of water consumption was greater when bare land at high moisture content, capping film can block most topsoil evaporation, reduced the 0～20cm’s consumption of water storage, and the rate of consumption changed with time small after irrigating.Film reduce the proportion of water consumption of surface in total water, weaken the soil water consumption’s differences on vertical direction. Film reduce the amount of total water consumption and its intensity of water consumption at the interface of drip point source are 7.59mm and 1.09mm/d, the film side in a irrigation period are 9.44mm and 1.35mm/d. For from the plant which at the drip tape 17.5cm, the film reduce 7d water volume’s consumption and its intensity of topsoil which is closely to wetting layer. Thus the water consumption of plant transpiration was more vigorous.4、The medium nitrogen application(240kg/hm2) and medium rrigation amount (2197～2315m/hm2) combined can get high level whole plant dry matter quality in whole growth period, but the grain harvest index decreased. The contribution of water to grain was decreased by the high irrigation level. Nitrogen deficit (192kg/hm2) causes a bigger inhibitory effect of photosynthetic rate than transpiration rate. The effect of increased irrigation quantity that improved photosynthetic rate has a less effect than transpiration rate. Growth duration (1351-1465m3/hm2) of low irritation quantity obstructs nitrogen’s effect to photosynthetic and transpiration rate. Water deficit can cause negative influence of over nitrogen treatment. Middle-high irritation amount under 1802-2315m3/hm2s nitrogen effect is obverse, and its application amount increases from 240kg/hm2 to 288kg/hm2 only has a weaker effect. The weakening effect for leaf WUE presented as excessive irrigation and nitrogen deficiency is less than excessive nitrogen and water deficit.The combination of nitrogen rate exceed 240kg/hm2 and irrigation amount exceeded 2197m3/hm2 does not significantly affect leaf WUE. The effects of water on Pn, Tr, Gs, and Ci more than nitrogen, but effects of water on leaf WUE less than nitrogen. The linear fitting relationship of photosynthetic factor in varying degrees reflects the the variation and correlation of actual field test.5、The low irrigation(1351-1465m3/hm2) cannot effectively increase the role of nitrogen fertilizer on the yield of maize. Combined application of 280-290 kg/hm2 of nitrogen with irrigation of 1 400-1800 m3/hm2 led to the fastest increase in maize yield, but without synergistic effects of water with nitrogen on the yield. Combined irrigation of 1800-2100 m3/hm2 with 250-280kg/hm2 of nitrogen obtained relatively higher vield and high synergistic effects of water with nitrogen on the vield. The residue of available nitrogen decreased from the shallow to the deep layer in the profile of 0-100 cm, after harvest, and the quantity of water and nitrogen applied mainly affected the residue of available nitrogen in the layer of 40-100cm. The residue of available nitrogen increased with the increasing nitrogen fertilizer. When the application rate was about 240 kg/hm2, the quantity of residual available nitrogen increased slowly. The residue of available nitrogen increased rapidly when the fertilizer increased to above 240 kg/hm2. The low irrigation (1351-1465m3/hm2) decreased the conversion of fertilizer nitrogen to soil nitrogen and quantity of nitrogen residue. Enhancing the irrigation amount to 1 802-2071 m3/hm2 promoted the conversion of nitrogen fertilizer to the soil nitrogen and increased the available nitrogen. When the irrigation reached about 2197-2315m3/hm2, the nitrogen migration with water in soil profile increased and reached to deep layer of exceed 1 m. The quantity of optimization of water and nitrogen coupling were in an approximate ellipse area. The irrigation of 2016-2100m3/hm2 with nitrogen of 228-250 kg/hm2 in intersection area can be used as suitable amount for planting maize under mulched drip irrigation in the transition from Song-liao Plain to the Inner Mongolia Plateau. |
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