| As far as the sustainable agriculture in arid and semiarid areas is concerned, it is an important problem to develop water-saving agriculture and increase Water Use Efficiency (WUE). Application of Super Absorbent Polymer (SAP) is an important technique to save water and fight a drought. In this paper, With a new SAP product named .EHAN 98?Super Absorbent Polymer as material and using glasshouse potted plant and field section experiment as main method, basing on researching the characteristic of SAP absorbing and holding water, interaction of SAP and fertilizer and effect of SAP on soil physics character, application of SAP in water-saving irrigation and its effect on crop growth and WUE are studied, field experiment has also been taken in Hexi area,Gansu province.The results are as follows: 1. SAP absorbent ability is negative correlation with the solution concentration. The retaining capacity of EHAN 98?SAP is 195.9ml/g in the tap water of our locality. 80 percent of water holding by SAP is available that can be easily used by crops. While adding 0.6 percent SAP of Lou soil (dry weight), 83 percent of water is available. SAP can decrease evaporation greatly, adding SAP to sand soil in the condition of evaporating at constant temperature, time of evaporation is extended, the moisture content of SAP treat is higher than CK. SAP can increase soil moisture greatly such as saturation moisture and field capacity. 2. While SAP is appreciated in the field, The method of using SAP its dosage and relevant irrigation system should be ascertained according to the different conditions such as irrigation and climate. The perfect method of using SAP should be as follows: Proper dosage of SAP is added to the soil and correct method of using it is adopted, forming moderate moisture intimidate in order to accelerate the growth of crops, thereby save water arid increase production; contemporary proper irrigation system should be adopted for fear that crops?root and SAP strive for water; in the same time, drought-enduring crops, the method of using SAP and its burying depth should also be considered. 3. Under the condition of the same dosage of SAP, water held in the soil increases with the quantity of water. At the vertical section of the soil, that is, 20 to 40 centimeters depth, it seems that a layer blocking water infiltration forms. SAP can increase moisture content of the layer but can抰 affect moisture content of deeper layer. SAP has less effect on maize height but more on leaf area, it can promote the growth of maize root. Maize yield is different when different dosage of SAP is added, but the effect of SAP increasing production on maize is little or minus when the water irrigated is less. In the spring wheat-maize cincture field in HeXi region, Gansu province, aplication of SAP in channel promotes irrigation WUE greatly. At the same yield of maize, SAP dosage of 15kg/bin2 can save water as much as 544. 13m3/hni2. At the same irrigation water use, SAP can increase maize yield. In range of the examination, the more the dosage of SAP is added, the more the yield of maize is produced. 4. The result of holding water, increasing production and saving water is affected by moisture condition, for SAP cannot produce water, it only can hold some water. A lot of conditions affect the resault of SAP such as method of using SAP, soil texture, water and fertilizer, climate and irrigation system. Economic rationality of using SAP lies on three factors: Price of SAP and its dosage, result of increasing production and price of the crops. quantit... |
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