A Study Of Crop Reponse To Water-salt Stress In Saline Soil Under Saving Irrigation

Under the situation of total irrigation water use decreasing greatly and it is essential to irrigate saline soil(saline soil and salt soil area constitutes 65% of the whole infield), a saving irrigation experiment study was carried out in hetao irrigation area, and crop response to water and salt stress was studied by way of pot and field experiment. On the base of Var. analysis significance of the experimental treatment, we investigated crop response to water-salt stress regularity, studied the quantity relationship about crop yield and soil water and salt, established a function about them referring to Blank and Jense water model. conclusions as follows: (1) the effect of germinating time and rate emergence are different in soil with different salt content, and limited seriously in heavy saline soil. (2) American Sunflower G101 is sensitive to salt in seedling period. The physiological indexes of crop is respondent to salt obviously. Ability of tolerance salt is increased during squaring period. compensable growth is showed for the effect of seedling period. Blooming period is also a sensitive period. (3) Effect of dry matter and yield are different on different irrigation level in same salt level treatment in squaring period. Too much or too less irrigation water use is not benefit for crop yield. Dry matter and yield decrease with salt increasing on same irrigation level. (4) The minimal soil moisture content increases with salt content increasing. Meeting minimal needs, crop yield is satisfactory in the soil with salt content bellow 0.6%, but not in soil salt content above 0.6%, so planting in this soil isn't suggested. (5) Varying trend of leaf water potential differs in different seasons. Leaf water potential changes significantly with temperature. The speed of leaf water potential rising with temperature in heavy saline is faster than that of in light saline. It can reflect soil water stress and salt stress. (6) Choosing soil solution relative concentration as suitable variable established a funct-ion about crop relative yield, soil water and salt. Using the way of testing model with actual data to valid its higher precision, it can reflect the relationship of crop yield, soil water and salt, and be considered as reference in water saving irrigation management.