通过二年回归水灌溉种稻的田间试验看出,只要排水系统完善,管理措施得当,用矿化度1.5克/升左右、钠吸附比低、残余碳酸钠为负值的河水灌溉,可使40厘米以上深的土层从平均含盐量大于0.2％下降到0.2％以下,使土壤的平均钠吸附比和平均碱化度也相应降低。重碳酸根含量和pH值虽有上升,但在湿润地区石灰性土壤上用上述水质的河水灌溉,未发现有碳酸钠的积累,因而土壤碱化的可能性不大。 Through two years of field experiment of returning water to irrigated paddy rice, we can see that as long as the drainage system is perfect and the management measures are proper, irrigating the river with the low sodium adsorption ratio and the negative sodium carbonate at a salinity of 1.5 g / Soil depths above 40 cm decreased from more than 0.2% to less than 0.2% of the average salt content, resulting in a corresponding reduction in the average sodium adsorption ratio and average alkalinity of the soil. Although bicarbonate content and pH value increased, soil water was irrigated by calcareous soil in wet areas, and no accumulation of sodium carbonate was found. Therefore, it is unlikely that soil alkalinization will occur.