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我国耕地盐碱化面积约占总耕地面积的7%,碱化土壤严重威胁了我国的农业发展和粮食安全;脱硫石膏是一种经济环保的碱化土壤改良剂,淋洗可以促进脱硫石膏改良碱化土壤过程中上层土壤脱盐。针对脱硫石膏改良碱化土壤对土壤盐分分布及作物生长的影响问题,在河套灌区采用田间试验的方法,对不同脱硫石膏用量(10.1、14.5和0t/hm2)配合不同淋洗量(1.52×103、2.20×103和0t/hm2)改良处理下土壤0~100cm土层的土壤化学指标(碱化度ESP、酸碱度pH和电导率EC)变化规律及2012年食葵的生长特性指标进行研究。结果表明:1)所有处理0~40cm土层ESP、pH和EC在第一年淋洗和秋浇后显著降低,之后逐渐趋向稳定,ESP和EC在年内有增加趋势;40~100cm土层各指标较0~40cm稳定,综合改良处理土壤ESP、pH略有降低,仅淋洗处理有升高的趋势;2)0~60cm土层综合改良处理改良效果优于其他处理,当深度大于60cm时,所有处理的改良效果不明显;3)高脱硫石膏配合淋洗对食葵的生长指标和产量的提高程度优于其他处理。脱硫石膏配合淋洗改良能够有效地改善碱化土壤盐分分布及作物生长情况,可为碱化土壤的改良提供借鉴。
China’s arable land salinization area accounts for about 7% of the total arable land, alkalized soil is a serious threat to China’s agricultural development and food security; desulfurization gypsum is an economical and environmentally friendly alkaline soil conditioner, leaching can promote the improvement of gypsum Soil alkalization in the upper soil desalination. Aiming at the effect of desulfurized gypsum on the salinity distribution and crop growth in alkalized soils, a field experiment was conducted in Hetao Irrigation District. The effects of different gypsum concentrations (10.1, 14.5 and 0t / hm2) with different leaching rates (1.52 × 103 , 2.20 × 103 and 0t / hm2), and the soil chemical indicators (alkalization degree ESP, pH value and conductivity EC) of 0-100 cm soil layer and the growth characteristics of fresh sunflower in 2012 were studied. The results showed that: 1) ESP, pH and EC of 0 ~ 40cm soil layer decreased significantly after the first year of leaching and after the fall of autumn, then gradually stabilized, and the ESP and EC increased in the year; The indexes were more stable than 0 ~ 40cm. The soil ESP and pH slightly decreased with the comprehensive improvement treatment, and the leaching treatment only tended to increase. 2) The improvement effect of 0-60cm soil layer was better than other treatments. When the depth was more than 60cm , The improvement effect of all the treatments is not obvious; 3) The improvement of the growth index and the yield of the edible sunflower is better than that of the other treatments when the high desulfurization gypsum is mixed with the elution. The improvement of desulphurization gypsum with leaching can effectively improve the salinity distribution and crop growth of alkalized soil, which can provide reference for the improvement of alkalized soil.