脱硫石膏配合淋洗改良碱化土壤对土壤盐分分布及作物生长的影响

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。

Effect of flue gas desulphurized gypsum and sodic soil reclamation by leaching water on soil salt distribution and the growth of crop

Salinization cultivated land area is about 7% of the total cultivated land in China.Sodic soil poses a serious threat to agricultural development and food security of China.Flue gas desulphurized (FGD) gypsum is a kind of economic and environmental soil conditioner,and leaching water can promote upper layer soil desalting when using FGD gypsum.Aiming to study the effect of GD gypsum and reclamation sodic soil by leaching water on soil salt distribution and crop growth while,a field experiment was conducted in Hetao irrigation region to analyze the changes of soil ESP,pH and EC in 0-100 cm depths and its effect on the growth and yield of edible sunflower in 2012 is investigated.Different application rate of FGD gypsum (10.1,14.5 and 0 t/hm²) with different water leaching rate (1.52×10³,2.20×10³ and 0 t/hm²) are used in the experiment.The results show that:1) At 0-40 cm depth,soil ESP,pH and EC of all treatments reduce significantly and tend to be stabilized gradually after the first leaching and irrigation,ESP and EC have increasing trend within the year,soil ESP,pH and EC at 40-100 cm depths are more stable than those at 0-40 cm,soil ESP and pH of combined treatments are slightly reduced,leaching-only treatments'' tend to rise;2) Combined treatments have a better improvement effect over all treatments at 0-60 cm depths,but the effect is not obvious under the depth of 60 cm;3) High rate of FGD gypsum with leaching treatments contribute to better growth and yield of edible sunflower at a high level than the rest.In conclusion,FGD gypsum and leaching water can effectively improve salt distribution of sodic soil and crop growth,which provides references for sodic soil reclamation.