【正文】 壤的Na 吸附比SAR(sodic absorption ratio)以及土壤溶液的pH值這2個(gè) 收稿日期： 基金項(xiàng)目： 作者簡介： 通訊作者：2005——Ol——06 國家高技術(shù)研究發(fā)展計(jì)劃“863”基金資助項(xiàng)目(2001AA527015)石懿(1979一)，男，碩士研究生．楊培嶺(1958一)，男，教授，博士生導(dǎo)師，主要從事灌排理論與新技術(shù)方面的研究 5 維普資訊 ] 圖2 堿土區(qū)改良前后SAR 對(duì)比圖 n I)u + 川“ 處州 — ★ 一讓 2()!j j l l{f1 ‘)f I』 Gill 圖3 強(qiáng)度堿化土區(qū)改良前后SAR對(duì)比圖 1)不同土壤的不同處理 從圖圖3可以得出以下結(jié)論：改良前，無論是強(qiáng)度堿化區(qū)還是堿土區(qū)，土壤耕作層(0～15 cm)的Na 吸附比SAR 較高，且在15 cm處達(dá)到了最大值，然后隨著深度的增大，SAR逐漸降低。交換模型中。處理Ⅱ的SAlt降低的范圍是o～55 cm，處理I的 AR降低的范圍是o～50 cm；無論處理I、處理Ⅱ，在o～15 cm 范圍內(nèi)，SAR遞減的速度都大于在其他范圍內(nèi)的遞減速度，但是在此范圍內(nèi)處理Ⅱ的SAR 遞減速度更快；在SAR降低速度比較小的范圍內(nèi)(處理I為15～50 cm，處理Ⅱ?yàn)?5～55 cm)，同一深度處理Ⅱ的 值小于處理I的SAR值。8 圖4 堿土區(qū)改良前后pH／t~i比分析 圖5 強(qiáng)度堿化土區(qū)改良前后pH 值對(duì)比分析無論是堿土還是強(qiáng)度堿化土，pH值在向日葵主要根區(qū)活動(dòng)范圍(o～15 cm)內(nèi)明顯降低，但不同處理問維普資訊 存在著較明顯的差異：對(duì)于jI來講，在O～15 cm深度內(nèi)，土壤pH值呈現(xiàn)出明顯減少的趨勢(shì)；在15~100 cm范圍內(nèi)，pH值先遞增后遞減，但是均大于背景值；對(duì)于JⅡ，在O～4O cm深度內(nèi)，土壤pH值呈現(xiàn)出減少的趨勢(shì)，在O～15 cm 范圍內(nèi)，pH值遞減的速度快，在15~40 cm 范圍內(nèi)，pH值遞減的速度慢；在40~100 cm 范圍內(nèi)，pH值略低于改良前的pH值。以上試驗(yàn)結(jié)果反映出經(jīng)過1年的改良后，對(duì)15 cm 以下土層的pH值影響甚微。尤其是jI處理，其下層的pH值反而較改良前增加，反映出堿土惡劣的滲透性能，使上層土壤淋洗的鹽分不能全部排出土體，導(dǎo)致Na 在下層積累，pH值升高。China Agricultural University，Beijing 100083，China；2．The Place for scientific research in water in Ba Meng，Linhe 015100，China；3．Department of Thermal Engineering，Tsinghua University，Beijing 1 0008 4，China)Abstract：The fact that different amount of desulfurized gypsum was used in sodic soil and strongly alkali soil was studied in the paper．The laws of the change of SAR(sodic absorption ratio)on both kinds of land and the change of pH in soil solution were studied．As it was turned out，the vale of SAR and Ph on amended soil was less than that of virgin soil．M eanwhile，the vale of SAR and pH changed greatly in different treatments．After a year，in which，sodic soil and strongly alkali soil were suffered by that desulfurized gypsum was used and the water was penetrated，the vale of SAR of sodic soil and strongly alkali soil w hich depth were more than 1 5 cm varied litter more，but the vale of pH didn’t almost vary at al1． This indicated that exchangeable sodium percentage(ESP)of sodic soil and strongly alkali soil was reduced，physical and chemic characters of that were improved in the 1 5 cm depth of soil． For the reason of the ability of infiltration is very poor in sodic soil and strongly alkali soil，the saline w hich was leached from 1 5 cm depth of sodic soil and strongly alkali soil was not excluded form the body of soil in all，the rest was remained in the soil body．It is not surprising that the time is very long before sodic soil and strongly alkali soil are improved in every inch in physical and chemic characters．As the case maybe，the result of m end for strongly alkali soil on the mence is better than that of sodic soil for the fact that initial character of physics and chemistry is difference between sodic soil and strongly alkali soil n essence．Key words：sodic soil；desulfurized gypsum ；SAR；pH 1O 維普資訊