【摘要】 江苏省里下河地区在—熟沤田改稻麦两熟田的改制中发生一种脱沼泽型水稻土。一系列野外调查,田间试验和室內研究的结果示明,脱沼泽型水稻土发生过程中土壤性状的变化包括三个阶段:第一阶段中表土产生浸水不化的块状结构和土壤有效磷的强烈固定,第二阶段中亚表土变为无结构而粘滞,土性很冷而过湿,使冬作生长不良,第三阶段中耕作层下由于土体的急剧收缩和胶结而产生极紧实的棱柱状结构,漏水漏肥,作物根不能穿入土体以吸收养份。改善以上恶劣性状的有效措施是:(1)排去田面积水、耕翻土壤、在阳光中充分晒干后迅速窨水化垡以造成疏松的团粒;(2)采用稻—麦—棉轮作,加速土壤脱沼泽,以消除土壤中、后期出现的不良结构;(3)施磷肥或种吸收土中磷素能力强的麻、油莱或其它绿肥作物;(4)掺入粉砂性河泥以逐渐改变粘性土壤的质地。更多还原

【Abstract】 A kind of degleyed swampy paddy soil has been developed during the changeof submerged paddy fields with a single crop of rice to the ordinary doublecropping system of rice and wheat in the“Lower River Basin”in North Jiang-su since the founding of new China.A series of field observations,experiments and laboratory researches re-vealed that during the development of the degleyed swampy paddy soil the ac-companying change in the soil properties underwent three stages.In the firststage a hard cloddy structure was formed in the surface soil and the availablephosphorus in the soil was strongly fixed.In the second stage the top soil be-came structureless and dispersed with high tenacity for water,being cooland too wet for winter crops to grow well.In the third stage,due to the pre-cipitation and accumulation of ferric oxide and humus,there formed a very com-pact prismatic-columnar structure below the plow layer,being liable to losewater and plant nutrients.The living roots could not extend into such hardcompacted layer to absorb nutrients for plant growth.The effective measures to ameliorate the above unfavorable conditions are asfollows:(1)Drain off the surface water,plow up the soil and dry it thoroughly inthe sun.Remoisten the soil by a quick flooding of the field in order to turn theclods into friable granules.(2)Adopt a rotation of rice-wheat-cotton to improvethe soil structure.(3)Add phosphorus fertilizer or grow rapes or green manurecrops that can vigorously absorb phosphorus from the soil.(4)Use silty rivermud as manure to change gradually the clayey properties of the soil concerned.更多还原