强酸性盐渍水稻土的发生

作     者：龔子同 周瑞荣 The strongly acid salty paddy soils derived from noncalcareous allitic sediment are widely distributed in the estuary of Chu-Kiang of Kwangtung province. Before recent sediments have deposited, the whole areas were densely covered by mangrove populations. A buried layer of decomposed products from residual plants is often underlaid at varied depth of present soil profiles. This layer contains large quantities of sulphide compounds. Oxidation of sulphides under acid conditions during dry period results the formation of sulfuric acid, which reacts with the kaolinitic clay to form aluminium sulfates. Periodical floodings of sea water add salinity of the soil and upon hydrolysis of the aluminium sulphate give a strongly acid reaction. The toxicity of the soil is mitigated with the increasing thickness of overlaid sediments. However, large areas of strongly acid salty soil with underlaid organic matter layer less than 25 cm below the sulface appear very harmful to rice growth. Reclamation of the soil can be accomplished by: a) irrigation of river water, b) keep the soil in a permanent moistened condition, c) liming, and d) addition of surface soil.

作者机构：中国科学院土壤研究所 

出 版 物：《土壤学报》 (Acta Pedologica Sinica)

年 卷 期：1964年第2期

页      面：183-191页

学科分类：09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

主　　题：强酸性 红树 水稻土 稻田土壤 耕作土壤 埋藏层 水稻生长 早稻 水稻 土壤溶液 毫克当量 河口区 OC 海水 咸酸田 

摘      要：强酸性盐渍水稻土在我国主要发育于南海沿岸各大河流的入海河口的酸性沉积物上。因那里过去曾遍长红树,由于海陆变迁而被沉积物所复盖,因此土壤剖面中普遍有红树埋藏层,其所含硫化物为当地地带性土壤的10—20倍。这类土壤含有大量水溶性硫酸盐和氯化物,且以铝盐为主。其硫酸根为红树分解的产物,氯离子来源于海水,当它们作用于酸性土壤物质以后,就使大量铝离子进入土壤溶液。因此,强酸性盐渍水稻土的形成是与红树林的埋藏、海水的浸渍及其作用于酸性土壤物质等因素密切相联系。强酸性盐渍水稻土的发育主要决定于红树埋藏层在剖面中的位置以及红树残体的分解程度。S层埋藏愈深,红树残体分解愈彻底,其对水稻的生长影响也愈小。反之,则影响大。强酸性盐渍水稻土的改良,应开深沟,利用潮水灌溉以充分洗盐,加厚复盖层,以免下层土壤盐分上升,经常保持水层以防止土壤“反酸;由于土壤含有大量游离酸,所以石灰必须接近插秧时施用,实践证明施用磷矿粉有显著的增产作用。