广东低塱渍水地区主要土壤理化性质及其利用改良

本文研究广东低塱渍水地区主要土壤理化性质及其利用改良。采取田间调查研究与分析化验相结合的办法,结果表明:水稻土的养分含量较高,如有机质、氮素和全钾量均较高,伹速效磷和钾均偏低,冲积土和堆叠土的养分含量则较低(全钾量除外);土壤阳离子交换量、活性铁、锰和有效锌含量均较高,符合一般作物的需要;耕层土壤多属强酸性,pH多为4.5～5.1;土壤质地偏粘(冲积土除外),粘粒含量达30～45％;土壤生态环境条件不良,容易发生涝害,生产没有保证。因此,土壤利用改良的主要措施应是:继续整治水利,改善土壤生态条件;适施石灰,每亩一造约施25kg,增施有机肥;增施磷、钾肥,特别要注意早造施磷肥,晚造施钾肥;在保证粮食生产的前提下,适当发展养鱼(塘与基的面积比例以3:2为宜)、种植甘蔗、花生和水果等经济作物。

THE PHYSIOCHEMICAL CHARACTERISTICS AND IMPROVEMENT OF THE MAIN SOILS IN WATERLOGGED AREAS OF GUANGDONG PROVINCE

This paper reports a study on the physiochemical characteristics of the main soils (Paddy soil, Alluvial soil, Stacked soil) in waterlogged areas of Guangdong province and their amelioration and utilization. The results, based on field survey and chemical analysis, showed that available phosphorus and potassium were deficient in the paddy soils though the total potassium, nitrogen and organic matter contents were generally high. However, nutrients except potassium were deficient in the alluvial soils and stacked soils. CEC, active Fe, Mn, and available Zn were in high levels. The pH values of the tilth fell into the range of 4.5-5.1. The soil texture except that of the alluvial soils, were all clayey, with a clay particle content of about 30%-45%. Because of the poor topographical conditions, the soils often suffered from waterlogging with resultant insecure yield. T?improve these soils, the following measures should be emphasized. Further improving the irrigation system and soil ecological conditions; applying lime at about 25kg/mu and farmyard manurej increasing the application of phosphorus and potassium fertilizers, particularly P fertilizer for early rice and K fertilizer for late rice; while ensuring grain production, to develop fish farming (2:3 is recommended for the ratio of the bank area to the water area of a pond) or the production of cash-crops such as sugarcane, peanut and fruits.