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1.华南的石灰化水稻土是具有石灰结核或石灰硬盘的一种低产水稻土。主要分布在华南有长期施用石灰习惯的农地,每造水稻产量每亩仅120—200多斤。2.石灰化水稻土中碳酸钙含量可高达10%以上,碳酸盐组成中,以碳酸钙占绝对优势,碳酸钙与碳酸镁的比例可高达30以上。碳酸盐在剖面中的分布,随深度增加而减少,一般以耕层含量最高,而石灰结核则以石灰板结层最多,这和一般干旱区域的钙成土和亚热带地区的石灰性土壤不同。3.石灰化水稻土的形成,主要是由于长期而过量地施用石灰的结果。土中有机质含量少,土壤渗漏差和耕作粗放,更引起石灰的聚积,形成石灰板结田。4.根据三个石灰化水稻土中碳酸钙的含量计算,1米土层内每亩含石灰约三万至五万多斤,如每年每亩土壤聚集100斤石灰,则须连续施用石灰340—540年。5.石灰化水稻土,可作为华南水稻土的一个亚类划分出来。防止水稻土的石灰化,应注意有机肥料的配合使用,在轮作中插种绿肥也是有效的措施。
1. South China’s calcareous paddy soil is a low-yielding paddy with limestone or lime hard disks. Mainly distributed in southern China have long-term use of lime habitat, each made only 120-200 kilos of rice per mu. 2. The content of calcium carbonate in calcareous paddy soil can be as high as 10% or more. Calcium carbonate accounts for the absolute superiority in the carbonate composition, and the ratio of calcium carbonate and magnesium carbonate can be as high as 30 or more. The distribution of carbonate decreases with depth, generally the highest content of tillage, while the limestone nodules have the largest amount of calcareous layer, which is different from calcareous soil and calcareous soil in the subtropical area in general arid area. 3. The formation of calcareous paddy soil is mainly due to the long-term and excessive application of lime. Less soil organic matter content, poor soil seepage and tillage farming, but also caused the accumulation of lime, the formation of lime plate junction field. 4. Calculated according to the content of calcium carbonate in three calcareous paddy soils, about 30,000 to 50,000 kilos per acre of lime in 1 meter of soil layer. If 100 kg of lime are gathered per acre of soil per year, lime 340 540 years. 5. The calcareous paddy soil can be divided into a sub-category of paddy soil in South China. To prevent the limeification of paddy soil, should pay attention to the use of organic fertilizers, in the rotation of green manure is also an effective measure.