摘要
根据野外采样分析、调查及田间试验结果，讨论了红壤区土壤有机质含量的变异规律及影响因素，分析了红壤有机碳的循环和平衡状况，初步探讨了红壤有机质含量变化及其与土壤肥力退化的关系，并根据红壤区有机物质资源特点提出合理利用的途径和措施。红壤区农田土壤有机质的平均含量低于东北黑土平原区、长江中下游平原区和珠江三角洲平原区，而高于黄淮海平原区以及黄土高原区；包括自然因素和人为因素所造成输入土壤的有机物质量的差异，是红壤有机质含量变化的主要原因。红壤中有机物料的腐殖化系数在０．１５～０．５５之间，物料的化学组成、土壤质地、土壤酸度、土地利用方式、原土有机质含量等是影响腐殖化系数的重要因素，瘠薄红壤中有机物料的腐殖化系数比一般红壤中要高４１％；红壤水田有机碳的年矿化率为２．４％～３．２％，有机碳含量越高，矿化率越大；总的来说，红壤耕地，特别是低产水田和旱地的有机碳库处于亏缺状态。退化红壤的有机碳含量大多＜８．７ｇ／ｋｇ，全剖面有机碳储量仅为熟化旱地红壤的４０％左右；其腐殖质组成中ＨＡ／ＦＡ比值较小，胡敏酸的Ｅ４值也较小；退化红壤不仅有机碳含量低，有机碳的循环水平也较低，并且呈现输入量小于分解输出量的特点；由于水土流失，每年?
On the basis of sampling analysis, investigation and field experiment results, this paper discussed the variation and its affecting factors of soil organic carbon content in red soil region, dealt with the cycling and balance characteristics of soil organic carbon, primarily elucidated the relationships between soil organic carbon and soil fertility degradation, proposed the rational measures and ways of organic material use according to regional condition. The mean soil organic carbon content in farmland of red soil region was lower than that in phaeozem plain(the black earth plain of northeast China), middle-lower reaches of Yangtze river and delta region of Zhujiang river, higher than that in Huang huai hai plain and loess plateau; the major causes resulting in the variation of soil organic carbon content were the different inputs of organic materials to soils resulting from different natural condition and human activity. The humification coefficients of organic materials in red soil were 0.15～0.55, which varied with chemical composition of organic materials, soil texture, soil acidity, landuse patterns, and natural soil organic carbon content, infertile red soil having a value 41% higher than that in common red soil; red soil organic carbon in rice field had annual decomposition rates of 2.4%～3.2%,the higher the soil organic carbon content, the greater the decomposition rate; in general, organic carbon pool of red soil farmland, especially in rice field with low yield and in upland farmland, was in a deficit state. The degraded red soil was characterized by less than 8.7g/kg of organic carbon content,Only about 40% of soil organic carbon storage in whole profile of upland soil with high fertility, little HA/FA ratio and E 4 value of humic acid, low cycling level of organic carbon with characteristic of lower input than output, and high loss of organic carbon by runoff. The soil organic carbon content of rice field would be increased with a moderate application of organic manure. At present, organic materials in red soil region are in a state of insufficient application, uneven distribution, low input to upland soil and infertile rice field. Therefore,applicable techniques ought to be developed for application of organic manure in rice field; and intercropping and rotation of trees and crops, intercropping of crops and green manure, semi-zero tillage, and ways of decreasing the runoff should be applied for increase of upland soil fertility.
出处
《长江流域资源与环境》
CAS
CSCD
1998年第2期140-147,共8页
Resources and Environment in the Yangtze Basin
基金
国家"九五"攻关专题
中国科学院网络项目
关键词
红壤区
土壤
有机碳
平衡
土壤资源
资源利用
red soil region,soil organic carbon,cycling and balance,organic resources, utilization
