摘要
通过长期田间试验 ,观测不同恢复利用模式下物质循环和瘠薄红壤中有机碳、全氮的积累特征。结果表明 ,不同的恢复利用模式下植物生物量、有机质归还量以及氮素平衡状况都有明显差异。如果林粮轮作处理配合合理施肥 ,可使地上部植物生物量达到纯林处理的 75 %～ 10 0 %水平 ,有机质的归还量相当 ,氮素处于盈余状态 ,系统的稳定性较高 ,作物的生产力不断增加。不同模式利用 11年后 ,纯林处理表层土壤有机碳含量水平达到 14～ 16g·kg-1,全氮含量达到 1g·kg-1以上 ;林粮轮作处理的相应值为 9～ 11g·kg-1和 0 .6～ 0 .9g·kg-1;常规耕作处理为 7g·kg-1以下和 0 .6 g·kg-1以下 ;这分别是目前较高熟化程度、中等肥力、低肥力红壤旱地的含量水平。采用较合理的种植模式和施肥措施 ,瘠薄红壤或低肥力红壤的肥力可在 10年左右时间恢复到中高度熟化水平。因侵蚀造成大量损失可能是旱地红壤的有机碳和全氮含量长期得不到提高的重要原因。瘠薄红壤恢复利用后有机碳的积累量大大增加 ,表明其在固持大气CO2 和减缓全球气候变暖趋势上具有巨大的潜力。
A long term experiment of 11 years was conducted at the Ecological Experimental Station of Red Soil, Chinese Academy of Sciences to investigate the characteristics of material cycling and C, N accumulation in infertile red soil under different treatments of rotation systems. Plant biomass, amount of organic materials returned to soil, budget of nitrogen in soil were obviously different under conventional cultivation, coverage by shrubs (Lespedeza formasa), rotation of shrubs (Lespedeza formasa) and crops (Peanut buckwheat). Rotation of shrubs and crops and combined with rational fertilization would has 75%-100% of biomass and similar amount of organic materials returned to soil as compared with that of coverage by shrubs, more input than output of nitrogen, high system stability, and increasing crop productivity. With distinct material cycling, different treatments of rotation systems influenced discriminatingly soil fertility. Soil organic carbon and nitrogen were respectively less than 7 g·kg -1 and 0.6 g·kg -1 by conventional cultivation, 9-11 g·kg -1 and 0.6-0.9 g·kg -1 by rotation of shrubs and crops, 14-16 g·kg -1 and more than 1 g·kg -1 by coverage of shrubs after 11 years, which represent low, middle and high levels of upland red soil fertility at current situation. It implies that with application of cultivation system and fertilization measures, the infertile red soil can be made into a soil with medium to high fertility in about 10 years rational utilization. Comparison of results from different treatments showed that a large loss of organic carbon and nitrogen caused by soil erosion resulted in a low level of C and N in upland red soil. It was suggested that increasing carbon storage in infertile red soil would sequester a great number of atmospheric CO 2 and mitigate the global warming potentially.
出处
《中国农业科学》
CAS
CSCD
北大核心
2002年第10期1236-1242,共7页
Scientia Agricultura Sinica
基金
国家自然科学基金重大项目 (3 98993 70 )
国家重点基础研究规划资助项目 (G19990 1180 1)
关键词
轮作
瘠薄红壤
碳
氮
积累特征
Red soil
Different rotation systems
C
N
