Meng Fan-qiao, Kuang Xing, Du Zhang-liu, Wu Wen-liang, Guo Yan-bin
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Huan Jing Ke Xue. 2010 Aug;31(8):1733-9.
In Quzhou County, Hebei Province where now intensive farming system is operated, original grassland and farming land under different tillage, crop straw return and fertilization measures were studied using isotope carbon for the analysis of the impact on soil organic carbon (SOC) properties. The research indicated that after change into farmland (34 years), SOC is significantly reduced and for 1 m of soil layer, the scope of reduction is from 13.3%-35% and this decrease happens in 0-40 cm of soil layer. After 8 years of fertilization, SOC can be increased at 0.83 g x kg(-1). No-tillage can significantly increase the SOC especially in 0-10 cm but plough will increase the SOC at 10-15 cm and 15-20 cm. Change of delta13 C of SOC due to land use change mainly happens in 0-20 cm, where input of organic materials from maize stored. In soil layer of 0-5 cm, only maximum 18% of SOC is from crop residues and in 15-20 cm, this percentage is about 5%.
在河北省曲周县（现采用集约化耕作制度），利用碳同位素研究了原始草地以及不同耕作、作物秸秆还田和施肥措施下的农田，分析其对土壤有机碳（SOC）特性的影响。研究表明，转变为农田（34年）后，土壤有机碳显著降低，对于1米土层，降低幅度为13.3% - 35%，且这种降低发生在0 - 40厘米土层。施肥8年后，土壤有机碳可增加0.83克×千克⁻¹。免耕可显著增加土壤有机碳，尤其是在0 - 10厘米土层，但翻耕会增加10 - 15厘米和15 - 20厘米土层的土壤有机碳。土地利用变化导致的土壤有机碳δ¹³C变化主要发生在0 - 20厘米土层，该土层储存着来自玉米的有机物质输入。在0 - 5厘米土层，土壤有机碳中来自作物残茬的比例最高仅为18%，在15 - 20厘米土层，这一比例约为5%。
