玛纳斯河流域绿洲棉田土壤有机碳和全氮含量及碳储量变化分析(英文)

Analysis on Variation of Soil Organic Carbon and Total Nitrogen Content and Carbon Storage in the Oasis Cotton Field of Manas River Valley

[目的]为了对绿洲棉田土壤有机碳、全氮的分布状况进行研究。[方法]以天山北坡玛纳斯河流域绿洲棉田为研究区，以弃耕地为对照，采用地统计学方法，研究连续23年种植棉花地的土壤0～30、30～60和60～100 cm土层土壤有机碳和全氮的分布特征。[结果]玛纳斯河流域绿洲棉田土壤有机碳、全氮含量呈垂直分布，且随着土壤深度的增加而降低，并且0～30 cm土层明显高于30 cm以下土层，土壤有机碳储量呈现增加的趋势；弃耕地土壤有机碳、全氮亦呈垂直分布，且随着土壤深度的增加而含量降低，有机碳含量差异明显，并且弃耕地土壤有机碳含量呈逐月下降趋势，而棉田土壤有机碳储量变化呈先减少后增加，即棉花生长初期，0～30和30～100 cm土层有机碳储量降低，到花期最低；而随着棉花进入生殖生长后期，有机碳储量呈现增加趋势；弃耕地有机碳储量因没有植株凋落物的输入而呈现逐月降低的趋势，二者有机碳含量差异明显。[结论]绿洲棉田土壤有机碳、全氮含量明显高于弃耕地，土壤有机碳储量呈现增加的趋势，且主要发生在0~30 cm土层，在30～100 cm土层中有机碳、全氮含量变化差异不大。

Objective] The research aimed to study soil organic carbon and total ni-trogen distribution in oasis cotton farmland. [Method] With the oasis cotton field of Manas River Val ey in Tianshan Mountains as the research area and abandoned farmland as a control, the distribution characteristics of soil organic carbon and total nitrogen content in the cotton field of Manas River Val ey in the last 23 years were investigated by using geographic methods. [Result] Presenting vertical distribution, cotton soil organic carbon and total nitrogen content in Manas River Val ey de-creased with the increase of soil depth, and those in 0-30 cm soil layer was sig-nificantly higher than those in soil layer of below 30 cm, while organic carbon stor-age showed the trend of increase. Also in vertical distribution, soil organic carbon and total nitrogen decreased significantly with the increase of soil depth, and soil organic carbon content in abandoned farmland decreased month by month. Howev-er, cotton soil organic carbon storage firstly decreased and then increased in the oasis cotton field that in the early growth of cotton, soil organic carbon in the layers of 0-30 and 30-100 cm decreased to the lowest in the bloom stage, and then or-ganic carbon increased with the reproductive growth of cotton into the later stages. However, due to no input of plant litter in the abandoned farmland, the soil organic carbon storage decreased month by month. There were significantly differences be-tween oasis cotton field and abandoned farmland in organic carbon contents. [Con-clusion] The soil organic carbon content and total nitrogen content in oasis cotton field were significantly higher than those in the abandoned farmland. The soil organ-ic carbon storage increased in the layer of 0-30 cm, while there was no significant change of soil organic carbon and total nitrogen content in the layer of 30-100 cm, which was consistent with the previous study on the distribution characteristics of soil organic carbon and total nitrogen content profile.