Kong Jun Qia, DU Ze Yu, Yang Rong, Su Yong Zhong
Linze Inland River Basin Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
University of the Chinese Academy of Sciences, Beijing 100049, China.
Ying Yong Sheng Tai Xue Bao. 2019 Jan 20;30(1):180-188. doi: 10.13287/j.1001-9332.201901.037.
The reclamation time was examined by combining field investigation and remote sensing image analysis in the Linze desert oasis area in the middle of the Hexi Corridor. Characteristics of soil organic carbon storage (SOCD) in cropland (0-20 cm) with different reclamation backgrounds were compared to understand the evolution trend of SOCD during reclamation. The SOCD of cropland (0-20 cm) varied from 2.41 to 32.97 t·hm, with an average of 17.22 t·hm. The ave-rage SOCD of cropland in saline-alkali land, Gobi and sandy land background was 19.36, 16.10, and 15.93 t·hm, respectively. The SOCD under three different reclamation conditions showed an increasing trend after cultivation. The cropland in sandy land and the Gobi background slowly increased after 20 years reclamation. The cropland in saline-alkali background showed a slowdown after 25 years reclamation. The SOC sequestration rates of the cropland under sandy land, Gobi and saline-alkali land background were 0.424, 0.485 and 0.811 t·hm·a, respectively. The SOCD were positively correlated with total nitrogen, total phosphorus, available nitrogen, and available phosphorus content, but had no significant correlation with available potassium and soil pH. In conclusion, the SOC sequestration rate in the saline-alkali land background was significantly higher than that in Gobi and sandy land background. However, SOCD were at a relatively low level after 30 years reclamation. Therefore, cropland management needs to be carried out for different reclamation backgrounds to improve land use efficiency and productivity in desert oasis.
通过野外调查与遥感影像分析相结合的方法，对河西走廊中部临泽荒漠绿洲区的开垦时间进行了考察。比较了不同开垦背景下农田（0-20厘米）土壤有机碳储量（SOCD）的特征，以了解开垦过程中SOCD的演变趋势。农田（0-20厘米）的SOCD在2.41至32.97吨·公顷之间变化，平均为17.22吨·公顷。盐碱地、戈壁和沙地背景下农田的平均SOCD分别为19.36、16.10和15.93吨·公顷。三种不同开垦条件下的SOCD在开垦后均呈增加趋势。沙地和戈壁背景下的农田开垦20年后缓慢增加。盐碱地背景下的农田开垦25年后增速放缓。沙地、戈壁和盐碱地背景下农田的SOC固存率分别为0.424、0.485和0.811吨·公顷·年。SOCD与全氮、全磷、碱解氮和有效磷含量呈正相关，但与速效钾和土壤pH无显著相关性。综上所述，盐碱地背景下的SOC固存率显著高于戈壁和沙地背景。然而，开垦30年后SOCD处于相对较低水平。因此，需要针对不同的开垦背景进行农田管理，以提高荒漠绿洲的土地利用效率和生产力。
