GEOGRAPHICAL RESEARCH ›› 2021, Vol. 40 ›› Issue (3): 657-672.doi: 10.11821/dlyj020200849

• Sustainable Utilization of Cultivated Land in Oasis • Previous Articles     Next Articles

Effect of cultivated land reclamation tracks on soil fertility changes in Changji Prefecture, Xinjiang

XU Yongmei1(), ZHOU Liming2, ZHANG Zhaotong3,4()   

  1. 1. Institute of Soil, Fertilizer and Agricultural Water Reduction, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
    2. Agricultural Technology Extension Center of Changji City, Changji 831100, Xinjiang China
    3. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    4. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-09-04 Accepted:2021-02-09 Online:2021-03-10 Published:2021-05-10
  • Contact: ZHANG Zhaotong E-mail:xym1973@163.com;zhangzt.19b@igsnrr.ac.cn

Abstract:

It is meaningful for guiding regional agricultural fertilization management measures and improving farmland soil fertility to quantitatively describe the impact of cultivated land reclamation tracks on soil fertility changes at a regional scale. This study identified the cultivated land reclamation tracks by superimposing multiple periods of land use data based on a large number of sample data in 1980 and 2018, to analyze the effects of initial land use and soil types and cultivation years on soil fertility changes in Changji Prefecture, Xinjiang. The result were as follows: (1) Among the current cultivated land in 2018, 90.12% of the original land type was grassland, and 9.88% of the original land type was unused land. The content of other soil fertility indexes increased except for the decrease of available nitrogen (AN) content. Except for soil organic matter (SOM), the spatial variability of other indicators increased. (2) The SOM content reduced because of the reclamation of high-coverage grassland. The reclamation of grassland and unused land would reduce AN content. (3) With the increase of cultivation years, SOM showed a slow increase and gradually stabilizes; while the available nutrient content increased in a short period of time, and stabilized or began to decrease after reaching a certain number of years because of the threshold effect. (4) The loss of SOM caused by grassland reclamation gradually recovered after the cultivation period reached the medium-long term. The SOM content of current cultivated land that the original land type was unused land was always positive. The loss of AN caused by reclamation of grassland and unused land had not been recovered after 38 years of cultivation. (5) The plots with the initial soil types of meadow soil and shrub desert soil had higher nutrient content, and brown calcium soil and gray desert soil had lower nutrient content. The SOM content of current cultivated land that the original soil type was meadow soil decreased. Therefore, it is recommended that the application ratio of fertilizer should be reasonably adjusted, and the potassium fertilizer should be increased. In addition, nitrogen fertilizer should be applied in low intensity and high frequency.

Key words: Changji Prefecture,Xinjiang, land reclamation track, soil fertility, land use type