The desert oasis in the arid area is a crucial agricultural production base in northwestern China, and converting the desert into farmland is the main reason for its continuous expansion. 

However, the effects of long-term conventional farming practices on soil carbon and nutrient pools after desert reclamation are still unclear in arid oasis farmland. 

A research team from Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS) investigated carbon and nutrient storage in farmland soil in Zhangye Oasis with different reclamation ages. 

Researchers used regression analysis to reveal patterns of change in carbon and nutrient storage over conventional farming years, as well as analyzed the key factors influencing these storage levels using a random forest model. 

The study was published in Geoderma on Apr. 21. 

It was found that the soil carbon pool in the 0-40 cm layer expanded by 4.2 times after desert reclamation, while nitrogen and phosphorus stocks increased by 1.2-6.5 times. 

However, regression analyses showed an exponential pattern of change in both carbon and nutrient stocks with farming years.  

Moreover, the stocks of carbon and nitrogen in the 0-40 cm soil layer, as well as phosphorus stocks in the topsoil layer, stopped increasing after 60 years of conventional cultivation.  

The study found that soil stoichiometry, pH, and mechanical composition were the key factors affecting carbon and nutrient pools in oasis farmland.  

This study highlighted that despite significant improvement in soil quality after desert reclamation, the long-term effectiveness of this improvement is limited by conventional management practices.  

Therefore, the conventional management system of oasis farmland in arid regions should incorporate appropriate conservation tillage measures to ensure sustainable soil production. 

Contact: 

HE Zhibin 

E-mail: hzbmail@lzb.ac.cn