TY - JOUR

T1 - Effects of plastic and straw mulching on soil microbial P limitations in maize fields

T2 - Dependency on soil organic carbon demonstrated by ecoenzymatic stoichiometry

AU - Ma, Zizong

AU - Zhang, Xucheng

AU - Zheng, Bangyu

AU - Yue, Shanchao

AU - Zhang, Xuechen

AU - Zhai, Bingnian

AU - Wang, Zhaohui

AU - Zheng, Wei

AU - Li, Ziyan

AU - Zamanian, Kazem

AU - Razavi, Bahar S.

N1 - Funding information: This study was supported by the National Key Research and Development Program of China ( 2017YFD02018018 ), National Natural Science Foundation of China ( 40501332 ), Foundation of Key Laboratory of High Water Utilization on Dryland of Gansu Province ( HNSJJ-2019-02 ), Project of Promoting Agricultural Science and Technology Demonstration of Yangling ( 2018-GG-29 ), Natural Science Foundation of Shaanxi Province ( 2016JQ3005 ), and Fundamental Research Funds for the Central Universities ( 2452015046 ).

PY - 2021/4/15

Y1 - 2021/4/15

N2 - Mulching rain-fed farmland ecosystems changes the soil physicochemical properties, especially soil organic carbon (SOC), but the metabolic limitations of soil microorganisms after these changes are unclear. We established a long-term experiment in 2012 with three treatments: no mulch (CK), straw mulch (SM), and plastic film mulch (FM). In 2019 the soil enzyme activities were measured in five maize growing periods: planting time, six-leaf period, silking period, milk period, and physiological maturity. Extracellular enzymatic stoichiometry models were used to examine microbial metabolic limitations. The vector length and angle were employed to determine the C and N/P limitations of soil microorganisms. Compared with CK, the average SOC and total nitrogen (TN) contents were 9.7% and 7.8% higher under SM, respectively, in each period. The SOC, TN, and total phosphorus (TP) contents were 5.6%, 4.8%, and 2.8% lower under FM, respectively. Compared with CK, the C- and N-acquiring enzyme activities were 20.5% and 5.2% lower under FM, respectively. The alkaline phosphatase enzyme activities were 2.7% and 13.5% higher under SM and FM, respectively, than CK. Soil nutrients, pH, and temperature influenced the C and P limitations of soil microorganisms. The different P limitation responses under SM and FM were mainly due to SOM. The decomposition of SOC was a key source of soil available P. The soil hydrothermal conditions under FM accelerated the decomposition of SOC in the early years, thereby increasing the P limitation. However, long-term SM increased the SOC due to the annual input of straw and its decomposition released available P to alleviate the P limitation for microorganisms. Thus, the temperature, water, pH, and SOC affect the P limitation for microbes under mulching conditions, but the SOC content of alkaline soil in arid farmland is the main factor that leads to microbial P limitation.

AB - Mulching rain-fed farmland ecosystems changes the soil physicochemical properties, especially soil organic carbon (SOC), but the metabolic limitations of soil microorganisms after these changes are unclear. We established a long-term experiment in 2012 with three treatments: no mulch (CK), straw mulch (SM), and plastic film mulch (FM). In 2019 the soil enzyme activities were measured in five maize growing periods: planting time, six-leaf period, silking period, milk period, and physiological maturity. Extracellular enzymatic stoichiometry models were used to examine microbial metabolic limitations. The vector length and angle were employed to determine the C and N/P limitations of soil microorganisms. Compared with CK, the average SOC and total nitrogen (TN) contents were 9.7% and 7.8% higher under SM, respectively, in each period. The SOC, TN, and total phosphorus (TP) contents were 5.6%, 4.8%, and 2.8% lower under FM, respectively. Compared with CK, the C- and N-acquiring enzyme activities were 20.5% and 5.2% lower under FM, respectively. The alkaline phosphatase enzyme activities were 2.7% and 13.5% higher under SM and FM, respectively, than CK. Soil nutrients, pH, and temperature influenced the C and P limitations of soil microorganisms. The different P limitation responses under SM and FM were mainly due to SOM. The decomposition of SOC was a key source of soil available P. The soil hydrothermal conditions under FM accelerated the decomposition of SOC in the early years, thereby increasing the P limitation. However, long-term SM increased the SOC due to the annual input of straw and its decomposition released available P to alleviate the P limitation for microorganisms. Thus, the temperature, water, pH, and SOC affect the P limitation for microbes under mulching conditions, but the SOC content of alkaline soil in arid farmland is the main factor that leads to microbial P limitation.

KW - Ecoenzymatic stoichiometry

KW - Microbial metabolism

KW - Mulching measures

KW - Rain-fed agricultural ecosystem

UR - http://www.scopus.com/inward/record.url?scp=85101228049&partnerID=8YFLogxK

U2 - 10.1016/j.geoderma.2021.114928

DO - 10.1016/j.geoderma.2021.114928

M3 - Article

AN - SCOPUS:85101228049

VL - 388

JO - GEODERMA

JF - GEODERMA

SN - 0016-7061

M1 - 114928

ER -