Effects of Straw Mulching on Soil Properties and Enzyme Activities of Camellia oleifera- Cassia Intercropping Agroforestry Systems

Huizhen Duanyuan; Ting Zhou; Zhe He; Yuanying Peng; Junjie Lei; Jieyu Dong; Xiaohong Wu; Jun Wang; Wende Yan

doi:10.3390/plants12173046

Effects of Straw Mulching on Soil Properties and Enzyme Activities of Camellia oleifera- Cassia Intercropping Agroforestry Systems

Plants (Basel). 2023 Aug 24;12(17):3046. doi: 10.3390/plants12173046.

Authors

Huizhen Duanyuan¹, Ting Zhou², Zhe He¹, Yuanying Peng³, Junjie Lei¹, Jieyu Dong^{1

4}, Xiaohong Wu¹, Jun Wang¹, Wende Yan¹

Affiliations

¹ National Engineering Laboratory for Applied Technology in Forestry and Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China.
² China International Engineering Consulting Corporation, Ecological Technical Research Institute, Beijing 100085, China.
³ College of Arts and Sciences, Lewis University, Romeoville, IL 60446, USA.
⁴ Key Laboratory of Subtropical Forest Ecology of Hunan Province, Changsha 410004, China.

Abstract

In order to explore the influences of rice straw mulching on soil fertility in agroforestry systems, the soil C and N contents and enzyme activities were investigated in a C. oleifera-cassia intercropping ecosystem in Central Southern China. Three straw mulching application treatments were set up in this study, in 2021, namely, straw powder mulching (SPM), straw segment mulching (SSM), and non-straw mulching as the control (CK). Soil samples were collected from three soil depths (0-10 cm,10-20 cm, and 20-40 cm) in each treatment on the 90th-day after the treatments. The soil organic carbon (SOC), total nitrogen (TN), microbial carbon (MBC), soil enzyme activities (including acid phosphatase (ACP), urease (UE), cellulase (CL), and peroxidase (POD)), and soil water content (SWC) were determined. The results showed that the SOC significantly increased due to the mulching application in SPM and SSM, in the topsoil of 0-10 cm when compared to the CK. The SWC, SOC, TN, and MBC increased by 0.8 and 56.5, 3.5 and 37.5, 21.3 and 61.6, and 5.8% and 76.8% in the SPM and SSM treatments compared to the CK, respectively. The soil enzyme activities of ACP, UE, CE, and POD increased significantly due to straw mulching compared with CK throughout all soil layers. The soil enzyme activities of CL and POD were significantly higher in SSM than in SPM across the soil depth except for ACP. The enzyme activities of ACP were 14,190, 12,732, and 6490 U/g in SSM, SPM, and control, respectively. This indicated that mulching application enhanced the enzyme activity of ACP. Mulching had no significant effects on UE and CL, while the POD decreased significantly in the order of SPM > SSM > CK across all soil layers, being, on average, 6.64% and 3.14% higher in SSM and SPM, respectively, compared to the CK plots. The SOC and MBC were the key nutrient factors affecting the soil enzyme activities at the study site. The results from this study provided Important scientific insights for improving soil physicochemical properties during the management of the C. oleifera intercropping system and for the development of the C. oleifera industry.

Keywords: Camellia oleifera; intercropping; soil enzyme activity; soil property; straw mulching.

Grants and funding

This study was supported by the Joint Funds of the National Natural Science Foundation of China (U21A20187), the National Natural Science Foundation of China (42007383), the Hunan Water Conservancy Science and Technology Project (XSKJ2022068–35), the Postgraduate Scientific Research Innovation Project of Hunan Province (CX20220698), and the Outstanding Youth Foundation of Hunan Province (2020JJ3064).