|
|
|
| Response and evaluation of soil enzyme activity to drip irrigation with brackish water and reclaimed water |
| WANG Yu1, LIU Chuncheng2-4*, LI Renjie1, ZENG Zhi5, CUI Bingjian2,4,ZHANG Fenghua1, YAN Mingli1, HU Chao2,4, MA Tian2,3 |
| 1. Xinxiang Hydrological and Water Resources Survey Bureau of Henan Province, Xinxiang, Henan 453000, China; 2. Institute of Farmland Irrigation of CAAS, Xinxiang, Henan 453002, China; 3. Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China; 4. Agriculture Water and Soil Environmental Field Science Research Station of Xinxiang City of Henan Pro-vince/Key laboratory of High-efficient and Safe Utilization of Agriculture Water Resources of CAAS, Xinxiang, Henan 453000, China; 5. China Railway Water Conservancy & Hydropower Planning and Design Group Co., Ltd., Nanchang, Jiangxi 330000, China |
|
|
|
|
Abstract In order to explore the reasonable utilization of brackish water and reclaimed water in areas with insufficient freshwater resources, three treatments were set, including reclaimed water irrigation(T1), mixed irrigation of 1∶1 with brackish water-reclaimed water(T2)and brackish water irrigation(T3), and local groundwater irrigation(CK2)was taken as the control, of which the saline degree of brackish water was 5 g/L. Based on the pot experiments, soil water content, soil salt content, soluble ions contents and soil enzyme activities including soil sucrase(S-SC), soil alkaline phosphatase(S-AKP/ALP), soil urease(S-UE)were measured. The responses of soil enzyme activities to the effect of brackish water and reclaimed water mixed irrigation was evaluated by the second generation integra-ted biological response(IBRv2)index method. The results indicated that: (1) with the increase of the proportion of brackish water in the mixture of brackish water and reclaimed water, the soil moisture content and salt content were higher. (2)The effects of mixed irrigation using brackish water-reclaimed water on soil enzyme activities were different. The soil alkaline phosphatase and urease activities under mixed irrigation were higher than brackish water irrigation and reclaimed water irrigation, and the soil sucrase activity was slightly lower than that of reclaimed water irrigation, but higher than that of brackish water irrigation. (3)Based on the IBRv2 index method, compared with CK, the deviation of enzyme activity caused by T1 treatment was the lowest, and the IBRv2 value was 2.12, followed by T2 treatment, the IBRv2 value was 2.42, and the highest deviation appeared in T3 treatment with the IBRv2 of 2.92. The activities of S-AKP/ALP, S-SC and S-UE were inhibited in T3 treatment. T2 treatment could induced the activity of S-AKP/ALP and S-UE, but slightly inhibited S-SC activity. T1 treatment induced the activity of S-AKP/ALP and S-SC, but slightly inhibited the activity of S-UE to a certain extent. Therefore, based on IBRv2, and considering soil enzyme activity and the limitations of reclaimed water resources such as large amount of reclaimed water resources and small daily discharge, reclaimed water and brackish water, it can be considered to used reclaimed water together with brackish water in arid and water shortage areas.
|
|
Received: 11 June 2021
|
|
|
|
|
|
|
