The objective of this work was to determine the temporal and spatial variations of soil respiration (Rs) in a greenhouse, as well as the factors causing them, in a soil covered with different mulching types and cultivated with cucumber (Cucumis sativus). Four mulching treatments were applied to a soil cultivated with cucumber: CK, conventional practice without mulch; FM, plastic film mulch; CM, combined mulch of plastic film with wheat straw; and SM, wheat straw mulch. Rs was measured by a soil respiration chamber connected to a portable infrared gas analyzer, and the differences of Rs between mulchings were evaluated. Rs was significantly lower in the control than in the treatments with mulch. In addition, Rs was higher in the position on the soil near plants (5.4 μmol CO₂ m^-2 s^-1) than in the positions between plants (4.7 μmol CO₂ m^-2 s^-1) and rows (3.9 μmol CO₂ m^-2 s^-1). Soil water content and temperature had an interacted effect on Rs. Cucumber root biomass and root vigor should also be incorporated as predictor variables for Rs in the succession crops, mainly for accurately estimating carbon cycling in agroecosystems in a greenhouse.

Soil respiration is an important component of the carbon cycle and is also recognized as one of the primary pathways that release CO₂ from the soil into the atmosphere in terrestrial ecosystems. Soil CO₂ flux resulting from soil microbial activity and root respiration is one of the major components of the total carbon flux in agro-ecosystems. However, the impact of agronomic practices such as mulching on soil respiration in greenhouses has been less thoroughly studied. Consequently, field experiments were conducted during the growing seasons of 2011 and 2012 in greenhouse to evaluate soil respiration and the biotic and abiotic factors that influence it in hot pepper cultivation under four types of mulch practices (without mulch, wheat straw mulch, plastic film mulch, and combined mulch with plastic film and wheat straw). Soil water content had an overriding influence on soil respiration in hot pepper culture during the growing season under mulching treatments in a greenhouse, whereas the influence of soil temperature was relatively less. Additionally, the study showed that root biomass and root vigor should also be incorporated as predictor variables for soil respiration under mulching in greenhouses.

Levying a water resources tax policy which is called ‘fee to tax’ is a regulation formulated by China to restrain and alleviate water poverty. To test the effect of the water resources ‘fee to tax’, this research employs a multistage dynamic difference-in-differences (DID) model to explore whether the implementation of the policy can help alleviate water poverty based on panel data from 2009 to 2019. The results indicate the water poverty in western China is significantly more serious than in other regions and the implementation of the water resources tax policy significantly alleviates water poverty (the sign of the policy is positive and significant at the 1% level) in China. Additionally, the mechanism effects suggest that the policy can effectively restrain water poverty by reducing groundwater exploitation and optimizing the water utilization structure. In terms of spatial heterogeneity, the effect of the water resources tax policy on alleviating water poverty is stronger in central and eastern regions than in western regions. The conclusions of this study may, to some degree, serve as a basis to scientifically guide the implementation of China's water resources ‘fee to tax’ policy and, thus, effectively improve the level of water resources management.

The River Chief System (RCS) in China plays a crucial role in addressing transboundary water pollution (TWP), which is vital for achieving the Sustainable Development Goal of "clean water." This study examines the static and dynamic effects of the RCS on TWP using a difference-in-difference-in-differences (DDD) model and manually collected RCS data from 104 counties between 2007 and 2020. The results show that the RCS significantly reduces chemical oxygen demand (COD) by 15.9% and ammonia nitrogen (NH₃-N) by 22.9% in border counties, though it has no notable impact on dissolved oxygen (DO). Additionally, RCS intensity contributes to a 13.8% reduction in COD. However, no sustained dynamic effects are observed for COD or NH₃-N reduction over time. Several robustness checks confirm the validity of these findings. Heterogeneity analysis indicates that the RCS’s impact is more pronounced in counties with higher economic development, upstream locations, lower initial pollution levels, and younger local government leaders. This study not only provides critical insights for water resource management in China but also offers international relevance for addressing TWP governance challenges in transboundary water bodies.

China’s water shortage is severe and has become one of the factors hindering economic growth. It is widely accepted that changes in water technology play a profound role in sustainable development. However, because water technology is embedded in water resources, it is difficult to clarify the effects of water technologies as a means of alleviating water scarcity to achieve sustainable development. The level of water technology can be measured by total-factor water efficiency. This study analyzes panel data from 2002–2018 using the stochastic frontier model and addresses water inputs and water technology by introducing the concept of water productivity into economic growth framework. We found that, with the introduction of water technology, the importance of water resources for economic growth increases; water inputs increase by 1%, and GDP increases by 0.349%. The progress of 1% water technology can drive 0.142% of GDP growth and have great potential as a water scarcity remedy for the economy. Due to lower prices, the substitution rate of water technology to water is six times that of water-to-water technology, which is very detrimental to water technology progress. In the short term, water technology can be policy-driven in water-scarce developing economies, and price-induced in the long term.

China is currently experiencing severe water scarcity issues in its agricultural production sector. To address this challenge, the Chinese government has taken steps towards implementing a nationwide reform in agricultural water pricing to accelerate the more sustainable management of the agricultural water resources sector. The present study adopted a multiple regression model to test four alternative irrigation water charging methodologies (charges based on ladder pricing, time, land area, and electricity) accompanied by supportive agricultural pricing policies to address the inherent conflicts between water conservation and agricultural development goals. This study focused on the Wei River Basin, which is recognized as a highly water-stressed region in China. This basin was chosen as a pilot area for comprehensive reform initiatives related to agricultural water pricing and served as the geographical scope for our research. Between June and July of 2022, we conducted comprehensive field surveys within the Wei River Basin, accumulating a dataset of 415 data points pertaining to the crop year of 2022. Our results showed that the ladder water price-based method exhibited remarkable potential in achieving substantial savings, with a minimum of 60.5239 m³/mu of irrigation water conserved for food crops and an impressive 67.8090 m³/mu for cash crops. However, regarding water-saving irrigation technologies, the estimation results indicated that electricity-based charging outperformed the other methods, resulting in an impressive 55.22% increase when ladder pricing served as the benchmark. In addition, regarding agricultural green production, the results for food crops and cash crops are different, with food crops being more sensitive to the ladder water price policies. Moreover, the results suggested that different water charging methods have significant heterogeneity effects from the perspective of the farmers’ scale, land fragmentation, and water price awareness capacity. This study forges an innovative path for water-stressed nations to execute agricultural water pricing reform and enhance agricultural production’s sustainable growth.