Greenhouse agriculture has become vitally important in promoting sustainable food supplies globally, especially by encouraging local production and consumption practices. However, it also represents an industry with a high risk for groundwater pollution due to much higher application limits allowed for nitrogen fertilizers compared to conventional agriculture. Although sufficient focus has been placed on characterizing any environmental impacts stemming from agriculture, including greenhouses, the influence of social, economic and political aspects on this process are generally overlooked. This one-sided focus may be partly due to the complexity of environmental systems, i.e. in measuring the state of the system accurately. However, any actions taken by a government, i.e. in the form of policy instruments, will play a key role in ensuring the safety and quality of agricultural products and the surrounding environmental systems. Insufficient knowledge regarding policy and related influential factors may thus slow the achievement of the UN Sustainable Development Goals and ultimately inhibit environmental protection. In light of this, a cross-national comparative study was carried out to enable a systematic understanding of Chinese and Danish greenhouse agriculture policy using the agro-environmental DPSIR (Driver, Pressure, State, Impact, Response) indicator framework. We critically examined whether current legislative steps for mitigating anthropogenic sources of N-pollution are suitably aimed at the parameters controlling (driving) specific pressures/impacts on groundwater. The potential for reaction (feedback/responses) within each legislative system, as well as the key gaps in policy responses for monitoring both water and N-fertilizer applied in greenhouses were identified. Notably, most responses are found to target only the pressure component of the framework. This discovery opens the door for the development of additional response mechanisms, which together could result in more sustainable policy measures for greenhouse agriculture that may be more effective, more quickly. Although many countermeasures exist for control of land, water and fertilizer use at the national level in both countries, their deployment depends heavily on effective stakeholder engagement and local-level adoption strategies, indicating a more holistic and multi-objective (less fragmented) policy approach is needed. Importantly, this paper demonstrates an alternative implementation of the DPSIR framework, where comparative study applications may be used to enable mutual learning that may enhance the uptake of disruptive solutions (technological and/or policy advancement), recognizing that incremental change may not be cost-efficient or sustainable especially for regions with critical water issues.