Gray and White Water Footprint Estimation in a Greenhouse Production

Abstract

Optimizing water use in agriculture is crucial for sustainable resource management and increased productivity. Water footprint analysis, which measures the total water used directly and indirectly throughout a product's life cycle, offers valuable insights for improving water management practices. This study investigated the gray and white water footprints of a greenhouses cultivation, bell pepper, under different conditions including misting and pot cover. Evapotranspiration rates were used to calculate water demand under various scenarios. Nitrate (NO3), potassium (K), and total phosphorus (TP) were monitored as key chemical parameters to calculate the gray water. Three scenarios including stringent (S1), normal (S2), and lenient (S3) are established based on water quality standards. The findings revealed that misting and covering pots significantly reduced the gray water footprint compared to non-misting or uncovered scenarios. The total gray water footprint for bell peppers under misting and covered conditions was 2976 m3/ton, while it reached 3968m3/ton under non-misting and uncovered conditions, this represents a reduction of nearly 33% due to the combined effect of misting and pot cover. Importantly, water quality standards also played a significant role, with stricter standards leading to a higher gray water footprint (e.g., a difference of 2655m3/ton between scenarios S1 and S3 under misting and covered conditions).The white water footprint, representing freshwater directly used for cultivation, also varied across different scenarios.

Keywords

• bell pepper
• gray water footprint
• greenhouse cultivation
• irrigation
• white water footprint