The treatment performance and nutrient removal of a garden land infiltration system receiving dairy farm wastewater

• Garden land infiltration system was established in the vineyard to treat dairy farm wastewater.
• Subsurface drainage system was installed to enhance the treatment efficiency.
• Ryegrass was intercropped in the autumn as a catch crop for nutrient removal.
• The system is of high performance efficiency, good adaptability and low construction cost.

Livestock wastewater is a major source of agricultural non-point pollution. Land treatment system is appropriate for livestock sewage treatment due to its low construction cost and high treatment performance. In this study, a garden land infiltration system (GLIS) was established to treat dairy farm wastewater. Our main concern was nutrient removal and plant uptake when the system is in operation. The removal rates in the outflow water of suspended solids (SS), NH4+N, total N (TN), total P (TP), chemical oxygen demand (COD), and total organic carbon (TOC) were 86.1%, 78.0%, 78.2%, 94.6%, 76.8%, and 74.6%, respectively. Approximately 79.4–81.6 kg/ha of nitrogen and 9.1–13.1 kg/ha of phosphorus were removed from the system by ryegrass harvesting, which accounted for 14.5–14.9% and 17.0–24.6% of the TN and TP in the effluent, respectively. These results demonstrate that the system has the advantage of high performance efficiency and has the potential for greater nutrient removal by plant uptake. Therefore, a GLIS can be considered as a viable alternative for dairy farm wastewater treatment in rural areas.