Influence of wastewater irrigation on nutrient profiles and heavy metal accumulation in warm-season turf grasses

Aim: The study aimed to evaluate the performance of warm-season turf grasses under different levels of wastewater irrigation, focusing on the growth parameters and heavy metal accumulation. Methodology: The research was conducted at the Division of Floriculture and Landscaping, ICAR- Indian Agricultural Research Institute, New Delhi, during 2022-23. Seven turf grass species were assessed under varying wastewater irrigation levels viz., T1 (Control), T2 (100% wastewater), T3 (75% wastewater+25% freshwater), T4 (50% wastewater + 50% freshwater) and T5 (25% wastewater + 75% freshwater). Growth metrics, biomass parameters, NPK content in the grass species were estimated. Additionally, the accumulation of heavy metals (Ni, Pb, Cu, Cr and Zn) were estimated in treated and control plants. Results: Stenotaphrum secundatum showed the highest fresh shoot and root weight gain under 50% wastewater irrigation, while the highest nitrogen and potassium content was recorded in Zoysia japonica. Heavy metal accumulation was most pronounced in 100% wastewater, particularly in Zoysia japonica for chromium and Cynodon dactylon var. Tif Dwarf – 419 for nickel, lead and copper. Interpretation: The study concludes that a 50:50 mix of wastewater and freshwater is optimal for warm-season turf grass growth, balancing plant development with minimal environmental risks. This mixture reduces freshwater use, supports sustainable water management, and enables turf grass to aid in phytoremediation of heavy metal-contaminated soils. However, higher wastewater concentrations elevated heavy metal accumulation, posing ecological and food chain risks. Key words: Biomass, Heavy metals, Sustainability, Turf grasses, Wastewater