Effects of Irrigation with Domestic Wastewater on Productivity of Green Chili and Soil Status

Abstract

Experiments were designed to determine the effect of untreated wastewater (T1), phytoremediated wastewater (T2), and rainwater (T3) irrigation on Capsicum annuum and soil. Morphological parameters of plants and accumulation of metal and nutrients in crop and soil were studied. The biomass of C. annuum was greatest under T1 followed by T2 and T3. Root/shoot ratio decreased in the order T3 > T2 > T1 (P ≤ 0.05), indicating lengthening of roots under nutrient stress. There was a significant increase in the nutrient [nitrate (NO₃ ⁻), phosphate (PO₄ ³⁻), potassium (K⁺), magnesium (Mg⁺⁺), and calcium (Ca⁺⁺)] content of the soil after harvest under T1 and T2. The metal accumulated by the plant in μg g⁻¹ of dry weight was in the order zinc (Zn) > copper (Cu) > chromium (Cr). The percentage accumulations of metals by the plant out of total applied were only 1–5% for Cr and Cu and 14% for Zn, and the remaining was left in the soil. There was no metal accumulation in fruits.

Keywords:

• Domestic wastewater
• fertigation
• irrigation
• plant growth

Acknowledgments

The authors are thankful to P. K. Sen, Indian Institute of Technology, Delhi, India, and P. A. Davies, Aston University, Birmingham, UK, for providing technical and financial support through EPSRC, a UK-funded project (Grant No. EP/E044360/1). Helpful advice from Phil Harris, Coventry University, UK, is gratefully acknowledged. Also the support given under a project (RPO1845) from Department of Land Resources, Ministry of Rural Development, Government of India, is gratefully acknowledged.