Growth, Biomass Production, and Nutrient Composition of Eucalyptus Seedlings Irrigated with Municipal Effluent in Loamy Sand Soil of Indian Desert

Abstract

An experiment comprised of five treatments [T₁ = municipal effluent @ 1 PET (without plant), T₂ = municipal effluent @ (1/2) PET, T₃ = municipal effluent @ 1PET, T₄ = municipal effluent @ 2 PET, and T₅ = good (canal) water @ 1 PET] was carried out with Eucalyptus camaldulensis. The aim was to utilize sewage water in growing tree plantation and to increase the supply of fuel wood to the growing urban population. Height, collar diameter, and number of branches were monitored periodically. Biomass and leaf and root growth were recorded at 24 months of age. Mineral composition and uptake were monitored to observe their removal from the soil. Increase in rate of municipal effluent application was associated with better tree growth compared to irrigation with canal water. At 24 month age, the T₄ was the best treatment in which E. camaldulensis attained 393 cm height and 6.6 cm collar diameter. Height and collar diameter of T₂ seedlings did not differ (P > 0.05) with respective parameters in T₅ treatment. Collar diameter increased by 1.2 times in T₃ treatment. Number of leaves and biomass increased with increase in quantity of municipal effluent. Modeling of total biomass against quantity of municipal effluent application produced better result with non‐linear fitting than the linear one. Mineral composition and accumulation in different parts of the seedling was high and varied with the quantity and nutrient composition of irrigation water. Concentration of total nitrogen (N), phosphorus (P), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) was high in the municipal effluent irrigated seedlings compared to the good water irrigated seedlings. However, sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) were high in the seedlings of T₅ compared to T₂ and T₃ treatments. Municipal effluent did not show any toxicity to the seedlings up to 24 months age. Conclusively, the municipal effluents could be recommended as a good source of water and nutrient for tree biomass production to fulfill the requirement of fuel need in the suburban area.

Keywords:

• Arid land
• Municipal effluents
• Nutrient accumulation
• Tree seedling

Acknowledgments

We wish to express our sincere thanks to the Director Arid Forest Research Institute for providing facilities to carry out research.