Effect of Treated Wastewater Irrigation Combined with Manure and Inorganic Nutrients on Fodder Yield and Proximate Parameters of Bajra Napier Hybrid Grass in Cauvery Delta Region of Tamil Nadu

Aim: In arid and semi-arid areas recycling of water may have a greater impact on future usable water supply than any of the other technologies aimed for increasing water supply. Efforts have been taken on maximizing the benefit and minimizing the detrimental effects on people or the environment due to continuous usage of treated wastewater. Hence, the current experiment was aimed to study the effect of treated wastewater in combination with organic and inorganic nutrients on bajra napier hybrid grass on yield and quality parameters.

Study Design: The field experiment was conducted using secondary treated wastewater, manure and inorganic nutrients in Bajra Napier hybrid grass variety CO(BN) 5 with a strip plot design and four replications.

Place and duration of study: The experiment was conducted in Veterinary College and Research Institute, Orathanadu, Thanjavur, Tamil Nadu, during 2018-19 (10.62ᵒ N latitude and 79.26ᵒ East longitude).

Methodology: The five ratios of irrigation water were used in horizontal factor treatments and four different nutrient combination treatments were allotted in the vertical factor. The plot was divided into 27 m2 with 2 m space between the plots. The two budded setts of bajra napier hybrid grass variety CO (BN)-5 were planted at 60 x 50 cm spacing. The flood irrigation and nutrients (basal and top-dressing) were applied as per the treatments.

Results: The use of treated wastewater for irrigation combined with manure and inorganic nutrients significantly increased the total green and dry fodder yields. Irrigation treatment with treated wastewater alone + 100% inorganic nutrients (I5N1) recorded significantly higher total green and dry fodder yields of 431.0 and 76.7 t ha-1 yr-1, respectively, than all other treatment combinations. Irrigated with groundwater alone (control) without nutrients (I1N4) recorded the lowest total green and dry fodder yields (222.5 and 47.6 t ha−1 yr-1, respectively). The average crude protein content of all total cuttings was significantly higher (13.53%) in I5N1 than all other treatments. On the other hand, the average crude fibre content (28.03%) was significantly lower in the treatment I5N1 as compared to irrigated with groundwater without nutrients (31.18%).

Conclusion: The perennial fodder crop Bajra Napier hybrid grass variety CO (BN) 5 cultivated under-treated wastewater combined with manure and inorganic nutrients increased the total green and dry fodder yields with beneficial proximates. The use of treated wastewater for fodder cultivation helps conserve groundwater and effectively utilize available nutrients in treated wastewater.