Efficient utilization of sewage water for improving the forage yield and quality of bajra-napier hybrid grass

Abstract

Field experiments were conducted at Agricultural College and Research Institute, Madurai to compare the effect of sewage effluent on yield and quality of Bajra Napier hybrid grass with two irrigation sources viz.. ordinary water (1,) and sewage effluent (1) as main plots and four N levels viz, 0, 50, 75 and 100 kg N ha-1 as sub plot treatment in a split plot design with three replications. BN 2 grass was grown as a test crop. Among the different levels of N, application of 100 kg N ha-1 recorded the highest green fodder (303 t ha-1). dry matter (61 ha-1) and crude protein (5.26 t ha-1) yield. Sewage effluent irrigation increased the green fodder, dry fodder and crude protein yield. The interaction effect between sewage effluent irrigation and N showed that 100 kg N ha with sewage effluent irrigation recorded the highest green fodder yield of 357 t ha-1, dry matter yield of 72 t ha-1 and crude protein yield of 6.37 tha. Sewage water irrigation showed increased total K, Ca, Fe, Mn and Zn content in BN 2 grass. The oxalic acid content was within the safe limit at all the levels of N tried (2.04- 2.08%) and with sewage effluent irrigation (2.14-2.61%). A decrease in crude fibre content was observed due to the increased addition of N at both the source of irrigation because of involvement of N in protein synthesis and consequent reduction in carbohydrate, ultimately leading to better digestibility of the grass.