RESUMEN
In the present scenario, waste management, especially agro-waste, is one of the major challenges. India is an agrarian country and the economy depends on agriculture and a huge amount of agro-wastes are generated. In this study, biochar was prepared from paddy straw and sugarcane bagasse and was used in the feed of genetically improved farm tilapia (GIFT) at 0.5% (w/w) basis to study its effect on growth and haematological parameters. An experiment was carried out in triplicate in 500-l capacity FRP tanks comprising two treatments and one control. Tanks were filled with inland saline soil to maintain 25-cm soil's bed and water with 12 ppt salinity. A total of 22 fish having an average length of 5.14 ± 0.07 cm and weight of 4.8 ± 0.05 g were stocked in each tank; the fish were fed at apparent satiation level, twice daily for 45 days. It was observed that growth parameters like SGR% (specific growth rate), weight gain (WG%), and feed conversion ratio (FCR) were significantly improved (p < 0.05) than the control. Biochar-enriched feed also significantly improved the haematological parameters like red blood cell (RBC), white blood cell (WBC), haemoglobin (Hb) haematocrit % (HCT), mean cell haemoglobin concentration (MCH), and MCV (mean cell volume) in treatment groups than the control. Feeding biochar as feed additives was also found to decrease catalase (CAT) and enhanced amylase and lipase activities in treatments as compared to control (p < 0.05). It can be concluded that the application of biochar as a feed additive enhanced the growth and overall health of the fish, and it can enhance fish production. However, biochar from sugarcane bagasse was found to be more effective than the paddy straw biochar in the diet of tilapia (GIFT).
RESUMEN
The current study, which lasted 45 days, was designed to find a more effective way to use the vast resources of salt-affected land and ground saline water for aquaculture. Biochar made from agrowaste was used as a sediment amendment. The 100 g of biochar was applied to 25 kg of sediment (i.e., 9.0 ton ha-1) in 300L capacity fiber reinforced plastic, and Penaeus vannamei (P. vannamei) (2.74 ± 0.03 g) was stocked at 90 juveniles m-2 in inland ground saline water of salinity 10 ppt fortified with potassium levels that are 50% equivalent to those of seawater. Among different treatments, T1 indicates paddy straw biochar (PSB) application in sediment; T2 indicates sediment amended with KOH-activated PSB; T3 indicates sugar cane bagasse biochar (SBB) application in sediment; and T4 indicates sediment amended with KOH-activated SBB. Compared to the control the potassium (K+), alkalinity, total hardness, calcium/magnesium ratio, and pH of the water increased significantly (P ≤ 0.05) in treatments where biochar was used as an amendment in sediment. The T3 treatment had the best Ca/Mg ratio (1.00:3.12). In water, the magnitude of increase in K+ concentration from high to low followed the order: T2 > T4 > T1 > T3 > control. The concentration of NH4+-N in water was found to be increasing in control, whereas in the rest of the treatments, it decreased significantly from day 1, until the end of the experiment. Compared to control, the bulk density was decreased, and sediment cation exchange capacity and water holding capacity were increased significantly in treatments where biochar was used as an amendment. The soil microbial parameter measured in terms of soil enzyme dehydrogenase was significantly different among treatments at the end of the experiment. Weight gain (%), specific growth rate (SGR), survival (%), and feed conversion ratio of P. vannamei varied significantly in T1, T2, T3, and T4 compared to the control. The SGR (2.38b ± 0.05% day-1) and weight gain (%) in T2, and survival (96.1b ± 2.0%) in T3 treatment were found to be the highest at the end of the experiment. When biochar was mixed with sediment in the inland saline system, an improvement was seen in sediment quality, water quality, and growth characteristics of P. vannamei.