Assessment of growth performance of striped catfish (Pangasianodon hypophthalmus) and yield of Guinea grass (Panicum maximum cv. Mombaça) under a biosaline integrated aquaculture-agriculture system

With freshwater scarcity and soil infertility being major challenges farmers face in arid and semi-arid regions, a biosaline-integrated aquaculture-agriculture system (IAAS) is key to diversifying yields with limited inputs in marginal areas. This research investigated the effect of varying brackish water salinities on the growth and yield of striped catfish (Pangasianodon hypophthalmus) and Guinea grass (Panicum maximum cv. Mombaça) in a biosaline-IAAS. The study followed a randomized completely block design under three replications of three aquaculture effluent salinity treatments and freshwater control, namely: 500 (control), 5000, 10,000, and 15,000 mg/L (i.e., CT, SM5, SM10, and SM15, respectively). Morphological plant parameters, forage quality and fish growth performance were evaluated. The plants were harvested in 3 consecutive cuts during the seven-month study period. The study results showed that the canopy height, leaf number, and tiller number decreased with the increasing number of cuts and salinity. At cut 3, the control significantly recorded higher values for canopy height, chlorophyll content, and tiller number per plant compared with other salinity treatments. Yield data showed no significant differences in stalk fresh and dry weights among the treatments at cuts 1 and 2, except for the control at cut 3. Results on forage quality parameters, such as neutral detergent fiber, acid detergent fiber, and acid detergent lignin, showed an increasing trend with the increasing number of cuts. Furthermore, the results also showed that plants irrigated with saline fish effluents exhibited lower values for crude protein compared with the control. Regarding in vitro digestibility, results revealed a general decrease in the in vitro true digestibility and digestible organic Matter percentages among salinity treatments with increasing cut numbers. For striped catfish, growth performance was affected when reared in water salinities exceeding 10,000 mg/L. The integration of striped catfish and Mombaca at water salinities not exceeding 10,000 mg/L could be a feasible alternative in diversifying food and feed production in marginal areas.