WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2026 59 FIGURE 6. Cost-sparing benefits of IAAS — a look at nitrogen fertilization. The complete elimination of the use of chemical fertilizers is not advisable in view of the delayed availability of nutrients to plants associated with the solid fraction of animal manures including fish culture solid wastes. However, a partial organic fertilization strategy of around 50% offers improved soil health, reduced nitrogen (N) losses and improved economic returns. Several studies have shown a 50% organic: 50% inorganic N fertilization strategy to yield near equivalent or better yields in irrigated plant crops (Tang et al., 2022; Salinas et al., 2024) and reduced N losses through nitrous oxide (N2O) and nitric oxide (NO) pathways while improving soil health and sustainability (Tang et al., 2022; Salinas et al., 2024; Wang et al., 2024). The economic rationale for IAAS is compelling. For example, a 49.4acre citrus farm applying 387.9 lbs urea/acre annually incurs costs of approximately US$6,194. Integrating a 46.7ton tilapia RAS unit could supply half the nitrogen requirement, reducing urea costs by US$3,097 (Figure 6). Comparable savings are achievable in apple orchards and vineyards (Tang et al., 2022; Salinas et al., 2024; Wang et al., 2024). Beyond Nitrogen: Broader Nutrient and Economic Gains While the above calculations focus on nitrogen, tilapia waste streams contain a full spectrum of macro- and micronutrients, further amplifying savings and soil health benefits. The broader agroecological and economic advantages of IAAS include: 1. Significant reductions in fertilizer costs and enhanced soil health through increased SOM loading. 2. Affordable aquatic protein production for local communities, potentially at a lower cost than broiler chicken using BFT tilapia aquaculture (Kourie and Dladla, 2022), using the same irrigation water. 3. Dual crop yields — fish and irrigated crops — from the same water supply, achieving the principle of “more crop with every drop” (Ahmed et al., 2014). Unlocking Aquaculture Potential Through IAAS Integration The integration of IAAS into existing crop irrigation infrastructure offers a transformative opportunity to scale fish production using existing, or a portion of existing, irrigation volumes. Even the allocation of just 1% of total irrigated water volumes across six southern US states — Texas, Arkansas, Louisiana, Mississippi, Georgia, and Florida — could yield meaningful and commercially viable tilapia production. These states collectively apply substantial irrigation volumes annually, as detailed in Table 2, which presents 2023 irrigation data sourced from USDA-NASS (2024) in both millions of acre-feet and cubic meters. To illustrate the aquaculture potential, two additional columns in Table 2 estimate the annual tilapia production possible under IAAS integration, assuming 1% of irrigation water is routed through either RAS or BFT units prior to crop irrigation. Conversion (CONTINUED ON PAGE 60) TABLE 2. Table 2: Annual tilapia production potential in millions of pounds (m lbs) or metric tonnes (MT) assuming the usage of 1% of 2023 cropland irrigation volumes in the southern US states when integrating tilapia production into existing farm irrigation systems using either a Recirculation Aquaculture System (RAS) or Biofloc Technology (BFT) system. State Estimated Irrigation Volumes RAS tilapia production potential BFT tilapia production potential (acre-feet) (cubic-meters, million) at 1% of water volumes (MT) at 1% of water volumes (MT) Texas ~ 10.5 million 12952 351,945 863,437 Arkansas ~ 9.2 million 11348 308,370 756,536 Louisiana ~2.1 million 2590 70,389 172,687 Mississippi ~1.8 million 2220 60,333 148,018 Georgia ~1.5 million 1850 50,278 123,348 Florida ~1.2 million 1480 40,222 98,679 Alabama Not determined Not determined Not determined Not determined Summed annual tilapia production potential in the southern US states by technology type, RAS or BFT: in metric tonnes (MT) 881,537 2,162,705 in millions of pounds (m lbs) 1.9435 4.7679 Notes: Irrigation volume estimates derived from USDA-NASS, 2024 < https://www.nass.usda.gov/Publications/AgCensus/2022/Online_Resources/Farm_and_Ranch_Irrigation_Survey/index.php >
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