AI – Mineral Nutrient Concentration and Uptake of Tomato Irrigated with Recirculating Aquaculture Water as Influenced by Quantity of Fish Waste Products Supplied

Mineral Nutrient Concentration and Uptake of Tomato Irrigated with Recirculating Aquaculture Water as Influenced by Quantity of Fish Waste Products Supplied

M. R. McMurtry, D. C. Sanders, and P. V. Nelson

Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695-7609

Additional index words. biofiltration, hydroponics, integrated aquaculture, Lycopersicon esculentum Mill., Oreochromis mossambicus (Peters), Oreochromis niloticus (L.), sand culture.


Fish and tomato (Lycopersicon esculentum Mill.) production were integrated (linked) in a recirculating aquaculture (water) system. Fish ,Tilapia (Oreochromis mossambicus and O. niloticus), were fed a commercial diet containing 32% protein. Tomato cultivars Laura and Kewalo were cultivated (grown) during summer 1988 and spring 1989, respectively, in a greenhouse in Raleigh, N.C. The plants were grown in sand biofilters at a density of 4 plants m-2 and (surface) irrigated eight times daily with water from the (associated) fish tank.

Four tank-to-biofilter volume (BFV) ratios were (established) tested by varying the biofilter size. Each system received identical nutrient inputs and equal water quantities (applied) per plant. Biofilter drainage was recirculated (returned)  back to the fish tanks. Biological filtration, aeration, and mineral assimilation by plants maintained water quality within acceptable limits for tilapia.

All essential nutrients were assimilated above deficiency levels. Tissue concentrations of N, P, K, and Mg were adequate (not limiting), while Ca (Calcium) was low and S (Sulfur) was high when fish waste was the sole nutrient source.

Micronutrients were assimilated in excess of sufficiency without toxicity symptoms. Metabolic products from each kg increase in fish biomass provided sufficient nutrients for two tomato plants over three months. However, K became limiting under reduced growth rates of mature fish.

Modifications (alterations) in fish feed mineral nutrient content are recommended (suggested) to better align (meet) with plant requirements while (still) remaining within the nutritional needs of the fish.


Recirculating aquaculture systems (RAS) offer significant(considerable) potential for the hydroponic cultivation of higher plants (Lewis et al., 1978, 1981; Watten and Busch, 1984; Rakocy, 1989a, 1989b). In these systems, dissolved and suspended organic materials accumulate rapidly and must be removed to maintain efficient fish production (Nair et al., 1985). Nitrates and phosphates accumulate rapidly in filtered recirculatory fish culture systems (Balarin and Haller, 1982; Watten and Busch, 1984).

Hydroponic vegetable production has been shown (demonstrated) to effectively control nitrate (NO3-) concentrations in recirculatory aquaculture water (Lewis et al., 1978, 1981; Watten and Busch, 1984; Rakocy, 1989a, 1989b; McMurtry et al., 1990a). Reciprocating biofilters, which alternately flood and drain, ensure (provide) uniform distribution of nutrient-laden water within the filtration medium and enhance (improved) aeration of the substrate with each dewatering, benefiting both nitrifying bacteria and plant roots (Lewis et al., 1978; Paller and Lewis, 1982; Nair et al., 1985; Rakocy, 1989a, 1989b).

Other integrated fish-vegetable systems have used sedimentation in clarifiers to remove suspended solids before plant application (Rakocy, 1989b). However, this removal (of the solid wastes) often results in insufficient residual nutrients for optimal (good) plant growth, necessitating substantial supplementation of plant nutrients to achieve acceptable fruit yields (Lewis et al., 1978, 1981; Rakocy, 1989b).

The objective of this study was to determine the mineral nutrient concentration, balance, and accumulation in tomatoes grown in sand biofilters and irrigated with aquaculture wastes. This research aims to optimize the integration of aquaculture and horticulture, enhancing the sustainability and efficiency of food production systems.

Materials and Methods

Olericulture was integrated with recirculatory aquaculture (McMurtry et al., 1990a, 1990b, 1990d). All-male hybrid tilapia were cultivated in tanks physically associated with a biofilter utilizing builder’s grade sand as the substrate. Four tank-to-biofilter volume (BFV) ratios were selected as treatments (McMurtry et al., 1990a). The experiments were conducted in a double-layered polyethylene-covered greenhouse in Raleigh, N.C.

The bacterial pathogen Pseudomonas solanacearum (Smith) Smith was anticipated, and preplant fumigation of the sand with methyl bromide-chloropicrin (98-2) was conducted (made) at 250 kg ha-1. Each biofilter was inoculated with 1.0 liter of Fritz-zyme #7 (a suspension of Nitrosomonas Winogradsky sp. and Nitrobacter Winogradsky sp.) and irrigated for nine days prior to tomato planting.

Hybrid tilapia (Oreochromis mossambicus (Peters) x O. niloticus (L.)) were grown in the aquaculture component of the culture system (McMurtry et al., 1990a). The fish were fed a diet of modified Purina Fish Chow 5140, which had an analysis of 32% crude protein (McMurtry et al., 1990a). The rate of daily feed application was a variable percentage of standing fish biomass, influenced by age and mean individual weight (Pullen and Lowe-McConnell, 1982). The fish also grazed on algae growing in the water and on the tank walls. Standing fish biomass and feed rates were adjusted monthly (McMurtry et al., 1990a).

Irrigation water and sediment were drawn from the bottom of the fish tanks eight times daily between dawn and sunset and pumped to the biofilter surface at a rate of 500 L m-2 of biofilter surface area per day (McMurtry et al., 1990a, 1990b). Water pH and elemental composition after a year of system operation were reported by McMurtry et al. (1990d). Specifics of fish and plant growth were previously reported (McMurtry et al., 1990a, 1990b).

Tomato seedlings were transplanted at 4 plants m-2 in each study, resulting in 4, 6, 9, or 14 plants per biofilter. The fish tank size and stocking densities were held constant, and fish biomass was maintained uniformly across treatments. Foliar tissue samples were taken at the harvest of the first mature fruit. Plants infected with bacterial wilt were excluded from foliar tissue analysis.

The fourth whole compound leaf from the growing tip was collected from each plant and collectively analyzed for each biofilter. Fruit samples were taken from trusses 3 and 4 and combined for analysis. All aerial plant tissue was collected for analysis at the termination of each crop.

Plant tissue and fish food analysis were conducted using the following procedures: atomic absorption spectrophotometry for K, Ca, Mg, Fe, Mn, Zn, and Cu; vanadomolybdophosphoric yellow procedure (Jackson, 1958) for P; a Kjeldahl procedure (Black et al., 1965) using a salicylic acid modification for N; a curcumin method (Grinstead and Snider, 1967) for B; and a turbidimetric procedure (Hunter, 1979) for S. All analyses are reported on a dry weight (DW) basis.

Total DW in each plant portion was calculated from the respective fresh weight DW ratio of representative tissue samples. Total plant mineral uptake was calculated from aerial whole plant and fruit DW, multiplied by the respective elemental concentrations in the assayed tissues. The percentage of elemental inputs assimilated by the plants was calculated from the above plant uptake (x100) divided by the summation of the respective elemental concentrations of each input, except those present in the water, multiplied by the respective input mass.

A randomized complete-block design with four replicates was used. Analyses were performed for factorial experiments with Statview TM 512+ on a PC, including Scheffe F-test and single degree of freedom contrasts. When F-test values were significant, LSD were calculated.


Experiment 1

Fish were stocked on 5 May 1988 and harvested on 23 August 1988 (McMurtry et al., 1990a). Tomato (Lycopersicon esculentum Mill. ‘Laura’) was transplanted 13 May 1988. This indeterminate greenhouse variety was grown single-stem and harvested through the fourth truss (McMurtry et al., 1990b). A cucumber crop was grown prior to Experiment 2, but results are not reported here.


Experiment 2

Fish were restocked 5 January and harvested on 27 May 1989 (McMurtry et al., 1990a). ‘Kewalo’ was planted 5 January, 1989. This semi-determinate, bacterial wilt-resistant variety was grown single-stem and harvested through the eighth truss (McMurtry et al., 1990b).



Experiment 1

All leaf nutrient concentrations were above normal sufficiency levels except Ca. No differences in leaf nutrient concentrations occurred between treatments except for B (Table 1a). Boron concentrations differed at P=0.01 and were positively correlated to the level of boric acid amendment of the medium (McMurtry et al, 1990b). There were no visual deficiency or toxicity symptoms, although concentrations of Fe, Mn, Zn, and Cu were each approximately 5-fold sufficiency recommendations.

Concentrations of all mineral elements assayed in the fruit tissue differed between treatments but we could not identify a pattern of assimilation (Table 1b). Aerial whole plant concentrations of P decreased with increasing BFV (Table 1c). Generally, K, S, and Fe concentrations decreased with increasing BFV, while N, Mg, and Zn concentrations generally increased with BFV. Boron concentration increased with BFV and was directly correlated to treatment amendment level (McMurtry et al., 1990b).

  • Minerals assimilated by all plants collectively in each biofilter increased with BFV (Table 2a). The percentage of total inputs assimilated by the plants also increased with BFV (Table 2b).

Experiment 2

The P and K concentrations in leaves decreased with increasing BFV while S, Cu, and B concentrations generally decreased with BFV (Table 3a). In general, Mg concentration in leaves increased with BFV. Levels of each element except N and K were found above sufficiency recommendations. N concentration was below deficiency levels in all treatments but showed no significant treatment effect. K concentration was above sufficiency levels in the 1:0.67 and 1:1.00 v/v ratios and below sufficiency but above deficiency levels in the 1:1.5 and 1:2.25 v/v ratios. No visible nutrient deficiency symptoms were seen. There was no visual evidence of toxicity symptoms although concentrations of Fe, Cu, and B were each approximately 4-fold, Mn 2 to 3-fold, and Zn 7 to 10-fold sufficiency levels.

Fruit K and S concentrations decreased with increasing BFV (Table 3b). Fruit Zn concentration increased with BFV while B concentration was highest in the intermediate treatment ratios.

Aerial whole plant Mg and Zn concentrations increased with BFV, while P, K, and B concentrations decreased with increasing BFV (Table 3c). Generally, Cu concentrations decreased with increasing BFV while Zn levels generally increased with BFV.

Uptake by the plants of all nutrients except K and Fe increased with BFV (Table 4a). The percentage of total inputs assimilated by the plants also increased with BFV (Table 4b).



In agreement with earlier studies (McMurtry et al., 1990b), plant growth was adequately maintained on minimal N, P, and K nutrient levels probably due to the constant replenishment by recirculated aquacultural water (Lewis et al., 1978; Winsor et al., 1985). The proportional balance of N, P, and K in the aquaculture waste was adequate for tomato nutrition.

This finding aligns with the principles of nutrient recycling in integrated aquaculture systems, where the waste products of one component serve as inputs for another, thereby enhancing overall system efficiency (Rakocy et al., 2006).

A slight increase in fish biomass and/or feed input rate in Experiment 2 would probably have raised all leaf tissue N concentrations to within the “sufficiency” range. Tomatoes may have also assimilated N in organic amino acid forms. Ghosh and Burris (1950) found that tomatoes utilized alanine, glutamic acid, histidine, and leucine as effectively as inorganic N sources. This suggests that the form of nitrogen available in the system can significantly influence plant growth and nutrient uptake, a concept supported by more recent studies on nitrogen assimilation in hydroponic systems (Sonneveld and Voogt, 2009).


All water quality variables remained within acceptable levels for tilapia by circulation through the biofilters (McMurtry et al., 1990a). Nitrogenous compounds, which frequently limit the production of fish in other recirculating systems (Lewis et al., 1978), never reached toxic levels (McMurtry et al., 1990a) and were apparently extracted by the plants (McMurtry et al., 1990a). Tomato fruit yields in Experiment 1 were considered to be acceptable from the first 4 trusses, and production was greater in Experiment 2 (McMurtry et al., 1990b). This underscores the effectiveness of biofilters in maintaining water quality, a critical factor for the health and growth of both fish and plants in integrated systems (Timmons and Ebeling, 2013).

 The growth of plants, their cation-anion balance, proton balance, and composition of metabolic products are greatly influenced by the form of nitrogen absorbed (Coic et al., 1962). Much of the ammoniacal-N in the aquaculture water was not oxidized prior to irrigation of the biofilter as in other integrated systems, and was available for tomato assimilation. Acceptable fruit yields (McMurtry et al., 1990b) were partially attributed to plant availability of both NH4+ and NO3- ions, a condition which produces the greatest growth and protein production in most plants (Cox and Reisenauer, 1973; Haynes and Goh, 1978). Highest N uptake rates were observed by Blondel and Blanc (1973) when both N forms, NH4+-N and NO3–N, were present in the nutrient solution.

Plant availability of NH4+-N at low concentrations, as in this system, may have stimulated NO3- reduction and thereby benefited plant growth and yield (Kirkby and Hughes, 1970). Because the reduction of NO3- to NH3 in the plant requires energy, it may be theorized that with uptake of NH4+ energy is conserved and diverted to other metabolic processes including ion uptake and growth. This energy conservation mechanism is crucial for optimizing plant growth in integrated systems, as it allows for more efficient use of available resources (Graber and Junge, 2009).

Earlier we reported that NO3- occurred at a much higher concentration than NH4+ (McMurtry et al., 1990a). High plant tissue concentrations of cations were attributed to the dominant NO3–N nutrition, which stimulated uptake and translocation of cations as counter-ions (Blevins et al., 1974).
Following the reduction of NO3- in the plant, organic anions accumulate to balance the cation charge originally accompanying the NO3- ions (Dijkshoorn and Ismunadji, 1972). Under high fish growth (feed) rates, N, P, K, and Mg availability were not limiting in any treatment. Irrespective of fruit yield (McMurtry et al., 1990b), metabolic by-products from each kg increase in fish biomass provided adequate nutrition for 2 tomato plants for a period of 3 months.

Under reduced feed rates applied to mature fish, we found that if we grew more than 1 plant per kg of standing fish biomass or the increase in fish biomass was less than 0.43 kg per plant, then K became limiting. We concur with Rakocy (1989b) that optimum ratios between feed input rate, standing fish biomass, system water volume, and biofilter volume need to be established for various combinations of fish and vegetable species. This optimization is essential for maximizing the productivity and sustainability of integrated aquaculture systems (Rakocy et al., 2006).


The fish feed formulation employed in these studies appears to be relatively low in Ca if residual quantities alone are used to support plant growth. Amendment of the biofilter medium with CaMg(CO3)2 was ineffective in supplying Ca to the immediate crop. Subsequent application, as in Experiment 2, of CaO was made primarily to maintain the water above pH 5.5, and tissue Ca concentrations reflected this input. The Ca component of the fish feed might be increased from 1.3% DW to approximately 3.0% DW to mitigate deficiencies in tomato crops irrigated with recirculatory aquaculture water. Available Mg levels in the fish wastes were adequately proportioned with respect to N, P, and K. Plant tissue Mg concentrations were substantially greater in Experiment 2, probably as a result of CaMg(CO3)2 amendments made in Experiment 1.


Available S levels in the fish wastes were high relative to N, P, and K. This suggests that the fish feed S concentration might be reduced from 1600 ppm to less than 800 ppm without detrimental effect on either fish or tomato production. Concentrations of Fe, Mn, Zn, and Cu were high in all plant tissues, but no toxicity symptoms were seen. A contributing factor to excess uptake of these elements, in addition to high availability levels, might be attributed to NO3- nutrition, which stimulates organic anion synthesis and hence cation accumulation (Coic et al., 1962; Dijkshoorn and Ismunadji, 1972). Kirkby and Knight (1977) showed that when the cation level of a nutrient solution is maintained, plant tissue concentrations of cations and organic anions increase dramatically in response to NO3- nutrition.

Concentrations of Fe, Mn, Zn, and Cu in the whole plant tissues were significantly higher than in the associated leaf or fruit tissues. This suggests that these metals were primarily incorporated into stem tissue. Tissue levels of Fe and Cu per kg feed input were not found to substantially differ between Experiment 1 and 2, suggesting that plant assimilation rates paralleled feed input rates less fish assimilation. This finding is consistent with the concept of nutrient partitioning in plants, where different tissues accumulate specific nutrients based on their metabolic needs (Marschner, 2012).

Leaf tissue and whole plant Zn concentrations were very high in Experiment 1 and even greater in Experiment 2. This suggests that Zn was disproportionately high in the fish feed and that the plants were not capable of extracting Zn at a rate approaching that residual from the feed input minus fish assimilation, regardless of BFV. Fish feed Zn concentration may be reduced from 65 ppm to approximately 10 ppm without detriment to the fish or plants. This adjustment would help in preventing potential Zn toxicity and ensuring balanced nutrient uptake (Broadley et al., 2007).


Mineral uptake by the plants in Experiment 2 in excess of input quantities was found for K, Ca, Mg, S, Fe, Zn, Cu, and B (Table 4b). This was attributed to the availability of residual nutrients from previous experiments, including fish feed, dolomitic lime, and the root masses of prior crops. This residual nutrient effect highlights the importance of considering the cumulative impact of nutrient inputs over multiple cropping cycles in integrated systems (Rakocy et al., 2006).

Based on tomato nutrient assimilation rates, it would seem appropriate to modify fish feed composition as follows without adversely affecting plant growth: N increased by 5 to 10%; P reduced by 50%; K reduced by 30 to 50%; Ca increased by 200 to 300%; Mg and B unchanged; S reduced by 50%; Fe, Mn, and Cu reduced to 25%; and Zn reduced to 15% of feed concentrations used in this study. These modifications would optimize nutrient availability for both fish and plants, enhancing the overall efficiency and sustainability of the integrated system (Timmons and Ebeling, 2013).


Literature Cited

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Blondel, A. D. and D. Blanc. 1973. Influence of ammonium ion uptake and reduction in young wheat plants. C.R. Acad. Sci. (Paris) Ser. D, 277. pp. 1325-1327.

Coïc, Y., C. Lesaint and F. Le Roux. 1962. Effects of ammonium and nitrate nutrition and a change of ammonium and nitrate supply on the metabolism of anions and cations in tomatoes. Ann. Physiol. Veg. 4:117-125.

Cox, W.J. and H.M. Reisenauer. 1973. Growth and ion uptake by wheat supplied nitrogen as nitrate or ammonium, or both. Plant Soil 38:363-380.

Dijkshoorn, W. and M. Ismunadji. 1972. Nitrogen nutrition of rice plants measured by growth and nutrient content in pot experiments. 2. Uptake of ammonium and nitrate fertilizer from a waterlogged soil. Neth. J. Agric. Sci. 20:44-57.

Ghosh, B.P. and R.H. Burris. 1950. Utilization of nitrogenous compounds by plants. Soil Sci. 70: 187-203.

Grinstead, R.R. and J. Snider. 1967. Modification of the curcumin method for low level boron determination. Analyst 92:532-533.

Haynes, R.G. and K.M. Goh. 1978. Ammonium and nitrate nutrition of plants. Biol. Rev. 58:465-510.

Hunter, A.N. 1979. Personal communication. Custom Laboratory Equipment, Inc. P.O. Box 757, Orange City, FL 32763.

Jackson, M.L. 1958. Soil clinical analysis. pp. 151-154. Prentice-Hall, Inc., Englewood Cliffs, NJ.

Kirkby, E.A. and A.D. Hughes. 1970. Some aspects of ammonium and nitrate in plant metabolism, pp. 69-77. In: E.A. Kirkby: Nitrogen Nutrition of the Plant., Univ. of Leeds, England.

Kirkby, E.A. and A.H. Knight. 1977. The influence of the level of nitrate nutrition on ion uptake and assimilation, organic acid accumulation and cation-anion balance in whole tomato plants. Plant Physiol. 60:349-353.

Lewis, W.M,, J.H. Yopp, A.M. Brandenburg and K.D. Schnoor. 1981 On the maintenance of water quality for closed fish production by means of hydroponically grown vegetable crops. Vol. I. pp. 121-129. In: Proc. World Symp. on Aquaculture in Heated Effluents and Recirculation Systems, Stavanger 28 … 30 May, 1980. Berlin.

Lewis, W.M., J.H. Yopp, H.L. Schramm, and A.M. Brandenburg. 1978. Use of hydroponics to maintain quality of recirculated water in a fish culture system. Trans. Amer. Fisheries Soc. 107:92-99.

McMurtry, M.R., R.G. Hodson, and D.C. Sanders. 1990a. Water quality maintenance and mineral assimilation by plants influence growth of hybrid tilapia in culture with vegetable crops. Trans. Amer. Fisheries Soc. (submitted)

McMurtry, M.R., D.C. Sanders and R.P. Patterson. 1990b. Yield of tomato irrigated with recirculatory aquaculture water as influence by quantity of fish waste products supplied. HortScience. (submitted)

McMurtry, M.R., D.C. Sanders, R.G. Hodson and B.C. Haning. 1990d. Food value, water use efficiency and economic productivity of an integrated aquacultureolericulture system as influenced by component ratio. Sci. Hortic. (submitted)

Nair, A., J.E. Rakocy, and J.A. Hargreaves. 1985. Water quality characteristics of a closed recirculating system for tilapia culture and tomato hydroponics pp. 223-254 In: Proceedings, Second International Conference on Warmwater Aquaculture Finfish. Division of Continuing Education, Brigham Young University. Laie, ID.

Paller, M.H. and W.M. Lewis. 1982. Reciprocating biofilter for water reuse in aquaculture. Aquacultural Eng. 1:139-151.

Rakocy, J.E. 1989a. A recirculating system for tilapia culture and vegetable hydroponics in the Caribbean. 24 p. In: Proceedings, Auburn Symposium on Fisheries and Aquacultures, Sept. 20-22, 1984. Brown Printing Co., Montgomery, AL (in press).

Rakocy, J.E. 1989b. Vegetable hydroponics and fish culture; a productive interface. World Aquaculture 20:42-47.

Watten, B.J., and R.L. Busch. 1984. Tropical production of tilapia (Sarotherodon aureus) and tomatoes (Lycopersicon esculentum) in a small-scale recirculating water system. Aquaculture 41:271-283.

Winsor, G. W., R.G. Hurd and D. Price. 1985. Nutrient Film Technique. 2nd Ed. Glasshouse Crops Research Institute. Growers Bulletin No. 5, Littlehampton, England. 59 p.

Broadley, M. R., White, P. J., Hammond, J. P., Zelko, I., & Lux, A. (2007). Zinc in plants. New Phytologist, 173(4), 677-702.

Graber, A., & Junge, R. (2009). Aquaponic systems: Nutrient recycling from fish wastewater by vegetable production. Desalination, 246(1-3), 147-156.Marschner, H. (2012). Marschner’s Mineral Nutrition of Higher Plants. Academic Press.

Rakocy, J. E., Masser, M. P., & Losordo, T. M. (2006). Recirculating aquaculture tank production systems: Aquaponics—Integrating fish and plant culture. SRAC Publication No. 454.

Sonneveld, C., & Voogt, W. (2009). Plant Nutrition of Greenhouse Crops. Springer.

Timmons, M. B., & Ebeling, J. M. (2013). Recirculating Aquaculture. Ithaca Publishing Company. This revised discussion section incorporates additional citations and expands on the original content to provide a more comprehensive and updated analysis.


Table 1. Nutrient concentration of leaves, fruit and aerial whole plant of ‘Laura’ tomato as influenced by tank to biofilter ratio.
Biofilter Ratio (v/v) Plants N p K Ca Mg s Fe Mn Zn Cu B
a) Leaf tissue
1: 0.67 4 mean 4.30 0.74 3.65 0.69 0.39 4908 223 143 99 31 53
1: 1.00 6 mean 4.32 0.72 3.70 0.76 0.38 4732 220 211 152 32 74
1: 1.50 9 mean 4.59 0.78 3.88 0.81 0.40 5366 235 170 118 33 76
1: 2.25 14 mean 4.62 0.76 3.80 0.90 0.43 5165 235 177 125 35 90
Contrasts I LSD (P= 0.05) NS NS NS NS NS NS NS NS NS NS 20
4 vs 6 plants mean difference -.02NS +.02NS -.05NS -.07NS +.02NS +176NS +3NS -68NS -53NS -1NS -21*
4 vs 9 plants mean difference -.29NS -.04NS -.23NS -.12NS -.01NS -458NS -13NS -28NS -19NS -2NS -24*
4 vs 14 plants mean difference -.32NS -.02NS -.15NS -.22NS -.04NS -858NS -13NS -34NS -26NS -4NS -37**
b) Fruit tissue
1: 0.67 4 mean 4.54 0.73 3.85 0.28 0.21 2151 86 44 80 20 29
1: 1.00 6 mean 4.91 0.65 3.80 0.21 0.23 2314 84 45 91 23 39
1: 1.50 9 mean 5.01 0.57 3.56 0.16 0.19 1787 75 37 61 19 33
1: 2.25 14 mean 4.82 0.66 3.66 0.31 0.27 2200 103 38 106 20 35
Contrasts I LSD (P= 0.05) 0.26 0.04 0.23 0.02 0.17 143 6 3 6 1 2
4 vs 6 plants mean difference -.37** +.08*** +.05NS +.07*** -.02* -163* +2NS -3NS -11*** -3*** -10***
4 vs 9 plants mean difference -.47*** +.16*** +.29* +.12*** +.02* +364*** +11*** +7*** +13*** +1NS -4***
4 vs 14 plants mean difference -.28* +.01*** +.19NS -.03*** -.06*** -485NS -17*** +6*** -26*** 0NS -6***
c) Aerial whole plant tissue
1: 0.67 4 mean 3.62 0.91 3.73 2.24 0.79 10814 171 457 907 43 104
1: 1.00 6 mean 3.92 0.71 4.03 2.37 0.78 10999 134 479 848 44 124
1: 1.50 9 mean 3.52 0.58 3.80 2.56 0.84 10606 139 420 1202 41 145
1: 2.25 14 mean 3.49 0.46 3.29 2.45 0.97 8267 131 390 1445 38 166
Contrasts I LSD (P= 0.05) 0.27 0.13 0.43 NS 0.14 2048 NS NS 390 NS 21
4 vs 6 plants mean difference -.30* +.20*** -.30NS -.13NS +.01NS -182NS +37NS -27NS +59NS -1NS -20NS
4 vs 9 plants mean difference +.13NS +.33*** -.07NS -.32NS -.06NS +208NS +32NS +37NS -30NS +2NS -41***
4 vs 14 plants mean difference +.13NS +.45*** +.45* -.21NS -.18* +2546* +40* +67NS -54* -14NS -62***

NS,*,**, *** Nonsignificant or significant at the P = 0.05, 0.01, or 0.005 levels, respectively


Table 2. Nutrient assimilation and percent of nutrient input assimilated per plot by ‘Laura’ tomato as influenced by tank to biofilter ratio.
Biofilter Ratio (v/v) Plants per plot Nutrient assimilation (g)
N P K Ca Mg S Fe Mn Zn Cu B
1:0.67 4 23.6 3.8 20.0 1.3 1.1 8.1 0.15 0.32 0.62 0.04 0.08
1:1.00 6 43.3 5.8 33.6 2.1 2.1 13.1 0.21 0.53 0.94 0.06 0.20
1:1.50 9 54.4 6.2 38.8 2.0 2.1 13.1 0.23 0.48 1.33 0.06 0.19
1:2.25 14 71.4 10.1 55.8 5.0 4.2 15.1 0.34 0.62 2.00 0.09 0.29
LSD (P=0.05) 10.8 1.5 8.3 0.6 0.5 3.7 0.07 0.20 0.34 0.02 0.06
4 vs 6 plants mean difference -19.7*** -1.9* -13.6*** -0.7* -1.0*** -5.0* -0.1NS -0.2* -0.3NS -0.03* -0.1***
4 vs 9 plants mean difference -30.9*** -2.4*** -18.8*** -0.1* -1.0*** -5.0* -0.1* -0.2NS -0.7*** -0.03* -0.1***
4 vs 14 plants mean difference -47.9*** -6.3*** -35.8*** -3.7*** -3.1*** -6.9** -0.2*** -0.3** -1.4*** 0.05*** -0.2***
Biofilter Ratio (v/v) Plants per plot Percent nutrient input assimilated (%)
N P K Ca Mg S Fe Mn Zn Cu B
1:0.67 4 2.9 4.9 11.2 1.1 2.1 38.8 2.3 13.5 30.1 8.9 3.8
1:1.00 6 5.2 6.9 18.2 1.6 3.8 54.0 3.0 21.6 44.6 15.2 6.8
1:1.50 9 6.5 7.1 21.1 1.6 3.9 54.0 3.3 19.5 63.6 15.0 4.4
1:2.25 14 8.5 10.5 30.3 4.0 7.6 62.1 4.9 25.5 95.4 20.2 4.7
LSD (P=0.05) 1.3 1.7 4.5 0.5 1.0 15.2 1.0 8.1 16.3 4.1 1.5
4 vs 6 plants mean difference -2.3*** -2.0* -6.9** -0.6* -1.7*** -15.1NS -0.7NS -8.1NS -13.9NS -6.3** -3.0***
4 vs 9 plants mean difference -3.6*** -2.1* -9.9*** -0.5* -1.8*** -15.1NS -1.0NS -6.0NS -32.8*** -6.1** -0.6NS
4 vs 14 plants mean difference -5.6*** -5.6*** -19.1*** -2.9*** -5.6*** -23.3** -2.6*** -12.0** -64.6*** -11.2*** -0.9NS

NS, *, **, *** Nonsignificant or significant at the P= 0.05, 0.01, or 0.005 levels, respectively



Table 3. Nutrient concentration of leaves, fruit and aerial whole plant of ‘Kewa1o’ tomato as influenced by tank to biofilter ratio.
Plants N P K Ca Mg S Fe Mn Zn Cu B
Biofilter Ratio (v/v)
a) Leaf tissue
1: 0.67 4 mean 3.23 0.59 3.80 3.99 0.88 9887 265 55 197
1: 1.00 6 mean 3.24 0.44 3.27 3.99 0.83 10375 165 67 209
1: 1.50 9 mean 3.42 0.33 2.00 3.47 1.08 8470 206 46 141
1: 2.25 14 mean 3.41 0.36 1.44 3.42 1.39 6076 221 41 183
Contrasts LSD (P= 0.05) NS 0.07 1.00 NS 0.37 2940 67 NS NS
4 vs 6 plants mean difference -0.02NS +0.15*** +0.53NS +0.00NS +0.06NS -488NS +100** -13NS -12NS
4 vs 9 plants mean difference -0.20NS +0.26*** +1.80*** +0.52NS -0.20NS +1418NS +59NS +10NS +56NS
4 vs 14 plants mean difference -0.18NS +0.23*** +2.40*** +0.57NS -0.51* +3811* +44NS +15NS +14NS
b) Fruit tissue
1: 0.67 4 mean 2.77 0.64 4.65 0.31 0.19 2189 268 1147 613 384
1: 1.00 6 mean 3.19 0.68 4.80 0.30 0.20 2238 317 NS -978NS -344NS
1: 1.50 9 mean 2.94 0.66 4.70 0.31 0.23 2082 NS +64NS +154NS +181NS
1: 2.25 14 mean 2.84 0.51 3.47 0.29 0.22 1635 NS -978NS -344NS -116NS
Contrasts LSD (P= 0.05) NS 0.22 1.38 NS 0.26 NS +64NS +154NS +181NS
4 vs 6 plants mean difference -0.42NS -0.05NS -0.17NS -0.07NS +0.13NS -20NS +107NS +554*** +25*
4 vs 9 plants mean difference -0.17NS -0.02NS -0.04NS +0.02NS -0.03NS +10NS +154NS +181NS +7NS
4 vs 14 plants mean difference -0.07NS +0.13NS +1.20*** +0.02NS -0.03NS +554*** +25* +7NS +22***
c) Aerial whole plant tissue
1: 0.67 4 mean 2.87 0.86 4.24 4.17 0.98 10908 451 419 502 645
1: 1.00 6 mean 3.12 0.82 4.51 4.50 0.95 12564 140 +32NS -51NS -194*
1: 1.50 9 mean 3.07 0.68 3.99 3.83 1.24 9570 26 +3NS -4NS -0NS
1: 2.25 14 mean 2.91 0.61 2.59 3.62 1.66 9139 32 -3NS -4NS -0NS
Contrasts LSD (P= 0.05) NS 0.22 1.38 NS 0.26 NS +64NS +154NS +181NS
4 vs 6 plants mean difference -0.20NS +0.04NS -0.21NS -0.33NS +0.03NS -1656NS +1339NS +1770NS +22*
4 vs 9 plants mean difference -0.20NS +0.18NS +0.25NS +0.34NS -0.20NS +1339NS +154NS +181NS +7NS
4 vs 14 plants mean difference -0.05NS +0.25* +1.70* +0.54NS -0.69*** +1770NS +25* +7NS +22***
NS, *, **, *** Nonsignificant or significant at the P= 0.05, 0.01, or 0.005 levels, respectively.


Table 4. Nutrient assimilation and percent of nutrient input assimilated per plot by ‘Kewalo’ tomato as influenced by tank to biofilter ratio.
Biofilter Ratio (v/v) Plants per plot N (g) P (g) K (g) Ca (g) Mg (g) S (g) Fe (g) Mn (g) Zn (g) Cu (g) B (g)
1: 0.67 4 72.5 19.5 111.7 64.9 16.4 18.5 0.99 0.11 0.72 0.06 0.20
1: 1.00 6 99.5 23.5 146.3 88.8 21.0 26.2 2.01 0.20 0.89 0.09 0.28
1: 1.50 9 122.4 27.3 170.2 105.2 36.0 28.1 1.66 0.20 1.41 0.09 0.27
1: 2.25 14 151.7 29.7 145.5 138.1 64.3 35.5 1.69 0.18 2.54 0.11 0.34
Contrasts l LSD (P= 0.05) 32.9 5.3 NS 36.0 12.6 8.8 NS 0.06 0.91 0.03 0.08
4 vs 6 plants mean difference -27.0NS -4.0 -34.6NS -23.9NS -4.6 -7.7NS -1.02NS -0.09** -0.17NS -0.03* -0.08*
4 vs 9 plants mean difference -50.0** -7.8** -58.5* -40.3* -19.6** -9.6* -0.67NS -0.08* -0.69NS -0.03* -0.05NS
4 vs 14 plants mean difference -79.3*** -10.2*** -33.5NS -73.2*** -47.8*** -11.0*** -0.70NS -0.07* -1.82*** -0.05*** -0.14***
Biofilter Ratio (v/v) Plants per plot N (%) P (%) K (%) Ca (%) Mg (%) S (%) Fe (%) Mn (%) Zn (%) Cu (%) B (%)
1: 0.67 4 22.0 31.2 131.1 23.0 82.7 162.8 69.5 30.7 155.5 66.4 126.5
1: 1.00 6 30.1 37.6 171.7 27.4 105.7 230.7 141.0 54.9 192.1 102.4 178.6
1: 1.50 9 37.1 43.7 200.0 41.9 181.2 246.9 116.0 53.2 305.7 102.0 175.5
1: 2.25 14 46.0 47.5 170.8 106.5 323.2 312.2 118.4 49.0 550.6 125.4 215.7
Contrasts l LSD (P= 0.05) 10.0 8.4 NS 22.3 63.5 77.2 NS 16.5 197.0 34.3 50.8
4 vs 6 plants mean difference -8.2NS -6.4NS -40.6NS -4.4NS -23.0NS -67.9NS -71.6NS -24.2** -36.6NS -36.0* -52.1*
4 vs 9 plants mean difference -15.1** -12.5** -68.6* -18.9NS -98.5** -84.2* -46.6NS -22.4* -150.3NS -35.6* -49.0NS
4 vs 14 plants mean difference -24.0*** -16.3*** -39.7NS -83.6*** -240.5*** -149.5*** -49.0NS -18.3* -395.1*** -59.0*** -89.2***

NS,*,**,*** Nonsignificant or significant at the P= 0.05, 0.01, or 0.005 levels, respectively





Note: 4 Tables not yet added.