A~,~i~ultulal ~4a.ste~ 2 l198()j 26[ 271

STUDIES ON THE EFFECTS OF POULTRY MANURE, DIGESTED SEWAGE SLUDGE CAKE AND COW-DUNG

ON THE GROWTH RATE OF CATLA CATLA (HAMILTON) AND CYPRINUS CARPIO VAR. COMMUNIS (LINNEAUS)

M. NATARAJAN* & T. J. VAR(;HESt

Unircrsity o~ Agricullural Science.~, ('olh,ge ~/ Fisheries. Mangalore .575 002. India

A B S T R A C T

The ~[]ects q/poultry manure, digested sewage sludge cake and cow-dung on plank mn production and.l~sh growth were evaluated. Both plankton production andl~'h growth (Catla carla and Cyprinus carpio var. Communis) were Jound to be highest in th~ poultl 3' manure treatment, jollowed by the sludge cake and cow-dung treatmenL~. Compared with the cow-dung treatment, lota/ fish production wa,~ 50"6 ° 0 more in/he pouhry manure and 19.0 o~] more in the sludge-cake treatment. In terms c?/drt' wetgttl o[ the manures, the fertiliser (manure) co~;[ficients (ki/ograrnme o/,[ertilLYer per k ilogramme oJfish production) were 5.2.6"6 and 7.8, re,spective/y/br pouh:)" manure'. ,sludge cake and cow-dung.

INTRODUCTION

The use of organic manures for fertilising fish ponds is one of the basic principles o1" traditional fish culture. Experiments carried out in India, as well as in other countries (Mechean, 1933: Hogan, 1933; Smith & Swingle, 1939, 1942; Sarig, 1955: Anon., 1957: Hickling, 1962: Gopalakrishnan & Srinath, 1963: Banerjec et al., 1969; Ray & David, 1969: Parameswaran et al., 1971 ; Schroeder, 1974, 1975 : Moa~ et al., 1977: Natarajan & Varghese, 1978) have proved beyond doubt that the fertilisation of fish ponds with organic manures can substantially increase the production offish from a unit area of water. Since the selection of the right manure is a prerequisite of successful fish culture, a thorough understanding of the relative merits of different types of manure is essential. Studies comparing the qualities of

* Present address: Recycling Project, Indian Veterinary Research Institute. lzamagar 243 122, Uttar Pradesh, India.

261 Agricultural Wastes 0141-4607/80/0002-0261/$02"25 Applied Science Publishers Ltd. England. 1980 Printed in Great Britain

262 M. N A T A R A J A N , T. J, VARGHESE

organic manures are meagre. With a view to understanding the relative merits of three locally available manures--poul try manure, digested sewage sludge cake and cow-dung--a programme of investigation was initiated at the College of Fisheries, Mangalore, India, and the data pertaining to the effects of the three manures on fish production are presented in this paper.

METHODS

The experiment was conducted in ten cement tanks of uniform size (25 m e) provided with a 15-cm thick soil bed. The tanks were completely drained and dried before being filled with water pumped in from a perennial well. The water level was maintained at 55 + 3cm throughout the experimental period of 97 days.

Fertilisation with the organic manures--poul t ry manure, digested sewage sludge cake and cow-dung--was carried out in two instalments at a dosage rate of 3500 kg hectare- 1 on a dry weight basis and the manures were used individually. Three tank s were used for each manurial treatment. The tanks were fertilised initially at the rate of 5.83 kg (dry weight) per tank. The second dose of manure was at half the initial dose; that is, 2.91kg (dry weight) per tank, applied 37 days after the initial fertilisation. The amount of manure required for each tank was calculated on the basis of the moisture content of each manure. It worked out at 7.21 kg (moisture content, 19-27 ~o) and 3'43 kg (moisture content, 14.91 ~o) of poultry manure for the first and second applications, respectively. Similarly, for sludge cake the amount was 6-25 kg (6.79 ~,, moisture content) and 3-16kg (7.71 ~o moisture content) and for cow-dung, 25.07kg (76-77% moisture content) and 7.82kg (62-75~o moisture content).

The manures were analysed for ash, acid insoluble ash and organic matter (loss on ignition) following the methods recommended by the AOAC's OJficial Methods oj Analysis (AOAC, 1970). Total phosphorus and total nitrogen were estimated respectively by the titrimetric method of Pemberton (Sankaram, 1966) and by a Kjeldahl method. Specific conductivity of the manure suspensions (1:100) was determined as described by Ray & David (1969) using a conductivity meter.

On the seventh day following initial fertilisation, each tank was stocked with eight fingerlings each of Carla catla (common name 'catla') and Cyprinus carpio var. Communis (common name "common carp'). The length of catla and common carp fingerlings stocked varied from 100 to 144 mm (average 119.25 + 1.23 ram) and 90 to 128mm (average 105.47 ___ 0-99mm), respectively. The total weight of each species stocked per tank was kept uniform at 190 g (average weight per fish, 23.75 g). The stocking rate worked out at 6400 fish per hectare. The growth of fish in the experimental tanks was assessed by sampling at least half the fish once every 10 days. Increase in length was measured individually whilst weight increase was determined by weighing all the sampled fish together and dividing by the number caught.

FISH GROWTH ON MANURES AND DIGESTED SEWAGE SLUDGE 263

Sampling was usually done between 07.00 and 10.00 h. At the end of the experiment i.e. after 90 days of rearing-- the lengths and weights of all surviving fish were

recorded. On each sampling day, the atmospheric and water temperatures were noted and

water samples from the tanks were analysed for various chemical parameters following the method recommended by the American Public Health Association (1965). The bottom soil was also analysed on alternate sampling days.

The plankton collected on each sampling day by filtering 45 litres of water through a plankton net made of No. 25 nylon bolting cloth (mesh size 6510 was analysed qualitatively. Quantitative estimates were limited to grading the abundance of different forms as 'swarm'/bloom', 'very abundant', "moderately abundant', 'common' and 'less common'.

RESUI.TS

The results of the chemical analyses of the poultry manure, digested sewage sludge cake and cow-dung used in the experiments are shown in Table 1.

TCIglJ)CI'LI[IlI'C

Minimum temperatures of air and water were 21 ~)C and 25 °C during the initial stages of the experiment: these gradually increased to maxima of 28-5~'C and 3(1.0 °C, respectively towards the end of the experimental period.

('heroical characteristics of water and soil The range and average values of the various chemical parameters studied are

given in Table 2. Poultry manure treated waters had the highest pH values, dissolved

TABLE 1 COMPOSITION OF THE ORGANIC MANURES USED IN THE EXPERIMENT

Parameter Poultry Dl~lHllrC

1 11

Moisture (0o) 19.27 14.91 Total ash (o~), 39.29 38.78 Acid insoluble ash

(sand) ( ~o)" 9.81 10.95 Loss on ignition

(organic matter) (?o)" 60.71 61.22 Total nitrogen (o~)a 3.55 3"33 Total P2Os (~.~,)" 5-64 5"51 Specific conductivity after 24 h

(mhos centimetre-~ x 10 -6 at 25°C) 1388.80 1430"89

Digested sewage Cow-dung sludge cake

I I1 I II

6"79 7-71 76-77 62'75 35.77 30.43 19.58 34.78

17.78 14-90 10-66 24.54

64-23 69-57 80.42 65"22 4.15 4-70 1.93 1-63 1-67 1.96 1-2! 1.23

698.61 707.03 652.32 593-40

Values on a moisture-free basis. I = First application, II = second application.

264 M. N A T A R A J A N , T . J. V A R G H E S E

T A B L E 2 THE RANGE AND AVERAGE VALUES OF THE CHEMICAL PARAMETERS OF WATER AND SOIL DURING THE

EXPERIMENT

Tank treatment Poultry manure Sludge cake Cow-dung

Water pH 6-45-9-75 6,22-9-05 6.30.7.85

(7"71)" (7-57) (7"23) 02 (ppm) 0-40-10-59 1,37-10.98 1-18-10-55

(5.67) (7-17) (5.39) CO 2 (ppm) 0.00-19-60 0,00-21.60 0.00-21.40 Alkalinity (ppm) 26-00.82.00 2.70-57.00 22-00-98.00

(59.24) (37.51 ) (66-94) Dissolved organic matter (ppm) 2.20-17-60 1.20-10.80 1-20-16.80

(10.72) (5-23) (7"23) PO4 (ppm) T-2.39 b T 0.04 T-0.25

(0"282) (0'009) (0-031) NH 3 (ppm) 1.13-3.32 0-01 1.59 0-02-1.89

(0.655) (0.542) (0.574) N 0 2 (ppm) T-0-44 T-0.02 T- 0.02

(0"026) (0-004) (0"005) NO 3 (ppm) T 0.94 T-0.83 T-0.62

(0.316) (0.223) (0.204) Specific conductivity 155.72-435.84 140.99-319.63 143.09-453-19

(mhos centimetre- 1 x 10 -6) (330.68) (235.50) (333.29) Soil pH 6.30-7-20 6.15-6.90 5-85 6.75

(6.59) (6.57) (6.39) Free CaCO3 (%) 0.25 1.01 0-13 0.77 0-19 0.70

(0.63) (0-46) (0-47) Available phosphorus 984.42 5445-28 99.71 1942.40 4-97 1044.87

(/~g per 100 g) (2794-24) (829.73) (470.57) Available nitrogen 21-62 3 6 - 2 7 1 8 . 6 7 - 4 0 - 4 7 17.50-32-37

(rag per 100 g) (28-39) (25-86) (24.57) Organic carbon (%) 1.00-2-78 0-6(~2.47 0"98 2.95

(I .84) (1.43) (1.67) Specific conductivity 48.23-172" 11 54-14~ 172" 11 55.38-102-44

(mhos centimetre- 1 x 10 6) (87.60) (79.73) (76.03)

"Values in parentheses are the averages. bT = in traces.

organic matter , inorganic phosphate and inorganic ni trogen (NH 3 + N O 2 + NO3). pH, dissolved oxygen and nitrate n i t rogen were higher in the sludge-cake t rea tment than in the cow-dung t reatment while dissolved organic matter, inorganic phosphate, alkalinity, a m m o n i a ni t rogen and specific conduct ivi ty were higher in the latter.

Average values of soil pH, free calcium carbonate , available phosphorus , available ni t rogen, organic carbon and specific conduct ivi ty were found to be highest in the poul t ry manure t reatment . The sludge-cake treated tanks showed higher values for free calcium carbona te and organic carbon than the cow-dung treated tanks whilst the other parameters were lower in the former.

FISH GROWTH ON MANURES AND DIGESTED SEWAGE SLUDGE ")65

Plankton Blue-green algae frequently occurred in large numbers in all three treatments.

However, they were especially abundant towards the end of the experimental period. Species of Microcystis and Anabaena were abundant in all three manurial treatments. Osci/latoria spp. was less common in the cow-dung treatment than in the other two treatments. Chlorophyceae dominated the phytoplankton population during the first half of the experimental period. In the poultry manure treatment, the green algal population decreased towards the end of the experimental period, but no such decrease was recorded in the other two treatments. Coelastrum spp., Pediastrum spp., Scenedesmus spp. and Eudorina spp. were more abundant than other species of green algae. Diatoms were abundant throughout the experimental period in all treatments, Melosira spp. being prominent. Throughout the present experiments a significant increase in the phytoplankton population (both in quality' and quantity) was noted in all treated tanks from the seventeenth day of fertilisation. in general, phytoplankton production was highest in poultry-manure treated tanks. followed by the sludge cake and cow-dung treatments.

Zooplankton production was highest in the poultry manure treatment. In the sludge-cake treatment it was slightly better than in the cow-dung treatment. On the seventh day after fertilisation, zooplankton occurred in abundance in all the tanks while the phytoplankton content was poor. A sharp decrease in the zooplankton population was noted between the seventh and seventeenth days in the poultry manure and sludge-cake treatments, although such a decrease was not very evident in the cow-dung treated tanks. Rotifers were dominant amongst the zooplankters throughout the experimental period in all manurial treatments, followed by copepods and cladocerans. Brachionus spp., Keratella spp.. Hexarthra spp. and Ascomot7~ha spp. were prominent. Whilst Moina spp. was common among cladocerans, cyclopoid copepods were the dominant forms among copepods.

Fish gron'lh The growth rates o fca t l a and common carp during the experimental period in

various treatments are compared and summarised in Table 3 and shown graphically in Fig. 1. From Fig. 1 it can be seen that the rate of increase in the weight of carla was high and steady during the entire experimental period in the poultry manure treatment except for a slight decrease on the last sampling day. ] 'he growth rate was much faster than in the sludge cake or cow-dung treatments. The growth rate was more or less similar for the sludge cake and cow-dung treatments during the first 20 days after stocking. On the thirtieth day a decrease in weight was recorded in both treatments. However, after the application of the second dose of manure, growth again became faster in both treatments. However, the growth rate in sludge-cake treated tanks was greater than that in cow-dung treated tanks and the difference became more pronounced from the fiftieth day onward.

In the case of common carp the growth pattern was similar to that of catla.

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FISH GROWTH ON MANURES AND DIGESTED SEWAGE SLUDGE 267

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The growth of calla (A) and common carp (B) in the three treatments.

Growth was fastest in the poultry manure treatment, followed by sludge-cake and cow-dung treatments. The growth of this species was very fast during the first 10 days in the poultry-manure treatment, being slightly slower thereafter. However, the fish weight continued to increase until the end of the experiment. In the case of the sludge-cake treatment the weight increase was gradual and steady until the end of the experimental period. No difference in growth was observed between the sludge cake and cow-dung treatments during the first 20 days. Thereafter growth was slower in the latter than in the former treatment. At the end of the experiment the difference became significant.

Total fish production (catla plus common carp)was highest in the poultry-manure treatment, followed by the sludge cake and cow-dung treatments• The estimated average total fish production was 2728, 2156 and 1811 kg ha - ~ year ~ in the poultry manure, sludge-cake and cow-dung treatments, respectively. Statistically, the difference between treatments was highly significant at the 5 3,~, level. Compared with the cow-dung treatment, total fish production was ,0.6/. , more in the poultry- manure treatment and 19-0 ~o more in the sludge-cake treatment. On average, calla contributed about 60 3~; to total fish production.

268 M. NATARAJAN, T. J. VARGHESE

DISCUSSION

Natural food production in the experimental tanks was the most important factor affecting fish growth. The increased production of fish in the tanks treated with poultry manure can be attributed to the higher production of plankton. Smith & Swingle (1938) showed that fish production in a water body can be directly correlated with the plankton produced. Production of plankton, in turn, is dependent upon the physico-chemical characteristics of water and soil. However, in the case of organic manures, zooplankters are produced directly through the saprophytic food chain, bypassing the phytoplankton link (Smith & Swingle, 1939; Alikunhi et al . , 1955; Alikunhi, 1957: Hickling, 1962; Schroeder, t975; Moav et al . , 1977; Meyers, 1977). In the present study, phytoplankters were recorded in appreciable numbers only from the seventeenth day following fertilisation, while zooplankters were in abundance right from the seventh day. This is in agreement with the findings of earlier workers. The decline recorded in the zooplankton population on the seventeenth day can be attributed to active grazing by the fish fingerlings which were introduced on the seventh day after fertilisation. Several workers (Schroeder, 1975; Moav et al . , 1977; Meyers, 1977) are of the opinion that zooplankton ingest small manure particles rich in bacteria which are responsible for the breakdown or mineralisation of the organic matter. These bacteria are digested and the residual particles are excreted. In course of time, the manure particles are completely mineralised and release nutrients and this results in the production of phytoplankters. Therefore, although the initial zooplankton production by organic manures is dependent on the saprophytic food chain, further production must invariably depend on the regular food chain, starting with phytoplankters. The higher concentrations of nutrients such as inorganic phosphate, inorganic nitrogen, dissolved organic matter, etc., found in the waters and the higher values of pH, free calcium carbonate, available phosphorus, available nitrogen and organic carbon and the specific conductivity of the soils in tanks treated with poultry manure appear to be responsible for the higher production of plankton as well as of fish in this treatment in comparison with the other two. The tests conducted by Ray & David (1969) indicated that poultry manure contains larger amounts of soluble inorganic salts than other manures. Some parameters studied--such as pH, dissolved oxygen and nitrate nitrogen of water and pH, available phosphorus, available nitrogen and specific conductivity of soil in tanks treated with sludge cake were higher than those in cow-dung treated tanks, whilst other parameters were slightly higher in the latter. Thus, plankton and fish production were only marginally higher in the sludge-cake treatment than in the cow-dung treatment. In the present experiment, both phosphorus and nitrogen appear to have determined the magnitude of plankton production. The influence of phosphorus was, however, more apparent. Phosphorus is often considered as the critical element in the maintenance of aquatic productivity (Maciolek, 1954; Banerjee & Ghosh, 1970). Hepher (1962) reported

FISH G R O W T H O N MANURES A N D DIGESTED SEWAGE SLUDGE 269

that phosphate in fertilisers was responsible ['or a greater increase in the weight of fish produced in ponds than was nitrogen. However, Saha eta/. (1968) stated that both nitrogen and phosphorus were limiting factors controlling the production of Indian major carp fry in nursery ponds. The chemical composition of the manures used in this experiment (Table 1) showed that poultry manure was rich in both phosphorus and nitrogen. Sludge cake had the highest concentrations of nitrogen ; however, its phosphorus content was much lower than that of poultry manure although slightly higher than in cow-dung. Cow-dungwas poor in both nitrogen and phosphorus.

In the sludge cake and cow-dung treatments, growth of carla slowed down to almost a complete stop on the thirtieth day after stocking. However, the second dose of manure resulted in an immediate improvement. Apparently the initial amount of manure became insufficient for maintenance and growth at the increased fish biomass. On the other hand, poultry manure was able to sustain a continuous growth of catla. Since catla feeds mainly on zooplankton ~'.,nd common carp on bot tom detritus, the fluctuations in plankton production tire more clearly reflected in the growth pattern of the former.

The poultry-manure treatment yielded 50.6~,, more fish than the cow-dung treatment while the sludge-cake treatment produced 19.0"~, more. Banerjee eta/ . (1969) have reported that a mixture of poultry manure and cow-dung resulted in better growth and survival of major carp spawn than did cow-dung alone. In the present study it was interesting to note that the digested sewage sludge cake gaxe higher fish production than cow-dung. Gopalakrishnan & Srinath (1963) showed that activated sewage sludge cake was an efficient manure for rearing carp fry and fingerlings. In the poultry-manure treatment the estimated net production was 2728 kg ha ~ year 1. This rate of production was quite satisfactory in view of lhe facts that no supplementary feed was given and the retiring period was short. The conversion of manure to fish flesh was the most efficient in this treatment, followed by the sludge-cake and cow-dung treatments. The respective fertiliser (manure) coefficients (kilogramme of fertiliser (manure) added per kilogramme of fish yield) worked out at 6.3, 7.1 and 29.5 on a wet-weight basis. The very high value for cm~- dung was due to its high moisture content. However, in terms of dry weight the corresponding values for the three manures were 5-2.6.6 and 7-8, respectively. In t hc case of liquid cow manure, Moav el al. (1977) reported a conversion ratio of 2.7 kg dry matter of manure to 1 kg of fish.

From the foregoing discussion it is evident that poultry manure is a better fertiliscr for increasing the productivity of fish ponds than digested sewage sludge cake or cow-dung. Moreover, from the economic point of view also, poultry manure is superior. In the present study the cost of manure per kilogramme of fish produced worked out at Rs. 1.27 (£0-07) for poultry manure, Rs. 1-06 (£0.06) for sludge cake and Rs. 2.95 (£0.17) for cow-dung. However, since fish production in the poultry manure treatment was much higher than that in sludge-cake treatment (2728 versus

270 M. NATARAJAN, T. J. VARGHESE

2156kgha -1 year-l), the net profit would be greater with the former manure. Further, since both poultry manure and sludge cake are comparatively dry, they have the advantage of easy transportability and storage.

ACKNOWLEDGEMENTS

M. Natarajan is grateful to the Indian Council of Agricultural Research for the award of a Junior Research Fellowship, during the tenure of which this study was undertaken. This paper formed part of the thesis submitted by M. Natarajan to the University of Agricultural Sciences, Bangalore, India, in partial fulfilment of the requirements for an MF Sc. degree.

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FISH GROWTH ON MANURES AND DIGESTED SEWAGE SLUDGE 27[

RAY, P. & DAVID, A. (1969). Poultry manure as potential plankton producer in fish nurseries. 'LABDEI/" Journal ~[ Science and Technology, Kanpur, India, 78(3), 229 31.

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in ponds. Transactions oJ the American Fisheries Society. 68, 309.. 15. SMITH, E. V. & SWINGLE, H. S. (1939). Effects of organic and inorganic fertilisers on plankton and blue

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