INTRODUCTION TO AQUAPONICS - arc.agric.za

INTRODUCTION TO AQUAPONICS

MARY-JANE THAELA-CHIMUKA

[email protected] ZA

REASONS FOR AQUAPONICS

FARMINGIn developed countries, farmers taking up

aquaponics for several reasons including;

Hydroponic growers view fish manured irrigation water

as a source of organic fertilizer that enables plants to

grow well.

Fish farmers view hydroponics as a bio filtration method

to facilitate intensive recirculating aquaculture.

Greenhouse growers view aquaponics as a way to

introduce organic hydroponic produce into the

marketplace, since the only fertility input is fish feed and

all of the nutrients pass through a biological process.

REASONS FOR AQUAPONICS

FARMING cont. Food-producing greenhouses – yielding two products

from one production unit – are naturally appealing for

niche marketing and green labelling.

Aquaponics can enable the production of fresh

vegetables and fish protein in arid regions and on water

limited environment (such as South Africa), since it is a

water re-use system.

Aquaponics working model of sustainable food

production where plant and animal agriculture are

integrated and recycling of nutrients and water filtration

are linked.

•In addition to commercial application, aquaponics has

become a popular training aid on integrated bio-systems

with vocational agriculture programs and biology classes

(Diver, 2010).

AQUACULTURE• There is a global call sustainable food production Climate

Smart Agriculture (CSA) for people/communities produce

affordable in context of;

– Dwindling water resources (i.e. reduced quality and

availability)

– Competition land uses (housing, urban development) due

to pressures of high

– Population growth rates and increased human activities

and impacts

– Land degradation, use of fertilisers, expensive due to

high processing costs.

AQUACULTURE• Aquaculture expected satisfy growing world

population’s demand

• Protecting ocean fish stocks –(over-fishing).

• 1990, growth rate estimated to be 7.8% per year,

• Major source of income 11 million of people (FAO,

2011, 7) & main source of animal protein for 1

billion of people

• Excellent feed conversion rate (FCR )hence lowest

carbon footprint.

AQUACULTURE cont• Present challenge aquaculture industry

development & implement sust intensify

fish cultivation while maximizing water and

nutrients reuse, and minimizing

environmental impacts

• technologies such as aquaponics

– reduce the rapid increase of greenhouse

gas(N2O) emissions,

– minimize water exchange, and

– maximize nutrient Recovery

AQUACULTURE

• Aquaculture direct environmental impact

release nutrient-rich waste waters

surrounding esp. aquatic environments

(Boyd and Tucker 2012).

• Some hydroponic also possess this potential.

Wastewater from aquaculture systems often

discharged into waterbodies, results nutrient

pollution and subsequent eutrophication.

FOUR MAJOR CATEGORIES OF

AQUACULTURE

1. Pond Culture 3. Flow-through raceways

2. Open water systems 4. Recirculating aquaculture

system (RAS)

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AQUACULTURE (CONT…)

1. Pond culture – traditional and simplest type of aquaculture operation

• Requires simple technology

• Low capital costs.

• Needs high chemical use of fungicides and herbicides to treat the system.

2. Open water systems – Single pass of water throughout the system before the water is discarded.

Trout farms - requires large volumes of high quality cold water.

• Have greater available space and low pumping cost.

• Water temperature is weather and climate dependent.

• Difficult to monitor health status of the fish and clean the system.

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AQUACULTURE (CONT…)3. Flow-through raceways – artificial channels used in aquaculture to culture aquatic organisms

• Requires less water treatment for intake water and effluent.

• Simple technology for water chemistry.

• Requires high water use and

• The farmer less control over water quality and temperature.

4. Recirculating aquaculture system (RAS) -most efficient water-saving system in fish farming

• Water is reused for the fish after a cleaning and a filtering process

• Expensive - higher investment, energy and management costs• Can increase productivity – controlled environmental conditions and

temperature

• Applicable method for integrated aquaculture systems

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DEFINITIONS AQUACULTURE, HYDROPONICS

Hydropponics–soilless culture of plants either in an inert growing media (substrates) or by submerging the plants' bare roots in an aqueous medium connected with nutrient-solution irrigation systems. The inert growing media offer support for plant roots as well as retention of moisture

• The farmer less control over water quality and temperature.

aquaculture production systems refers to the water-holding facility in which the organisms are grown

Several kinds of water-holding facilities are used for growing cultured organism.

facilities are grouped into four types: ponds, cages, raceways, (tanks).

.

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HYDROPONICS DEFINITION

• Soil-less culture Instead of soil, growing

media (substrate) is employed. The media

provides plant support and moisture

retention. Irrigation system equipped with

nutrient-rich solution is integrated within the

media to provide plant roots with required

nutrients for growth and food production.

INTRODUCTION

HYDROPONICSHydroponics (Soil-less

culture)

• Method of growing plants

without using soil.

• Growing media

(substrate) is used.

• Substrate - plant support

and moisture retention.

• Irrigation - nutrient-rich

solution.13

HYDROPONICS

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• During culture directly

plant available stock

nutrient solution are

added to water(i.e. ionic,

inorganic forms produced

via designed

• salt variety additions)

(Resh 2013).

INTRODUCTION TO AQUAPONICS:

HYDROPONICS (CONT…)Strengths

• Uses minimal water and fertilizers

• Requires less labour

• Can be practiced in urban areas

• Decreased presence of soil-borne

diseases and pathogens

• Improved growing conditions leading

to increased yield

Shortcomings

• High initial cost is required – Set up cost

• Technical expertise

• Energy - increased production cost

• Plants grown in hydroponics system are

prone to fungal diseases

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HYDROPONIC SYSTEMS

• . Water Based Culture:

• Floating Hydroponic Technique

(Raft Culture, Deep water Culture)

• Nutrient Film Technique (NFT)

Media Based Culture:• Reciprocating Systems

• (Ebb & Flow, Flood & Drain)

• Dutch Bucket

• Drip System – Rockwool Slabs

Air Based Culture:• Aeroponics

• Vertical Gardens

PLANTS AQUAPONICSThe adaptation plant species directly related

fish stocking density in tanks & nutrient

concentration aquaculture effluent. Leafy

plants that do well any aquaponics system:

herbs lettuce and leafy greens (chives,

lettuce, basil) as nutrient requirements is low

to medium.

PLANTS AQUAPONICS contPlants that have higher nutritional demands

(Fruit yielding plants such as tomatoes, bell

peppers, and cucumbers) and will only do well

in a heavily stocked, well established

aquaponics system: Clearly the plant species

choice for aquaponics cultivation is largely

determined or dependent on the fish stocking

density in the fish tanks meaning that is

effluent nutrient concentration.

DEFINITIONS: AQUAPONICS

Is the integration of recirculating aquaculture (growing fish) and hydroponics(Ponos Greek growing plants with or without in one production system. In an aquaponic unit, water from the fish tank cycles through filters, plant grow beds and then back to the fish

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INTRODUCTION TO

AQUAPONICSAquaponics

• Integration of recirculating

aquaculture and

hydroponics in one

production system.

• Water from the fish tank moves

through filters, plant grow-beds

and then back to the fish.

• Allows the fish, plants, and

bacteria to live symbiotically in

order to create a healthy

environment for each other.

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HOW DOES AQUAPONICS WORK?Waste products from the fish are converted by bacteria into soluble nutrients,

which are absorbed by the plants, and allows “clean” water to be returned

back to the fish (FAO, 2014). Figure 1: Biological components in the aquaponics

process: fish, plants and bacteria

• System design

options are many

• Systems are

typically scalable

• Various fish options

• Various herb/

vegetable options

• Materials from

cheap to high tech

and expensive

AQUAPONICS

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Comparisons between hydroponics and aquaponics

Hydroponics Aquaponics

Energy requirements

Need aerators and pumps

Frequent water circulation leads to higher energy requirement

Maintenance Requires frequent checks

Natural ecosystem balances everything, ammonia and pH level checks once a week only while nitrate levels are checked once a month

Waste Disposal Periodic replacement of water-based solution leads to large amounts of wastewater; can pose environmental risk.

Solid waste in excess of broken down waste by nitrifying bacteria is minimal and pose no risk to the environment.

Cost of Chemical

Expensive chemical nutrients

Requires mostly use of fish feed which is cheaper.

Risk of Diseases

Risk from fungal infections is higher;

An outbreak can spoil an entire batch.

Built in a natural ecosystem thus, resistance to diseases is higher.

Nutrient Solution Retention

Periodic unloading of water due to toxicity from salt and chemical build-up.

Has natural balance of nitrogen; water is seldom replaced; topped up only due to evaporation

Solid Media Needs 6-inch deep beds when pebbles and clay balls are used

Needs 12-inch deep beds of pebbles and clay balls to sustain waste-eating microorganisms

Setting Up Faster set-up with no required time for gestation period

Requires 3-6 months for the system to be fully functional.

Mechanical Failure Risks

No lasting damage Problems in circulation can adversely affect fish mortality

Organic Growth Makes use of costly mixture of chemicals and salts to feed plants

Makes use of natural waste conversion process resulting in better plant growth and lower disease rates.

ADVANTAGES AQUAPONICSA well-managed aquaponics

• Improve nutrient retention efficiency

• Reduce water usage and

• Waste (mostly nutrients) discharge to the

environment, and

• Improve profitability by simultaneously producing

two cash crops

• In near future aquaponics, with nutrients recovery,

will one widely accepted methods of sustainable

food production

COMPONENTS OF

AQUAPONICS• For past three decades,

aquaculture (RAS)

practices, and

hydroponic(s) plant

compartments were

integrated to alleviate

the accumulation of

nutrients especially, N

compounds in the

culture system.

STRENGTHS WEAKNESSES OF

AQUAPONICS

STRENGHTS WEAKNESSES COMMENTS ON OVERCOMING

WEAKNESSES

Sustainable and intensive food production

system.

Expensive initial start-up costs compared with

soil vegetable production or hydroponics.

Design will to take into account cost and

availability of materials

Two agricultural products (fish and vegetables)

are produced from one nitrogen source (fish

food).

Knowledge of fish, bacteria and plant production

is needed for each farmer to be successful.

Training will need to be provided

Extremely water-efficient. Fish and plant requirements do not always match

perfectly.

Will need to provide design that is most efficient.

Need extension assistance to allow adaptations

(flexibility)

Does not use fertilizers or chemical pesticides. Not recommended in places where cultured fish

and plants

Water in North West favours tilapia and catfish =

good aquaponics species.

Daily tasks, harvesting and planting are labour-

saving and therefore can include all genders

and ages.

Alone, aquaponics will not provide a complete

diet.

Fish and vegetables/ leafy greens will be a

valuable nutritional addition to existing diets.

STRENGTHS AND

WEAKNESSES OF AQUAPONICS

Economical production of either family food

production fish or cash crops in many

locations.

Unsustainable fish food

Natural feed for fish grow algae and worms to

supplement or replace ingredients that are costly

for

Construction materials and information base

are widely available

For commercialisation initial cost to set up higher

initial cost than other production methods, such

as home gardens. It will depend on the size of the

system and its technological level. Consider that

pumps and plumbing items are required.

One can always start small

Higher yields than soil culture by using same

land for production agriculture and fishes.

Land Conservation;

Produces 2-6 times as it allows use of multiple

platforms on top of each other. cultivate

different crops in same area

Reduced management choices compared with

stand-alone aquaculture or hydroponic systems.

(This could also be a positive) Operation needs

to be according to guidelines.

Higher control on production leading to lower

losses.

Mistakes or accidents can cause catastrophic

collapse of system.

Training and extension in initial phases very

important.

Higher level of biosecurity and lower risks from

outer contaminants.

Daily management is mandatory. Since it is a ‘home’ system, daily management is

possible.

STRENGTHS AND WEAKNESSES

OF AQUAPONICS

No-Floor required Can be used on non-arable

land such as deserts, degraded soil or salty,

sandy islands. Can also be practised in cities

where it is arable land is practically non-

existent.

Energy demanding. Optimise the use of gravity to reduce pumping

costs. Heating should not be required since NW

is good for warm-water fish.

Creates little waste.

Requires reliable access to electricity, fish seed

and plant seeds

Generator/ manual/ battery options must be

explored. Fingerlings are available but reliable

supply must be secured. Seedlings/seed typically

easy to acquire.

Produces 2-6 times because it allows us to use

multiple platforms on top of each other. No

matter where and what condition you are it you

can cultivate different crops in same area

Multidiscipline skills and technology necessary

compared to other production. Multiple points of

failure fish and plants

Training and mentorship

Alone, aquaponics will not provide a complete

diet.

It can be combined with other faming methods

Closeness to the markets, as it can be installed

anywhere even at food markets and

distribution centres. Reducing transport costs

and also delivery products while still fresh.

Cannot meet their optimal temperature ranges Alternative energy/ renewable

APPLICATIONS OF

AQUAPONICS

Small-Scale Aquaponics

Semi-Commercial

and Commercial Aquaponics

Educational Aquaponics

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MAIN AQUAPONICS

CONSTRAINTS SA cont.• Many SA farmers are fish-only focusing enterprises, as they started

as aquaculture farms and evolved as aquaponics and have better

fish than vegetable market

• Further more aquaponics are regulated neither by Department of

Environment, Forestry and Fisheries (DEFF) nor by Department of

Rural Development and Land Reform (DRDLR) policies (personal

communication Neale Strauss).

There is therefore a need for research studies supporting the policy-

making process and also helping the aquaponics farmers to

source funding, and credit, Hence, this project will developing

model “A one-house one-aquaponics and one-school one-aquaponics

systems” program to address that challenge

•

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MAIN AQUAPONICS CONSTRAINTS.

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Challenge Solution

Technical challenges

pH stabilization (fish, plant and bacteria) ● Nutrient supplementation addition of

dissolved limestone.

Pest (plants) and disease management (plants

and fish)

● Maintain the nitrification biofilm.

● Observation of Sanitary measures.

● Control of environmental conditions – by

not allowing an increase in relative

humidity around the plants.

Solid accumulation in the system. ● Use sump to collect excess solids.

Socio-ecological challenges

Water scarcity ● Capturing water from the vapour.

● Harvest rainwater.

● Use of reverse osmosis for

contaminated water.

Energy availability ● Use renewable energy hybrids (solar

energy and Production of biogas from

waste).

Shortage of space for urban farming and short

supply chains

● Rooftop gardens.

● Use old industrial neglected buildings.

Economic challenges Start-up cost ● Apply for government grants.

● Start up with a small system and expand

over time.

Energy cost ● Use of renewable energy

Education

Lack of knowledge and understanding (Skills) ● Skills development to address and

reduce unemployment among youths,

young graduates and women.

THANK YOU

.

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