AGRICULTURAL RESEARCH ANDEXTENSION UNIT

(Food and Agricultural Research Council)

HYDROPONIC FERTILIZERScommercialized in Mauritius

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(Comparative study of the differenthydroponic fertilizer formulations. available in Mauritius)

11.0 Introduction IHydroponics can be defined as the science of growing plants in amedium, other than soil, using mixtures of the essential plant nutrientelements dissolved in water. The word hydroponics is derived fromtwo Greek words: "hydro" (water) and "ponos " (labour).The plants that are grown in hydroponic are 'fed with a nutrientsolution. The nutrient solution consists of water into which all theessential elements needed by the plants for their growth anddevelopment are dissolved.

12.0 The Hydroponic utrient Solution 1

Plant requires 16 essential elements for its growth and development.These are made up of the major elements (nitrogen, potassium,phosphorus, calcium, magnesi ,ulphur) and also carbon, oxygenand hydrogen available in the form of water and carbon dioxide. Theminor elements (iron, boron, manganese, copper, zinc, molybdenum,chlorine) are required in very little amount. These 13 major and minorelements are mixed in water to gi e the hydroponic nutrient solution.Research has been carried out to develop different formulations sothat a specific amount of each element is used to prepare the nutrientsolution. This eliminates any problems of toxicity (due to excessfertilizer) and deficiency (due to limited fertilizer).Two important components of hydroponic solution are the pH(acidity) and E.C. (Electrical Conductivity)pH: The pH value is a measure of the acidity or alkalinity and it rangesfrom a value of 1 to 14. ApH less than 7 indicates acidity; 7 is neutraland above 7 it is alkaline. The pH of the nutrient solution determinesthe availability to the plant roots of the various elements found innutrient solution. Most plants prefer a pH level between 5.8 to 6.5 foroptimum nutrient absorbtion.E.C.: Inorganic fertilizer dissolved in water and dissociates intoindividual electrically charged units called ions and these ionsconduct electricity. The desired range of ErC. is generally betweenl.9mS/cm to 2.3 mS/cm.

Hydroponic fertilizer is available or prepared as concentrated solutionA and concentrated solution B. The purpose of preparing two separatesolution A and B is to prevent mixing of element like calcium withphosphate or sulphate salts.

Three types of fertilizer formulations are commercially available inMauritius for use by hydroponic growers and these are:

(a) Chemco Nutrient Solution A and Chemco Nutrient Solution B.(b) Chemco Granular Fertilizer known as Hydro Packs (A + B).(c) Individual compound fertilizers in the granular form which are

used to prepare nutrient solution according to specificguidelines.

PART!

(i) Chemco Nutrient SoSolutionB

ion A and Chemco Nutrient r

The hydroponic solution A and hydroponic solution Bareconcentrated liquid feritilizer and are available in the followingconsignment.

Fertilizer Available in Price of 1 L of Total Costconsignment A+ 1 LofB (Rs)of

Hydroponic5L Rs30 150solution A and B

Hydroponic25 L Rs 20 500solution A and B

Hydroponic200 L Rs20 4000solution A and B

To prepare the final diluted nutrient solution 1 L of concentratednutrient solution A and 1 L of concentrated nutrient solution Baremixed in 100 L of water. This solution will contain all the nutrients inthe concentration given below at a pH of 5.5 - 6.5 and E.C. of 2.3mS/cm.

Element ConcentrationNitrate Nitrogen 200ppmNPhosphorus 50ppm PPotassium 300 ppm KCalcium 180 ppm CaMagnesium 50 ppmMgSulphur 120ppm SIron 3.0 ppm FeManganese 0.3 ppmMnZinc 0.3 ppmZnCopper 0.1 ppm CuMolybdenum 0.05 ppmMo

Note: The same formulation is used for any vegetable crop throughout thewhole crop cycle.

(ii) Chemco Granular Fertilizer (Hydro PacksAand B)"-

The hydro pack fertilizer:s ~re gran lar fertilizers which are availablein three different formulations to cater for three different stages ofplant growth. (see table below)

Stage Formulation Price/Pack1 Hydro pack 1 (A & B) Rs 8002 Hydro pack 2 (A & B) Rs 10003 Hydro pack 3 (A & B) Rs 1200

Note:The different stages of the crop cycle can be divided into:Stage 1-From transplantation of seedling to the development oftbird flowerStage 2- From appearance offourth flower up to the harvest of econd bunch offruits

. Stage 3-After harvest of s cond bunch offruit to the end of erop cycle

Each pack contains two separate products (A & B) in granular form andthese have to be dissolved separately in 2 containers of70 litres of watereach to give the concentrated nutrient solution stock. Each 70 litres ofthis stock solution of A and B needs to be further diluted to give thediluted nutrient solution. For its application, the final solution isprepared by diluting 1 L of A plus 1 L of B in 100 L of water. Thissolution ill contain all the nutrients in a well balanced formulaessential for hydroponic culture as given below at a pH of 5.5 - 6.5 andE.C of 2.3 mS/cm.

(iii) Individual compound fertilizers in the granular form

Instead of purchasing the pre-mixed fertilizers, growers can preparetheir own stock solutions using individual compound fertilizersfollowing recommended guidelines.

The amount and cost of individual compound fertilizers used Inrecommended formulation is given below.

Available in Price/kg Total PriceFertilizer consignmentof

(Rs) (Rs)

Microelements 20 L 1051L 2100Calcium Nitrate 25 Kg 22 550Monopotassium

25 Kg 55 1375Phosphate (Mkp)Magnesium

50 Kg 33 1650SulphatePotassium Sulphate 25 Kg 22 550Monoammonium

25 Kg 45 1125PhosphatePotassium Nitrate 25 Kg 24.50 612.50

The nutrient solution stocks are prepared in two separate 50 Lcontainer (concentrated solution A and concentrated solution B).Thisprevents formation of insoluble precipitates of calcium phosphateand calcium sulphate. Each 50 litres solution of A and B is now in theconcentrated form and need to be further diluted. For application to

. plants, the nutrient solution is prepared by mixing 0.6 litres ofsolution A + 0.6 litres of solution B in 100 litres of water. Theresulting nutrient solution should have an E.C. within the range of2.12.3 mS/cmanda pH within the range 5.5 - 6.5.

The individual compound fertilizers in the granular form are mixedaccording to three different formulations to cater for different stagesof plant growth. These are listed below:

Formulation for preparation of Hydroponic stock Solution Aand Solution B:

Stage 1 Stage 2 Stage 3

Fertilizer Salts Amount Amount Am unt(kg) (kg) (kg _

Potassium nitrate 2.351 3.396 2.0~ -,---Monoammonium 0.233 0.116 0phosphateContainer A Magnesium sulphate 4.375 3.750 3.750--

(50Lof water)Potassium sulphate 0 0.940 1.880Monopotassium 2.048 2.048 2.731phosphate

Container B Potassium nitrate 2.351 3.396 2.090Calcium nitrate 11.579 9.474 10.526(50Lof water)Microelements(kanieltra) 1.0 L 1.0 L 1.0 L

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ote: The microelements (Kanieltra) used !in the prepar tion of the stocksolution should consi t of the followingmicroelements;

Microelements (Kanieltra) Concentration (% per pint)Boron 0.5Copper 0.5Iron 2Manganese 0.5Molybdenum 0.02Zinc 0.5

PART 2

The amount of the different fertilizer formulations and their cost withrespect to the crop and its crop cycle are given below:

ote: In all the calculations, it has been assumed that 1 plant uses1 litre of solution per day throughout the whole crop cycle.

Crop: TOMATO (Crop cycle 6 months) (1256 plants)

Stage 1= 1month; Stage 2 =2 months; Stage 3 = 3 months

Chemco Nutrient Chemco Granular Individual compoundSolution Fertilizer fertilizer formulationFertilizer Amount Fertilizer Amount Fertilizer Amount

(L) (No. ofpacks)

Cone. Nutr. 2262 Hydro6 Microelements 30LSolution A oack I

Hydro12 Calcium Nitrate 330 kgCone. Nutr. 2262 pack 2

Solution B Hydro 18 Monopotassiumpack 3 phosphate 90 kg

Total No.Magnesiumof Hydro 36 120 kg

oacks sulphate

Potassium sulphate 60k!!Monoammonium 6 kgphosphate

Potassium nitrate 210 kg

Total cost: I Rs 45,240 Rs 38,400 Rs 26 055

Crop: CUMCUMBER AND MELON (Crop cycle: 3months) (1256 plants)

Stage 1= 3 weeks; Stage 2 = 4 weeks; Stage 3 = 5 weeksChemco Nutrient Chemco Granular Individual compoundSolution Fertilizer fertilizer formulationFertilizer Amount Fertilize Amount Fertilizer Amount

(L) (No ofacks

Cone.Nutr.SolutionA

Cone.Nutr.SolutionB

1131

1131

5

6

8

19 Magnesiumsulphate

PotassiumsuI hate

IS L .

165 kg

45 kg

60 kg

30 kg

Monoammonium, hate 3 kg

Pota siumnitrate 105 kg

TotalCost Rs22,620 Rs19,600 Rs13,028

Crop: SWEET PEPPER ( rop cycle: 5 months) (1256plants)

Stage 1= 1month; Stage 2 = 2 months; Stage 3 = 2 monthsCbemco utrient Cbemco Granular Individual compoundSolution Fertilizer fertilizer formulationFertilizer Amount Fertilizer Amount Fertilizer Amount

(L) (No ofacks

Cone, Nutr. 1885 Hydro 6Solution A aek I

Cone Nutr. 1885 12Solution B

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30

Potassium nitrate 175 kg

Total Cost Rs 37 700 Rs 31200 Rs 21,713

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Summary table of cost each commercial nutrientformulation with respect to specific crop

Fertilizer Tomato Sweet Cucumber/Pepper Melon

(1256 plants) (1256 plants) (1256 plants)Chemco Nutrient Rs 45,420 Rs 37,700 Rs 22,620Solution (A +B)Chemco Granular Rs 38,400 Rs 31,100 Rs 19,600Ferti lizer(H ydropack A+B)Individual compound Rs 26,055 Rs 21,713 Rs 13,028fertilizer formulation

Pre-mixed fertilizer materials though easy to use, are relativelyexpensive compared to individual compound fertilizers. The pre-mixed fertilizers leave little room for making changes inconcentrations of individual n trients. r

A comparison of the values for the cost of different commercializednutrient solution shows that using the individual compound fertilizerformulation is the cheapest as compared to the pre-mixed fertilizers.

However the only hassle is that the grower has to weigh individualfertilizer prior to preparing the concentrated stock solutions.

List of Hydroponic Fertiliser Suppliers

1. .Mauritius Chemical Fertilizer Industry(CHEMCO)Chaussee Tromelin, Fort GeorgesPO Box 344, Port LouisPhone No.: 2163965Fax No: 240 9969(Mr. Ajay Luximon)

2. Bonns AgribusinessBonne- TerreVacoasPhone No. 4255922, 761 9760Fax No: 4261193(Mr. Gobhurdun)

3. Best Agri Ltd.13, Jacmin Street,Roches BrunesPhone / Fax No.: 467 5631Mobile No.: 2512021(Mr. Ajagen Veerapen)

4. Greenworld Company Ltd.Solferino No.1, VacoasPhone No.: 427 8113Mobile No.: 2544013

. Fax No.: 424 5160(Mr. Gunsham Boodram)

Agricultural Research and Extension UnitSt. Jean Road, Quatre Bornes

Tel: 230 466 3885 - Fax: 230 464 8809Email: areu@intnet.mu