Snehasish Majumder

Principles Of Fertigation In Micro Irrigation

National Seminar On Fertigation

Date: 15th Sept. 2017

Venue: Hotel Surya Palace, Vadodara

FERTIGATION

Fertigation is the process of application of Fertilizers along with Irrigation through

Micro Irrigation System.

Fertigation is the injection of fertilizers, soil amendments and other water-soluble

products into an irrigation system.

Fertigation is practiced extensively in commercial Agriculture and Horticulture.

Fertigation replenishes Nutrients that plants take from soil.

Fertigation is used to add additional nutrients or to correct nutrient deficiencies

detected in plant tissue analysis. It is usually practiced on all crops such as Cotton,

Vegetables, Sugarcane, Banana, fruit Crops, spices & ornamentals.

BENEFITS OF FERTIGATION

Maximizing Crop & Soil Productivity

Higher yields and top quality of produce, Marginal lands, like sandy soils, rocky

soils, shallow soils and salt affected soils can be successfully put into cultivation.

Maximizing fertilizer efficiency by accurate & uniform application

Reduces nutrients losses by leaching and/or volatilization

Increase in Nutrient uptake due to distribution of Fertilizers being uniform and at

active root zone area

Considerable savings in Fertilizers, Labour, Fuel costs

CLASSIFICATION OF NUTRIENTS

NUTRIENT CHEMICAL SYMBOL CATEGORY

Nitrogen N

Major OR Primary Nutrient

Phosphorus P

Potassium K

Sulphur S

Calcium CaSecondary Nutrient

Magnesium Mg

Iron Fe

Micro Nutrient

Manganese Mn

Zinc Zn

Boron Bo

Copper Cu

Molybdenum Mo

Chlorine Cl

SOURCE OF NURIENTS

C

H

O

N P K S

ALL SECONDARY & MINOR NUTRIENTS

In order to plants grow and develop they need

the supply of Carbon, Hydrogen & Oxygen (get

from atmosphere), in addition to this 13

essential mineral elements, which they get from

soil

NITROGEN (N)Nitrogen is the nutrient with the greatest influence on crop yield through the effect on chlorophyll and protein production.

Nitrogen

1. Intensifies the green color which is necessary for chlorophyll production

2. Increases leaf size

3. Increases growth rate.

4. Increases final yield and protein production

ROLE OF MAJOR NUTRIENT

ROLE OF MAJOR NUTRIENT

PHOSPHOROUS (P)Phosphorous is important in root development, the ripeningprocess and particularly in the manufacture and use of sugars andcomplex carbohydrates.Supply of phosphorous is essential in the early stages of a plant’slife and for early maturity.

Phosphorous

1. Stimulates root development

2. Helps plants to become established in the season

3. Encourages Maturity

ROLE OF MAJOR NUTRIENT

POTASSIUM (K)Potassium is associated with the regulation of water within theplant and with the control of water loss from the leaves.It is also vital for the root nodule bacteria on legumes which fixesnitrogen from air.

Potassium

1. Encourages healthy growth.

2. Renders crop more resistant to drought and disease.

3. Improves the quality of produce

ROLE OF MAJOR NUTRIENT

SULPHUR (S)Sulphur is constituent of few Amino Acids – Cysteine (26% S) & Methionine(21% S). Insectcide (Miticide) & Fungicide

Sulphur

1. Plays crucial role in Protein synthesis

2. Gives shining colour to fruits

3. Increases oil content in case of oil seeds

FERTILIZER SOLUBILITY

Fertilizers

Maximum

amount (kg)

dissolved in 100

L at 20°C

Time to

dissolve

(min)

pH of the

solution

Insolubles

(%)Comments

Urea 105 20(a) 9.5 negligible Solution cools as urea dissolves.

Ammonium nitrate [Nitram®

NH4NO3]195 20(a) 5.62

Corrosive to galvanised iron and

brass. Solution cools as product

dissolves

Sulfate of ammonia

[(NH4)2SO4]43 15 4.5 0.5 Corrosive to mild steel.

Mono-ammonium phosphate

[MAP]40 20 4.5 11 Corrosive to carbon steel.

Di-ammonium phosphate

[DAP]60 20 7.6 15 Corrosive to carbon steel.

Muriate of potash [KCl] 34 5 7.0–9.0(b) 0.5 Corrosive to brass and mild steel.

Sulfate of potash [K2SO4] 11 5 8.5–9.5(b) 0.4–4(b) Corrosive to mild steel concrete.

K-spray [K2SO4] 11 1 8.5–9.5(b) 0.4–4(b) Corrosive to mild steel concrete.

Potassium nitrate [KNO3] 31 3 10.8 0.1Solution cools as product

dissolves. Corrosive to metals.

SOIL TYPES

SANDY, SILT & CLAY SOILS

Sand is the largest particle in the soil. When you rub it, it feels rough. This is because it hassharp edges. Sand doesn't hold many nutrients or water.

Silt is a soil particle whose size is between sand and clay. Silt feels smooth and powdery.When wet it feels smooth but not sticky.

Clay is the smallest soil particle. Clay is smooth when dry and sticky or plastic when wet. Soils high in claycontent are called heavy soils. Clay can hold a lot of nutrients, and can hold quite a bit of water, but thestructure of clay doesn't let air and water move through it well.

Most of the water in a clay soil is so tightly bound to the clay particles that plants can't get it loose.

SOIL TRIANGLE

SOIL TRIANGLE TO IDENTIFY TYPE OF SOIL

Examle: SAND 30% + CLAY 30% + SILT 40%

soil type is Clay loam

SOIL WETTING PATTERN

FERTILIZER TANK

Model FT 30 - volume of tank: 30 litresModel FT 60 - volume of tank: 60 litresModel FT 90 - volume of tank: 90 litres

FERTIGATION PRINCIPLE: Pressure difference

WATER WATER +

FERTILIZER

FERTILIZER

Advantage: Head loss is minimum

Disadvantage :Concentration is varying and not uniform

VENTURY

VENTURI ¾” 1” & 2”

VENTURI with Manifold

TECHNICAL DETAILS OF VENTURY

¾” Venturi :- Injection rate 51-150 lphOperating pressure at inlet- 1 to 1.5 barHead loss : 0.2 to 0.6 bar

1” Venturi :- Injection rate 150- 270 lphOperating pressure at inlet- 1.1 to 1.6 barHead loss : 0.3 to 0.6 bar

2” Venturi :- Injection rate 650 -1000 lphOperating pressure 1.5 to 1.9 barHead loss : 0.5 to 0.8 bar

Advantage : Concentration is uniform

Disadvantage: Head loss is high

FERTIGATION PRINCIPLE: VENTURY

V-MAX, P-MIN Suction

P2 P1

P1 > P2

INLINE DOSING CONTROLLER FOR FERTIGATION

The In-Line Dosing system has many design features to ensure that acid & Fertlizers

are dosed accurately & safely. It offers cost effective alternative to mechanical fertilizer

injectors

Venturies are used for Fertilizer and acid dosing to provide a rugged design with

minimum moving parts

Dosing system uses a unique algorithm to give accurate pH & EC control with varying

flow rates

Fertilizer flow rate will depend on no. of Venturi Injectors

Booster Pump is used to drive Venturi Injectors and will depend on line pressure and

number of Injectors

INLINE DOSING SYSTEM

21

THANK YOU