Efficient irrigation and fertigation management of high value cash crops under polyhouse

Dr SP Dixit (Head)Department of Soil Science, CSKHPKV Palampur

CULTIVATION IN POLYHOUSE

•Protected cultivation•Controlled Temp (Soil & Air)•Controlled Atmospheric demand• Easy to maintained soil water around field capacity•Recommended for high value cash crops with high water requirements

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GREENHOUSE WITH RAIN WATER HARVESTING

• Collection of rainwater incident on the rooftop of greenhouses, storing the collected water, and providing irrigation to the to plants using the harvested water through drip irrigation systems.

• GI gutters are provided to the sloping roof of the greenhouse to collect rainwater. The harvested water is filtered and stored in rain barrels.

• Provision can also be made to collect overflow of water from these barrels. Water from the barrels is fed to the drip irrigation system through sand filters.

Data collected shows that the water harvested from the roof top is adequate and of acceptable quality for irrigating crops inside the greenhouse. (UAS Studies)

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What is Drip Irrigation?

The method of applying water below the ground surface in the form of droplets in the root -zone.

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Drip irrigation system

TRADITIONAL DRIP IRRIGATION SYSTEM

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The merits of drip system includes

30-70 per cent water saving, 30-100 percent increase in yield, 40-60 per cent savings in fertilizer and chemicals, saves land, 44-47 percent saving in energy, better quality of crop, high returns per unit area and time, saves labour cost, Improved water penetration, poor quality water can be used safely and eco-friendly technology.

Merits of Drip irrigation

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Profile water distribution with drip irrigation

• Normally the soil water distribution is done to a small area relative to the total soil surface area

• Water distribution into the soil follows a three dimensional infiltration pattern, different from the one dimension (vertical) infiltration type of conventional irrigation systems, where the soil surface wetted area is the whole soil surface area

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Moisture and Aeration Distribution around drippers in cauliflower

Moisture Content Aeration Porosity

Drip-Irrigation scheduling

• Climatologically approach

IW/CPE =1 (Water lost and water applied)we work in range from 0.4 to 0.8 CPE = 5 mm than IW = 5 mm when ratio is 1 CPE = 5 mm than IW = 4 mm when ratio is 0.8

CPE = 5 mm than IW = 2 mm when ratio is 0.4

Micro-Irrigation scheduling

• Available Water Depletion / % decrease from Field capacity

20 to 40 % depletion • Use of tensiometers Should be placed in strategic

locations within the plant root- and wetted zone

• Plant water based irrigation RLWC and XWP

Fertigation

Application of fertilizers with irrigation water

Fertigation is used to spoon feed additional nutrients or correct nutrient deficiencies detected in plant tissue analysis

Fertigation

Most plant nutrients can be applied through irrigation systems

Fertigation allows the landscape to absorb UP TO 90% OF THE APPLIED NUTRIENTS, while granular or dry fertilizer applications typically result in absorption rates of 10% to 40%

Why Fertigation…?

Our irrigation system does the work.Overfeeding and Underfeeding is decreasedDry applications need water to dissolve the

granules.With precise application, the overall

amount of chemicals applied is reduced vs. the dry application.

Advantages• Increased nutrient absorption by plants • Reduction in fertilizer and chemicals needed • Reduced leaching to the water table and,• Reduction in water usage due to the plant's resulting

increased root mass being able to trap and hold water • Application of nutrients at the precise time they are

needed and at the rate they are utilized

Disadvantages

• Concentration of solution decreases as fertilizer dissolves, leading to poor nutrient placement

• Results in pressure loss in main irrigation line• Use of Chemical fertilizer of low-sustainability ,

instead of organic fertilizers

Fertigation techniques

• The total fertilizer quantity of water soluble fertilizers calculated is divided into equal parts and each part is applied at regular intervals. In venture system, each split of total water soluble fertilizer quantity is generally dissolved in 4 litre of water and is applied in 6-8 minutes. In fertilizer tank system, each split of total water soluble fertilizer quantity is dissolved in 20 litre water and is applied in 4-5 minutes.

Effects of NPK Fertigation (2010-12)

Fertilizer doses Caulifloweryield (t/ha)

Capsicum Yield (t/ha)

Garden pea (t/ha)

Broccoli Yield (t/ha)

33 % RDF 10.87 23.89 8.12 41.90( 50% RDF) 66 % RDF 13.03 28.00 8.83

100 % RDF 14.26 31.21 9.25 49.50Rec Fertilization 14.80 26.16 8.62 29.95

CD (5%) 0.73 1.47 0.84

Water soluble fertilizers 19:19:19, 0:0:50 and urea are used

Venture systemFertigation tank system

Component to be refined

Existing technologies Proposed refinement in existing technologies

Irrigation scheduling

Adhoc recommendations of drip irrigation system operated twice a week during summer and once in a week during winter with 4 litre /m2 water applied

Climatologically based drip irrigation system to be operated on alternate days during summer and winter with irrigation applied based on averaged cumulative pan evaporation data

Fertigation scheduling

There is no recommended dose of fertilizer for drip fertigation. Either conventional fertilizers are applied as soil application or 19:19:19 water soluble fertilizer is applied @ 2.2 g/litre of water

The 50 to 200 % of recommended doses of fertilizers (RDF) for open cultivation with fertigation applied through drip will be evaluated to find out the optimum fertilizer dose

Water Soluble fertilizers

Only 19:19:19 water soluble fertilizer is used

The different combinations of 19:19:19, 12:61:0 and urea will be calculated depending upon fertilizer doses as per treatment

Fertigation duration

Adhoc recommendation of fertigation initiation after 25 days of transplanting and fertigation applied through drip, once or twice in week and continued till 15 days before harvest of produce

The calculated fertilizers doses will be applied in 45-50 equal splits twice a week with its initiation from 21 days after transplanting

S.No Name of the crop

Duration of crop

Fertigation details

1. Cucumber 3 months 5,7, 10 and 20 splits with the intervals of 15 days, 10 days, weekly and twice a week

2. Tomato 8-9 months

14, 21, 28 and 56 splits with the intervals of 15 days, 10 days, weekly and twice a week

3. Capsicum 8-9 months

14, 21, 28 and 56 splits with the intervals of 15 days, 10 days, weekly and twice a week

Fertigation under protected conditions •Application of 25 % of RDF as basal through conventional fertilizers and 75% of RDF through fertigation using water soluble fertilizers i.e. 19:19:19 + 12:61:0 + urea with four nutrient levels 50, 100, 150 and 200 % RDF to be applied as per details given as

Irrigation Monthly evaporation rate (mm)2.0 3.0 4.0 5.0 6.6 7.0 8.0

Daily Irrigation requirements (Litres/ m2)

1.6 2.4 3.2 4.0 4.8 5.6 6.4

Drip operation time (minutes)

6.4 10.0 12.8 16.0 19.2 22.4* 25.6*

Irrigation water requirements in capsicum, tomato and cucumber

*Irrigation can be given in morning and evening hours but at a gap of at least 6 hours

Marketable yield ( q/ha) Total Irrigation applied (Litre)/ m2 area

Area can be irrigated (m2) /1000 litre of water

Increase in area with drip

Flood + Fertilization

Drip + Fertigation

Flood Drip Flood Drip

100 109 800 186 1.25 5.4 4 times

Drip based NPK fertigation in cauliflower

Drip based NPK fertigation in broccoli

Marketable yield ( q/ha) Total Irrigation applied (Litre)/ m2 area

Area can be irrigated (m2) /1000 litre of water

Increase in area with drip

Flood + Fertilization

Drip + Fertigation

Flood Drip Flood Drip

73 85 760 172 1.31 5.81 4 times

Micro-sprinkler based NK fertigation in pea

Marketable yield ( q/ha) Total Irrigation applied (Litre)/ m2 area

Area can be irrigated (m2) /1000 litre of water

Increase in area with Micro-sprinkler Flood +

Fertilization Sprinkler + Fertigation

Flood Sprinkler Flood Sprinkler

91 96 625 250 1.60 4.00 2.5 times

Precision irrigation through drip irrigation systemसटीक सिसंचाई ड्रि�प प्रणाली

Precision irrigation through drip irrigation system in polyhouseपोली हाउस में सटीक सिसंचाई ड्रि�प प्रणाली

Precision fertilizer application through fertigation सटीक फर्टिटंलाइजेशन - Fertigation

Precision irrigation through micro-sprinkler irrigation systemसटीक सिसंचाई सूक्ष्म स्प्रे प्रणाली

Commonly available water soluble fertilizers

Grade 19:19:19 17:44:0 0:52:34 13:0:45 12:61:0 0:0:50Total Nitrogen by wt (%) 19 17 0 13 12 0Ammonical N(%) 4.5 12Amide N (%) 10.5 0 0 0 0 0Nitrate N(%) 4.0 0 0 13 0 0Water Soluble P2O5

(%) 19 44 52 0 61 0Water Sol K2O(%) 19 0 34 45 0 50

Crop Basal Dose(g/ m2)

Fertigation Doses /spilt (g/ m2) No of splits

Fertigation Interval (Days)Urea SSP MOP 19:19:19 12:61:0 0:0:50 Urea

Tomato 14* 34 4 1.2 0.4 - 0.7 28 5 -7Capsicum 10 22 4 1.2 0.1 - 0.3 28 5 -7 Cucumber 12 18 6 3.0 2.3 - 1.2 10 5 -7 *25 % of the fertilizers doses applied through basal and 75 % through fertigation

Fertilizer schedule with 25 % basal doses & 75 % fertigation under protected conditions