Retractable green house vs closed green house

Hi friends ,
Few days back i had a chance to come across retractable roof greenhouses which is said to be more cost effective and better in performance than standard closed polyhouse .[ol]
[li]Retractable Roof Green house can use soil and no need to go for coir pith with extra cost[/li]
[li]can use naturally available panchagavya as fertilizer instead of buying  NPK rich fertilizer for a cost[/li][/ol]

May i know whether this is true.

thanks
ganesh

The retractable ph or curtain type ph are convenient to control when and where would one need ventilation. Also the roof retract makes the soil like heat sink during the night.

Having said above, I have seen lot of polyhouses naturally ventilated without any curtain thermal screens which have soil as grow medium and panchgavya bein used as organic Fertilizer.

So IMHO having a retractable option would be more of site specific environmental parameters and shouldn’t be considered a rule of thumb.

Hoping to see more views on the same.

Regards

Dear Ganesh
Thanks for starting this discussion. I am thankful to you and farmnest team to initiate such discussion on this forum.
Cravo which has been challenging conventional greenhouse technology through its innovative Retractable roof greenhouse technology for tropical and mild locations which does not require fan and pad system to cool down air temperature, suitable for year round production and also effective against tropical cyclones.
We have started our Indian operations in 2015 and established our first retractable roof for one hectare with Namdhari Fresh at Bangalore in India which is one of the largest producer and exporter of fruits and vegetable from India to Middle East
Major advantages of retractable roof greenhouse technology are
• Increase Revenues higher than any production system
• Extending the growing season or target off season production of any crop.
• Growing more fruit or flowers per plant in less area
• Growing higher quality fruit (longer shelf life, less chemical residue, bigger size, higher brix)
• Expanding possible production locations in climates where it is difficult to grow with traditional technologies
• Can grow different varieties of crops which were previously impossible to grow under CEA.
Decrease operating costs by reducing the need for:
• Labour
• Electricity
• Water
• Fungicides and pesticides
Reduce risks of crop loss due to weather variability
• Reduce the inherent variability that comes with relying on the weather i.e,rain,hail,snow,wind etc
• Reduce risk of loss from catastrophic events (i.e. hurricanes)

With best regards
Rajender Kumar

Dear sir
Thanks for your response.
This technology is to be seen from different prospective from conventional thinking.Our knowledge and experience is confined to what we have seen and learned but this technology is going to make considerable changes in controlled environment technology in India.
kindly go through our website for better understanding.
Regards
Rajender 

In Indian climate there need only roof for “green house” there is no need for sidewalls or curtains unless there is very high wind or below 25 degree cold in your area.

The whole idea of enclosing the greenhouse is to increase the heat.

In India the roof can protect the plants from direct heat and direct heavy seasonal and unseasonal rain.

Send the collected rainwater from the roof to the well or a percolation tank/pool.

You dont necessarily need raised beds if you use drip irrigation as raised beds are used to decrease the moisture in soil.

The structures can be of Steel, aluminum, PVC pipes or bamboo. If you grow bamboo you could have a greenhouse for almost free as you could cut and use them.

So you will have a mini-green house and also a rainwater harvesting solution at very low cost.

Dear sirs,

The whole idea of enclosing the green house is, not only for increasing the heat but also for giving the Green House Effect to the plants,farming inside.

The plants breaths air in the atmosphere throughout the day and night. In the day, they consume Carbon dioxide and omit Oxygen. they consume oxygen and omits carbon dioxide in the night time.

The plants require high quantity of carbon dioxide in the next day, from morning ,for its photosynthesis process for food preparation. In green house, the throughout night omitted carbon dioxide will be stored as the side curtains will not allows it to go out. The carbo dioxide is a heavy gas and cumulates in the bottom portion of the green house.

This is my known knowledge and experts may correct it ,if any mistake, as it is a technical authority subject.

That is the reason, the poly houses are closed all around it and they become Green Houses.

with best wishes,  g.p.rao,  farmer

You are right g.p.rao… the screens have more than one purpose to hold the gases, to prevent infection etc.

But the main purpose of complete enclosure is to make the green house more hot and humid than outside “temperature”. When we talk of greenhouse effect it means… increasing the heat… or trapping the heat its the same principle a solar cooker uses. Complete enclosed greenhouse can be used in places with below 25 degree summer temperature…

In India if you have a completely enclosed greenhouse in 40 degrees summer temperature they will surely need air-conditioning which will again increase the cost…

There is nothing very technical about it… but we can make it more technical, complicated and hugely expensive by adding air-conditioning, LED Lights, hybrid seeds, temperature sensors, liquid nutrients, pesticides, breathing sensors, soil sensors, computers, servers, CCTV cameras, air curtains, air showers, the list is endless…

and yes Ganesh you can grow crops without the above list using traditional fertilizer but if one wants to pass traditional fertiliser through drip lines then either it has to be filtered to keep out bigger particles that can block the pipes…

Bamboo greenhouse innovation: youtube.com/watch?v=VcmAAf9kNkI

Professional green houses cost around 20 Lakhs per acre… which is really crazy price… that to in India… a country which is the father of farming. Its like selling Refrigerator to an Eskimo.

So go low cost… use natural farming methods, harvest rainwater and use the plastic as shade and rain shelter… nothing more…

Dear Friends
I am happy that many people are talking about retractable roof greenhouses in India.
Let me make it clear that this technology is only for those people who are looking for large scale commercial farming in hot and mild climates for year round production and who has capacity to invest minimum 1.5 crores. Small and medium farmer can,t afford it .
We can meet out  ROI in 3-5 years without government subsidy also by harvesting crops during high price windows when open field is not in production locally.
Moreover we provide customized solution to our clients depending upon their climate and crops.We never do not believe in cut and paste methods which most of Indian manufacturer do. They will supply to you same type of model which is suitable in Pune and Bangalore region to all over India whether in Rajasthan or Himachal or Assam or Madhya Pradesh called as “Hockey model” because of specifications laid down by NHB or NHM or other schemes.
Kindly watch this link video although it is long but very informative
youtu.be/z8Fp4ODWvvI
Kindly contact me further for any information
Rajender Kumar

talk about selling refrigerator to Eskimo. 1.5 crores…HAHAHHA Most of these consultants sell above 20Lakh systems to make the most profit

Put 1.5cr in Fixed Deposit in bank and get Rs 87,500 per month guranteed… give a little tax… give a little charity… why get hands dirty?..no need to face labour problem, demand-supply problem, daily left right in farm problem, huge heart attack like Electricity bills… lol

Actually there is no use of this greenhouse thing in India as it is unless people live in SNOWING areas… One thing I will never understand is in hot areas air conditioning is used to cooldown the temperature. THIS IS ONE OF THE MOST STUPID THING EVER!!! to use Airconditioning to cool outside air and then spend thousands of rupees on electricity and water for cooling.

All this when all crops can be grown FREE… without spending hardly anything… SHOW ME ONE STATE OF INDIA WHERE FARMING CANNOT BE DONE???

Its like the Jersey cow and Desi cow issue… we Indians are being fooled by foreigners… and once they hijack our education system how simple and easy it is… they keep telling us Jersey gives more milk but we SHOULD HAVE KNOWN that Desi cows give milk for 15 yrs instead of just 5 for Jersey before the Jersey cow is sent to be killed. On top of that the diarys are mixing buffalo milk and cow milk and selling it and teaching us how to check for adulteration.
See Amul Ghee made up of Cow & Buffalo fat: ecx.images-amazon.com/images/I/8 … SX425_.jpg

Its unbelievable that even after lakhs of farmer suicides due to chemical farming we are being taught that modern chemical farming is good… now add hydroponics and greenhouse and keep increasing the cost of growing crops… a thing so basic that if one eats a mango and spits the seed out and covers it with mud… and waters it… in 15 days a mango tree is born…

To pay lakhs of rupees on hydroponics and green houses are one of the most STUPID THINGS EVER!!!

Only those in

  1. high temperature areas above 40 degrees need use this kind of roof… only for shade…
  2. Heavy rainfall area… to shield their crops from rains… and get extra 3 months of crop output in monsoon too
  3. and safety from unseasonal rains or wind.

ANY SMALL FARMER CAN PUT BAMBOO POLES AND USE ANY TRANSPARENT PLASTIC ON TOP and use for shade and rain shelter. ANY type of plastic can be use thin, thick uv, non-uv on the roof… you can use the cheapest plastic you can buy… one which will last you at least one year.

Bamboo, a fast growing crop is so useful… but how many of our farmers grow it?

One can also use ropes instead of bamboo on the roof as the plastic on top of it will not be too heavy.

Where were these located? I would like to visit one. Do you have images of the structure.