Monthly Archives: September 2014

Clay Pot Irrigation part 2 of 3

The Chinese first wrote about Clay pot irrigation 2000 years ago.  The book Fan  Sheng-chih shu which described the setup as follows (Bainbridge, 2000)

“Make 530 pits per hectare, each pit 70cm across and 12 cm deep.  To each pit add 18kg of manure.  Mix the manure well with an equal amount of earth.  Bury an earthen jar of 6 L capacity in the center of the pit.  Let its mouth be level with the ground.  Fill the jar with water.  Plant four melon seeds around the jar.  Cover the jar with a tile.  Always fills the jar to the brink if the water level falls.”

Clay pot irrigation has shown a dramatic increase in efficiency over traditional watering methods.  As in drip irrigation, clay pot irrigation decreases the amount of water used and the time required to attend to the crop.  After the initial setup, clay pot irrigation allows the farmer to fill the pots intermittently, between once to twice a week on average.  Water savings may be as great as 90% when compared to conventional surface irrigation.  (Bainbridge, 2000)

It is estimated that 30% of a farmers time is taken up by weed management.  (Grattan, Schwankl, & Lanini, 1988) As shown with drip irrigation, clay pot irrigation has demonstrated a significant reduction in weeding.  The time saved between a reduction in the time of weeding and watering your crop would be beneficial to any farmer.  This is especially critical when “In 2008, 90 percent of all income for farm house-holds came from off-farm activities.”  This is also beneficial to individuals who would like to have a home garden.  (Briggeman)

Mr. Daka (PhD student) demonstrated the efficiency of the clay pot irrigation in terms of water usage.  This individual wrote a PhD titled Development of a Technological Package for Sustainable use of Dambos by Small-Scale Farmers. Chapter 7.2 describes the site selection of his experiment on clay pot irrigation.  The region that used for the experiment experienced 600-800 mm of rainfall/year and was in a semi-arid region of agroecological zone II of the southern province of Zambia.  They chose this region because of the difficulty of transporting water from wet zones and good drainage.  This presented the problems of water transport as well as increased drainage leading to difficulty of maintaining soil moisture.  (Daka, 2001)

This experiment compared water requirement, yield responses, and suitability of clay pot irrigation to small-scale farmers in comparison to watering can irrigation.  The experimenter did not use sprinkler irrigation but does include comparative data of sprinkler data.  The experimenter found in his study that  “statistically significantly higher yields with the clay pot irrigation system than with the watering can system were obtained for three of the seven crops, viz. cauliflower, maize and rape.”  (Daka, 2001) Maize had an increase in yield of 58% while cauliflower and rape had increases of 38% and 26% respectively.  The study also noted “In no case did the clay pot system give significantly lower yields than the watering system or substantially lower yields than the sprinkler system.”  (Daka, 2001) I was unable to find a direct study between clay pot irrigation and drip irrigation.  (See image 1)

It is important to note that water savings between 50% and 70% occurred compared to the conventional watering can system.  (See image 2)  Furthermore clay pot irrigation maintained favorable aeration and soil moisture retention while the above ground watering led to crusting of the soil, causing low soil infiltration of the water and poor aeration.  (Daka, 2001) Similar crusting may occur with sprinklers and typical rainfall.  Decreased water usage in clay pot irrigation may be due to the following; a decrease in the transpiration of water through greatly reduced competitive weeds and a decrease in surface evaporation due to the clay pot being buried beneath the surface.  The researcher found that the roots of the tested plants surrounded the clay pots directly or penetrated deep into the soil within the portion where moisture remained.  (Daka, 2001)  (See image 3)  Water flow through the pot depends on moisture density in the soil and air.  (Vasudevan, Thapliyal, Sen, Dastidar, & Davies, 2011)

The clay pots irrigate the plants due to the porous nature of the clay used.  The plants themselves automatically regulate the water intake thus removing any guesswork from irrigation calculations.  Water is pulled from the leaf of the plant into the stem, the roots, through the soil, and then from the clay pot irrigator because of the cohesive properties of water.  Once placed, the water in the clay pot seeps into the soil until the soil is saturated.  At this time, the water no longer seeps through the pores of the pot.  (Vasudevan, Thapliyal, Sen, Dastidar, & Davies, 2011) 

Once a seed or transplant enters the saturated area, it will begin to imbibe the water from the soil.  As the plant uses that water, the pull of water goes from that plant, through the soil, and to the pot.  When needed the pot seeps more water into the soil to make up for what the plant has transpired.  This process is continuous allowing the plant to use as much or as little water as it desires.  The farmer then needs only fill the pot regularly (recommended when pot is half full).  (Daka, 2001) The time frame generally accepted for filling the pots is around 3 days to a week depending on size, and climate.  Automatic filling of clay pots would be a simple irrigation procedure further decreasing the work required by the farmer.

Image 1

NewImage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Image 2

NewImage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sources on post 1 of 3

Advertisements
Image

#findlibertyfindamerica

LibertyBlastsmall

Clay Pot Irrigation part 1 of 3

The four basic needs for living organisms to survive are food, water, shelter, and oxygen.  While this paper does not intend to discuss shelter and oxygen it will discuss the first two.  Clay pot irrigation, while thousands of years old, (Bainbridge, 2000) may be a reasonable solution to water conservation and high quality food sourcing.  While agriculturalists of the developed world know little about clay pot irrigation, agriculturalists in India, Iran, Brazil, and Burkina Faso practice clay pot irrigation regularly.  (Daka, 2001)

In order to pique an interest in the study of an ancient, yet emerging, technology we must pose questions as to why we should pursue this research.  Some of these questions are as follows.  
1. Is clay pot irrigation a capable substitute to modern irrigation technology?  

2. Are there problems with conventional agriculture?  If so, can clay pot irrigation solve these potential problems?

3. Has the abundance of the United States allowed modern American agriculturalists the leniency to ignore solutions to problems that are now in their infancy in the developed world?

4. Are modern food sourcing techniques generating healthy food sources?  If not, what is an alternative?

5. How important is clean, fresh water to you?  

6. How important is your time?

7. How important is your health?

It is my belief that if we are capable of saving time, and resources, while improving health, through a sustainable change in food sourcing then we must pursue fresh ideas with an open mind.  Current trends in health and wellness, as well as changing demographics throughout America, require a radically different approach to the feeding of our population.

Central Texas is currently facing a drought.  Other areas of the US are facing this as well.  Most weather and climate patterns are cyclical, however one may not be certain that this drought will end.  Agriculture, and subsequently our food supply, is dependent on water.  Human beings are dependent on food and water.  It is critical that humans research and discover any system that allows the efficient reduction of water use combined with potential increases in crop production.  

The current methods of irrigation in the United States can be broken down into three broad categories: flood, sprinkler, and drip.  Flood irrigation is as it sounds.  Producers flood fields from a local waterway for a predetermined timeframe.  This may be through furrows or throughout the entire field.  This method is cheap, simple, and used by many societies throughout the world and the US. (The USGS Water Science School – Irrigation Techniques, 2014)   This method is also extremely inefficient in terms of water usage.  Water losses are upwards of 50% when using flood irrigation.
Sprinkler irrigation is more efficient than flood irrigation.  Sprinkler irrigation requires the use of machinery, pipes, and engineering throughout the sprinkler system.  These systems include center pivot irrigation, lateral movement irrigation, and your typical home landscape irrigation system with pop up sprinklers.

Drip irrigation is the most efficient use of water in the above cases.  Drip irrigation delivers droplets of water directly to the soil in order to irrigate the root zone of the plant.  Irrigation occurs through drip tape on the soil or through subsurface channels.  Drip irrigation decreases the amount of evaporation dramatically.  It also uses far less water compared to the above systems.  Flow rates on drip irrigation range between ½ to 2 gallons per hour.  Pop-up sprinklers rate their flow rates by the gallon per minute. (Smith, 1997) Clay pot irrigation is a form of drip irrigation.  Drip irrigation has many benefits and little detraction.

A few of the noted benefits of drip irrigation are: (Smith, 1997)

1.  Water placed in root zone with minimal evaporation

2.  Reduced weed growth

3.  Beneficial growth noted in plants

A few of the noted disadvantages of drip irrigation are: (Smith, 1997)

1.  Filtration required

2.  Complex management possible

Clay pot irrigation has many of the above benefits while potentially limiting some of the disadvantages of traditional drip irrigation.  Clay pot irrigation is as simple as burying an unglazed porous clay pot in the ground and filling it with water and fertilizer.  As mentioned earlier, this method is widely used in arid, low-income regions of the world.  There is evidence that there is little indication of water stress on plants and does not require filtration.  Clay pots are simple to install however they are labor intensive upon installation.  Clay pot irrigation has been shown to successfully irrigate many plants including perennials, annuals, fruits, vegetables, and many crop trees.

References

Bainbridge, D. A. (2000). Buried clay pot irrigation: a little known but very efficient traditional method of irrigation. Agricultural Water Management , 79-88.

Bayuk, K. (2010, September 16). Ollas: Unglazed Clay Pots for Garden Irrigation. Retrieved June 22, 2014, from The Permaculture Research Institute: permaculturenews.org

Briggeman, B. C. (n.d.). The Importance of Off-Farm Income to Servicing Farm Debt. Retrieved June 22, 2014, from Kansas City Fed: http://www.KansasCityFed.org

Daka, A. E. (2001, April). Development of a Technological Package for Sustainable use of Dambos by Small-Scale Famers. Pretoria: University of Pretoria.

Grattan, S. R., Schwankl, L. J., & Lanini, W. T. (1988, May-June). Weed control by subsurface drip irrigation. California Agriculture .

Lori. (2012, May 29). Basics of Ollas. Retrieved June 22, 2014, from Dripping Springs Ollas: drippingspringsollas.com

Murray N.D., M., Pizzorno N.D., J., & Pizzorno M.A., L.M.T, L. The Encyclopedia of Healing Foods. New York: Atria Books.

Smith, S. W. (1997). Landscape Irrigation Design and Management. New York: John Wiley and Son, Inc.

The USGS Water Science School – Irrigation Techniques. (2014, March 17). Retrieved June 20, 2014, from USGS – Science for a Changing World: http://water.usgs.gov/edu/irmethods.html

Vasudevan, P., Thapliyal, A., Sen, P. K., Dastidar, M. G., & Davies, P. (2011, August). Buried clay pot irrigation for efficient and controlled water delivery. Journal of Scientific & Industrial Research , 645-652.