Digging into Conservation Agriculture Websites and Publications

What is Conservation Agriculture (CA)?

CA is a set of soil management practices that minimize the disruption of the soil’s structure, composition and natural biodiversity. Despite high variability in the types of crops grown and specific management regimes, all forms of conservation agriculture share three core principles. These include:

  • maintenance of permanent or semi-permanent soil cover (using either a previous crop residue or specifically growing a cover crop for this purpose);
  • minimum soil disturbance through tillage (just enough to get the seed into the ground) ;
  • regular crop rotations to help combat the various biotic constraints;
  • supports soil health and the rich natural ecosystem

CA also uses or promotes where possible or needed various management practices listed below:

  • utilization of green manures/cover crops (GMCC’s) to produce the residue cover;
  • no burning of crop residues;
  • integrated disease and pest management;
  • controlled/limited human and mechanical traffic over agricultural soils.

When these CA practices are used by farmers one of the major environmental benefits is reduction in fossil fuel use and greenhouse gas (GHG) emissions. But they also reduce the power/energy needs of farmers who use manual or animal powered systems.

From the Conservation Agriculture Knowledge Portal at Cornell University


Dirt: The Erosion of Civilizations ‪David R. Montgomery, 2012dirt

This is where many people begin their experience with CA

Dirt, soil, call it what you want—it’s everywhere we go. It is the root of our existence, supporting our feet, our farms, our cities. This fascinating yet disquieting book finds, however, that we are running out of dirt, and it’s no laughing matter. An engaging natural and cultural history of soil that sweeps from ancient civilizations to modern times, Dirt: The Erosion of Civilizations explores the compelling idea that we are—and have long been—using up Earth’s soil. Once bare of protective vegetation and exposed to wind and rain, cultivated soils erode bit by bit, slowly enough to be ignored in a single lifetime but fast enough over centuries to limit the lifespan of civilizations. A rich mix of history, archaeology and geology, Dirt traces the role of soil use and abuse in the history of Mesopotamia, Ancient Greece, the Roman Empire, China, European colonialism, Central America, and the American push westward. We see how soil has shaped us and we have shaped soil—as society after society has risen, prospered, and plowed through a natural endowment of fertile dirt. David R. Montgomery sees in the recent rise of organic and no-till farming the hope for a new agricultural revolution that might help us avoid the fate of previous civilizations. From the Preface

The Conservation Agriculture Group at Cornell University

This site maintains a very diverse international resource for CA.  Academic articles, international groups, monthly news, upcoming conferences, the Two-wheel Tractor Newsletter and much more is available at this knowledge portal/website.  It is an excellent first stop for up to date CA resources and news.


This organization and their website has excellent information, including videos, equipment, conference information and presentations as well as links to a very large number of regional CA groups.

Dirt First, a renegade soil scientist is transforming American agriculture,  Kristin Ohlson, in Orion Magazine, 2016

In a very accessible way this Orion magazine article by Kristion Ohlson tells the story of the critical importance of soil health,.

Thousands of years of poor farming and ranching practices―and, especially, modern industrial agriculture―have led to the loss of up to 80 percent of carbon from the world’s soils. That carbon is now floating in the atmosphere, and even if we stopped using fossil fuels today, it would continue warming the planet. In The Soil Will Save Us, journalist and bestselling author Kristin Ohlson makes an elegantly argued, passionate case for “our great green hope”―a way in which we can not only heal the land but also turn atmospheric carbon into beneficial soil carbon―and potentially reverse global warming. From the Amazon review:  The Soil Will Save Us


Landscapes Transformed: The History of Conservation Tillage and Direct Seeding, edited by C. Wayne Lindwall and Berie Sonntag


Jeff Esdaile’s Two-Wheel Tractor Newsletter
There is a wealth of very creative mechanization for farmers who have access to two wheel drive tractors.  The site is hosted by the Cornell Conservation Agriculture website.

  • http://conservationagriculture.mannlib.cornell.edu/pages/resources/twowheel.html

Roller/Crimper Designs for Cover Crops Management on Different Farm Scales Using Conservation Practices, Ted S. Kornecki, Agricultural Engineer, USDA, 2014

This is good example of much needed CA equipment being scaled down in size and weight. Test results are presented very clearly.


Here is a fun example of citizen science and a good measure of soil health that children can dig into. One of Earth Link’s first projects was an environmental group for high school students and as one of our activities we sold worms.

Three images of the “Jua Kali Planter” from Earth Links’ coming open source equipment database

Earth Links is working on a database and website for small-holder farmers who need well designed, tested, and very inexpensive tools that can be be construct by local blacksmiths or manufactured regionally. Designs will be available as CAD files, PDFs, photos and videos.

Planter-JuaKali-170123-copy-2-3 Planter-JuaKali-170123-copy-2-1 Planter-JuaKali-170123-copy-2-2

Women Farmer Links

  1. SRI and It’s Impacts on Women
  2. SRI Cultivates Well-Being for Women
  3. System of Rice Intensification (SRI) and Labouring Bodies
  4. Gender Issues in Weeder Design
  5. SRI4Women
  6. Small Farmers Can Reap Big Benefits with Affordable Tools
  7. Mechanical Advantage: Oxfam working with RACHANA to modify weeders for women farmers.
  8. Weeding Out Complexities of Rice Farming
  9. Women Showing the Way with Agroecology
  10. Understanding dynamics of labour in System of Rice Intensification (SRI): Insights from grassroots experiences in Odisha, India, Sabarmatee’s Phd .pdf
  11. Workload on Women Using Cono Weeder in SRI Method of Paddy Cultivation. I do not have a hot link for this article yet. Link for ANGR Agricultural University, Rajendranagar, Hyderabad Journals is: 
  12. Women Friendly Equipment with Photographs From the Central Institute of Agricultural Engineering (ICAR) India Drudgery Reducing Technologies for Women in Agriculture
    https://farmech.dac.gov.in/Women%20Friendaly%20Equipment-  With%20photographs.pdf
  13. System of Rice Intensification (SRI) and Labouring Bodies
  14. Gender Issues in Rice Based Farming Systems
  15. Final report of RACHANA/Oxfam project to modify tools for women rice farmers
    No link. Note: this I a comprehensive report of the field studies conducted in number 7, “Mechanical Advantage: Oxfam working with RACHANA to modify weeders for women farmers.”
  16. Ergonomical Evaluation of Cono-Weeder with Farm Women
  17. Cono weeder: An economic hand tool for women labour in paddy field
  18. Gender Dimensions of the Adoption of the System of Rice Intensification (SRI) in Cambodia

Click here to Download PDF of Women Farmers Links

Earth Links has been invited to participate and present at two events this Fall

The “International Rice Conference” in Singapore and the “International Workshop to Enhance Cooperation and Sharing among

SRI National Networks” in Malaysia

The IRC is taking place in Singapore, October 14-17 at the Marina Bay Sands and the Workshop is being held at the The Leverage Business Hotel-Skudai, Johor Bahru, Malaysia on the 18th-19th of October.

A Very Special Thanks to Oxfam for making the SRI Rice booth possible at the IRC
At the IRC Stephen Leinau will making a presentation on “Reducing Injuries and Increasing Yields for Smallholder Women Rice Farmers through Additive Manufacturing and the Design, Modification and Testing of Rotors for use with SRI Weeders” and making a presentation on “The Future Guardians of Rice: Bali, World Heritage, and the Next Generation of Farmers” on behalf of the paper’s four authors; Wiwik Dharmiasih, Micah Fisher, Lucy Fisher and Stephen Leinau.  http://ricecongress2018.irri.org

At the Malaysian meeting as part of the “HIGHLIGHTS OF GLOBAL INITIATIVES” Stephen will be discussing the development of an international SRI Equipment Network.

One Road to SRI Mechanization

In favor of using the “brush cutter” weeder in its various forms for mechanization is that it is widely available and relatively inexpensive.  It represents a first step towards mechanization for many small-holder farmers.  It is faster than a manual weeder, and avoids a push and pull motion that many weeders require for thorough weed removal.

In the USA a simple brush cutter with “string trimmer” can be purchased for about 150 USD for the version where the motor is attached directly to the cutter.  The backpack versions are of higher quality and cost approximately 300 USD and up.

The brush cutter has its challenges, but we believe it can be adapted for use as an effective SRI Weeder.  Here are some of the challenges we see:

The high RPM of the rotor makes the machine difficult to control and this forces the user to expend considerable energy guiding the weeder down the rows to avoiding damaging the rice plants.  Slowing the rotor speed would require a new gearbox.   We have not found a commercially available part/gear box to accomplish this.   Although the brush cutter can be used/adapted for multiple rows, control of the weeder remains difficult, and as the rotor/paddles must then be made much larger to go over the rice plants when doing two or more rows.  For With the multi row weeders, the larger rotors/paddles further increasing the tip speed of the rotor.

We know that Japanese versions of a single row covered weeder, that adds a single blade in a cover/sled, are is commercially available that adds a single blade in a cover/sled. The sled can be plastic or metal. This adaptation uses the commonly available “head” that holds “string” for grass and weed cutting.  We have attached plans for two versions of a single blade version that we are working on.  The added cutting blade will need to be modified to get the best possible weed removal and least damage to the plants.  We will test these in the near future at a farm testing site that has just become available to us.

This covered version has the advantage of covering the blade to a certain extent, taking some of the weight off the farmer, as well as providing some stability and tracking for the weeder.  We are looking forward to doing our construction and testing.


Thanks go to Supachai Pitiwu and the Weekend Farmers Network in Thailand for all the considerable testing and videos they have produced on this weeder:

Brush cutter, Backpack version:


Another advantage of this tool is that it can also be adapted to harvesting with an inexpensive conversion.  The safety of this use is unknown?


Japanese equipment site, (in Japanese): http://www.hirakishoji.co.jp/aigamon/index.html

Picture of plastic version  http://www.kaientai.ne.jp/fs/hiraki/ag-001

Picture of metal version  http://www.kaientai.ne.jp/fs/hiraki/tt-001


Prices without motor, in yen, 18,000    $160 USD

Prices with motor, in yen, 59,400           $530 USD

Less expensive versions can be purchased from Chinese Manufacturers.

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Six Publications that tell the stories and possibilities of SRI

SRI is a set of sustainable rice farming technologies that can help small farmers to significantly increase their rice yields. It is a low-input technology, which can be flexibly applied based on the local factors and farm conditions.

SRI methodology is based on four main principles that interact with each other:

  • Early, quick and healthy plant establishment
  • Reduced plant density
  • Improved soil conditions through enrichment with organic matter
  • Reduced and controlled water application

Based on these principles, farmers can adapt recommended SRI practices to respond to their agroecological and socioeconomic conditions. Adaptations are often done to accommodate changing weather patterns, soil conditions, labor availability, water control, access to organic inputs, and the decision whether to practice fully organic agriculture or not.

sri-cover1. From The System of Rice Intensification (SRI), Responses to Frequently Asked Questions, Norman Uphoff  Norman Uphoff has lead the worldwide movement to understand and promote SRI,  a work for which he has won numerous awards. His SRI FAQs is just one of an extraordinary number of publications he has produced.


2. SRI has been successfully adapted to many cultures andmore-rice environments. Here is a link to an excellent joint publication which highlights the successes that Oxfam, WWF and AfricaRice have all had with SRI.




3. Here is a link to the worldwide Leisa issue on SRI. This is an excellent introduction to SRI and how it has been adapted to local conditions by farmers, researchers, governmental organizations and NGOs.

4. Here is the SRI-Rice website at Cornell which is the most comprehensive resource in the world. There are academic articles, reports on conferences as well as how SRI has appeared in both the popular and business press worldwide. The site is media rich and it is possible to search for resources by country as well as language.  Monthly updates are provided in several forms.

  • http://sri.ciifad.cornell.edu

5. This Handbook for the Peace Corps was done to provide an Introduction to SRI for West Africans.  It was part of a very successful, multi-year project that expanded SRI in 13 West African countries using groups familiar with SRI as the trainers or “Champions”.  It is an excellent example of how training materials have been used to successfully adapt SRI for countries around the middle of our planet.

feed-the-future6. Here is a link to a major West African SRI project. SRI-RICE at Cornell was a major consultant on the SRI-WAAPP project, which will hopefully have a second phase/expansion. Thanks to Devon Jenkins, returned Peace Corps volunteer, and and Erica Styger for their work on this publication.


Coming Publications

Equipment for small scale farmers that can be built at the village level, for less than 50 USD, by metal workers and blacksmiths is a critical element of the successful adoption and spread of  SRI.  Here is an example of a weeder, called the “Mandava” Weeder that has been successfully used in many countries in flooded rice fields.  Earth Links produced these CAD drawings as part of our work to make these well tested designs available worldwide without cost. Earth Links also contributed some of these early weeder plans to the West Africa project above as well as to Latin American demonstration projects with IICA..

The NGO (SRI Global Inc) which Earth Link helped start, in turn helped to start the NGO, 3ASahel, that was a Champion promoter for Mali.  The first phase of the WAAPP project has successfully ended.


SRI has many benefits such as climate change adaptation and mitigation which is described in the publications above.  An emerging issue and critical health problem is the high levels of Arsenic in some rice. The real reduction in arsenic that appears to be produced by SRI growing techniques (from significant reductions in water use) is an area of research that needs to be done and shared worldwide. Here is a link to the study that should have published results soon.

Stephen Leinau
Executive Director
Earth Links Inc




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