You are currently browsing the category archive for the ‘Uncategorized’ category.

Last month, the article, “Productivity limits and potentials of the principles of conservation agriculture,” published in Nature by Pittelkow, C. et al. generated great interest and controversy in the scientific and farming community alike. The study, which conducted a global meta-analysis using 5,463 paired yield observations from 610 studies compared no-till, one of the pillars of conservation agriculture, with conventional tillage practices across 48 crops and 63 countries, and found that no-till reduces yields. The article also revealed that combining no-till with the other two conservation agriculture principles of residue retention and crop rotation, minimized its negative impacts and in rainfed and dry climates crop productivity was significantly increased with no-till, suggesting that it may become an important climate-change adaptation strategy for ever-drier regions of the world. The full article can be found here.

The CA Cornell Group was contacted by several CA experts who were looking to find an outlet for their insight on the findings of the Nature article, and their viewpoints are featured here.

Photo credited AgWeek

Photo credit: AgWeek

Don Reicosky is a soil scientist emeritus of the USDA Agriculture Research Station and has won international recognition for his ground-breaking work on tillage-induced carbon dioxide loss, carbon sequestration, and other related research.

Reicosky commends the thoroughness of the study. The paper did confirm and provided proof that no-till alone does not work well in all locations. Much of the research reported in the article provided the data, lessons and impetus to consider continuous crop residue cover and diverse crop rotations and/or cover crop mixes to provide a proper carbon balance in the CA system. The paper should serve as a “wake-up call” to the CA community for improved definitions of methods used in CA research and better communication of the environmental benefits to the broader community. Reicosky raises the following issues with Pittelkow et al. (2014):

1. Too much emphasis on no-till: Is it the most important principle?

FAO Bulletin: 3 Principles of Conservation Agriculture

FAO Bulletin: 3 Principles of Conservation Agriculture

The authors place undue emphasis on no-till and equates no-till with CA. Only by addressing all the principles of conservation agriculture will no-till be a successful system. The authors describe no-till as the original and central concept of conservation agriculture, which it was, but over 30 years ago. More farmer experience has discovered that continuous crop residue cover is more important than minimum soil disturbance. In fact, there are three factors of equal weight in conservation agriculture that must be evaluated in a balanced analysis: a) continuous crop residue cover; b) absolute minimum soil disturbance; and c) diverse crop rotations and, if used, multiple species of cover crops for maximum photosynthesis and capture of carbon to nurture the living biological system.

2.  Is it all the same? The tillage terminology dilemma

One concern is related to the “tillage terminology dilemma”. Many research articles in the previous 40 years did not explicitly describe the amount of soil disturbance in the no-till system. To some, no-till simply means no plow. To others, the terms of minimum tillage, mulch tillage, reduced tillage, strip tillage, rotational tillage, vertical tillage, disc tillage, rotary tillage, ridge tillage, chisel tillage, conservation tillage, etc., can be lumped into the category of no-tillage. The definition of conservation tillage with a minimum of 30% residue cover is not the same as CA. As a result of this confusion, there was no way for the authors to differentiate between the studies that met the “minimum soil disturbance” criteria in CA.

Comparison of productivity: Maize cultivated under conventional vs. CA system. Picture credited to IFAD.

Comparison of productivity: Maize cultivated under conventional vs. CA system. Picture credited to IFAD.

3. Wait for longer term benefits.

Though the authors do separate their data based on the duration of no till, they do not discuss the relatively large number of research reports with only two or three years of data. However it has been shown that long-term benefits of No-Till take a minimum of two or three years to have tangible benefits. Part of this is learning to work with the complexities of nature and the time required for the biological system to adjust to the changes in management. Additionally, the study included few research reports with more than 10 years of data. The authors do acknowledge that the yields of no-till increase with greater than 10 years of No-Till. It is important to recognize the “publish or perish” pressure for promotion on scientists doing no-till research, which can reduce the number of years of study and bias experiments against longer term trials. Longer term trials are also mostly done on experiment stations and these don’t always represent actual farmer situations. 

4. Beyond yields: What about the sustainability benefits of CA?

Unfortunately, the authors only focus on yield differences between the two different systems. Yes, yield is the primary output commodity from CA systems. However, we need to consider the long-term positive economic, environmental, social, cultural, and policy dimensions of the CA system as opposed to the corresponding negative attributes of conventional agriculture/inversion tillage. The authors chose to ignore all the other additional ecosystem services provided by the conservation agriculture system that are negatively affected and exacerbated by conventional tillage systems. We recognize that conventional tillage systems and the associated soil loss and degradation are not a sustainable system for future generations. Thus it becomes important that we understand all of the benefits of conservation agriculture, not just the yield impacts. Also what alternatives are there if the present system leads to soil degradation and a non-sustainable system?

5. Farm profit versus yield as an indicator of potential?

CA info graphic from IFPRI.

CA info graphic from IFPRI.

Economics is not addressed. Yield is not absolute: profit is more important for farmers and for true sustainability.  The authors place too much emphasis on yield differences and fail to mention anything about the economic differences between CA systems and conventional systems. They completely ignore the large fuel savings and lower carbon footprint associated with the CA system relative to the conventional system.  While there may be some question about the quantitative impact of conservation agriculture on carbon sequestration, there are other ecosystem services that overshadow this one aspect. In addition, some scientists believe carbon cycling is more important than carbon sequestration in agricultural production systems. It is more important to recycle the carbon within agricultural systems to maintain food security than it is to sequester the carbon and make it unavailable to the soil biology so critical in maintaining nutrient availability and cycling. Unfortunately we do not have simple means to estimate the economic benefits of ecosystem services like minimizing soil erosion, improvement in water quality, and all the other ecosystem services enhanced by conservation agriculture.

More Research Needed

The paper also points to the need for more basic research to understand the interactions in this complex system. These include:

  1. Why are the yields from large field, on-farm research studies as good as or better than inversion tillage agriculture on large fields, but not on small research plots?
  1. What type and how much more detail do we in the scientific community need to accurately characterize CA research methods and materials to enable us to compare “apples to apples, not apples to oranges”?
  1. What can we do to learn from and better understand the historical results of the last 40-50 years of research to continue the development and improvement of sustainable agriculture production systems?

Check out our Scoop-it Newsletter, where we have compiled a special issue of scientific articles relevant to this blogpost.

What do you think? Please feel free to comment or ask questions and CA experts Don Reicosky and Peter Hobbs will reply!

Last month we launched our newest website feature: a monthly review of selected research articles. These articles are compiled using the publishing platform, which allows us to directly link our viewers to the recommended journal article.

Readers can view a short summary of the article and insight on its significance.

Readers can view a short summary of the article and insight on its significance.

The articles featured are chosen from a review of all recent journal publications relevant to conservation agriculture. Each month, as we systematically curate CA literature for our RefWorks research database, we select a handful of articles that stand out from the most recent publications. These articles are recommended based on several qualities, including implication of findings, originality of research theme, and rigor of research design and methods. Topics often include the potential of CA for smallholders in Africa, the role of inputs in CA, the impact of CA on climate change resilience and soil carbon sequestration, soil and water resources as impacted by zero-tillage and cover cropping practices, and more.

Our RefWorks research database contains over 2,000 publications on CA.

Our RefWorks research database contains over 2,000 publications on CA.

This review aims to keep everyone interested in CA, be it farmers, researchers, policy-makers, students, extension-workers, updated on recent developments in conservation agriculture research. With this review, we also hope to draw viewers to our extensive research database of over 2,000 articles on CA. This incredible resource, which is the result of years of curation, includes Spanish, French, Portuguese, and Chinese language databases. If you’d like to look further into CA topics of the articles you read in our research review, a word-search in our database will lead you to other relevant publications.

The wealth of conservation agriculture knowledge published each month by the scientific community can be overwhelming in its entirety. Cornell Conservation Agriculture’s Recommended Research Review seeks to make valuable resources easily available and accessible to the public. As a result, we hope to increase awareness of CA’s potential as a sustainable agriculture methodology to address the social, environmental, and economic inadequacies of modern agriculture.

New Guidelines Reflect Benefits of No-till Farming

North Dakota university made history as the first in the U.S. to make no-till soil fertility recommendations for corn. As North Dakota’s land grant university, NDSU’s corn guideline has reaching implications for 3.85 million acres of corn planted in the state.

NDSU Extension Service recommendations could impact corn cultivation practices on more than 3 million acres in the state. Photo credited to NDSU extension.

NDSU Extension Service recommendations could impact corn cultivation practices on more than 3 million acres in the state. Photo credited to NDSU extension.

The recommendations are based on no-till data dating back to the 1970s and over 50 test sites comparing fertility requirements for no-till and conventional tillage fields. NDSU faculty and extension agents explained this difference as the result of the associated increase in biological activity in no-till soil boosting stored nitrogen in soil.

“With this much microbial activity in your soil and this much organic carbon… this is the potential of your soil to supply X amount of nitrogen.”

The recommendations are an endorsement of a growing conservation agriculture movement in North Dakota. However while the release of these guidelines have generated excitement, it is unsure whether other land grant universities will follow NDSU’s example. Funding that prioritizes research on the benefits of no-till and conservation agriculture practices is limited, and NDSU faculty cited it as the biggest impediment to changing the fertility standards in North Dakota.

Read full article here.

Arnason, Robert. August 28 2014. New guidelines reflect benefits of no-till farming. The Western Producer.

More Crops Per Drop: No-Till Farming Combats Drought

“I wanted greater productivity and healthier soils with less reliance on machinery.” 

This article uses Paul and Elizabeth Kaiser of Northern California as prime examples of the factors that push farmers toward no-till farming, and the financial and environmental benefit this change can bring. No-till soil management also increased the farm’s soil organic matter from 2.3 percent to over 6 percent ( ata 12-inch depth). This improvement was qualified with the staggering fact that,

Soil that is left un-tilled stays cooler and retains more moisture. Photo courtesy of the USDA Natural Resources Conservation Service - See more at:

Soil that is left un-tilled stays cooler and retains more moisture. Photo courtesy of the USDA Natural Resources Conservation Service – See more at:

“With every 1 percent increase in SOM, an acre of topsoil can hold an additional 16,000 gallons of plant-available water.”

Especially in view of the current drought in California, which is estimated to cost the agriculture industry as much as $2.2 billion in losses, the increased SOM and lower soil moisture evaporation attributes of no-till could be enough to convert more farmers to no-till.

While the water-saving benefits of no-till could popularize the practice, the lag-time before farmers see these benefits could inhibit adoption of no-till. The increased herbicide usage associated with no-till could reduce its environmental and economic advantages. However some experts argue that, if no-till is practiced correctly, weed control is not an issue.

It comes down to whether or not the farmer is willing to try a new method of farming. And currently it looks like enough farmers are ready to put down the plow. No-till farming is increasing at a rate of 1.5 percent per year, and makes up around 10 percent of overall farm land in the U.S.

Read full article here: Maki, Olivia. August 26 2014. More crops per drop: No-till farming combats drought. Civil Eats.

There are a number of great conservation agriculture conferences that are coming up within the next few months! They are a great way for professionals and academics involved in conservation agriculture and soil health issues to meet up, network with other professionals, gain a new perspective, and learn some new information about the world of conservation agriculture today. We highly encourage you to try to attend a few (or all) if your time permits! They are truly great opportunities.

This month, in just a couple of weeks, there will be a conference located in Kathmandu, Nepal from March 26-27 called “Frontiers in Conservation Agriculture in South Asia and Beyond” at Hotel Himalaya. This conference focuses on recent findings concerning conservation agriculture in South Asia, as well as other regions. They will have four themes that they will focus on throughout the conference; agriculture production technologies, economics, soil, and gender/food security/other issues. It cost $40 dollars to attend, as well as an additional fee for a field trip taking place on the 27th. Last day for paper submission is March 15th. For more information on the conference, see the link below.

“Frontiers in Conservation Agriculture in South Asia and Beyond” conference information

There will also be a conference in Nakuru, Kenya, October 20-25 called “Transforming Rural Livelihoods in Africa: How can land and water management contribute to enhanced food security and address climate change adaptation and mitigation?” presented by the Soil Science Society of East Asia (EASSS) and the African Soil Science Society. It will focus on a number of different issues surrounding land and soil management issues within Africa. For information on paper deadlines, email For more information, see the link below.

“Transforming Rural Livelihoods in Africa: How can land and water management contribute to enhanced food security and address climate change adaptation and mitigation?” conference information

Click to access SSSEA_and_SSSA_First_Announcement_-_November_2012.pdf

December 8 -13 there will be a conference located in Bangladesh called “Conference on Conservation Agriculture for Smallholders in Asia and Africa.” Topics for the conference include machinery, weed management, soil/water/agronomy, commercialization/adoption/continuous improvement of CA-based technologies, and policy/institutional framework. For more information you can e-mail Professor Dr. Richard Bell <> or Dr. Md. Enamul Haque <>. More information will be posted about the conference as it gets closer to the conference date! For more information, see the link below.

“Conference on Conservation Agriculture for Smallholders in Asia and Africa” conference information

We will continue to post about new conferences as they begin to show up. For an up to date list of conservation agriculture conferences, feel free to check out our website

This is a Delhi based group interested in promoting conservation agriculture. A paca-newsletter-issue-6 has many useful items including a summary of the 4th Congress on Conservation Agriculture held in New Delhi. Plus 10 tips for sustainable soil management. PACA also has a web site at You can also subscribe to this newsletter.


Following the successful 4th World Congress on Conservation Agriculture in New Delhi 4-7th February 2009, the following statement was released in regards to recommendations from this conference:

The New Delhi Declaration on Conservation Agriculture


The 1,000 delegates, gathered in the 4th World Congress on Conservation Agriculture, held from 4 to 7 February 2009 in New Delhi, India, among them farmers, private sector enterprises, scientists, development organizations, donor organizations and policymakers from all world continents, recognizing the urgent need


  • to double agricultural production over the next few decades,
  • to reverse the trend of degradation of natural resources, in particular soil, water and biodiversity,
  • to improve the efficiency of the use of ever scarcer production resources,
  • to address the fact that agriculture and agriculturally induced deforestation cause 30% of the actual green house gas emissions,
  • to answer the increasing threats of a changing climate to agricultural production,


agreed that Conservation Agriculture based on the three principles of


  • minimum mechanical disturbance of the soil
  • permanent organic cover of the soil surface, and
  • a diversified sequence or association of crops


is the foundation of a sustainable intensification of crop production, being as such the necessary condition to achieve, along with other complementary technologies, a sustained increase of world agricultural production and at the same time a recovery of the natural resource base and environmental services.


The delegates therefore urge all stakeholders involved at international, regional andrational level in agricultural production, research and policy making to mainstream Conservation Agriculture as the base concept for agricultural production.


Governments of the world are requested to


  • harmonize their policies in support for the adoption of Conservation Agriculture
  • introduce mechanisms which provide incentives for farmers to change their production system to Conservation Agriculture
  • pursue the case of Conservation Agriculture as the central mechanism for agricultural sector climate change mitigation in the international negotiations for a post Kyoto climate change agreement
  • include Conservation Agriculture as base concept for the adaptation of agriculture to the challenges of climate change in the National Action Plans for Adaptation
  • support the UN Food and Agriculture Organization in the endeavour to establish a special programme on Conservation Agriculture to facilitate this process in its member countries.


New Delhi on February 6th, 2009


The 4th Conservation Agriculture Congress opened in the splendid Vigyan Bhawan conference hall in Delhi with the Minister of Agriculture, Shri Sharad Pawar, the Chief guest. The guest speakers raised many issues:
1. That the timing of the conference was very timely since the number of hungry are increasing (The Millenium Development Goals is supposed to reduce this), the land available per person is decreasing and demand for food is increasing. There are also signs of soil fatigue in some places as factor productivity declines. The big question is how to produce the additional food to meet the demand? But at the same time maintain small farm profit. This conference’s them is “Innovations for improving efficiency, equity and environment”.
2. Conservation Agriculture (or farming) is an attitudinal change or mindset change in the way food is grown.
3. 80% of Indian farmers have 1 hectare nor less. They need to produce for their own subsistence needs but also the country needs surpluses to feed those without land. There is a need to incresae efficiency per unit of land and per unit of water. This can only be done by promoting much greater farmer participation in identifying constraints and experimenting with new technology.
4. There needs to be a policy for farmers, that seems to be missing in India. The new farm Bill in USA is an example of thinking at the top level of governance is needed in developing countries.
5. Introduction of sustainability, soil health and CA needs to be incorporated into University curricula in developing countries to create awareness of the issues among future agricultural stakeholders.
6. Much of the equipment used in India for CA could have been developed a 100 years ago. What is needed is to use modern engineering to develop more efficient and quality machines for all types of farmers from larger land holders to marginal ones.
7. Agriculture in India uses 57% of the wrok force, contributes 18% of GDP and 12% or exports.
8. Irrigation is used on 29% of agricultural land but with only 40% efficient. Rainfed areas also need to be brought under CA practices since they will play an important role in food productiuon in India in the future and these are the areas where poverty is highest.
9. The energy crisis brought home the serious situation in conventional farming that is dependent on fossil energy.

All this led to a statement that CA holds the hope of improving this situation in the future if it can be promoted from the top Government level down to the small land holder and all the stakeholders in between.

Another interesting issue that I would like comment relates to the fact that most of the conference talked about CA and production. We need to go one step further and talk about conserving the production through better storage and value addition enterprises. Equitable distribution of food is another issue. For example, the Indian Government raised the support price for wheat and rice last year. Farmers responded by increasing production. Now the Government has 45 million tons of grain, but only storage for 25 Mt!! Buffer stocks are needed to dampen any future crisis peaks in food production, but good storage is key.

Another interesting comment was “CA is only good for large corporate farmers and no good for poor farmers”. I believe this is not true since through use of local rental and service providers farmers without tractors and small land holdings can avail of this technology. Comments?

Last, but not least one comment that was made that soils are more hungry than thirsty. The soil biological component of the soil has been neglected leading to reduced soil biodiversity leading to many of the problems associated with declining productivity — more pathogens, poor nutrient cycling, erosion, poor water holding capacity and declining soil carbon.

Please comment on any of these issues.

This blog will open on February 1, 2009.

Blog Stats

  • 14,046 hits