Discussions about no-till
-tropical vs temperate-
(7/11/03 - 7/25/03)

postings: 21
countries: Brazil, France, Germany, Honduras, United States (Kansas, Maryland, New York, Texas)
organizations/institutions/companies: Association Las Encantadas, CIIFAD, CIMMYT, CIRAD, COSECHA, Cornell University, CRWRC, GTZ, Embrapa Soil Center, Minifarms Network, University of Hohenheim, University of Maryland, University of Tennessee, USFDA

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From: Minifarms@aol.com
Date: Fri, 11 Jul 2003
To: MULCH-L@cornell.edu

Mulchers,

Re: Jamie's email:
"why so many of the techniques exported from temperate countries have been so disastrous for tropical agriculture."

That is true but the opposite is true. Take techniques from the tropics such as Roland's - An Odyssey of Discovery: Principles of Agriculture at http://www.echonet.org/tropicalag/knowledgebank/EDN_articles/edn_58_1.htm and apply it in the temperate countries and it works. Ruth Stout has applied it to gardening and Fukuoka to farming. A few farmers in the USA are using it. Steve Groff has land that has not been plowed in 30 years. Most farmers cannot accept it because they can not imagine not plowing. I have a denominstration garden to prove it, too.

Ken Hargesheimer
Gardens/Mini-Farms Network
Box 1901
Lubbock TX 79408-1901
Workshops in organic, no-till, permanent-bed gardening, mini-farming, mini-ranching worldwide in English & Spanish

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Date: Mon, 14 Jul 2003
From: "Tom Post"
To: <MULCH-L@cornell.edu>
Subject: Re: Temperate climate

My understanding is that no-till farming practices are now used by many, many farmers in N. America. So, I don't think it's accurate to say that few farmers use it in N.Am.

Although no-till, N. Am style involves herbicides and machinery----to me it's still a variation of the mulching dynamics that Roland advocates, and you do see plant roots thriving in the mulch of no till plots in N. Am.

Tom Post
CRWRC

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From: Minifarms@aol.com
Date: Mon, 14 Jul 2003
Subject: no-till
To: MULCH-L@cornell.edu

What percentage of the farmers in north America practice no-till?

Ken Hargesheimer
Gardens/Mini-Farms Network
Lubbock, Texas

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From: rolando
To: MULCH-L@cornell.edu
Date: Tue, 15 Jul 2003
Subject: Re: Temperate climate/no-till

Dear Tom & mulchers,

You are right: when I was last in Illinois, they said that something like 40% of all the maize farmers in Illinois had switched to zero tillage in the last decade alone. So zero tillage is not just a Southern Cone phenomenon (ie Brazil, Paraguay, Argentina).

Sincerely, Roland Bunch
COSECHA, Valle de Angeles
Honduras

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From: "Raymond R. Weil"
To: MULCH-L@cornell.edu
Subject: Re: no-till

Off the cuff:
about 25% of the hectares of US cropland are no-tilled. In Maryland (my state in the humid, east) the percentage is 60 to 70%. These hectares are mainly in grain crops. No till is still very rare (but outstanding successes exist) for vegetable, peanut and cotton growers. The Conservation Tillage Technology Center has the national database on tillage use. In general, the US practice of no-till is not as cover crop intensive as it probalby should be. Savings of time, machinery, energy costs are the main motiviators, in addition to erosion control. Soil quality is just begining to enter the farmer's tillage calculus.

-- Ray Weil
University of Maryland

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From: "Peter Hobbs"
To: <MULCH-L@cornell.edu>
Subject: Re: no-till
Date: Thu, 17 Jul 2003

Dear All: Figures I have seen quoted by Ralph Derpsch who work in Latin America, is just over 21 million hectares or 50 million acres in the USA. This is quoted as conservation agriculture that includes no-till and residue cover and NOT conservation tillage which is probably more. That was quoted in 2001 and may have changed by now. I hope that helps.

Regards
Peter Hobbs
CIMMYT/Cornell University

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From: "Donald Kass"
To: MULCH-L@cornell.edu
Subject: Re: no-till
Date: Thu, 17 Jul 2003

Dear Mulchers,

While everyone is talking about no-till as a transfer of tropical to temperate technology, they are ignoring the minor matter that no-till in "developed" areas generally requires the use of herbicides while slash-mulch systems generally do not. Herbicide use brings in a whole new range of environmental and energetic factors so I don't think the systems are truly comparable. Use of lignaceous material for mulches again brings in a whole range of variables--if water conservation and weed control are the primary objectives of a mulch system, something that decomposes slowly or not at all is of course preferred. If the mulch system is being relied upon to supply nutrients, the most suitable type of material is different--and generally mulch systems work less reliably in supplying nutrients than in suppressing weeds or conserving moisture. There is the added inconvenience that a rapidly decomposing material that will supply nutrients won't be around long enough to be of much good in weed control or moisture conservation. It was the hope of agroforesters that a woody material with rapidly decomposing leaves could somehow combine all mulch functions but even these materials have their defects in supplying nutrients, controlling weeds and conserving moisture. Several years ago, there was research on combining fast and slow decomposing mulch materials to combine nutrient release, moisture conservation and weed control factors --there is also the effect on soil structure. I don't know if a successful combination was ever found--Erick Fernandes should be able to summarize this research.

Don Kass
Northeast Regional Laboratory
US Food and Drug Adminsitration
Jamaica, New York

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From: "Peter Hobbs"
To: <MULCH-L@cornell.edu>
Subject: Re: no-till
Date: Thu, 17 Jul 2003

Dear All: The use of no-till leading to more weeds and therefore more herbicides may be a problem in some systems but NOT all systems. In the rice-wheat systems of South Asia, weeds are significantly less in no-till systems for wheat (It would be a major problem for rice) even without the mulch. I believe that the success of no-till in South America has been when no-till is combined with residue mulch and rotations. There may be a few transition years when weeds are a major problem and require some form of integrated management, but I believe that over time using no-till, mulch and rotations (sometimes cover crops) weeds become less of a problem and this is one of the reasons why farmers are happy with the technology. Work in rice-wheat systems in China (Yangtze River Basin) bears out this hypothesis when they moved from full tilled wheat and transplanted puddled rice to a no-till rice and wheat system. Lots of weeds in rice the first few years but by the tenth year no weed problems. So we must be careful not to generalize and exchange information with a good description of the local situation.

Best regards
Peter Hobbs
Cornell University/CIMMYT

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From: "jamie" <jamie@tiscali.fr>
To: <MULCH-L@cornell.edu>
Subject: RE: no-till (mulches)

Don also raises the question of the types of mulches used and their varying effects on soil.

Therefore, I had better define more clearly what the chipped wood is supposed to provide. Obviously, chipped wood has a very high carbon to nitrogen ratio and cannot be said to give much in the way of nutrients to the soil. However, this is not intended to be the use of the wood. Rather, the wood breaks down to provide the stable complex organic molecules that act as the substrate within which the MOs and plant roots cycle nutrients, and not as nutrient provider itself.

Lemieux claims that all the great agricultural land of the world (both temperate and tropical) has been created from beneath climax hardwood forests because that is where the necessary humic compounds are found to provide the medium for the cycling of nutrients that creates healthy plants. It is a well known fact in the world of ecology that such climax hardwood forests support the greatest biodiversity - and, in contrast, conifer forests have a very reduced plant diversity. It is for this reason that Lemieux advocates the use of hardwood and not softwood chips (or not more than 20% maximum).

Jamie Nicol
Association Las Encantadas
France

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From: Minifarms@aol.com
Date: Thu, 17 Jul 2003
Subject: no-till
To: MULCH-L@cornell.edu

I have never been able to understand why we think herbicides are "required." There are some subsistence farmers who have never learned that. Fukuako never did believe it.

Ken Hargesheimer
Minifarms Network

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From: "Forbes Walker"
To: MULCH-L@cornell.edu
Subject: Re: no-till
Date: Fri, 18 Jul 2003

No-till percentages around the USA vary by state and crop. Here in Tennessee in 2001 over 80% of our crops were either no-tilled or use others form of conservation tillage (ridge till, strip till and mulch till). In some of our major row-crop counties no land has been plowed for many years. A major benefit for us has been erosion control, soil moisture retention (and thus yield improvements) and a dramatic reduction in the amount of times you need to drive a tractor across the field.

I would also like to add that there is a growing interest in this technology in many parts of the world and not only among commecial farmers. I recently visited Zambia where AIDS is seriously impacting the labor supply and the ability of subsistence households to prepare land for planting after the rains come. Several NGOs are working on several innovative approaches to weed control using simple handheld equipment that uses very low rates of herbicide or interrow animal drawn cultivators.

Forbes Walker
Environmental Soils Specialist
University of Tennessee

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Date: Mon, 21 Jul 2003
To: MULCH-L@cornell.edu
From: Kenneth Schlather
Subject: Re: no-till

Two main points to this note:

1) Peter Hobbs' point about being careful to not make generalizations, and the importance of a good description is critical. I would add that we should remind ourselves that we are dealing with dynamic systems, and therefore, not to be redundant, things change. Fukuoka's experience on his own farm bears this out: I visited his farm just after he completed his book on the "Natural Way of Farming", in 1985 and the system he had described in both "One Straw Revolution" and the aforementioned book was in disarray, caused by the invasion of an exotic weed. The construction of the bullet train railroad required that elevated tracks run across rice paddies adjacent to his, and he believed the train brought the seeds of the exotic species (I don't remember the name). He was having a difficult time dealing with the species which was outcompeting his rice crop.

Given his vast knowledge of plant ecology and his tremendous powers of observation he may well have overcome that problem, but the main point here is that even systems that appear to have "stabilized" in terms of weed populations after a disruptive change such as shifting from one cultivation system to another ("conventional" to no-till, for example) there will almost inevitably be both gradual changes that we may not see too clearly in the short-term as well as perturbations more easily seen. Knowledge of plant ecology and a constant polishing of observational skills are pretty important in any ag system, especially if one is trying to reduce chemical use.

2) In South America, at least in Brazil and Paraguay, a lot of farmers began the practice of no-till using the packages designed by herbicide companies. The financial incentive was there right from the start however to reduce herbicide use, and as the farmers came to understand their systems and the practice of no-till they were able to begin experimenting with reduction of herbicide use in their systems. That of course is where cover crops entered the picture, because the best of them could compete with the weeds in the system and of course they were an easier "weed" to manage, either through simply cutting or pushing over, or through frost damage or other natural means. One of the many very good things Rolf Derpsch did in the last few years of his work in Paraguay was actively look for ways to reduce herbicide use in these systems, and Ithink a lot of the success came about from his skillful blend of the desire on the part of farmers to reduce costs, their own knowledge and skills of observation with his knowledge of cover crops, and experimentation.

ken schlather
CIIFAD Fellow
Ithaca, New York

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From: "Peter Hobbs"
To: <MULCH-L@cornell.edu>
Subject: Re: no-till
Date: Tue, 22 Jul 2003

Dear Ken:

Couldn't agree more with your response. Farmer experimentation is a must for this type of technology and the dynamics of local conditions. We have to reduce costs, dependence on fossil fuels and make agriculture more appealing and profitable for young farmers, male or female. Conservation agruiculture principles are a good way to go.

Best regards
Peter Hobbs
Cornell University, CIMMYT

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From: "Rolando Bunch"
To: MULCH-L@cornell.edu
Subject: Ken's comments
Date: Wed, 23 Jul 2003

Dear Mulchers,

Ken made some very important points.

And I would like to add very quickly that the importance of farmer experimentation in this field is very frequently underestimated. Of the approximately 90 different sustainable gm/cc systems--one of the major ways of avoiding herbicides in zero till systems--that I have personally observed around the world (yes, I've made a list), very close to 1/2 were developed by small farmers themselves, in the absence of an outside program. And obviously, these systems were developed through experimentation. And if all that was accomplished by farmer experimentation, how many UNsuccessful experiments were probably done?

Certainly here in Central America, farmer experimentation has been far more important in the development of gm/cc systems than has the research of professionals. I'm not at all saying that's the way it necessarily should be; I'm just referring to a historical phenomenon. I would personally prefer to see much more collaboration/interaction between the two kinds of research, as has developed here over the last eight or ten years.

Sincerely,
Roland Bunch
COSECHA
Tegucigalpa, Honduras

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From: Bernard Triomphe
To: MULCH-L@cornell.edu
Subject: Re: Ken's comments: farmer experimentation

Dear all:

Of course I fully agree with Ken, Roland and Peter about the importance of farmer experimentation. But one has to be aware that far too often, farmer experimentation gets unnoticed and hence unexploited because it it not properly documented, "objectively" evaluated and shared by those experimenting with others, be they neighbors or outsiders.

In my opinion, one of the most promising areas for strenghthening autonomous processes of experimentation and beyond experimentation, innovation, is to collaborate more actively with farmers organizations. Among other advantages, it has the potential of offering almost automatically opportunities for scaling up beyond the very local successful experiences of small (or bigger!) farmers.

Unfortunately, many among us still stick to traditional, probably more immediately rewarding (publication, visibiltiy) collaboration with NARS and other well-established institutions, and neglect to 'dirty' their hands and accept the risks and challenges (scientific, political, personnal) of exploring true partnerships with farmers and their organizations.

And those who do collaborate too often don't find the time to analyze and write up their experiences and lobby with the mainstream researchers and techniocians to open their minds.

What a dilemma!

Best
Bernard Triomphe
(CIRAD, France)

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From: "Pedro Freitas"
To: <MULCH-L@cornell.edu>
Subject: No-Till Systems and the use of herbicides
Date: Mon, 21 Jul 2003
Organization: Embrapa Solos - APDC

Dear Mulchers,

The discussion about No-Till Systems and the use of herbicides has has often raised concerns about its ecological and economical consequences. The impact of herbicides here in Brazil, where more than 50% of the annual cropping area as well as an expressive area with perennial crops, pasture and forestry, are under no-till system (with no soil turn over + agrobiodiversity using crop rotations + soil surface covered permanently with residues of both cash and cover crops), has been compensated by the mitigation of several offsite erosion-related problems, including land degradation, typical of tropical and subtropical climates.

Among the positive impacts of the adoption of ZT systems, the reduction in weed emergence has been observed. We have studies were a 97.7% decline in weed infestation after 5 years was observed. Rolf Derpsch has reported observations that systematic use of cover crops and rotations combined with proper use of chemicals reduced the amount of herbicide use in NT by 80% of the level used in plowed soils. Other colleagues have observed that approximately 6 ton/ha of dry matter of black oat rolled down on the soil surface eliminates the need of herbicide applications. In Paraguay, a comparison to soybean-wheat rotation, sunflower/black oat/ soybean-wheat/soybean-lupine/maize reduced herbicide rates to zero with a 3-year, reducing also soil compaction and erosion.

In our observations (Freitas and Machado, 2003) we concluded that more research is needed to improve the use of Integrated Weed Management system, with the main goal of decreasing the use of herbicides. This is possible with the use of mulch as a part of the weed suppression effort. We do think that this should be the main interest of this list.

Pedro Freitas
Agronomist, Ph.D. in Soil Science
Agricultural Researcher for Embrapa Soil Center
(Brazil)

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From: "Donald Kass"
To: MULCH-L@cornell.edu
Subject: Re: No-Till Systems and the use of herbicides
Date: Tue, 22 Jul 2003

Dear Pedro,

I think most mulchers will agree that mulch is the preferred alternative to herbicides. What is the full citation of the Freitas and Machado publication???

Donald Kass
Northeast Regional Laboratory
US Food and Drug Adminsitration
Jamaica, New York

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From: "Christian Thierfelder"
To: <MULCH-L@cornell.edu>
Subject: : no-till
Date: Tue, 22 Jul 2003

Whenever we come to the point of no-till or conservation agriculture (which, in my view is a better term for the same thing, because it avoids the word "tillage" in its name) a common criticism is herbizides. Given the possibilities and conditions of Southern African farmers the better focal point of investigation should be how we can deal with the weed problem without being too much dependent of external inputs. Farmers in marginal/rural areas of Africa often do not have the resources and access to herbizides, even though they might be useful at the beginning of transformation from a conventional to conservation system. Other solutions must be found which could be increased ground cover, competitive ground cover plants, mechanical weed control etc. etc.

Christian Thierfelder
(GTZ, University of Hohenheim)
Deizisau, GERMANY

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From: "Steiner Kurt 1030"
To: <MULCH-L@cornell.edu>
Subject: AW: no-till

Christian is right, our target group, African smallholder farmers have hardly access to commercial inputs, and usually no cash at all. In addition transport of water to the fields and maintenance of sprayers are other serious constraints. Herbicides are just applied in regions were cash crops are grown, such as cotton, coffee or cocoa. Here farmers dispose of cash, sprayers and adequate knowledge as well as access to inputs.

What we try is to suppress weeds with crop residues and covercrops. The reduced time spend for weeding in these system is what makes it attractive to farmers. In dry savannahs, where only minimum tillage, ripping, is applied due to lack of soil cover, weeds become a serious problem. When farmers dispose of draught animal power, they can use this for superficial weeding with a broad duckfoot.

This in short from Africa...

Kurt Steiner
Senior Technical Advisor - Sustainable Land Management
GTZ Dpt. 103/45
web: www.gtz.de/conservation-tillage

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From: "Stan"
To: <MULCH-L@cornell.edu>
Subject: No-Till

Dear Mulchers:
Regarding no-till. Here in Northwest Ks. no-till is rapidly replacing tillage. I would contend 80% of NW. Ks. is in no-till acreage at any one time, and across the state 50-60% is no-till. While this is an attractive method to conserve water and control erosion both wind and water, and to control weeds, it poses many questions. The methods used here are numerous herbicide applications on a very large bases. This is becoming a big concern of mine as well as many others, but with the market control the giant chemical companies such as "Monsanto" you speak softly. Furthermore, Monsanto has "GMO" seed that is patented so you can only use their chemical with their seed. They are vastly attempting to corner the market with complete control of both seed and chemical thus making the farmer subservient to them. Cross pollination, and chemical drift are other areas of great concern as well.

Sincerely
Rob