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A project of the Management of Organic Inputs in Soils of the Tropics (MOIST)
in association with
the Cornell International Institute for Food, Agriculture and Development (CIIFAD)
and the Tropical Soil Cover and Organic Resource Exchange (TropSCORE)

Discussions regarding conservation agriculture
and soil quality in Africa

(1/24/04 - 2/3/04)

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Date: Mon, 26 Jan 2004
From: "Tom Post"
To: MULCH-L
Subject: Re: Conservation Agriculture
Reply-To: MULCH-L

Jan 26, 2004

Christian,

3 of the most promising practices related to soil/water conservation, that we see in our work in East and Southern Africa are:

Tom Post
Christian Reformed World Relief Committee
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From: Ami Kadar
Subject: Re: Conservation Agriculture
To: MULCH-L

Hi Tom,

How would one go about getting your water harvesting CD? And how much would it be?

Ami

______________________________________________________

From: Christian Thierfelder
To: MULCH-L@cornell.edu
Date: Sat, 24 Jan 2004
Subject: AW: Conservation Agriculture

Thanks for answering me Tom,

Your 3 practises sound very interesting especially the third one. Perhaps you could give me some more insights. Do you have some literature on this already published?

Kind regards,

Christian Thierfelder
Institute of Soil Science and Land Evaluation
University of Hohenheim

______________________________________________________

Subject: Conservation Agriculture
Date: Fri, 30 Jan 2004
From: "Steiner Kurt 1030"
To: MULCH-L

Tom,

Excuse me, but I want to contradict you. The most effective SWC technology, is conservation tillage, i.e. ripping combined with sub-soiling in case of plough pans or other types of soil compaction, or whereever possible (free grazing!!) direct planting though a mulch of crop residues and cover crops. As longer term observations in Tanzania prove, we are able to increase rainwater productivity with these technologies by a factor of 3. In addition we decrease draught power requirements, and what farmers appreciate most labour requirements for weeding.

Attached is a paper* my colleague Johan Rockstrom and I have presented at the Workshop on Water Conservation technologies for Sustainable Dryland Agriculture, held in Bloemfontein, South Africa in April 2003. (*Conservation Farming – A strategy for improved agricultural and water productivity among small-holder farmers in drought prone environments)

In a later paper I have included data from Sudan and Madagascar, which show the same effect.

With best regards,
Dr. Kurt G. Steiner
Senior Technical Advisor - Sustainable Land Management
GTZ Dpt. 103/45
Eschborn/Germany
web: www.gtz.de/conservation-tillage

______________________________________________________

Date: Fri, 30 Jan 2004
From: Tom Post
To: MULCH-L
Subject: Conservation Agriculture

Jan 30, 2004

Dear Kurt,

Thanks for "contradicting" me! Thanks for sharing the good paper also!

Actually, I appreciate your contribution here so much because it shows how getting more water to penetrate into the soil is SO important. That is a key guiding principle, I think for the semi-arid areas of Africa.

John Sanders, et al. (The Economics of Agricultural Technology in Semiarid Sub-Saharan Africa 1996, John Hopkins Univ. Press) also show that the most important first step is to get more water infiltration into the soil and then increasing soil fertility and adding market-drivenness will make the use of improved varieties really profitable. They based their work on long experience in the semi-arid regions of western and eastern Africa.

When I shared what "we" had found to be effective, the "we" I was referring to was merely the work of the NGO I work with, the Christian Reformed World Relief Committee (CRWRC). I did not mean to imply that I was speaking for everyone who has worked to improve food security in the semi-arid zones.

I hope this little dialogue continues to be so productive! Thanks again for sharing the results of your research. I would hope that many will be able to see how those farmers carried out the conservation tillage practices your paper describes and be able to use them.

Yours,

Thomas Post
CRWRC

______________________________________________________

From: Christian Thierfelder
To: MULCH-L
Subject: AW: Conservation Agriculture
Date: Sat, 31 Jan 2004

Dear Tom and Kurt,

Some results from South-Western Colombia show exactly what you mentioned. Minimum tillage significantly improves infiltration and water use efficiency. I have attached a graph that demonstrates this. The measurements were taken with a mini-rain-simulator on 12-year old research plots. For further details please contact me.

Regards
Christian Thierfelder

______________________________________________________

From: Peter Hobbs
To: MULCH-L
Subject: Conservation Agriculture
Date: Mon, 2 Feb 2004

Kurt and Tom:

Thanks also for sharing your work on conservation agriculture. We are also using the principles of conservation agriculture in the Indo-Gangetic Plains of South Asia in the rice-wheat system. It is equally appropriate for irrigated systems. I agree that it may be necessary to rip the soil before applying the no-till and residue retention in conservation agriculture although we haven't done this in S.Asia in the rice-wheat system even though we have definite plow pans after puddling rice. What we are doing now is promoting 0-tillage wheat and rice. The rice phase has problems with weeds but scientists are working on that. What we hope to accomplish is improved soil health (physical and biological) through adoption of CA practices over time. Microbial diversity and improvement is a way to help nutrient recycling and to biologically control diseases and pests. That means 0-tillage and residue mulch of some form. We believe this will take time for the soil to respond and there may be a transition period to overcome before it stabilizes. A bit like composting or vermiculture in situ. Inoculating the soil with earthworms may hasten the process. I also worked in rainfed areas in pakistan and getting water into the profile was the first step to improving productivity just like suggested by you two. Hope this helps.

Best regards,

Peter Hobbs
Cornell University

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From: Winfried Scheewe
To: Mulch-L
Subject: Conservation Agriculture

Dear Christian,

With great interest, I read your call for research results and citations of 24 January 2004. I cannot offer these but rather would like to suggest considering the inclusion of trees and shrubs in possible schemes. Even though I assume that eastern and southeastern Africa is arid, I hope that besides zero and minimum tillage systems and other appropriate practices, trees or shrubs could play an important role. Following the paradigm that agricultural systems ideally mimic the natural habitat, trees might be essential to stabilize agroecosystem.

Ecologically, alley cropping is certainly a sound practice and probably the best soil conservation and soil fertility management strategy, especially for sloping areas. Nevertheless, for several reasons, it is difficult ‘to sell’ alley cropping to farmers, even here in the Philippines, where many upland farmers successfully practice it.

I have read that in many countries, especially in arid areas alley cropping was not successful. I suppose that is to some extent a question of the choice of the nitrogen fixing shrubs (not trees) - they should definitely not compete with the crop - and the design (spacing) as well the maintenance (the way of pruning). Possibly there are overlooked opportunities.

Here in the northeast of Mindanao, we started last year to promote hedgerows of nitrogen fixing shrubs in coconut farms. Some farmers in southern Mindanao have made very good experiences with it. The mulching of the palms with cuttings from the shrubs at least the doubles the yield after one year. Often the results are even better. The scheme is quite similar to the use of nitrogen fixing shrubs in orchards. I like to imagine that these schemes could also work in other locations.

For more information see among others the PDF file “A Guide to Orchard Alley Cropping for Fertility, Mulch and Soil Conservation” on http://www.agroforestry.net/ The website of the Mindanao Baptist Rural Life Center http://mozcom.com/~mbrlc/index.htm contains further hints on alley cropping (Sloping Agricultural Land Technology - SALT).

On request, I can share an electronic file discussing the experiences with alley cropping from my book “Nurturing the soil – feeding the people.”

My best wishes for your undertakings!

Yours sincerely,

Winfried Scheewe
Surigao del Sur, Philippines
Philippines

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