Introduction

Our continent is bleeding to death: megatons of topsoil wash out to sea every year due to soil structure degraded by ploughing.

Conservation Agriculture (CA) – or “Conservation Tillage” as it was often called – is a cost-effective, environmentally friendly method of farming which does not use regular ploughing and tillage, but promotes permanent soil cover and diversified crop rotation to ensure better soil health and productivity. Society also benefits from reduced atmospheric carbon dioxide emissions.

CA (as defined by the Food and Agriculture Organisation of the United Nations, FAO) has come to be accepted as the umbrella term for describing agricultural farming practices that conserve ecological systems. The most common forms of CA are no-tillage, conservation farming, direct seeding, ridge till, chisel & disc, rip-on-row and stubble mulching.

All of these methods leave plant residues on the soil surface between growing seasons. The plant residues provide a protective cover that diminishes wind and water erosion, reduces evaporation losses, minimises water runoff and can thereby dramatically increase soil water (from irrigation or rain) availability. Organic matter, the key ingredient in soil productivity, increases, as do earthworms, conservation tillage’s ‘biological plough’, reducing diesel requirements by up to 50% or more.

Conservation and efficient utilisation of natural resources at national, regional and farm level is no longer a luxury but an imperative, and the adoption of conservation farming practices an essential component of good farming practice.

Green Trust/WWF SA media field trip

 

A closer look at conservation agriculture. Photos used courtesy of Helen Gordon, WWF SA.

Some forms of Conservation Agriculture

Conservation Agriculture, as defined by the Food and Agriculture Organisation of the United Nations (FAO), is receiving growing acceptance internationally as the optimal crop production system, and includes all farming systems which involve simultaneous adherence to the principles of:

  • Continued minimal soil disturbance (including NO soil inversion) – to retain root channels and encourage the build-up of soil biota populations and hence soil structure;
  • Permanent organic soil cover (either by living crops or by crop or other plant residues) – to diminish the impact of raindrops and reduce water runoff (and consequently soil loss); and
  • Diversification of crop species growing in sequence and/or associations (especially crop rotation) – to increase the diversity of food sources and hence soil biota, especially predators, and break pest and disease cycles.

Note that, although some organic farmers practice Conservation Agriculture, where production systems require the inversion or cultivation of the soil more than is necessary to insert the seed or seedling (for example, in the incorporation of manures), such systems can not be described as Conservation Agriculture systems.

No Till (also called Zero Till or Direct Seeding)

This is a crop production system that involves no seed bed preparation other than the opening (via a slit or punched hole) of the soil for the purpose of placing seed or seedling. No cultivation is performed during the growing season. As with Conservation Agriculture, weed control is accomplished using mulches, allelopathy (the antagonism of some plants or plant residues to other plants), crop rotation or appropriate (preferably narrow spectrum bio-friendly) herbicides.

Minimum Tillage

These are systems that involve minimal soil manipulation for crop production. Also referred to as reduced tillage, Minimum Tillage’s major objectives include:

  • to perform the minimum number and severity of operations thought necessary to optimise soil conditions, frequently differentiating between the in- and inter-row areas;
  • to minimise the number of trips over the field to avoid soil compaction and structural degradation;
  • to conserve moisture;
  • to reduce soil erosion; and
  • to reduce mechanical energy and labour requirements

Some common Minimum Tillage systems include:

Till and Plant: Tractor-driven equipment prepares narrow strips utilising shallow secondary tillage after the primary tillage and just ahead of the planter.

Strip Tillage: Combination units perform strip or zone tillage just ahead of the planter in untilled soil (usually utilising a chisel plough, with the sole aim of improving porosity and rooting depth in root zone). Specific practices include

  • Rip-on-row: A heavy tine at a depth of 300-450mm is drawn in the line of the planned (often also the previous) row ahead of the planter.
  • Chisel: Lighter chisel tines are drawn at a depth of 200-300mm as the sole cultivation prior to planting.
  • Chisel & disc: Primary tillage is conduced using chisel tines only, followed by a light disc immediately prior to planting.
  • Disc-plant: One discing operation before planting is done to loosen the compacted soil surface, to control weeds, and to leave most of the residue on the surface.
  • Bed-plant: This method is commonly used for soil moisture management especially in surface irrigated crops where furrows are made at appropriate intervals raising the bed between.

Ridge Till

This is a planting method where crops are planted on the ridge top, in the furrow or along both sides of a ridge. The ridges may be on the contours with graded furrows draining into a grassed water way, or use short cross-ties to create a series of basins to store water in ‘tied-ridges’.

Mulch Till

This is a system that involves cutting the roots of weeds and other plants, leaving the crop residue on the surface or mixed into the top few centimetres of the soil.

To plough or not to plough – old and new paradigms in crop production

Old paradigms New paradigms
Soil tillage is necessary to produce a crop

  • burying of plant residues with tillage implements
  • bare soil for weeks and months
  • soil temperature extremes due to direct radiation
  • burning crop residues allowed
  • strong emphasis on soil chemical processes
  • first option – chemical pest control
  • green manure cover crops and crop rotations optional
  • soil erosion is caused by excessive rain
Tillage is not necessary for crop production

  • crop residues remain on the soil surface as mulch
  • soil never bare – permanent soil cover
  • soil temperatures buffered by mulch
  • burning mulch prohibited
  • emphasis on soil biological processes
  • first option – biological pest control
  • green manure cover crops and crop rotations essential
  • soil erosion is caused by soil mismanagement
Consequences of soil cultivation & bare soil

  • wind and water erosion are unavoidable
  • reduced water infiltration into the soil
  • soil water less available
  • soil organic matter content & consequently soil quality unavoidably reduced
  • soil carbon is lost as carbon dioxide into the atmosphere contributing to global warming
  • soil degradation (chemical, physical and biological)
  • crop productivity reduced
  • fertiliser use and costs of production high
  • survival of the family farm threatened (lower yields, production without profitability, insufficient income)
  • rural poverty > urban drift > increased pressure on urban infrastructure and employment > urban poverty > slums > crime > social conflict > political volatility
Consequences of No-till & permanent soil cover

  • wind and water erosion near zero
  • increased water infiltration into the soil
  • soil water more available
  • soil organic matter content and consequently soil quality maintained or enhanced
  • carbon is sequestered in the soil, enhancing soil quality and reducing global warming
  • soil improvement (chemical, physical and biological)
  • crop productivity increased
  • fertiliser use and costs of production reduced
  • survival of the family farm ensured (more even, sustainable and profitable crop production)
  • basic needs satisfied > rural living standard and quality of life increased > increased and diversified productivity > increased rural prosperity > return to the land > national stability
 Off farm effects of soil erosion

  • sedimentation of rivers, dams, lakes etc.
  • reduced water quality & increased purification costs
  • problems in hydroelectric power plants
  • sedimentation of roads
  • higher costs for the government and for society due to off farm effects of soil erosion
 Off farm effects of new production system

  • reduced rate of sedimentation of rivers, dams, lakes etc.
  • enhanced water quality & reduced purification costs
  • less problems for hydroelectric power plants
  • less sedimentation of roads
  • reduction of costs for the government and for society due to off farm effects of soil erosion
 Result:

  • Sustainable land use is not possible (ecologically, socially and economically).
  • Soil resource exploitation
 Result:

  • Sustainable land use ensured (ecologically, socially & economically).
  • Rational, site-oriented use of the soil

Source for above table: After Derpsch 2004.

International business environment

Conservation Agriculture has been tested, proven and is being practised under a wide range of agro-ecological conditions throughout the world, and is a major factor in the growing dominance of South American grain producers on world markets. By emitting less carbon dioxide and capturing more carbon in the soil, CA helps counter the effects of global warming.

  • There is an annual World Congress on Conservation Agriculture. Find information on the UN’s Food and Agriculture Organisation (FAO) website, www.fao.org/ag/ca. A number of international links and publications (for download) can be found on this website.
  • WOCAT (World Overview of Conservation Approaches and Technologies) is an established global network of Soil and Water Conservation (SWC) specialists, dedicated to sustainable land management (SLM). Visit www.wocat.net.
  • The African Conservation Tillage Network (ACT), www.act-africa.org.
  • www.rolf-derpsch.comRolf Derpsch is a well-known advocate of CA overseas. Dr Ademir Calegari of Brazil’s Institute of Agriculture is another. Write to him at calegari [at] iapar.br or visit www.iapar.br.
  • No-till on the Plains, a non-profit educational organisation in the USA – www.notill.org
  • NO-TILL FARMER, www.no-tillfarmer.com
  • La Asociacion Argentina de Productores en Siembra Directa (Aapresid), www.aapresid.org.ar, the Argentina Association of Direct Seeding Producers
  • Conservation agriculture is championed by the International Maize and Wheat Improvement Centre. See www.cimmyt.org.
  • The Centre for Learning on Sustainable Agriculture (ILEIA) coined the acronym LEISA (Low External Input Sustainable Agriculture), www.agriculturesnetwork.org.
  • Find out about the European Conservation Agriculture Federation at www.ecaf.org. Numerous organisations and contact details are listed.
  • There are notes on conservation tillage (and much else) on the Conservation Technology Information Centre (CTIC) website, www.ctic.org.

Local business environment

In South Africa, the best adoption rate has been in the Western Cape, with nearly 80% of farmers having no-till machinery. There’s a strong group of no-till farmers around Bergville and Winterton in KZN. These areas lead the way with CA in the country.

As producers realise the benefits of the system, especially in drier years, this will change. South Africa is a water-scarce country and there’s limited soil for agricultural production. The use of no-till helps with carbon sequestration and lowers the loss of carbon and moisture from the soil. It prevents large-scale erosion through wind and water. CA helps improve soil health, leading to improved yield and sustainable production over time.

The practice of no-till has grown immensely in SA and involves emerging farmers as well. Smaller planters and sprayers have been developed for them.

Source: Dr Johann Strauss and Richard Findlay

National strategy and provincial contact

The Agricultural Policy Action Plan (APAP), based on the Department of Trade & Industry’s Industrial Policy Action Plans (IPAPs), have featured CA under the Promoting Climate-Smart Section.

Find information on, and contact details for, the different directorates of the Department of Agriculture, Forestry and Fisheries (DAFF) at www.daff.gov.za.

Provincial Departments of Agriculture that are involved with CA initiatives include the Eastern Cape Department of Agriculture, KwaZulu-Natal Department of Agriculture and Rural Development and the Western Cape Department of Agriculture. Find their details in the “Agriculture in the Provinces” chapter.

Role players

Associations and NGOs

Training and research

Institutions offering agricultural degrees/diplomas include CA in the syllabus.

  • Africa Land-Use Training
    • Tel 014 717 3819 / 078 228 0008
  • Agri-IQ
  • ARC-Grain Crops (ARC-GC)
  • ARC-Soil, Climate and Water (ARC-SCW)
  • ARC-Plant Protection Research (ARC-PPR)
  • ARC-Small Grains (ARC-SG)
  • Elsenburg Agricultural Training Institute
    • Tel: 021 808 7691
    • veronicac [at] elsenburg.com
    • gertym [at] elsenburg.com
    • johanl [at] elsenburg.com
    • theunsb [at] elsenburg.com
    • www.elsenburg.com
  • Foundations for Farming
  • KZN Department of Agriculture and Rural Development / Cedara
    • Tel: 033 355 9100
    • www.kzndard.gov.za
    • Annual workshops are conducted for small-scale farmers. Short courses are also run, and research on CA carried out.
  • North-West University (Potchefstroom)
    • Unit for Environmental Sciences
    • IPM Programme
    • johnnie.vandenberg [at] nwu.ac.za
  • South African Sugarcane Research Institute (SASRI)
    • Tel: 031 508 7400
    • https://sasri.org.za
    • SUSFARMS, the Sustainable Sugarcane Farm Management System, includes Conservation Agriculture in its programme. Contact SASRI for more information.
  • Stellenbosch University (SU)
    • Department of Conservation Ecology and Entomology
    • Tel: 021 808 3728
    • samways [at] sun.ac.za
    • SU Department of Agronomy
    • Tel: 021 808 4803
    • www.sun.ac.za
  • University of Fort Hare (UFH)
    • Traction Centre (TC)
    • Tel: 040 602 2125
    • This Centre trains owners and operators in the use of animal-drawn equipment, especially Direct Seeders, and their use in Conservation Agriculture systems suited to field and vegetable production. The TC co-operates closely with the Conservation Agriculture Thrust (CAT), a joint initiative between the provincial government and the University of Fort Hare.
  • University of the Free State
    • Centre for Sustainable Agriculture, Rural Development and Extension
    • Tel: 051 401 3765
    • www.ufs.ac.za/censard
    • This centre offers a masters degree in sustainable agriculture which includes topics such as conservation tillage.
    • Soil, Crop and Climate Sciences
    • Tel: 051 401 2212
    • www.ufs.ac.za

Implements and distributors

Trade name, country of origin, distributor contact details:

Animal-drawn No Till Planters

Trade name, country of origin, distributor contact details:

  • Mealiebrand (Zimbabwe) Afritrac 016 421 5184 www.afritrac.co.za
  • Knapik (Brazil) Inttrac Trading 016 365 5799 inttrac [at] cyberserv.co.za

Manual

Trade name, country of origin, distributor contact details:

Consultants

Role players listed earlier under heading 6 (e.g. Grain SA and the ARC) are available to offer advice.

  • Agri Field Services Tel: 079 974 7343 www.agrifieldservices.co.za
  • Agricultural Resource Consultants Dr Jim Findlay Tel: 011 486 2254/074 104 7081 richardfindlayntc2 [at] gmail.com, agrecon [at] telkomsa.net

Websites and publications

Visit the websites listed earlier in this chapter.

  • The excellent, annual Maize Information Guide (MIG) from the ARC includes notes on CA. Download the publication at www.arc.agric.za.
  • Call 012 842 4017 or email iaeinfo [at] arc.agric.za for the following publications, available from the ARC in Silverton: (i) Jukke vir dieretrekkrag (ii)Yokes for animal traction (iii) Animal traction implements (iv) Comparative review of technical specifications for no-till jab-planters
  • Conservation Agriculture is frequently covered in both agricultural weeklies Landbouweekblad and Farmer’s Weekly. Find stories like “Conservation farming helps Zambian smallholders thrive” and “Pursuing soil health precisely” at www.farmersweekly.co.za. Look for the option “Bewaringsboerdery” at www.landbou.com.
  • ASSET Research has several booklets and papers on CA. Visit www.assetresearch.org.za.
  • No-Till Advantages and Benefits in Crop Production and The Beginner’s Guide to No-Till by Aubrey Venter, and A Guide to No-Till Crop Production in KZN, 2nd Edition (1999). Available from the KZN No-till Club. A booklet on no-till is alsoavailable in isiZulu.
  • Find No-Till for KwaZulu-Natal’s small scale farming systems by Charmaine Mchunu and Alan Mason, and other documents on the KwaZulu-Natal Department of Agriculture website, www.kzndard.gov.za.
  • Find the “Introduction to Conservation Agriculture” manual and other resources on the Mahlathini Development Foundation (MDF) website, www.mahlathini.org.
  • Conservation Agriculture in Africa. Ademir Calegari, John Ashburner & Richard Fowler. FAO, Accra 2005. ISBN: 9988-627-04-01.
  • Find the No-tillage Training Manual at www.agis.agric.za/efarmer/
  • http://ca.ecoport.org is an interactive dedicated website initiated in South Africa and containing a wealth of information on Conservation Agriculture of use to farmers, advisers, researchers and educationists throughout the world.
  • Find videos on YouTube like “Weed Response to No-Till and Cover Crops, Randy Anderson” and “Seedling Emergence in Conventional and No-Till Fields“.
  • No-Till Farming Systems (2008). Special Publication No.3, World Association of Soil and Water Conservation, Bangkok. ISBN: 978-974-8391-60-1, 544 pp. A global collection of information presented by farmers, extension specialists, discipline professionals and research scientists.
  • Conservation Agriculture: A manual for farmers and extension workers in Africa (2005). IIRR, Nairobi and African Conservation Tillage Network (ACT), Harare. Obtainable from admin [at] iirr-africa.org.
  • Digital team. 2018, March 29. “Conservation agriculture builds a better life for Phumelele Hlongwane”. African Farming. Available at www.africanfarming.com/conservation-agriculture-builds-better-life-phumelele-hlongwane/

Our gratitude to the late Richard Fowler and Dirk Lange (University of Fort Hare) for notes used in this chapter.

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