CONSERVATION AGRICULTURE: THE ONLY HOPE LEFT FOR FOOD SECURITY

Conservation Agriculture was first defined during the First World Congress on Conservation Agriculture (1-5 October 2001)

It is a set of soil management practices that minimize the disruption of the soil's structure, composition and natural biodiversity. CA has proven potential to improve crop yields, while improving the long-term environmental and financial sustainability of farming.

Put differently, CA is an approach to managing agro-ecosystems for improved and sustained productivity, increased profits and food security while preserving and enhancing the resource base and the environment.

Credit: courtesy

According to the UN Environment official, studies show that nature based agriculture can increase yields by up to 128 percent under the changing climate to enhance food security. More here

This is opposed to conventional farming practices, whereby farmers remove, burn crop residues or mixes them into the soil with a plough or hoe. As a consequence, the soil is left bare, so it is easily washed away by rain, or is blown away by the wind

Conservation Agriculture Potentials

CA holds tremendous potential for all sizes of farms and agro-ecological systems, but its adoption is perhaps most urgently required by smallholder farmers, especially those facing acute labour shortages. It is a way to combine profitable agricultural production with environmental concerns and sustainability and it has been proven to work in a variety of agro-ecological zones and farming systems.


Conservation Agriculture makes sustainable and rural development practicable through its integration of crop bio-diversity, mixed crop/livestock farming, and other activities, all characterized by efficient use of resources. This results in a more productive agriculture, which improves food security and rural livelihoods.

The many economic, social and environmental benefits of Conservation Agriculture justify a fundamental re-appraisal of conventional farming methods. And conservation Agriculture should be considered as a theme which cuts across various disciplines, organizations and ministries.

According to FAO (Food and Agricultural Organization of the United Nations), Conservation agriculture (CA) aims to achieve sustainable and profitable agriculture and subsequently aimes at improved livelihoods of farmers through the application of the three CA principles: minimal soil disturbance, permanent soil cover and crop rotations.

Aims  -

To  pursue  more  sustainable  agriculture and rural development through the application of three  major  principles:  minimal  or  no  soil disturbance,  permanent  soil  cover  and  crop rotations.

It emphasizes that:

•      Soil is a living body

•      Importance of 0-20cm of soil as the most active zone and most vulnerable to erosion and degradation

•      Essential to quality of life on the planet

It seeks to preserve soil composition, structure, natural biodiversity and sustainable food production through:

·         Utilization of green manures/cover crops (GMCC's) to produce the residue cover;

·         No burning of crop residues;

·         Integrated disease and pest management; using IPM bags

·         Controlled/limited human and mechanical traffic over agricultural soils

NOTE: Organic farming involves growing crops and livestock without using agrochemicals. It is possible to do Conservation Agriculture in an organic way (without using fertilizers, herbicides or pesticides), but many types of conservation agriculture use these agrochemicals - but in small amounts and with care.

Major Principles/Characteristics of Conservation Agriculture

1. Continuous minimum mechanical soil disturbance,(just enough to get the seed into the ground) 
2. Permanent  organic soil  cover 
3. Crop rotations (Diversification of crop species grown in sequences and/or associations.)

1.      Continuous Minimum/No Soil  Disturbance

This done through  minimum  or  zero  tillage (direct seeding)

Zero tillage aims to enhance and sustain  farm  production  by  maintaining  a permanent  or  semi-permanent  organic  soil  cover that protects the soil from sun, rain and wind and allows soil micro-organisms and fauna to take on the  task  of  "tilling"  and  soil  nutrient  balancing. Farmers  can save their labor time and fuel costs

Advantages of Continuous minimum mechanical soil disturbance

•      The crop residues remain on the soil surface and produce a layer of mulch. This layer protects the soil from the physical impact of rain and wind

•      It stabilizes the soil moisture and temperature in the surface layers.

•      The zone becomes a habitat for a number of organisms, from larger insects down to soil borne fungi and bacteria. These organisms macerate the mulch, incorporate and mix it with the soil and decompose it so that it becomes humus and contributes to the physical stabilization of the soil structure.

•      At the same time this soil organic matter provides a buffer function for water and nutrients.

•      Larger components of the soil fauna, such as earthworms, provide a soil structuring effect producing very stable soil aggregates as well as uninterrupted macropores leading from the soil surface straight to the subsoil and allowing fast water infiltration in case of heavy rainfall events.

2.      Permanent Organic Soil  Cover.

•      Keeping the soil covered and planting through the mulch will protect the soil and improve the growing environment for the crop 

•      Permanent  soil cover needs to be integrated into farming systems to  obtain  additional  benefits. 

•      Crop  residues  will not  be  burnt  since  they  are  made  part  of  the permanent  soil  cover,  and  air  pollution  will  thus be  reduced. 

•      Residues from previously planted crops, other cover crops, and  green  manure  cover  crops  are  utilized  for permanent or semi- permanent organic soil cover.

•      The  dead-residue  biomass  of  the  cover  crops functions as mulch, protecting the soil physically from  sun,  rain  and  wind. 

•      Soil  mulch  reduces water evaporation, conserves moisture, and helps moderate  soil  temperature,  making  conditions more  hospitable  for  below-ground  biota.

•      Mineralization  and  nutrient  losses  are  reduced, and more satisfactory levels of organic soil matter are built up and maintained.

3.      Regular Crop Rotations. (Diversification of crop species grown in sequences and/or associations) to help combat the various biotic constraints:

• Which include nitrogen-demand crops such as cereals growing in rotation with atmospheric nitrogen-fixing legumes and/or Cruciferae.
• Help control pests, diseases, weeds and other biotic  factors. 

Well-balanced  crop  rotations  can neutralize  many  of  the  possibly  negative  aspects of minimum/no-tillage,  such  as  pest  build-up,  as they  increase  the  diversity  of  favorable  insects and  organisms  that  can  help  maintain  checks  on the spread and impact of pests and diseases.

 Tools Used in CA

1. Jab planter
2. Mulch planter
3. Shallow weeder
4. Traditional hoes, panga,
5. And using a special herbicide that kills only weeds and has no chemical adverse effect on the microbes. Stays in the soil for only three days. It is called WOUND OUT.

Benefits offered by Conservation Agriculture

It brings socio-economic  benefits  to farmers  and  ecological/environmental benefits  to  climate  change  mitigation:

•      Increased  profit  with  decreasing  inputs  of labour,  time,  farm  power  and  fuel consumption

•      Improved long-term  productivity  and  more stable yields

•      Reduced soil erosion - Soils under CA have very high water infiltration capacities reducing surface runoff and thus soil erosion significantly

•      Increased  organic  matter  and  improved  soil fertility/health

•      Recharge of the aquifers  through  improved water infiltration

•      Decreased soil compaction 

•      Better traffic ability in the field through Controlled  Traffic  Farming  (CTF) or Permanent  Raised  Beds  (PRB)

•      Reduced air pollution through reduced release of carbon gases and nitrous oxides No till fields act as a sink for CO₂

•      Increased carbon sequestration

•      More micro biota and improved biodiversity

Where to Practise Conservation Agriculture

Conservation agriculture can be used in all parts of Africa, except where it is too dry to grow crops. It can be applied in various climatic zones and under different conditions, though it may look very different from place to place. 

• In semi-arid lands, conservation agriculture retains water in the soil, keeps the soil temperature even, and protects the land from erosion during heavy downpours. Maintaining soil moisture is the main challenge in these areas, so rainwater harvesting methods can be very useful to increase the amount of water available for crops. 
• In sub-humid and humid areas, weeds and erosion are likely to be more of a problem. Crops are planted at closer spacings, and cover crops help suppress weeds and protect the soil. 
• On slopes, conservation agriculture can be used in association with terraces, contour grass strips and other erosion-control methods. 
• Where labour is scarce, perhaps because of HIV/AIDS, conservation agriculture enables farmers to produce good yields with less labour. 
• In densely populated areas, conservation agriculture increases yields on small plots of land under intensive cultivation. 
• On good soils, conservation agriculture keeps the soil healthy and maintains yields.
• On poor soils, it is a good way to rebuild soil fertility and enhance water-holding capacity, so increasing production.

Implementation of Conservation Agriculture

Conservation agriculture has been successfully implemented in both small-scale (Sorrenson et al., 2001) and large-scale (FAO, 2000e) farming, where it has given economic benefits as well as improved water resources. CA is therefore based on enhancing natural biological processes above and below the ground. More reading here

State of Conservation Agriculture in Kenya

During the  Second National Conservation Agriculture Conference, Nairobi, Mr Ruto, The Deputy President, Kenya, said in order to reap the dividends of Conservation Agriculture, we need to have a minimum of 10 percent of farmers countrywide to adopt the practice, saying county governments were perfect partners in ensuring the success of the programme

Photo credit: DP press

Mr Ruto challenged the Ministry of Agriculture and Irrigation to formulate sound policies and a viable implementation framework so as to anchor the approach to sustain productivity. 

Jeniffer Muthoni Maina has one acre farm in Kibubung’i location in Laikipia East sub-county which she grows maize, black beans (njahi) and dairy farming.

Until 2013, Muthoni could only harvest half a bag or one bag of 90kg maize from her one acre farm. She said, with these yields, she could hardly make ends meet for her family of four children.

Muthoni says that through the CA, she has been able to reduce on labour costs which would add up to her spending about Ksh3,000 monthly. Read more here

Case study of CA in Kenya

Constraints and limitation towards adoption of CA

•      Lack  of  knowledge  and  information : - Information  has  to  be relevant, factual, locally appropriate, and useful in order to generate mindset change among farmers.

•      Lack  of  direct  seeding  implements  for  planting into the permanent soil cover (In order to implement  CA,  the minimum a farmer needs is a zero-tillage planter.) CA will reduce machinery  sales,  particularly  of large  tractors.  The cost-effective  and  efficient direct  seeding  machines  suitable for developing countries

•      Inadequate institutional support, 

•      The  farmer’s attitudes toward CA and farmer’s  mindset  that  favors  the  status  quo ontillage and the fear of failure.

Policy recommendations 

•       An  institutional  framework  of  government services  to  mainstream  sustainable agriculture development and GHG mitigation into  national  policies,  laws,  investment strategies,  education  and  extension programmes;

•        Raise  public  awareness  to  facilitate  the extension  of  CA  techniques  by  full involvement  of  all  concerned  stakeholders, including  farmers,  researchers, technicians, extension specialists and agronomists;

•        Enhanced  research  and  manufacturing  of suitable direct seeding implements    supported by both public and private sectors;

•        Sharing  of  knowledge  about  all  aspects  of minimum/no-tillage  system  by farmers, researchers,  technicians  and  extension specialists;

•        Demonstration of good practices to promote farmers’  mindset  change  toward minimum/no-tillage CA;

•      Subsidies  for  buying  new  implements  and phasing out of the old ones;

•        Policy on financing the application of Clean Development Mechanism (CDM) in agricultural sector;

•        Promote  the  public-private  partnership  in financing  of  the  CDM  application  to  the agricultural sector.

Information links

• African Conservation Tillage Network (ACT). www.act-africa.org
• IIRR and ACT (2005). Conservation agriculture: A manual for farmers and extension workers in Africa. International Institute of Rural Reconstruction , Nairobi; African Conservation Tillage Network, Harare. ISBN 9966-9705-9-2. 
• FAO  
• The Organic Farmer No. 40, September 2008
• The Organic Farmer No. 141 February 2017

PRUNING: THE MOST IMPORTANT TREATMENT FOR TREES

Pruning is the removal of live or dead branches from standing trees.

It also means to trim (a tree, shrub, or bush) by cutting away dead or overgrown branches or stems.

Most trees require pruning. But remember not all trees need pruning. Some are self-pruned, like eucalyptus species.

Photo credit: independent.ie

WHY PRUNE

1. To improve stem quality( knot-free lumber/bole) Increases its commercial/stumpage values by 20% to 25% 
2. To reduce disease and pathogens
3. To remove parasitic plants e.g. mistletoe
4. To enhance safety( by roadsides & powerlines.)
5. To improve appearance/aesthetic quality
6. To facilitate free air circulation in a tree stand. 
7. To encourage growth and hasten tree maturity

WHEN TO PRUNE

Hardwood/ deciduous/ flowering/broad-leaved/seeds covered/slow-growing e.g teak, mahogany, camphor, oak, rosewood, melia etc: Should be pruned during rainy seasons as their wounds may exude excessive sap or become vulnerable to disease causing insects or pathogens

Photo: courtesy

Softwoods/Conifers/Evergreen/ Needle-like leaves/seeds exposed/fast-grower e.g pine, auracaria, fir, cypress, etc:  Should be pruned during dry seasons as they produce enough resin/sealant that seal the wounds enhancing quick healing.

Did you know:

That despite their names, hardwood isn’t necessarily harder than softwood, and softwood isn’t always softer than hardwood. The difference actually comes down to the type of trees they come from.

Photo credit: Medium.com

Tips to differentiate softwood from hardwood.

Using you thumb nail, dig into the wood and draw a line on the surface. If your nail leaves a mark on the surface, then it is a softwood. If it doesn't, it is hard wood.
Also look out for spores, or small pocket on the surface. If you spot any, it is hardwood.

Photo credit: qoura.com

Point To Note:

While conifer and dead branches may be pruned at any time of year, it is best to prune live branches during their dormancy  or during the cooler, less busy, more insect-free months.

TOOLS USED TO PRUNE

1. Hand or pruning saw
2. Pole saw
3. Secateurs
4. Clippers
5  Loppers/lopping shears
5. Ladder.

Choice of tool depends on the size of the branch.

TIME TO PRUNE

• Every tree species have a specific schedule/planned intervals for pruning.
• Mostly pruning for timber trees start from year one onwards.
• It is best to begin pruning while the tree is young and the branches are small. This will allow the most clear timber to grow on the bole; since knots form as each year's new growth surrounds a branch, living or dead.
• Also, it is easier, more efficient and healthy for the tree to prune small branches regularly than to prune large limbs. 
• Usually the tree should be pruned after it is at least 3 or 4" diameter. 
• One should never remove more than 1/3 of the live crown of the tree. 
• This operation may be repeated regularly until the lower  the right bole height is achieved, in case of lumber/timber.

WHICH TREE TO PRUNE

Newly planted trees: Should not be pruned unless a branch is broken, diseased or dead, because these trees need foliage to produce carbohydrates (sugars) that are then transported to the root system for initiation of new roots.

Young trees: After a young tree is established for one to five years, the tree can be pruned to encourage a well-branched canopy. Lower branches can be removed to raise the canopy, if desired.

NB: Always only  remove no more than 1∕3 of the total crown of a tree at one time. Young trees also need corrective pruning to remove crossing branches, double leaders, watersprouts, and root suckers.

Older trees: Established trees, if properly trained when young, require little pruning.

STEPS OF PRUNING OF OLDER TREES

Before you prune have with you a sharp pruning tool, disinfectant e.g. hydrogen peroxide to clean your tool to avoid spread of diseases from one tree to the other and a ladder for trees higher than 2m

Steps:

1. Walk around the tree to determine the formation of branches
2. Decide on which branches to remove.
   - branches with 1 inch diameter or more should be removed.
   - Root suckers that are a threat should be removed.
3. Make three pruning cuts:
  a) First undercut
  b) Upper cut to remove the branch
  c)  Final cut

Select the branch that you want to remove. On large limbs, the first cut should be 12 to 18 inches from the limb’s point of attachment.
The cut should be made right at the point where the branch meets the stem( branch collar), as shown here below.

The first pruning undercut is made 1∕2 way through the branch.

The second pruning cut should be made on the outside of the first cut (i.e., farther from the trunk). Cut all the way through the limb from the top down, thus removing the weight of the branch.

The final cut is made next to the tree’s trunk outside of the branch collar. Cut from the top down and cut all the way through the remaining branch stub.

Note:

The branch collar should be left intact. DO NOT cut the branch flush with the tree’s trunk. A proper cut avoids large wounds, and allows the tree’s wound to close quickly.

PRUNING STEP FOR MELIA VOLKENSII ( MUKAU)

Melia is one of the strangely fast growing first class hardwood, with a growth rate of  1m/yr and matures after 15-20 years, attaining a height of 6-20 m tall with diameter of up to 25 cm; unlike others that are slow. It is an indigenous tree that is endemic to semi arid and arid areas (ASALS) of Eastern Africa (Ethiopia, Somalia, Kenya and Tanzania), in the family MAHOGANY (Meliaceae). Besides being fast growing and melia produces high quality termite resistant timber in Kenyan drylands , that is, Kitui, Makueni and Machakos Counties.

Source: www.betterglobeforestry.com

Photo credit: Betterglobe media

Objective of planting Melia

• To produce quality timber, post, poles, fodder, bee forage and as an agroforestry tree.

Why prune Mukau

• To obtain a clean quality bole height of 5m, with 10cm DBH by year 4

Photo credit: Betterglobe media

Principles of pruning melia

1. All branches 1inch (2.5 cm)  and above in diameter should be selectively removed.
2. All double leader/ multiple stem should be, assessed and the most vibrant spared as other are removed.
3. All whorls must be removed, but progressively.

When to start pruning.

• From year 1 onward.

Schedule for pruning.

Year 1: No pruning except for double leader and whorls
Year 2: Pruning after rains
Year 3: 2-4 passages
Year 4:  2-4 passages

Melia pruning steps:

1. The three step above are the same here.
2. Remove whorls,( in 2-3 time),  double leader and also cut back poorly formed multiple stems to encourage re-sprouting/ coppicing.
3. Remove branches smaller than 2cm  with secatuers and bigger with pruning saw.
4. Use ladder for trees higher than 2 metres.

It is therefore only prudent that a serious tree farmer must undertake pruning, if any valuable benefit is to be achieved. 

Always seek professional advice and guidance from qualified forest expert or arborist.