Expert Agricultural and Environmental Advice for Land Managers

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TechTalk Example Questions

The questions copied below have been posed to some of our advisors during the past year. They have been placed here so that all interested parties can see the style, scope and range of questions our advisors receive.


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International Development Project Help and Advice

Question from an NGO in Ethiopia

There are a number of Lupin species which are used as food for human and livestock feed (such as blue lupin, white lupin, yellow lupin) in the Mediterranean and other parts of the world but are not widely used in Ethiopia. Why? Is this due to climate or because of other factors?

Tests of Lupin seeds harvested within and around the programme area are too bitter to be used for human consumption/livestock feed. Is this crop poisonous at all and to what extent? Can you provide information on different varieties that might be better suited for consumption?

What are the advantages and the disadvantages of the crop/ its seed with respect to food for humans, livestock consumption, inproving soil fertility and stabilising physical soil and water
conservation structures or as an income for poor families?

Do you have advice on its cultivation/preferred agro-climatic conditions?

The Answer


While I can't answer specifically why lupin isn't used much in Ethiopia, I suspect that the answer lies in the fact that the local varieties are too bitter. The main species cultivated are, as you state, Lupinus album (white lupin), L. angustifolius (blue or narrow-leaved lupin) and L. luteus (yellow lupin). Given the altitude of Dessie, blue lupin, which is the hardiest, may be the most suitable if frost and/or water logging are problems, although L. alba is indigenous to Ethiopia.

Ethiopian L. alba (white lupin) is known for its bitter seeds and in general, lupins naturally contain a bitter alkaloid toxin in the seeds, which can cause livestock poisoning. Newer varieties contain less alkaloid (so-called sweet lupins). They can be de-toxified by soaking for several days in salt solution. Low alkaloid varieties of white lupin include 'Kiev', 'Dieta', 'Amiga' and 'Volos'. Note that these (apart from Kiev) are the varieties currently approved in UK, and may well be suitable for Ethiopia, but I recommend that they are thoroughly tested in situ in small plots at various sites before any testing against local varieties is contemplated. White lupins are more tolerant of alkaline (limestone) soils, and yellow and blue species do better on more acid soils.

Use of Lupins

With regard to the advantages and disadvantages of the crop and its seed for the following uses:

Food for humans
The seeds contain 30 - 40% protein with no amino acids being deficient and have about 10% oil content, so they make good human and livestock food and are incorporated into both.
Lupins for human consumption have many different uses, including flour, pasta, tofu, tempe, soy sauce and snack foods. Lupin seeds possess many nutritional and food processing qualities, making them an attractive alternative to dry beans and soybeans. Lupin seeds are high in protein and high in the dietary fibre component that is associated with lowering cholesterol. In many EU countries, bitter large seeded lupins are commonly eaten as a snack food preserved in brine (information resource portal for lupins).

Livestock consumption
Lupins are often used as a substitute for high protein soybean meal in livestock feeds. The composition of the lupin grain has different nutritional characteristics for ruminants (cattle) and monogastrics (particularly poultry). The hull of lupins is a readily digestible fibre for ruminants yet is of limited value to monogastrics. Dehulling (removing the hull or outer coating) can improve the utilisation of lupins, with the kernel directed to monogastric feeds and the hulls and other particles processed into stockfeed for ruminants. Australia, Europe and Japan use sweet lupins in dairy production. However, in Australia the largest utilisation of lupins is whole grain feeding to sheep, to supplement low grade roughage diets. Commercial pig producers have successfully used up to 30 per cent narrow leafed lupin seed in pig diets. Poultry diets normally contain less than 10 per cent lupins because of ‘sticky’ or ‘wet’ droppings. This is aesthetically undesirable and a potential health risk to the birds, but is not known to affect feed conversion rates.

To increase soil fertility
Lupins are leguminous so have an ability to fix atmospheric nitrogen into ammonia that, in turn, can have a fertilising effect in the soil for subsequent non-legume crops and pasture. This process occurs through bacteria, known as rhizobia, found in the root nodules of legume plants. Because of their nitrogen fixing ability, lupins (and other pulse crops) can be used in cropping rotations to replenish nitrogen depleted soils. Soil inoculation is used prior to lupin planting in the commercial sector, so, in the absence of commercial inoculants, digging up some soil from where lupins grow already and mixing a few handfuls where the farmers intend sowing a new crop, would result in effective nodulation with a suitable rhizobium bacterial strain. Check for effective nodulation by digging up a few plants about mid-season and look for nodules on the roots - cut nodules open with a sharp knife and if they are pinkish inside it indicates active N fixation.

-Stabilizing physical soil and water conservation structures
Lupins are deep rooted, and are known as a biological plough so they will aid rainfall infiltration. Regarding soil stabilisation, as a deep- rooted perennial soil stabilisation qualities will depend on plant density.

Source of income for poor farmers which will contribute to their livelihoods
In Australia, one of the main global producers of lupins, a field crop a density of 45 plants/ square metre will and should yield some 1-1.5 tonnes per ha. This should be compared with ACCURATE ESTIMATES of production of local pulses in and around Dessie. The usual UNDERESTIMATION that occurs in household surveys must not be taken as the norm for horse beans or even grass pea. Do your own assessment properly from local fields using 10 samples of 1 square metre taken at regular intervals in a “w” shape across typical local fields at harvest time- from fields where beans have not already been taken green. If, following your assessment and successful growing of your chosen variety in your own, small- plot trial planting, lupins still look an attractive proposition, remember that they have to be sold....someone has TO WANT TO BUY THEM!

If seeds are treated by soaking or low alkaloid varieties can be obtained, then lupin could be a source of income for farmers. The tops can be fed to livestock and are rich in proteins. Wilt the tops first and introduce gradually with the usual grass fodder in case the diet is too 'rich' and leads to bloat disorder.

Cultivating Lupins

Avoid water logging soils as lupins are very prone to root-rots. Lupins are very sensitive to high temperatures (above 30ºC) or hot drying winds during flowering.

Albus lupins are especially susceptible to heliothis damage.

Water requirements are similar to wheat and barley and common Ethiopian legumes viz- horsebeans.

Lupin grows best on well drained, light textured, acid to neutral soils with a pH in the range of 4.5-7.5. They can tolerate some alkaline soils up to pH 8.0 provided the soils are free-draining and not subjected to prolonged water logging and do not contain free lime in the top 0-60 cm of soil. Free lime content of the soil should be below 4%. Crops flower in 95-105 days. Lupin is susceptible to frost damage if the first heavy frosts occur at flowering. The crop appears more tolerant if heavy frosts occur during the vegetative stage. Flowering ceases at temperatures above 30ºC.

Populations of 30-45 plants/sq metre are recommended under most situations. This is equivalent to a range of 70 kg/ha for narrow leaf lupin varieties to 120kg/ha for Albus lupin varieties. Sow in rows into wet soil for best effect.

Lupin does not require nitrogen fertiliser provided that are properly inoculated. The crop has a high phosphorus requirement. Aim to apply 8-10 kg P/ha in deficient soils.

Hand weed or apply pre- emergence or post- emergence herbicides.
Diseases ( Global- not specifically Ethiopia)
Cucumber mosaic virus (CMV) is potentially the most important disease. The viral disease is spread by aphids and through infected seed. The Albus lupin varieties are all resistant to CMV.Brown leaf spot, phomopsis stem blight, and grey leaf spot are serious problems but have not been a problem in the northern areas to date.

Intensively monitor for heliothis from flowering until pod fill. Albus lupins are especially susceptible to heliothis damage.
Other insect pests include lucerne seed-web moth (Etiella), aphids, thrips, and blue oat mite.

Lupin should be harvested as soon as they are ripe as pods become brittle and can shatter badly. Losses up to 40% can occur from shattering at harvest. As noted above yields of 1-2 t/ha are achievable.


Smallholder Europe Help and Advice
Question from an NGO in South Sudan

What are the most appropriate techniques for honey processing and what equipment is necessary for both processing and packaging of honey?

The Answer

The answer below connects to considering beekeeping as a livelihood option for poverty alleviation. Size and scale of the plan and the current stage of beekeeping reached, plus whether the enterprise is investor orientated will determine the type of equipment needed. The answer below is, therefore, designed for beekeeping as a livelihood option for farm families and is appropriate for groups handling up to 15- 20 tonnes of honey per annum.

In our experience, frame free beekeeping is the most effective option using traditional hives or top bar hives. The methods given below also work for frame hives that are not using wired foundation (if frame hives ARE being used without wired foundation then the full benefit from the technique is not being gained and their use should be reconsidered).

Honey Extraction

Personally, I dislike the word processing and have tried to discourage its use in places where I have worked. It can have negative connotations that may make some buyers think the honey has been degraded in some way, which is not true. Honey extracted using either method is very pure. The correct term is honey extraction not honey processing.Honey processing does not have to be complicated and can be done very effectively using a simple method. Beekeepers should be trained and encouraged to do this for themselves before selling honey to packers. This ensures they get the best price for their honey and that they also keep the wax from their honey harvesting, which they can then clean and sell separately.

No special equipment is needed. The process is as follows:-

1. Take a clean bucket and place all the honeycombs into the bucket.
2. With a large knife cut up all the honeycombs so they are very finely chopped. This breaks down the honeycomb cells and releases the honey.
3. Take a second clean bucket and cover it with a straining cloth with reasonably large sized holes (say about 1mm across – see picture). Tie the straining cloth rather loosely around the rim of the bucket so that it forms a well in the centre of the cloth. I find net curtain material is ideal and I have usually found that suitable cloth can be purchased locally from street traders.
4. Pour the honey, little by little, into the well in the straining cloth. The honey will run out and the wax will be retained in the cloth. It will take some time and patience to do this. When all the honey comb has been put into the
straining cloth cover the bucket and cloth with the upended second bucket to keep the bees out and put it all to one side until all the honey has run out. This may take 24 hours. About 95% of the honey will be extracted this way. The procedure may be hastened by squeezing the honey through the cloth but this will result in poorer quality honey.
5. The beeswax will remain in the cloth and can also be cleaned to make it into solid wax blocks.

Cleanliness is the most essential part of this process. No heat (such as leaving the honey in the sunshine) should be applied to the honey if it is to retain its high quality and medicinal effects.

Some people with a lot of honey to extract may wish to use a honey press. I have seen many of these purchased in hope but have never seen one used in the long term. I have also designed an equally effective but inexpensive version that can be constructed by beekeepers themselves. The group I work with in Malawi accept 10-15 tonnes of high quality honey annually that has all been extracted using the simple method.

If requested AA International Ltd, who run TechTalk will send you a beekeeping manual, which explains the extraction method described in pictorial detail plus other information that you may find useful.

Packaging/Bottling of Honey

If less than about 20 tonnes of honey per annum is being packed then again very little in the way of special equipment is needed. Honey can easily be bottled simply by using a pouring jug to fill the bottles. Another alternative is a honey bucket fitted with a ‘honey gate’ that can be opened and closed to release the honey. A plastic one is cheaper than a stainless steel honey gate and just as effective. I suspect it is unlikely that you will be able to get a honey gate in South Sudan so you might have to make arrangements to import one from a beekeeping equipment supplier such as EH Thorne  at ; Tomas at or Swienty at all of whom have online beekeeping catalogues.

Good quality, bottles with secure lids should be sourced. The best I have seen in Africa are made of PET. You will also need attractive labels for retail sales of honey. A set of scales (that will weigh small amounts up to 1kg) is helpful as it allows the content weight of sample jars to be checked. Once packing exceeds 20 –30 tonnes annually then you may wish to look at more sophisticated packing procedures. There is a confusing selection of sophisticated, complex and expensive equipment available as you will see if you access the website suggested. However, my experience is that it is rarely necessary and should your enterprise become this large then I would be happy to advise you further about what you might need.


Hores and Pony Questions and Answers
Question from an NGO in the Afar Region of Ethiopia

We are working on the development of preventative/control management strategies and techniques for Prosopis juliflora. What advice do you have or experience can you share on this subject?

The Answer

Prosopis chilensis/P.juliflora (often known as mesquite) has been the cause of much controversy over the last 30 years. It is a highly drought tolerant dryland species from South America that not only survives but flourishes in desert conditions with summer temperatures of up to 50C, as long as the roots can find groundwater fairly near the surface.

It has been introduced as a valuable desert encroachment control species in areas where there is zero or very low rainfall (such as in Northern Sudan) and has played an important part in reducing sand movement and stabilizing sand dunes.

However, as with all introductions, its ecology and biology needs to be well understood before it is introduced to a new area. In the case of mesquite, the species has, unfortunately, been introduced into areas where it is unsuitable and it has now spread, covering very large areas and forming impenetrable thickets of thorny stems, making these areas unsuitable for agriculture or other forms of land use.

The primary requirement for introducing mesquite is that there must be zero or almost zero rainfall. The reason for this is that the seeds, which make very palatable and nutritious animal fodder, are scarified in the gut of ruminants and germinate readily wherever moisture is found. So areas that receive as little as 50mm of rainfall a year, or where irrigated agriculture is found, are unsuitable for mesquite introduction as it will spread very rapidly in these conditions.

The spread of mesquite in such unsuitable areas is rapid, with flowering and seed production starting as early as 7 months into the first year of growth of the tree. By the time the tree is 2 years old, it is producing many kilos of pods and these are distributed by animals or rainfall to other areas where they readily germinate and colonise new areas. In Sudan vast areas of the fertile eastern plains towards the Red Sea (near Port Sudan) have been rendered unsuitable for agriculture by mesquite invasion.

Mesquite is especially problematic in the Tokar and Gash spate irrigation schemes of Northern Sudan. Recently, more funds have been mobilized to combat the weed. In Tokar, a Sudanese company is clearing the scheme of mesquite, although the cultivated area of sorghum and millet, limited by the presence of mesquite trees, has not yet increased. On Gash scheme, clearance of the weed has been partially achieved under a rehabilitation programme by the International Fund for Agricultural Development, which is set to continue until 2012.

The introduction of mesquite has not always resulted in problems – it can be seen in near Ed Debba in Northern Sudan holding back sand dunes up to 20m high. No other tree species can do this in these conditions and mesquite shelterbelts have enabled agriculture to continue in these areas, allowing many communities to remain in areas that would otherwise become unable to support them. Rainfall in this area is effectively zero and the mesquite does not spread in this environment. It is the introduction of mesquite into inappropriate areas that causes the problems.


• Removal - the most effective control is to remove the trees but this becomes difficult once trees are established. Large trees can only successfully be removed on any scale by using bulldozers or diggers to dig out the root systems and of course, such equipment is often unavailable. Once removed they can be burnt or used for charcoal production.
• Control of seed production - removal of seed pods is possible on a small scale but the thorniness of the trees makes it very difficult to reach all the pods. If the pods are fed untreated to animals the resulting dung is full of ready to germinate seed, so spreading the trees further. It is better to crush the seeds first. However, if only a few pods are not collected they will still enable the species to spread.
• Weeding - to reduce the spread, vigilance in rooting out new seedlings is vital. As noted above, from seed a mesquite tree can reach the flowering stage within 7 months where conditions are suitable, so it is essential to pull up seedlings every few weeks. Once they are more than a metre or so high it becomes extremely difficult to pull them out and the broken off root system will produce new shoots. It is the extraordinary precociousness and resilience of mesquite that makes is such a formidable weed.
• Burning – I don’t know how effective this would be – I suspect that the root systems would just produce vigorous new stems once the fire had passed.
• Chemical control – I have not used herbicides on mesquite but a strong formulation of e.g. dicamba or triclopyr may be appropriate – however, there are many good reasons not to recommend such chemical treatments. In temperate forestry, the stumps of trees that have been cut down can be treated with proprietary chemicals to prevent them from regrowth. However, such chemicals are unlikely to be available or cost effective given the scale of the problem and present environmental risks.
o In South Africa, chemicals were found not to be a cost effective solution to the mesquite problem when used alone, but may be effective as part of an integrated control programme (HDRA, 2005).
• Regular coppicing – if the trees are cut every few weeks they will eventually become weakened and should die, but this may take months or years and is probably impractical. If the coppice shoots are allowed to grow too much then they will actually strengthen the rootstock, thereby making the situation worse.
• Biological Control Agents – In South Africa, two species of seed-feeding bruchid beetles have been shown to be effective as a biological control agent for mesquite (Zimmerman, 1991). TechTalk has contacted the South African Department of Water Affairs and Forestry to see if they have experiences about this that they can share with us and we shall get back to you as and when we hear back from them. The introduction of biological control agents is, however, often complicated and costly and can cause more problems than it solves.

Uses of mesquite

The very thorny stems make working with this material difficult. On a small scale they can be coppiced and the resulting straight stems used to make fencing (I made a lot of fencing panels from coppiced mesquite and used them to protect newly planted seedlings). They can also be coppiced for small scale charcoal production (in the US mesquite charcoal is the favourite charcoal for barbeque cooking, especially in the southern States). In the US the wood of mature mesquite trees is also highly valued for joinery and furniture making. The pods, as already noted, are very nutritious and can be used for animal feed. Again in the US, flour is made from the seeds and this is mixed with wheat flour to make bread and cakes. However, the technology for this is unlikely to be available locally. The FARM Africa report provides very useful information on a project designed to find ways to control and use mesquite in Ethiopia.


Once established on large areas of land, mesquite control is very difficult. If appropriate to the project concerned, bulldozers and other heavy plant can be used to rid the land of the trees but follow up is essential to prevent reinfestation from seedlings, and this vigilance must be continued for several years until the seed bank in the soil is exhausted. On a small scale there are several valuable uses of mesquite and as long as suitable tools and equipment are available, and there is a local market for mesquite products, there may be an economic case for productive management rather than eradication. However, if eradication is required then one or more of the above techniques is required and long term vigilance needed to ensure that, once removed, the trees don’t reappear.


H. G. Zimmermann, Biological control of mesquite, October 1991, Prosopis spp. (Fabaceae), in South Africa, Agriculture, Ecosystems & Environment, Volume 37, pages 175-186.

Henry Doubleday Research Association, Department for International Development, Forestry Research Council and Agricultural Research Council, 2005, Realistic approaches to the management of Prosopis species in South Africa,

Example question from Welsh Farm
Question from Welsh Farmer

I am a Welsh farmer and have several acres of poor quality woodland on my farm. I would like to start using my own wood to heat my home but am not sure quite how to proceed. Would I have to process the wood into pellets or chips in order to run a heating system. What practical options do I have?

The Answer

Modern, efficient, wood heating systems can be operated using pellets, chips or logs.

Wood pellets are the most convenient fuel and are suitable for use in domestic central heating boilers and room heaters. However, converting your own wood into pellets is not practical at a single farm-scale. Manufacturing wood pellets is a specialised process requiring expensive equipment. If you want to use your own wood, this option is not practical.

Wood chip boilers are also convenient but wood chip heating systems tend to be designed for larger heat loads of 30kw and above. This might be a very large single house or a collection of farm buildings or a house with a swimming pool. The advantage of using chips is that you can chip your own wood. A specialist chipping machine is required to produce consistent, high quality chips so for most individual farms it is probably advisable to contract out the chipping operation once or twice a year. You would need adequate dry covered space to store the chips. You also need to ensure the logs are well seasoned before chipping. Wood dries out better as logs than it does as chips.

I would expect that the best option for most single farms would be to use logs. Logs can be burned either in traditional wood burning stoves (with or without back-boilers) or in modern efficient central heating boilers. The efficiency of stoves is improving all the time but they do still require a fairly high amount of attention to keep them going over the day and may not be the most practical solution for a busy farmer.

What I would think would be a very good option for you would be to install a high efficiency batch-burning log boiler. These boilers need to be filled with logs once per day (or less often in the summer) and lit. The logs are burned over a period of a few hours and the heat output is stored in a hot water accumulator tank. Your heating and hot water controls take heat from this tank and when the temperature drops to a certain level you know it is time to relight it. Thus, this system is fairly low maintenance and reasonably cost-effective.

For more information on grants and installers in your area contact the Biomass Energy Centre

International Development Project Help and Advice
Question from an NGO in Rwanda

We are quite keen to promote small scale vegetable gardens as part of our food security strategy. The key constraint is water. The ability to use grey water would obviously do much to resolve that constraint. Can grey water (containing any type of soap) be used for irrigating home/vegetable gardens? Are some soaps benign and others damaging?

The Answer

TechTalk reducing Carbon Footprint

Vegetable and fruit cultivation has a high potential for generating income for poor households or for improving diets where the products are not sold. However, a major constraint on production is often the availability of water. The use of grey-water deriving from domestic use for irrigating vegetables/ fruit trees is a helpful means of prolonging the growing season while maximising the use of a precious natural resource. Generally, the use of household wastes for agricultural production has particular resonance in Africa as witnessed by the better growth of crops nearest the tukul/ hut.  


Grey-water is non-industrial wastewater generated from domestic processes including i). dish washing, ii) laundry and iii) bathing. In general, grey-water contains oils, fats, detergents, soaps, nutrients, salt, particles of food, hair, skin cells and lint.

Is Grey Water Re-use safe?

Yes. The only evidence comes from the USA where there are eight million formal grey-water systems in the US with 22 million users. In 60 years, there have been one billion system user-years of exposure, yet there has not been one documented case of grey-water transmitted illness.

General rules for single households

The safety record noted above notwithstanding

We recommend you DO NOT use your kitchen sink/ washing-up bowl grey-water for irrigation. Although it contributes least to the total grey-water volume of a household, it accounts for the bulk of the fats, oils and food particles, components that cause an irrigation system or the soil to clog.

We strongly recommend you DO use your grey-water from the washing area/bathroom and laundry which accounts for the majority of the grey-water volume.

Using bathing and laundry grey-water

Do not store untreated grey-water for more than 24 hours. Whilst grey-water does not contain toilet waste, it may still contain the same pathogenic micro-organisms as found in toilet waste from bathing and washing soiled clothing, though in lower numbers. Therefore, grey-water should not be stored for over 24 hours - it is best used immediately once it is cool, ideally within a few hours of collection. UV light and natural soil microbial breakdown will neutralise bacteria. 

Keep use of soaps, detergents and bleaches to a minimum. All soaps and detergents have a minor potential to introduce chemical contamination to the soil. Check the types of soaps and detergents used within the households.

It is preferable to use soaps and detergent products with low sodium levels. Hard, long bar soaps are unlikely to be used in sufficient quantity to cause problems.   

Modern detergents break down quickly in the soil so should not be a concern but opt for low sodium content where possible.

As a general rule, ensure all detergents, bleaches, or other household cleaners and disinfectants are used sparingly to reduce impact on plants and simply because overuse of these materials is wasteful.

Grey-water coming from specific one- off cleaning jobs containing high concentrations of bleaches, disinfectants or strong chemical cleaners with caustic soda should not be included for irrigation.

Application to crops

Apply carefully do not use a sprinkler-box or a watering-can or spray the water on to the leaves. For edible green vegetable growing, grey-water should be applied at the base of the plants rather than on the leaves using the ‘ponding’ technique to maximise water to the plant roots and minimise risks of microbiological contamination of edible parts. Do not splash the leaves in the process.

Use efficiently. Regular weeding maximises water to help plants rather than weeds. Early morning or evening watering reduces evaporation so makes the best use of the water. Better still, combine the use of grey-water with water from other methods of water-harvesting from roofs, roads and rock-faces and pass through a simple farm –family drip irrigation system based on gravity.

General rules for multiple households

Be aware that grey-water from multiple households may be contaminated

Whereas single households can exercise total control over the constituents of the grey-water they use, there can be no such guarantees with grey-water from multiple households. Therefore, reduce contamination as much as possible by introducing rules that all households must obey if they wish to participate in the scheme. Such rules should involve the strict use of a collection system within each household that separates sources viz- grey from raw sewage run-off.

Choose a network system to reduce exposure to children. Opt for a wide-bore piped gravity system of collection from households to small temporary reservoirs/ tanks; cover the small temporary reservoirs / tanks. Filter the outflow from the reservoirs / tanks to remove clogging particles and pipe to the field under gravity.

Deliver the water to plant basins through a drip or a bubble system

Planning use to best advantage

Use for tree crops: Avoid risk by using multiple-household un -treated grey-water only on fruit bearing, timber, firewood or multi –purposes trees. Orchard/ wood lots should be planted at the closest suitable point that allows gravity water supply; and strips allocated to participants to manage as they wish.

Development plans:  If the simple system proves to be effective, use a subscription charge/ tariff on the water received to fund the introduction of a treatment system to improve water quality, reduce risk and facilitate vegetable/ root crop production.


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