Hand-hoe/ Fully Manual farming systems

Name: Pot holing

E.mail: itdg@samara.co.zw

E.Chuma, Institute for Environment, University of Zimbabwe, tel: ….

Name: Tied Furrows

Category: Ridge based technologies

Other Names: 

Local Names: 

Country or Site:Zimbabwe

The technique is only suitable for marginal rainfall regions.

Description:

This technique is similar to tied ridging except that planting is done in the furrows or in the flanks of 1 meter wide rows. Re-ridging and reconstruction of ridges is carried out at the beginning of each season 

The principle of operation of tied furrows is similar to tied ridges. The tied furrows may however be pegged at zero grade for maximum water retention. The wider the ridges the larger the amount of water harvested into the furrows but the lower the plant population. The optimum width of furrows recommended from studies at Chiredzi Research Station in Zimbabwe is one metre. 

The soil on the ridge has higher fertility than the furrows hence planting on the flank gives the best compromise for both fertility and moisture in the furrow. 

Insert picture showing tied furrows (Isaiah)
 
 

Evaluation:

The system is very effective particularly on clayey soils where water retention is high.

Advantages and/or Opportunities

The water harvesting effect of the ties helps to increase water available to the crop from the furrows where the most water accumulates. 

Gives the optimum chance for good yields in marginal rainfall regions ( Regions IV and V).

Disadvantages and/or Limitations

Weeding can only be carried out by hand hoes. 

Stage of development

Has been subjected to some on-farm testing but still not widely adopted in the low rainfall areas. 

Still needs further development. Similar equipment as for tied ridging is required

Adoption Potential

This system has very high potential for adoption in low rainfall areas provided the awareness among farmers is created and relevant equipment availed. In areas where waterloging is likely to occur this technique is not recommended

Source and Further Information:

Chiredzi Research Station 

Department of Research & Specialist Services

Box 97, Chiredzi 

Zimbabwe. Tel: 263-31-2397/8

E-mail: rsschiredzi@mango.zw

Name: Ridge & plant

Category: Ridge based technologies

Other Names: 

Local Names: 

Country or Site: Uganda

Site: Mukono 

Agroecology: Southern and western tall grassland

Description:

The technology is applied in Mukono district, Uganda for surface drainage, erosion control and improving fertility. The practice relates very much to other Ridge Based Systems

Ridging is a physical conservation practice. Ridge and furrow systems are aligned parallel to the contour lines to have the dual purpose of erosion control and surface drainage. Ordinary ridges are 20-30 cm high and are spaced between 60 and 80 cm. In some areas, bigger broad ridges are made which may be 50 cm high and spaced at 1.5 cm. Ridges are commonly made using the hand hoe, though in some areas draught animals are used.
 
 

Evaluation:

Advantages and/or Opportunities

Enhances infiltration

Reduces run-off

Disadvantages and/or Limitations

High labour requirements for making ridges

Source and Further Information:

NARO, Uganda
 
 
 
 
 
 

Furrow planting and ripping technologies

Tram-lining, sub-soilers, chiselling

Name: Mulch Tillage

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zimbabwe

Description:

Mulch Tillage systems were developed for situations where crop residues could be utilised for soil protection and improvement. This technique is most popular amongst commercial farmers. Due to the wide use of combines in commercial farming areas direct planting into previous crop residue can be achieved using a direct drill planter (such as the Tinto Supa Nova). Weed control is achieved by the use of suitable herbicides and the field is kept weed-free during the dry season or fallow periods. Ripping is done to a depth of about 23 cm or more using a tractor mounted ripper or an ox-drawn ripper-tine mounted onto an ox-drawn plough beam. Crop rows alternate between seasons. Conventional ploughing is only undertaken during the first year of implementation. For small-holder farmers the technique involves ripping into stubble with an animal drawn ripper and planting into the rip-lines

Insert figure showing crop with mulch

Insert figure showing plough beam mounted to the ripper tine

Evaluation:

Stage of development

The technique is now well developed in commercial farming. Concepts still have to be developed for small-holder farming. Animal drawn machinery capable of planting in trash or crop residues still needs developing. Whilst the major argument against this practice is the lack of stover after the dry winter during which crop residues are fed to livestock experiences from Chinamhora, Chiweshe and Musana communal lands in Zimbabwe have shown that farmers actually burn the little (less than 30 %) left-over stover before the onset of the season so as to have a "clean" field 

Advantages and/or Opportunities

Reduces run-off and soil loss effectively.

Temperature fluctuations in the top soil are minimised. 

Reduced or No-Till improves organic matter status in the soil thereby improving soil structure .

Water infiltration into the soil is increased and soil evaporation minimised.

Draught power requirements are minimised ensuring timely planting.

Reduction of Costs.

Disadvantages and/or Limitations

Requires at least 30 % mulch cover on the surface. Stover is often limiting in communal areas

During ripping stover can get caught on to the ripper impeding penetration of the ripper if the stover is not initially moved away from the rip line or is not threshed to small pieces. 

An ox-drawn mulch cutter /chopper has been developed to alleviate this problem for animal drawn systems. Where combine harvesting is carried out the stover is cut to very small pieces which alleviates clogging up of the ripper.

If applied to wet or cold soils the technique results in depressed yields.

Weed management has to be improved as weeds can pose a serious threat especially soon after establishment.

Source and Further Information:

Literature

Brunner, E. and W. Mariki, with H. Elwell, 1998, Available Technologies in Conservation Tillage, Paper presented at the Workshop on Conservation Tillage for Sustainable Agriculture.

I. Nyagumbo, SWC Branch, IAE, Hatcliffe, Zimbabwe

Name: Semi-incorporation of mulch (chisel plough)

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Tanzania

This technology is used in the highlands and semi arid areas for commercial large scale farming of wheat. It is a reduced tillage system that was started as an improvement to the conventional flat cultivation system.

Description:

The semi-incorporation of mulch with the chisel plough is a method of land preparation where the soil is not inverted used in large scale farming as a reduced tillage operation.

The Replacement of the disc plough by the chisel plough (ripper) has been investigated by the project mentioned below (Brunner, 1998).

The system involves the ripping of the entire area at a depth of up to 25 cm. In most cases most of the stubble, crop residues and weeds get mixed. The operation is done by tractor pulled chisel ploughs. 
 
 

Evaluation:

This technology is not widely practiced.

Advantages and/or Opportunities

Reduces number of operations and saves time and energy.

Soil disturbance reduced 

Leaves some mulch left on the surface.

Disadvantages and/or Limitations

Incorporation of residues leaves little mulch on the surface.

Difficult to work in maize stover.

Weed control is difficult.

Problems with Nitrogen availability in early season.

Source and Further Information:

Brunner, E. and W. Mariki, with H. Elwell, 1998, Available Technologies in Conservation Tillage, Paper presented at the Workshop on Conservation Tillage for Sustainable Agriculture.

FAO Soil Paper No. 54, No. 57

Institutes - Selian Research Institute, Tanzania

Name: Subsoiler (Ox-drawn)

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zambia

In Zambia it is used in region 2 where a Farmesa field site is located in Muswishi.

(Agro-ecology: Region 2 in Zambia). It is also used in Zimbabwe.

Description:

The ox-drawn subsoiler is an implement for breaking a pan. 

Drawing, picture

The implement is drawn using four oxen attached on a beam. It breaks the hard pan to allow rain (water) infiltration. This harvests water into the field, minimizes chances of erosion and improves the physical condition of the soil.
 
 

Evaluation:

Adoption rate is rather low. Potential use is wide in region 2 of Zambia when DAP is used.

In Zimbabwe it is practiced quite extensively.

Advantages and/or Opportunities

Disadvantages and/or Limitations

Reducing numbers of draught animals in Zambia has affected the use of this technology.

Source and Further Information:

DAP Unit MAFF Lusaka, Zambia, Palabana Farm Power Mechanization Centre.

ART Farm, Zimbabwe (Check Address).
 
 

Name: Subsoiler (Tractor)

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Tanzania

This technology is used in plateau and highland areas by large scale farmers in annual cropping systems. It is an improved system from the conventional disc ploughing to break plough pans.

Also in Zimbabwe quite extensively used by commercial farmers.

Description:

The subsoiler (tractor) is used for deep ripping of fields in large scale farming to break plough pans.

The practice involves deep ripping by spaced subsoilers to break plough pan formed as a result of continuous use of tractor drawn ploughs. The subsoiler works 350-450 mm beneath the soil without incorporation of the residues. The exercise has to be repeated once in 3 years where disc ploughs are still used. Effective subsoiling requires high draught power (tractors).

Evaluation:

Subsoilers can be used to improve water infiltration in areas with plough pans.

Advantages and/or Opportunities

Subsoiling improves infiltration by breaking compacted layers.

Disadvantages and/or Limitations

High draught requirement, hence not easily done using small tractors.

Costly, high energy comsumption.

Hard Pan formation on sandy soils, thereby continuation of problem.

Source and Further Information:

Literature - E. Brunner

Institutes -TFSC, Tanzania, Selian Research Institute, Tanzania

Implements..

Name: Clean Ripping, (Ripping without Mulch)

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zimbabwe

Description:

This is a primary tillage technique similar to mulch ripping except that mulch is removed or burnt. Observed soil loss and run-off levels from this technique are above the tolerable levels although less than those from conventional tillage, hence the technique is not considered the most sustainable. Recommendation - rip to a depth of 23 cm after harvest or after the first planting rain planting. Clean ripping is most appropriate on: relatively flat land less than 2% and fields with little weed infestation.

It is recommended on soils that have developed a plough pan. It can be used in conjunction with cover crops or other biological soil erosion control methods (then the practice might be referred to with another name). 
 
 

Evaluation:

This technique is adapted and widely used by farmers in Zimbabwe with draught power limitations enabling timely planting. As used by most farmers in Chiweshe communal lands it involves opening planting furrows using the plough in unploughed fields at the usual spacing for maize. Once the crop has emerged early weed control is undertaken with the aid of an animal drawn cultivator to knock out the early weeds characteristic of unploughed fields. The System is very effective for early planting but can only be used successfully if planting is carried out immediately after receiving the first rains. Delays in using this technique after the first rains results in heavy weed infestations which make subsequent weed control efforts almost impossible. Most fields in communal areas are weed free at the onset of the season due to grazing by livestock. It can be used in conjunction with herbicides in situations where these are affordable.

Advantages and/or Opportunities

Requires less draught power per ha hence enables timely planting to be achieved where draught power is a constraint.

better build-up of soil structure. 

Disadvantages and/or Limitations

A bare surface is more susceptible to splash and sheet erosion.

High weeding demands.

Source and Further Information:

Soil & Water Conservation Branch

Institute of Agricultural Engineering

Box BW 330, Borrowdale, Harare

Zimbabwe , Fax: 263-4-860136
 
 
 
 
 
 

Name: Ripper with DAP

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zambia

This technology has been developed in Zambia.

More info possible, see article.

Description:

Ripping is a practice where furrows are opened by a ripper parallel to each other. The furrows are the planting furrows. In between the soil is not worked. Ripping can be an important way of tilling the soil, either in addition to plowing, or to replace plowing prior to planting. Ripping is fast and light, and it improves timeliness of planting. It gives the crop an even and optimal start and allows for easy weeding.

The implement used is called a ripper. It is hardly more than a single chisel tine fixed to a common (plow or ridger) frame. The chisel digs into the soil and leaves behind a small furrow with loose soil on either side. The major parts of the ripper are: 

The Chisel Tine, which is the device that opens up the soil.

The Wings (of the Mogoye Ripper), which prevent the soil from falling back, thus keeping the furrow well open (especially for sandy soils).

The Sub-Frame, which can be an ordinary plow or ridger frame from which the plow or ridger body has been taken off.

Among the alternative uses of the ripper are:

Dry-ripping (using the ripper early in season, before the rains have started)

Ripping after winter plowing

Alternative ripping with plowing

Ripping after plowing

Ripping on the row (using the same row always)

Inter-row ripping (to increase water infiltration)

Planting.

Weeding.
 
 

Evaluation:

Adoption has been high but limited by availability of rippers in the region. There is enormous potential once this handicap is overcome, especially in the semi arid areas. 

Advantages and/or Opportunities

It is faster than ploughing, and does not disturb the soils like conventional ploughing.

Larger acreage can be prepared

Can be easily done on soils that tend to cake during the dry spell

Increases water conservation

Does not form hard pan

Disadvantages and/or Limitations

Weeding using a ripper is cumbersome

Ripper not available to many farmers in the region especially Kenya.

Source and Further Information:

Stevens, P., 1998, Ripping with Draft Animals, IMAG-DLO extension brochure, SAMEP (Smallholder Agricultural Mechanization Promotions) and Africare, 

PO Box, 31905, Lusaka, Zambia

Fax/Tel: +.260.1.264560 / 235665

Email: samep@zamnet.zm

Name: Direct seeding

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zambia / Tanzania / Uganda

In Zambia this is done on some commercial farms in region 2 where Muswishi also belongs.

The technology is also used on commercial farms in Zimbabwe (for instance at Hinton Estate). And in Arusha region, Tanzania it is also practiced.

Description:

Direct Seeding is the classical no-till solution for mechanised agriculture. It used to require heavy and relatively expensive machinery, but alternatives are known and practiced (Zambia and Zimbabwe), which encompasses lighter equipment for oxen and donkeys, or even a hand planter.

(Tools book for hand planter) 

Weed control before seeding is usually done with herbicides. 
 
 

Direct seeding using planter

The direct seeding technique is applied using a planter. Row crops are planted directly into the soil through residues without any prior tilling operation. A herbicide is used for weed control.

The planter has a single or double disk opener(s). It can be animal or tractor drawn.
 
 

Direct seeding by broadcasting

Direct seeding by broadcasting and shaking the seed through the residue using drills, or 

Direct seeding by broadcasting and shaking the seed though the residue using a roller

Also see Tramlining and Potholing

Evaluation:

Advantages and/or Opportunities

Disadvantages and/or Limitations

Source and Further Information:

Brunner, E. and W. Mariki, with H. Elwell, 1998, Available Technologies in Conservation Tillage, Paper presented at the Workshop on Conservation Tillage for Sustainable Agriculture.

FAO Soils Bulletin 54

Agriculture et development CIRAD – SIST

Hinton Estate (Oldreive, 1989)
 
 
 
 
 
 

Name: Tram Lining

Category: Furrow planting and ripping technologies

Other Names: 

Local Names: 

Country or Site: Zimbabwe / Uganda

The tram lining technology is described by Hinton Estate in Zimbabwe. It is mainly used by large scale commercial farmers.

Description:

Tram lining is a practice used to minimize compaction problems, where the same tracks are used for each of the operations from year to year. The emphasis is on shallow cultivation so that the soil structure is not destroyed.

After harvesting the previous crop , the stover should be knocked down, as flat and evenly as possible, to break the life cycle of the stalk borer by exposing the pupae to heat and sunlight. It also provides mulch cover. 

Before planting in the residue of the previous crop, care must be taken to remove all the weeds (left on the surface as mulch). 

Marking out for the first time might go as follows:

To mark out a straight edge at each end of the land up and down the slope.

Place short pegs at 75 cm intervals along the lines.

Join a string from the peg at one end to the corresponding peg at the other end to give the planting row.

Dig oval holes at regular (plant dependent, maize 60 cm) intervals along this string line.

When the row is completed, move the string to the next peg.
 
 

Evaluation:

The potential for wider application is high as conservation tillage becomes prominent.

Advantages and/or Opportunities

Minimizes soil compaction in the planting line.

Marking has been done each season.

Residual fertilizer from last year is at the spot.

The roots of the previous crop hold the soil in position and the rotten roots will leave channels for the new roots, water and air.

Disadvantages and/or Limitations

Need precision operation to effectively work.

Labour intensive the first time.

Source and Further Information:

Literature - B. Oldreive, full title
 
 
 
 
 
 
 
 
 
 
 
 

Physical or Biological Barriers

Name: Contour bunds

Category: Physical or Biological Barriers

Other Names: Fanya Chini, Fanya Juu

Local Names: Makinga maji

Country or Site: Tanzania / Kenya

The technology is applied in Isangati, Gairo Mlali areas in the highlands and semi arid areas where farmers use the subsistence cropping system. It is a structural/mechanical measure introduced in the region pre-independence.

Description:

Contour bunds, locally known as "Makinga maji" or "Fanya chini/juu" are earth bunds laid across the slope along the contours and eventually will transform into terraces. They are used for erosion control in the region. Fanya Juu is Khiswahili for "Throwing soil up-slope", which is exactly how this kind of contour ridge is constructed. The system originates from Kenya, but is used in many parts in Africa, especially in Mountainous areas. When moving the soil downhill from the excavated ditch the resulting structure is called Fanya Chini, which is less suitable on steeper slopes than the Fanya Juu.

While a standard contour is constructed by throwing the soil down-slope, a Fanya Juu is done the opposite way. A ditch is constructed along the contour. The soil is placed either below or up the ditch to form an embarkment which is 1,5 - 2 m wide. The bunds are placed 10 - 20 m apart depending on the slope. The embarkment impounds water, soil and nutrients while the excavated trench acts as a retention ditch. Fodder grasses such as Napier, Guatemala grass and trees are planted on the embarkment to stabilize them.

Contour bunds can be made by using the hand hoe, animal or tractor drawn plough. They should be laid along the contour and should be big enough.

The Fanja Juu contour conserves soil and water behind the ridge, and in a few years the trapped soil develops into a kind of bench terrace (more level fields).

Regular maintenance of bunds is necessary especially after heavy storms. Silt from the trench should be thrown up slope onto the embarkment to allow water flow.

The dimensions of a Fanya Juu differ from one area to the other, sometimes even from farmer to the other (Hagmann and Twomlow, eds.). A useful guideline to the dimensions that has proven valuable in Zimbabwe are given in the box.

As is advised with most physical structures along the contour, pegging (using a line level) is required.
 
 

Evaluation:

Contour bunds are effective in controlling soil erosion and in conserving moisture.

Contour bunds have been adopted in many areas and are the most common mechanical measure used both by small and large scale farmers in the conventional flat cultivation. The potential is high as flat cultivation is still practiced and this technology is suitable for slopes of up to20%.
 
 

Advantages and/or Opportunities

Top soil that would have been carried away in a standard contour drain is now kept in the field

In the case of a dry spell, the water kept by the Fanya Juu will reduce or delay water shortage

Disadvantages and/or Limitations

Labour intensive, but less labour required in the longer run than for standard contour ridges or bunds

Regular maintenance is required especially in high rainfall areas an water logging may appear

Fanya Chini not suitable for steeper slopes, Fanya Juu less suitable in very steep areas, and on flat fields

If not properly lead, might lead to gully formation down the field.

Source and Further Information:

Literature - FAO No. 57 pg. 32

Institutes - MAC, Tanzania; Ministry of Agriculture, Livestock Development and Marketing, Kenya
 
 
 
 
 
 

Name: Bench Terraces

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Tanzania/Uganda

This technology is applied in highlands in northern Tanzania for mixed cropping where coffee is dominant In Uganda it is applied in the highland districts of Kabale, Kisoro, Mbale and Kapchorwa

Bench terracing is a mechanical soil conservation measure introduced in the region since pre- independence.

Description:

Bench terraces are a series of level steps constructed on the contour and separated by embankments known as risers. They are used in steep slopes up to 30° and control erosion by reducing the slope of the cultivated land and increasing the infiltration.

Photo FAO No. 57 page 7.

The levelled steps across the slope reduce the length of the slope into shorter stretches, thus reducing run-off. After pegging the terrace (step to be levelled) according to the slope, the soil is excavated and levelled. Embankments are constructed and compacted to separate the terraces.

Bench terraces are constructed using hand tools and thus the labour requirement is high making them expensive structures.

Terraces are normally stabilized with grass such as nappier grown on the risers, which require regular maintenance to prevent erosion. Animals should be prevented from crossing the risers and any damage caused by runoff should be repaired.

Evaluation:

Terraces are effective in controlling run offs in steep slopes (30%) 

Limited adoption and mainly recommended in steep slopes where crops with high cash return are copped such as coffee. 

Advantages and/or Opportunities

Effective in controlling soil erosion and increasing infiltration in steep slopes 30° .

Disadvantages and/or Limitations

High cost of construction and labour requirement

Excavation leads to reduced fertility as the soil is exposed

Reduces the net area for cropping

Need deep free draining soils + 1.5 m depth) as shallow soils lead to water logging.

Source and Further Information:

Institutes - MAC, Tanzania; Sokoine University, Tanzania
 
 

Name: Cut off drain

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Tanzania/Uganda

This technology is applied in Isangati northern and southern highlands with high rainfall. The farmers practice mixed cropping with maize/bean/potato, banana/coffee.In Uganda it is applied in the highland districts of Kabale, Kisoro, Mbale Kapchorwa, Bundibugyo, Kabarole and Kasese which receive high rainfall. One of the structural measures introduced in the region intended to protect cropland against run off from adjoining non-arable land.

Description:

The cut-off drain is a graded channel constructed across a slope, used in slopping fields to intercept surface run off and convey it safely to an outlet such as a waterway.

The cut off drain collects water from the hillside and discharges it safely to an outlet. A cut off drain is usually constructed along the boundary of the farm adjoining a non-arable land. This is made by digging soil to make a ditch which is 60 cm wide and 30 cm deep. The excavated soil is used to make an embarkment on the lower side. The channel may be lined with grass to stabilize it. To minimize sedimentation and overtopping the ditch should not be more than 250 m long.

Excavation can be done by hand tools or plough or scoop.
 
 

Evaluation:

The technology is not used in many places because of small fragmented fields and land tenure problems. There is potential for application in high altitude areas but catchment approach is essential.

Advantages and/or Opportunities

Effective in intercepting run off in high sloping fields thus protecting the cropped land from soil erosion

Disadvantages and/or Limitations

Labour and maintenance costs are high

If not properly designed the discharge can lead to gully erosion

Difficult to apply in small individual farms as per effective water discharge, the ditch may have to cross several fields.

Source and Further Information:

Institutes - MAC, Tanzania, SUA Tanzania

Ministry of Agriculture, Animal Industry and Fisheries, Uganda

DAO's Kumi & Mukono

Name: Infiltration pits

Category: Physical or Biological Barriers

Other Names: 

Local Names: Chibatamvura

Country or Site: Zimbabwe

The technique is widely used in Zaka, Zvishavane and Chivi districts in Zimbabwe and is suitable in semi arid areas in the region. 

Also described in Uganda.

Description:

Infiltration pits locally known as "Chibatamvura" are deep trenches dug along the contour ridge.

As water flows in the contour trenches the water is trapped in the pits allowing it to infiltrate slowly. Trenched are dug along the contour and embarkments are made by the excavated soil. Pits are then dug in the trench spaced at 5,10 or 20 m according to the slope. The pit sizes are 1 x 1 x 0.5 m, 1 x 2 x 0.75 m and 1 x 2 x 1 m respectively.

The contour trenches can be done by hand hoes, tractor or oxen drawn ploughs, while the pits are dug by the hand hoe. Labour requirements in pit making are high.

Regular maintenance of the contour drains is required and the embarkment can be stabilized with fodder. The pits have to be excavated when sedimentation is high.
 
 

Evaluation:

Infiltration pits are an improvement to contour ridges so as to increase the infiltration as water is trapped and retained in the pits. It is a farmer innovation technique.

Advantages and/or Opportunities

Infiltration pits are effective in trapping water and increasing infiltration as water is allowed to percolate slowly.

Can easily be applied on land already with standard contour bunds.

Reduces surface run off and hence soil loss.

Disadvantages and/or Limitations

Require regular maintenance, as deposited soil has to be scooped out

Pits pose a danger to children and livestock if dug too deep.

Source and Further Information:

Murwira, K. 1998, Compilation and Assessment of Promising Technologies in Smallholder Agriculture in Zimbabwe (Farmesa and Agritex).

Institute of Agricultural Engineering, Hatcliff, Harare, Zimbabwe
 
 
 
 
 
 
 
 
 
 

Name: Infiltration/Retention Ditches or Pits

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Uganda

All agro-ecological zones and farming systems with slopes of 50% - 50%.

Also described in Zimbabwe.

Description:

Cross slope ditches are constructed usually within banana plantations, to catch runoff. They are valued by farmers for moisture conservation. Also runoff from roads and tracks is harvested into infiltration ditches & pits within banana plantations. The use of ditches laid along the contour to spread harvested water through out the banana plantation is increasing.

As water flows in the contour trenches the water is trapped in the pits allowing it to infiltrate slowly. Trenched are dug along the contour and embarkments are made by the excavated soil. Pits are then dug in the trench spaced at 5,10 or 20 m according to the slope. The pit sizes are 1 x 1 x 0.5 m, 1 x 2 x 0.75 m and 1 x 2 x 1 m respectively.

The contour trenches can be dug by hand hoes, tractor or oxen drawn ploughs, while the pits are dug by the hand hoe. Labour requirements in pit making are high. Regular maintenance of the contour drains is required and the embarkment can be stabilized with fodder. The pits have to be excavated when sedimentation is high.
 
 

Evaluation:

The technology is effective and quite on the spread rapidly throughout the country. The ditches/pits assist in reducing erosive power of runoffs, store silt carried by runoff from roads & tracks which later when scooped returns soil which would have gone long way and also stores water which infiltrates slowly. Labour and skill are needed in their construction and the socio-economic attributes can not be measured directly and immediately.

The technology is applied by both small and medium farm owners and was introduced during the colonial periods in the 1930/40s (Miiro & Briggs 1997). 

Advantages and/or Opportunities

Infiltration pits are effective in trapping water and increasing infiltration as water is allowed to percolate slowly.

Can easily be applied on land already with standard contour bunds.

Reduces surface run off and hence soil loss.

Disadvantages and/or Limitations

Require regular maintenance, as deposited soil has to be scooped out

Pits pose a danger to children and livestock if dug too deep.

Source and Further Information:

MAAIF, Staff

Beneficiaries

Soil & Water Conservation in the farming systems of Kamwezi, South West Uganda by Miiro & Briggs, 1998

Name: Trash lines

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Uganda, Zambia, Kenya, Tanzania

Observed in region 2 in Zambia. References exist for Kenya and Tanzania; In Tanzania (Arusha Region) they have been described. In Uganda, this technique is used in all the four agro-ecological zones I, II, III and IV

Description:

The use of trash lines is a practice where crop residues are collected and placed along contour lines. Trash lines provide a good environment for natural grass growth and reinforce this type of cross slope barrier, which eventually could develop into a bench terrace. 

The lines are formed by weeds for example. couch grass (Digitaria scaralum), Wandering Jew (Commelina benghalensis) and black jack (Bidens pilosa) and certain crop residues like sorghum, maize, finger millet laid across the slope of a field 10-30% slope in a heap about 45 cm high and 60 cm wide.

After two or three seasons the trash lines can be broken up and the fertile organic material can be incorporated into the soils in the field, which will help improve the soil structure fertility.

Weeds are sorted during secondary tillage operations by hand, left in the field to dry before being heaped in lines a cross the slopes usually on around crop plots. The life span of a trash line is usually between 1-3 seasons (1-1.5 years( by which time. The Organic. Matter material is decomposed. In the following season new Trash lines are constructed in new locations with in the field thereby spreading their manuring effect.

Evaluation:

Trash lines act as permeable barrier to run off resulting in increased infiltration and soil deposition. Soil fertility, soil water availability and yields are all influenced by the location of a trash line within a field. 

Advantages and/or Opportunities

The technology reduces slope length, slowing run off and facilitating infiltration.

It is relatively cheap.

Thrash lines help improving soil fertility: they work like compost strips, the organic material decomposes over time. 

Disadvantages and/or Limitations

Weed infestation when not properly managed.

Trash lines do not withstand big storms or floods.
 
 

Source and Further Information:

Ministry of Agriculture Animal Industry and Fisheries, - Soil and Water Conservation Section, Zambia.

Ministry of Agriculture, Animal Industry and Fisheries, Uganda

DAO's Kumi & Mukono

Per Assmo, RSCU (Technical handbook no 7.)
 
 

Name: Vetiver grass (Vetiveria)

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Zambia, Zimbabwe

Vetiver is available and used in both Lusitu and Muswishi Farmesa sites in Zambia.

Vetiver can be used in high and low rainfall areas. 

Description:

Grass and Trash lines, in this case the planting of Vetiver Grass (Vetiveria Zizanioides), require far less physical input as compared to the Physical measures. Vetiver is a distinctive clump grass of tropical areas, and can quickly be recognized in the field. It is native to Southeast Asia, Australia and Africa.

A vetiver hedge could replace the digging mechanical contours, Fanya Juu or Fanya Chini. Usually it is combined. A continuous and dense hedge of vetiver grass will conserve soil and water just as good or in some cases even better than other options.

Drawing (Zimpaper), Zambia.

the leaves and the stem slow the silt;

silt is deposited behind the plant;

water continues down the slope;

the spongy root system binds the soil to a depth of 3 meters.
 
 

The use of Vetiver grass originates from India. The root system holds water and binds the soil. The leaves just above the ground trap the eroding soil. The vetiver grass can be planted on contour lines and can be used to sure gullies and stabilize water ways. Vetiver grass is an infertile plant, which means that the seeds of the grass do not germinate when sown, and since the plant does not produce shoots either, it never becomes a weed that spreads into the field. Therefore, it is advisable to have a nursery as a permanent feature. 

Pegging is done before planting the vetiver on the contours.
 
 

Evaluation:

Advantages and/or Opportunities

The grass is very effective and frequency of maintenance is less compared to bunds.

Disadvantages and/or Limitations

The disadvantage is mostly to do with availability of planting material which is limiting. Planting material is localized. 

Soil moisture competition between Vetiver hedges and crop could affect crop yield.

In Zambia, in region 2, the grass has received favourable attention by the farmers. In region 1 more awareness campaigns need to be done.

Source and Further Information:

Source of this information - Vetiver Network, //www.vetiver.org

Murwira, K. 1998, Compilation and Assessment of Promising Technologies in Smallholder Agriculture in Zimbabwe (Farmesa and Agritex), Zimbabwe.

Soil & Water Conservation Branch, Institute of Agricultural Engineering, Zimbabwe

Name: Grass Strips - (Indigenous grass)

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Zambia

The technology is commonly applied in Zambia region 2 where Muswishi Farmesa field site is located. 

Further in Tanzania (Arusha Region) they have been described by Per Assmo for RSCU (Technical handbook no 7.)

The technology is indigenous but has been improved putting the strips along the contours.

Description:

Grass strips can be established by leaving unploughed strips (0.5-2 meters) for natural grass to establish. For more productive grass strips especially on small-scale farms, high yielding (fodder) grasses can be introduced. 

The grasses need protection against free grazing. Grass Strips can also be interplanted with various types of trees suitable for intercropping. Grass strips along contour lines are generally effective barriers to keep the soil in place, particularly on medium to coarse textured soils (Assmo, RSCU 7). Grass strips can be used to initiate formation of bench terraces.

See also Vetiver.

Evaluation:

Advantages and/or Opportunities

Disadvantages and/or Limitations

Source and Further Information:

Name: Contour hedge row

Category: Physical or Biological Barriers

Other Names: 

Local Names: 

Country or Site: Zambia / Kenya

The technique is used in Farmesa site 2 in Zambia in Muswishi area. Other sites where references on exist - Kenya

Description:

The contour hedge row technology is used to reduce the velocity of overland flow. No physical barriers like bunds are used. The upper foliage reduces the velocity of the water flow, and keeps the sediment. For a detailed description see also Vetiver.

Grass such as Androppogon gayanus could be used. Other grass like Bana grass is also used on hedge rows.
 
 
 
 
 
 

Evaluation:

Advantages and/or Opportunities

Disadvantages and/or Limitations

Source and Further Information:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Supportive technologies: crop rotations, manuring, cover crops, herbicides
 
 

Name: Ridge-Mulch

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Zimbabwe

The technology is used in the Chivi district of Zimbabwe, Natural regions 4 & 5 where the farming system comprises subsistence crops and livestock. It is a farmer innovation/adaptation to overcome water logging.

Description:

The ridge mulch technology is used in Zimbabwe for maize and rice production in low lying areas prone to water logging. 

Furrows are laid and made along the contour (after pegging is done) using a ridger before onset of rains. Then mulch is laid by hand on the ridge (which is basically the difference with Broad-based Tied Ridges). Rice is planted on the furrow and maize on the ridge. Mulch is incorporated to enhance soil fertility. The ridge size is variable depending on farmer preference, ideally 1 m with a furrow of about 0.6 m.

Diagram

Evaluation:

The technology has enormous potential in areas prone to water logging.

for wider application

Advantages and/or Opportunities

Farmers are able to grow rice and maize at the same time

Conserves water and soil

Increases yields and soil fertility

Disadvantages and/or Limitations

Labour intensive

Source and Further Information:

Source of this information: Mr Edward Chuma 

University of Zimbabwe, Institute of Environmental Studies.
 
 

Name: Crop Rotation

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: All Countries (description from Kenya, Uganda)

Crop rotation is used worldwide in countries with variable agro-ecology and farming systems. In some countries, it is an indigenous technology whilst in others, it was introduced. Therefore, different rotations exist.

It is practiced by farmers in both Uganda Farmesa sites (Kumi and Mukono) and no R&D done yet.

Description:

Crop rotation is an agronomic conservation practice where crops from different families are grown on a piece of land following a set sequence one after another. It’s practiced by both small scale farm holders e.g. vegetable farmers and large scale farm holders e.g. annual crops. The choice for a particular rotation depends on the reason for a particular crop, like the need to control pests, improve soil structure, soil conservation or water infiltration. 

Crop rotations can be as simple as Maize/Fallow, (Fallow being described elsewhere). Other examples are:

Uganda: (1^st year) Cotton, (2^nd year) Millet long rains, Cowpeas short rains, (3^rd year) Sweet Potatoes/Cassava, (4^th year) Fallow (grass + L/stock).

Zimbabwe: Maize / Groundnuts; Tobacco / Grams (or Sunhemp); Maize / Soyabean / Wheat.

When rotating crops, an area is intensively cropped with one or more crops alternately with a fallow or each other. The technique is applied intensively to improve soil fertility, pests and disease control, improve soil structure/conservation. Agronomic practices are followed for each crop as recommended.

A crop or several crops are grown in a system where one crop produces high crop residue followed by one with low crop residue. The low residue crop being the main one and the high residue crop being the minor crop. 

Evaluation:

The practice is very effective in sustaining land productivity. It controls born pests and weeds, improves soil fertility and structure but requires good skills and knowledge in Agriculture with a reliable supply of labour force. The technology is quite common and can easily be adopted. More data on crop combinations, inputs, outputs and socio-economic benefits is needed.

Advantages and/or Opportunities

Low capital requirement

Enhanced soil fertility

Reduces erosion, compaction etc. because of different types of tillage for different crops.

Increases moisture conservation

Operation costs are low

Disadvantages and/or Limitations

Needs better managerial skill.

Farmers with very small parcels of land cannot adopt rotation with a fallow season.

Crops with high residue may face competition from livestock.

Source and Further Information:

Source of this information – Tillage systems for Soil conservation, FAO Soils Bulletin 54.

Ministry of Agriculture Animal Industry and Fisheries (MAAIF), Zambia

Kwanda Agricultural Research Institute (KARI), Kenya

Serere Agricultural and Animal Production Research Institute (SAARI)

Namulonge Agricultural and Animal Production Research Institute (NAARI)

Participatory Rural Appraisal, PRA. Report of Mukono and Kumi districts of Uganda

Name: Fallow

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: All Countries (description from Kenya, Uganda)

This worldwide technology is both an indigenous and adopted practice. In a way it is a form of crop rotation. When practiced on different sites it is called Shifting Cultivation. The practice is used on a variety of soils, with many different farming systems.

Description:

The fallow technology is used worldwide for soil and water conservation, erosion control, soil fertility improvement and pest, disease and weed control.

When using this technology, land is left to rest i.e. no cultivation whatsoever for, for example, one or two seasons after intensive cultivation has taken place for 4-5 seasons. One can also leave the land at rest by planting green manure, like for instance Sun Hemp

Evaluation:

The fallow technology is very effective. Operation, resource and labour requirements are low. No maintenance is required.

Advantages and/or Opportunities

Land has time to recover 

Water conservation

Improves soil fertility and conserves soil

Pests and diseases are naturally controlled

Disadvantages and/or Limitations

Difficult to adopt when high population and/or where farm sizes are small.

Source and Further Information

Source of this information - Tillage systems for soil conservation FAO Soils Bulletin 54.

Name: Agroforestry, Improved Fallow (with Sesbania Sesban)

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Uganda

KUMI - Agroecological zone III

- Short grasslands and practicing cotton-finger millet mixed farming systems.

- Other sites

Description:

Agroforestry improved fallow is when land is rested under grass and a legume or a multi-purpose shrub/tree. For example. chloris gayana, or Panicumiq maximum and sasbania sesban or Tithomia or Lantana camara

In conventional agriculture, after fallow the land is cultivated and left to rest under grass or root crop (cassava) for a season or two.

Evaluation:

This technology is an adopted technology and is generally very effective. Land is allowed to recover for at least 2 seasons while grass and shrubs are grazed by livestock encouraging mixed farming. It encourages natural control of pests while conserving water and improving soil fertility. It’s cost effective but requires large farm owners.

Note: Lantana camara is poisonous to cows.

Advantages and/or Opportunities

Enhanced soil fertility

Reduces erosion

Increases moisture conservation

Disadvantages and/or Limitations

Farmers with very small pieces of land cannot adopt improved fallow because it is not cost effective.

Source and Further Information:

Ministry of Agriculture Animal Industry and Fisheries

Kwanda Agricultural Research Institute (KARI)

Serere Agricultural and Animal Production Research Institute (SAARI)

Namulonge Agricultural and Animal Production Research Institute (NAARI)
 
 
 
 

Name: Inter cropping

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: All Countries (description from Uganda)

This technology is in agro-ecological zones III and IV (Northern & Eastern short grassland zone: short grasslands and practicing mixed farming systems and Southern & Western tall grassland zone: tall grassland practicing perennial & annual crop growing in mixed farming systems respectively).

Farmesa field sites: Mukono - Zone IV

Kumi - Zone III

Description:

Inter cropping, as opposed to sequential cropping, refers to growing together two crops simultaneously on the same plot at proper spacing. Basically there are four forms: Mixed intercropping (two or more crops from different families on the same plot), Row intercropping (two or more crops simultaneously with one or more crops in rows), Strip intercropping (two or more crops simultaneously in different strips, wide enough to permit independent cultivation, but narrow enough to interact agronomically; see No Till Strip Cropping), and Relay intercropping (two or more crops simultaneously during part of the lifecycle of each).

Diagram

An example is the Maize (90 x 60 cm) Beans inter-row at 15 cm with 2 plants per hill per crop. Farmers make use of both improved and local seeds with good knowledge on agronomy. May be manual or machanised.

Evaluation:

Effective where rainfall is high - moderate and its widely practiced in both Farmesa field sites. Example Cassava + beans, young bananas + beans, young coffee + beans

Advantages and/or Opportunities

Crop diversification for food security

Soil improvement (by legume crop)

Run off control if lines are along contour

Provide soil cover

Disadvantages and/or Limitations

Requires skilled labour and is labour intensive

If lines are along the slope , can lead to soil erosion

If maize & beans seeds are planted on same hill maize plants become weakened hence reduced yields

Source and Further Information:

MAAIF

Kawanda Agricultural Research Institute, KARI

Namulonge Agricultural and Animal production Research Institute, NAARI

Serere Agricultural and Animal production Research Institute, SAARI

FAO, Soils Bulletin 54, page 179
 
 

Name: Mixed (inter)cropping

Category: Supportive Practices

Other Names: Multiple cropping 

Local Names: 

Country or Site: All Countries (description from Uganda)

This technology is in agro-ecological zones III and IV (Northern & Eastern short grassland zone: short grasslands and practicing mixed farming systems and Southern & Western tall grassland zone: tall grassland practicing perennial & annual crop growing in mixed farming systems respectively).

Farmesa field sites: Mukono - Zone IV

Kumi - Zone III

Description:

Mixed (inter)cropping is the growing together of two or more crops from different families on the same plot. Other forms are Row intercropping (two or more crops simultaneously with one or more crops in rows), Strip intercropping (two or more crops simultaneously in different strips, wide enough to permit independent cultivation, but narrow enough to interact agronomically), and Relay intercropping (two or more crops simultaneously during part of the lifecycle of each). See intercropping.

Diagram

Mixed cropping may be broadcast (annuals) or planted to utilise available vertical and horizontal space for maximum land coverage. Examples : Sweet potatoes, Maize & Beans for the case of Kumi and Bananas, Coco yams and Pumpkins for Mukono
 
 

Evaluation:

Advantages and/or Opportunities

Ensures crop diversification from local seed.

Provides ground cover against sunshine, rain drops.

Enhances water infiltration.

Requires less skilled labour to broadcast seeds and pulverise soil.

Disadvantages and/or Limitations

Encourages competition among crops for nutrients, water and space.

Yields can be lower if the wrong combinations of crops are used.

Source and Further Information:

Ministry of Agriculture Animal Industry and Fisheries

DAO’s Kumi & Mukono
 
 

Name: No Till Strip (inter)cropping

Category: Supportive Practices

Other Names: Multiple cropping 

Local Names: 

Country or Site: Zimbabwe

This practice has only been tested on station and still needs further testing and development with farmers.

Description:

Strip (inter)cropping is the growing together of two or more crops from different families on the same plot. Other forms are Row intercropping (two or more crops simultaneously with one or more crops in rows), Strip intercropping (two or more crops simultaneously in different strips, wide enough to permit independent cultivation, but narrow enough to interact agronomically), and Relay intercropping (two or more crops simultaneously during part of the lifecycle of each). See intercropping.

Diagram

This is a technique which involves growing of a variety of crops in 3-9 meter wide strips. Ideally the rotation should constitute for example 70% maize, 20% soya beans and 10% rapoko. Other suitable crops can be put in this rotation. The strips rotate one strip down slope after each season. The maize strips receive manure in the form of compost prepared from a variety of waste residues or grasses. This manure is applied along crop rows opened up by a tine or spike to about 50 mm deep, into which planting is done. If available inorganic fertilizers can be applied as a supplement.

Evaluation:

Advantages and/or Opportunities

Ensures crop diversification from local seed.

Provides ground cover against sunshine, rain drops.

The legumes improve soil fertility through nitrogen fixation.

Diseases are minimised through rotation of strips annually.

Disadvantages and/or Limitations

Ox-drawn cultivators cannot be used for weeding as in a sole maize crop.

Compost preparation is rather labour intensive.

Source and Further Information:

Soil & Water Conservation Branch

Institute of Agricultural Engineering

Box BW 330, Borrowdale, Harare

Zimbabwe, Fax: 263-4-860136
 
 

Name: Mulch cropping (Cover cropping)

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Uganda

This technology is in agro-ecological zones III and IV (Northern & Eastern short grassland zone: short grasslands and practicing mixed farming systems and Southern & Western tall grassland zone: tall grassland practicing perennial & annual crop growing in mixed farming systems respectively).

Farmesa field sites: Mukono - Zone IV

Kumi - Zone III

Description:

Mulch cropping is where a crop (usually legume) is planted/broadcast closely for purposes of primarily covering bare-soils and secondarily to get food. It relates to Ground Covers.

Mulch cropping for example cow peas immediately after millet crop. The cow peas will cover the soil during the short rain and provide leaves for vegetables and seed for food (common in Kumi district). Some times beans are broadcast or planted 30 x 30 cm 2 seed/hill in young plantation crops (bananas, coffee etc) to cover exposed ground due to wide spacing. Sweat potatoes are also used.

Evaluation:

The practice is effective in areas with short second rains in bi-modal rainfall regime. Usually the crops are broadcast so closely that weeds are smoothened.

Adoption has been high but limited by availability of rippers in the region. There is enormous potential once this handicap is overcome, especially in the semi arid areas. 

Advantages and/or Opportunities

Cheap ground cover material against rain drop splash erosion

Diversification and utilises short rains

Controls couch grass growth

Good management practice as Nitrogen is added to soil

Does not form hard pan

Disadvantages and/or Limitations

There must be rainfall or irrigation water other wise can compete with crop

Ripper not available to many farmers in the region especially Kenya.

Source and Further Information:

MAAIF

Institutes - KARI, SAARI, NAARI, MUARIK

FAO soils Bulletin No 60 page 63
 
 

Name: Ground covers

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Uganda

This technology is in all the four agro-ecological zones I, II, III and IV 

Description:

This practice relates to Mulch Cropping.

Examples are:

Planting cow peas (vigna) as a ground cover, plant rice without burning or plowing;

Planting velvet beans (Mucunas) when the maize tassels or the first small ears emerge; leave the maize stalks standing to help the beans grow better and control weeds later.

Plant beans (Phaseolus vulgaris) in the oat stubble after hervest (S.A) ect.

Evaluation:

The technology is wide spread and encourages; continuous cultivation on permanent fields, soil fertility and organic matter conservation, forest regeneration diversification, secure land tenure and discourages field burning. More R&D is required to determine effectiveness on yields and socio-economic interactions.

Adoption has been high but limited by availability of rippers in the region. There is enormous potential once this handicap is overcome, especially in the semi arid areas. 

Advantages and/or Opportunities

Helps control erosion.

Improves soil fertility.

Disadvantages and/or Limitations

Labour constraints might occur.

Source and Further Information:

Ministry of Agriculture Animal Industry and Fisheries

Kwanda Agricultural Research Institute (KARI)

Namulonge Agricultural and Animal Production Research Institute (NAARI)

F.T.P. Newsletter No. 35 March 1998 pp. 14-19

Name: Farm Yard Manuring

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Uganda

Site: Mukono

Agro-ecology IV: Southern and Western tall-grasslands 

Farming Systems: perennial and annual crops in mixed farming with Banana - coffee mixed. 

Also found in agro-ecological zones I and II

Description:

Farmyard manuring is the application of farmyard manure either by putting in holes/furrows or broadcasting in the field plots. It is labour intensive and kraals and zero grazing units need some maintenance.

The farmyard manure is a mixture of cow dung, urine and bedding/grass fodder which is collected from kraals or zero grazing units. It is collected in heaps or pits and left to cool down for several weeks then incorporated in the soil-planting holes or broadcast in the field before or after planting to provide nutrients to crops. It can be added to compost heaps or pits then applied as compost manure after 3 months. It is practiced by small and large farm holders. It is very common in Mukono site.
 
 

Evaluation:

The technology is very effective as it encourages mixed farming and is sustainable if skillfully practiced.

It adds organic. matter and nutrients to the soil which encourage soil microorganism growth and activity, resulting in healthy strong crops and increased yields.

It requires more labour in collection and application while loss of nitrogen in form of ammonia can be experienced through evaporation or leaching.

Potential for wider application is very high, particularly in zero grazing livestock systems.

Advantages and/or Opportunities

Preserves surface structure.

Enhances fertility.

Disadvantages and/or Limitations

Labour intensive in collecting & applying farm yard manure.

Loss of Nitrogen in form of ammonia through evaporation.

Source and Further Information:

Ministry of Agriculture Animal Industry and Fisheries

NARO Institutes:- SAARI, NAARI, KARI

Send a Cow Project, Mukono

Heifer Project International Organisation, Mukono
 
 
 
 

Name: Green manuring with sun hemp

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Zambia

Practiced in Zambia Region 2 on Farmesa Field sites

Take information of project on the subject in Zambia Muswishi

Description:
 
 

Evaluation:

Advantages and/or Opportunities

Disadvantages and/or Limitations

Source and Further Information:
 
 

Name: Herbicides

Category: Supportive Practices

Other Names: 

Local Names: 

Country or Site: Zambia (description)

It is practiced in Region 2 of Zambia and also widely in Zimbabwe with the large scale commercial farmers. 

Description:

If weeds are present, they can be eliminated by using herbicides. For application one can use a knapsack or ulv sprayer, if sufficient funds are available for the purchase of the herbicides.

Herbicides are chemicals used to control weeds in no-tillage systems. Herbicides are selective and can be applied at different cropping stages. To avoid crop damage, herbicides must be compatible with present and future crops. The technology can be very effective when done properly. They are especially useful for the control of persistent perennial weeds and grasses such as couch grass. Timing is essential in using selective herbicides as these chemicals work best on dust-free, small weeds that are growing actively, (Oldreive, 1993).

Herbicide Application using Roundup

The herbicide used for eradicating perennial weeds is glyphosfate (Roundup) or "pre emergent". Pre-emergent herbicides are applied before crop and weeds emerge. Roundup is best used at low volumes and high concentrations. 

On Hinton Estate LF1 or LF2 nozzles are used at a pressure of about 1.8 bars with a concentration of 2-3% (i.e. 300 to 450 ml of Roundup in 15 liters water). The operator walks rapidly, about 2 meter per second, when spraying less troublesome weeds, but slow right down to 0.5 meter per second when spraying couch or star grass. 

This chemical (and others like fluazifop-p-butyl (Fusilade Super), ethoxydim (Nabu), and quizalofop-ethyl (Pilot) will kill the crop, so they must be applied before the crop emerges. 

Pre-emergent herbicides are applied before the crop and weeds emerge. If properly applied they give residual control for 5-7 weeks. 

Herbicide Application Post-emergent or "Lay-by"

The herbicide application post-emergent technology applies when the crop is growing and the weeds are starting to grow again (when the residual effects of the pre-emergent herbicides have worn off). The technology is particularly useful in cotton production and is also effective in maize and even soyabeans. has moderate adoption. This is where a knap-sack sprayer is particularly useful. 

Herbicide application using a knapsack

The technology works with human physical power by hand pumping.

Operates with pressure input through human hand pumping. 

Maintenance - avoid clogging

Manufacturing - agro hardwares and dealers

Evaluation:

Herbicides are not essential, but may allow the experienced farmer to grow a greater crop area (Oldreive).

Advantages and/or Opportunities

Using herbicides can be cheaper than mechanical weeding. Especially when using reduced tillage, or when short of labour. 

Disadvantages and/or Limitations

Application depends on availability of the chemicals, at the proper place and right time.

It can damage humans and crops and result in loss of cost when not done properly (like the mixing of the chemicals). Needs proper training.

Source and Further Information:

Zambia: Mulenga, Field Services

Zimbabwe: Agritex, Henderson, Cotton Research Institute

Farmers Tools - A Farmesa Publication page 36-39

Oldreive, B., 1993, Conservation Farming, a Farm Management Handbook.

  Table of Contents