To obtain insights into conservation farming practices and approaches in the African Region the participants were offered a selection of three field excursions. 

4.2.1 Hinton Estate Farm and its Outreach Programme 

Hinton Estate (Pvt) Ltd, is a large scale commercial farm in the „middle veld" of Zimbabwe, 140 km north east of Harare. It began to implement conservation tillage on a small scale in 1984 due to the tremendous soil and water loss being experienced on the farm. The system was gradually incorporated into the cropping programme and, in the 1987/88 season, all arable land was brought under conservation tillage. 

Currently Hinton Estate has a summer cropping programme of 2700 ha, up to 1000 ha of which is double cropped with winter wheat depending on the availability of irrigation. 

4.2.1.1 Outreach Programme 

Apart from its normal farming activities, Hinton Estate has been involved in a Christian service-based outreach programme in the neighbouring Chiweshe Communal Area since the mid-1980's. The programme is motivated by management's determination to practically and spiritually 'care for their neighbour', and aims to alleviate the poverty in rural communities through the promotion of appropriate conservation tillage practices and good resource management. 

Since 1992 the outreach programme has grown tremendously and, by last season, there were 58 field sites scattered all over Zimbabwe. The programme is executed through farmer clubs, cooperatives, individual farmers, church groups, schools and resettled farmers. It involves demonstrations, training, marketing assistance and the provision of small amounts of credit in the form of inputs. 

The field demonstrations are farmer managed in order to expose farmers to conservation tillage. Both on-farm and off-farm training is offered. Training involves time management, farm budgeting and appropriate crop husbandry practices. One season's inputs are offered on credit at an interest rate of 1.5% per month, or 20% per annum (compared to bank interest rates of 38 - 40%). Pay back is good as there is close interaction and monitoring of farmers’ activities. The programme also facilitates the marketing of crops in order to ensure that farmers get a fair price. 

A) Chiweshe Village 

The participants visited the Musonza farming family, which has been participating in the Outreach Programme since 1992. The household farm includes 3ha arable land. Main crops are maize, groundnuts and cow peas. The family practice conservation tillage on the field close to their homestead (0.4ha). Reduced tillage is done with an animal drawn cultivator at their 2ha field, which is further away. Crop rotation is practised with maize and groundnuts. Improved seed, farm yard manure and fertilizers are in use. 

After harvesting, the stover is left in the field. Controlled grazing ensures proper residue management. The cattle are allowed to graze for just one month, leaving at least a 10-20% soil cover. The field activities are all done by hand as follows: 

• Planting holes are made using a hand hoe in September (Early planting!). Manure or fertilizer is put in the hole and covered by a layer of soil. After the first rains in November seed is dropped in the holes and covered with soil.
• Weeding is done three times: First by using the hand hoe immediately after the emergence of the crop seedings. Second mid season and the third is a late weeding operation, done after harvesting but before the grass seeds. During winter broadleaf weeds are chopped down to conserve soil moisture, and left on the field to add to the mulch.
• Crop protection pesticides are occasionally used to control stalkborer.
• Harvesting is done by hand and transported by scotch carts.

The farmer appreciates the reduced soil erosion and labour required inherent in conservation tillage. By starting the activities early June it spreads the labour requirement thus avoiding labour peaks during land preparation and planting. This ensures early and timely planting. However the participants appreciated the difficulty of maintaining a 30% residue cover as the farmer has to graze his animals. It was noticed that in many households there were stooks of stover and other crop residues for dry season feeding of the livestock. Therefore there was a high competition for the residues between the need to feed livestock and the maintenance of adequate soil cover. 

B) Shopo Primary School 

Shopo Primary School is one of the 10 schools which are participating in the outreach programme. The main crops grown are maize, soya beans and sunflower. The school has been practising conservation tillage for the past seven years. Pupils from grade 1 to 7 attend two classes per week on agricultural production. The crop production and field operations are similar to those described above. 

Constraints 

• Mulch maintenance and retention is a major problem, as livestock from the communal areas graze their fields;
• Agricultural demonstration is not given sufficient time because of other curricula activities. The weeding operations are not done timeously because of the long Christmas holidays.
• Lack of continuity because of teacher transfers.
• Conflicting messages with some extension agents who advocate conventional tillage.

4.2.1.2 Hinton Farm 

Hinton Farm practices conservation tillage with some of the fields having been cropped twice annually for the past 14 years. This has enabled maintenance of a mulch cover of 50% and above. Forward planning, management and implementation, maintaining standards on time and without waste has been a corner stone of the farms’ success. Soil structure and organic matter content is returning to almost virgin status despite the intensive cropping. 

The main crops include soya beans, wheat, maize, cotton, sorghum, sunflowers, sugar cane, coffee, potatoes, groundnuts, vegetables, pecan nuts and macadamia nuts. Through conservation tillage, crop yields have dramatically improved and stabilised and the process of soil degradation has been reversed. The average yield of maize, wheat and soya beans is now 8.9, 7.0 and 2.6 tons/ha respectively. 

Field Operations 

• Planting is done by hand or by tractor drawn planters and drills which can work in trashy conditions. Air seeders are also used. Where precision planting and fertilizer application is needed it is done by hand. Holes are made in straight lines, fertilizer is dropped in the holes, covered by soil, then the seed placed and firmly covered by soil. A team of 200 people can plant 40ha/day. This way plant populations in maize have been maintained at 48,000/ha.

• Herbicides are used for controlling weeds, with the first application early in the season. A late application (just prior to harvest) is applied in order to kill the weeds before seeding and so reduce the seed bank. Hand weeding is also practised as it has proved to be cheaper at $56/ha compared to $119/ha using herbicides.

• Fertilizer application is undertaken by both machines and hand. Top dressing is done early in maize where 2/3 of the fertilizer is applied when the seedlings are 15cm high, and the remaining 1/3 applied at tasselling depending on weather conditions. About 280 - 320 kg/ha of urea is used. Lime is broadcast on the surface.

• Combine harvesters with attachments which chop the stalks are in use. Sometimes before wheat is grown the stover is chopped by a standard disc harrow adjusted to cause minimum soil disturbance. Controlled traffic 'tramlines' are used to reduce compaction.

General Comments and Learnings 

• The provision and retention of mulch is a core problem in communal farming areas, having a major influence on the development of the balance between biological, cultural, physical and spiritual parameters required for conservation farming;
• The conflicting messages emanating from different agencies, such as in this case Hinton Farm and the government extension service, is a major constraint to the adoption of conservation farming by small scale farmers;
• A concerted effort to develop nodes of conservation tillage practitioners may be more effective than a thinly spread widely dispersed programme;
• Profitability is crucial to the adoption of new technologies, and marketing, access to credit and training in management skills are major incentives;
• Every effort must be made by outsiders to understand the socio-cultural, economic and spiritual dynamics within communities;
• The reversion by participating farmers to traditional practices is far more frequently due to their not being fully consulted and empowered in the decision making process than other reasons, such as e.g. demonic forces;
• Care should be taken to deal with communities and not individuals, unless these have been identified by the community or emerge after community consultation.

4.2.2 The AGRITEX Conservation Tillage Programme, Institute of Agricultural Engineering (IAE) and Musana Communal lands 

This excursion was divided in two parts. In the morning farmers in a small-holder farming area known as Musana Communal Lands in Mashonaland Central Province were visited, and in the afternoon Domboshawa Conservation tillage research site at Domboshawa Training Centre, 33 km north of Harare. 

4.2.2.1 Musana Communal Lands 

Characteristics of the area: 

Agriculture in Zimbabwe is divided into two main sectors, the large scale commercial farming sector and the small holder farming sector (which includes small scale commercial, communal and resettlement farmers). Commercial farmers grow cash crops such as tobacco, cotton, maize and vegetables, often on sandy clay loams or clays, with some of the heavy red soils having a clay content of 60%. Communal farmers on the other hand often have to farm on poor sandy soils. Rainfall in the district visited ranged between 750 mm - 1000 mm per annum. 

Farming systems 

The two farmers visited in Musana are part of an on-going work by the Conservation Tillage programme run by AGRITEX under the Soil & Water Conservation Branch based at the Institute of Agricultural Engineering. The farmers have participated in the testing and development of a conservation tillage technique locally known as no-till tied ridging since 1990. 

The farms visited were 4-6 acres. Crops grown were hybrid maize, groundnuts, cotton and cow-peas as an intercrop. Maize yields in a good season were 3 200 kg/acre. Vegetables were grown for home consumption. In addition farmers owned cattle, poultry and rabbits. 

Conservation Technologies 

Two types of tillage methods were in use: 

• The conventional animal drawn mouldboard ploughing system where planting is carried out on the flat in plough opened furrows, the standard practice used by most local farmers.
• The no-till tied ridging system where planting is carried out on semi-permanent tied ridges which are prepared by ox-driven implements. This system is the improved system recommended for its effectiveness on soil and water conservation. However yields over the seasons have tended to be erratic.

Both farmers visited have used tied ridges over the past 10 seasons, and maintained this system is gaining in popularity among farmers in the area. 

Fertilizer 

The farmers use self-made compost which is applied to maize grown in the household gardens at a rate of approximately 1 ton/acre. They also use compound D fertilizer (8% N, 14% P₂O₅ and 7% K₂O) applied at the rate of 100kg/acre. Top dressing is normally done with Ammonium Nitrate (34.5 % N). 

Manure is applied on top of the ridges after opening up planting furrows on the ridges. 

Herbicides 

One farmer has used herbicides on an experimental basis after obtaining advice from the Agricultural Research Trust Farm (a commodity-funded research organisation). The farmer considered the results as excellent but thought herbicides (glyphosate) were too expensive for him and therefore did not continue to use them. He however did not know the exact current price of the herbicides. Generally herbicides are beyond the reach of many farmers costing typically $180.00 per 5l of Roundup flowable. The current packaging of herbicides does not seem to cater for small farmers where smaller quantities are required for example 0.5 litres would suffice for a farmer with only 2ha of land. The use of herbicides in the area is generally almost non-existent although a considerable number of farmers do own knapsack sprayers, which they use for spraying pesticides in cotton and vegetables in gardens. 

Constraints 

• Accessibility of inputs is very limited as farmers have to source these from Harare.
• Marketing is difficult as markets are distant and prices erratic.
• Pests such as maize stalk borer were a problem.
• Mid-season droughts were also considered a problem.
• Absence of fences resulted in livestock allowed to roam early in the dry season often destroying long season crops like cotton.
• Other constraints identified included poor access roads, lack of water pumping equipment for small irrigation projects etc.

Entrepreneurship 

One of the farmers is already a stockist of Pannar maize hybrid seeds and sells the seed to other farmers in the area. The group recommended that the farmer also stocks chemicals and fertilizers. However it was later noted that the nearest retail outlets also stock some inputs. Agri-business entrepreneurship was seen as a way forward in ensuring timeous access to inputs. 

4.2.2.2 Domboshawa Training Centre Contill Site 

The site is one of the three on-station research sites started by the Conservation Tillage Programme in 1988. The trial objectives were to assess the relative merits of various animal-draught based tillage systems in terms of soil loss, water run-off, soil water retention, crop growth and maize grain yields under rain-fed conditions. The trials are long-term experiments to establish long-term trends under the various tillage systems. 

The five tillage systems under test include: 

• Mulch ripping (or ripping into residue)
• Clean ripping (ripping between row without residues)
• No-till tied ridging
• Hand-hoeing or Badza holing
• Conventional annual mouldboard ploughing

These treatments are being tested relative to the conventional farmer practice, annual mouldboard ploughing. Whilst all the above are based on animal drawn implements there is also an additional tractor ploughed bare fallow treatment which was put in to test the erodibility of the soils under the extreme condition of a continuous bare fallow. These plots are set in a completely randomized block design replicated 3 times. 

From the on-going studies whose results have been published in research reports and journals, some of the major conclusions reached so far include: 

• That no-till tied ridging and mulch ripping are the most sustainable crop production techniques of the treatments tested in terms of run-off and soil loss, having maintained soil loss levels (according to data from the first 6 years) below the tolerable limit of 5 tons/ha/year.
• That the advantages of tied ridging over conventional mouldboard ploughing are most pronounced under waterlogged conditions.
• That there is not much scope for blanket recommendations, as yield results from on-farm trials have tended to be site-specific and dependent on seasonal rainfall, soil type and farmer management capability.
• That socio-economic and socio-cultural constraints play a very important role in the adoption or rejection of innovations. These problems can sometimes override the technical constraints associated with an innovation. Experience has shown that some of these problems can be alleviated through the use of various (PRA) tools which encourage farmer participation.

Results indicated increasing yields with conservation tillage. Erosion reduced below tolerable limits on conservation tillage plots compared to conventional tillage. 

The group was also shown a range of implements being developed for conservation tillage, including ridgers, ploughs, cultivators and rippers. 

Recommendations from the team included the use of pigeon pea to penetrate the hard layer which tended to cause waterlogging problems during wet spells. 

4.2.3 Sanyati Communal Area, Kadoma District 

Sanyati Communal Area is situated 220 km south of Harare. The region is in the semi-arid tropics, with an un-modal rainfall pattern and <600mm rainfall. Rains start in November and stop in March. Droughts are frequent. Soils are mainly sandy loams. Soil fertility status is generally low, due to the parent material and insufficient restoration of organic matter and plant nutrients. 

Farming Systems 

Average arable is about 3 ha. Main crops are cotton and maize. Most farmers raise cattle on the communal grazing lands and, after harvest, on the crop residues in the fields. Ploughing and ridging with draught animals is wide spread. Yields are generally low, due to low soil fertility status, frequent drought stress and inappropriate cropping practices. 

Research and Development (R&D) Programme 

A) Dissemination approach 

The Cotton Research Institute in co-operation with an EU funded extension programme runs a R&D programme in the area. The programme started in 1995 with a number of farmers groups. The groups, called „The Big 12", each comprise 12 farmers, of whom four were considered below, four above and four average farmers. The number of groups has increased steadily and comprises now more than 300 farming families, including female household heads. 

B) Conservation Technologies 

In the first phase the programme focused on the homestead. Fruit trees were planted and run-off water collected to water trees. In addition trees were watered with a simple drip irrigation system, consisting of an upside down placed water-filled bottle. Farmers were encouraged, to build tanks and collect rainwater from the roofs. Thus two objectives were met, rainwater being recovered for productive purposes and run-off from homesteads being reduced causing less damage to the adjacent fields. 

As plant available water is the first limiting factor to plant production in the area, farmers were encouraged to lead run-off water from roads and pathways into the fields. Surplus water is caught here by dead-level contour bunds and infiltration pits. The farmers explained that in dry years they still got a decent yield in the fields below the contour bunds, due to the collected and infiltrated water. 

In the fields ploughing was replaced by ridging, made either by plough or ridger. Cotton is planted on the ridges. Surplus water is collected in the furrows between hand-made ties (tied ridges). Weeding is done usually by re-ridging. In the following year maize is planted in the furrows. The maize plants profit from the organic material collected in the furrow. No tillage is required prior to planting. Weeding is combined with ridging. The farmers usually pass twice. In the following year cotton is planted on the ridges. 

The system consists thus of semi-permanent ridges, which require only reduced tillage. Main advantage is water harvesting, leading to sustained and higher yields. As no ploughing is required the system reduced labour demand. Only in the early start-up phase does labour demand increase, as diversion channels, contour bunds and infiltration pits need to be constructed. Labour requirements for maintenance of the structures are low, as due to the tied-ridges there is hardy any siltation in the pits. 

Appraisal of approach and technology 

The group approach seems to be very successful. Farmers were proud to be group members. The group dynamics encourages farmers to try new practices. The steadily growing size of the groups shows that the new techniques increase yields and income and that learning is easier in a group. 

As crop residues are used as forage for livestock and as cotton stalks have to be burned by law, hardly any crop residues remains on the ground. Under these conditions zero-tillage systems are not applicable at all, and the tied-ridge system could be said not to qualify as conservation tillage as ground cover is less then 30%. Despite this fact, tied ridges are a viable alternative to mouldboard ploughing, being much less destructive and conserving soil and water. 

From the cotton stalks in the fields, it was estimated that cotton yield on the field with tied-ridges was about ten times higher than that in adjacent fields using conventional practices. This yield increase is probably not only the result of the tied-ridges system but also of the management capacity of the farmer. Improving the management capacity of farmers can therefore be assumed to be crucial.