The Zimbabwean method of basin planting – where small pockets of soil are hoed and filled with seed and fertiliser – is practical and will improve your soil as years go by.
Basin planting is one of several techniques available to small-scale farmers to produce a crop using conservation agriculture (CA).
Conservation agriculture is defined by the United Nations’ Food & Agricultural Organisation (FAO) as the simultaneous application of the following:
1. no-till planting
2. rotational cropping and
3. keeping a permanent cover of plant material on the soil surface.
Basin planting apparently originated on the commercial tobacco farms of Zimbabwe. Such a farm generally had a large labour force to plant the maize crop by hand before the rainy season. Fertiliser, seed and water were placed in small basins dug with hoes.
A Zimbabwean farmer, Brian Oldrieve, came to realise that, with some minor adaptations, small-scale farmers could produce yields comparable to those of commercial farmers.
This system was introduced by Pastor August Basson to the village of Tebellong in Lesotho, where it has been used successfully for several years.
The technique can be used for a wide range of crops. Those which have been grown successfully in Lesotho and South Africa include maize, sorghum, wheat, peas, beans and cabbages. Some work has been done on growing potatoes under a cover of grass and leaves, without any hoeing.
The basin technique is most suit¬able for farmers who have a large permanent labour force, or for small-scale operators for whom using a tractor is expensive or not available.
MAKING THE BASINS
- The same basin positions are used every year, so this should be done properly in the first year to avoid having to redo them later on.
- The work of making the basins can be done during periods when there are no crops in the field.
- In this way the heavy work load is spread over a number of weeks.
- The same basins are used for different crops and the number of plants per basin varies according to the crop.
- Generally, square planting − where the space between rows is the same as the space within rows − is used. Locally this is 75 cm.
- What a farmer needs is a heavy hoe, a planting line made from a piece of light rope marked every 75 cm with a knot or bent-over cooldrink bottle caps, two sticks for holding the planting line in position, and a number of sticks to mark the rows.
- There is nothing wrong with using 90 cm rows and spacing the basins at 60 cm. But this does require two lines; one for the spacing between rows and one within rows.
- Start by placing the planting line along the edge of the field and place a marker stick at every marker.
- Then go along the first row for the length of the planting line and at that distance place another row of markers indicating the new rows.
- Return to the first two markers and place the planting line between them.
- Working backwards, dig a small hole at each marker. This can be 2 to 4 strokes of the hoe.
- In the first year there could be more strikes, since the deepest strike should preferably be deeper than the usual ploughing depth.
- At 75 cm x 75 cm there are about 18 000 basins per hectare.
- The number of seeds per basin is determined by the plant population required.
- Local farmers plant 3 maize seeds a basin and thin them out to 2 after germination.
- If the fertiliser has not yet been applied, add it and mix with the soil, then place seeds in the soil.
- In humid areas, do not leave a hollow, as seeds will drown if heavy rain follows planting.
- In dry areas, a hollow may be beneficial to concentrate moisture around the seed.
The following recommendations for seeds per basin come from Conservation Agriculture: A Manual for Farmers and Extension Workers in Africa.
- The basin technique lends itself to the use of either organic or inorganic fertiliser.
- If manure is to be used, compost it before use in order to reduce the number of weed seeds present in the manure.
- If compost is used, one or two cooldrink cans full of compost are added to the soil and mixed in lightly, or at least covered with some soil.
- This can be done before planting; chemical fertilisers are usually added at the time of planting.
- Cooldrink bottle are a useful tool for applying chemical fertilisers to the basins.
2 caps per basin will be about 175 kg/ha to 225 kg/ha.
- The farmer can adjust the quantity by how full he makes the cap or by grinding down the cap so that it will hold less fertiliser.
- Kitchen measuring spoons can also be used.
- A top dressing of LAN can be used, either as recommended or depending on the farmer’s financial resources.
- Weed control is the most important aspect of any conservation agriculture system and is a non-stop process.
- While the present crop is growing, maintain good weed control and prevent weeds from seeding.
- Slash off weeds and leave plants on the soil.
- Hoeing should also be used, but the weeds must be “shaved off” at ground level and allowed to dry on the soil.
- Exceptions are weeds which can propagate from cuttings, such as Kikuyu grass or Wandering Jew, which should be removed from the field.
- Chemical weed control is what really allowed no-till to be broadly adopted.
- For the small-scale operator it allows weed control to be undertaken much quicker, with a lot less effort, and it is more cost-effective than hiring hand labour.
A basic chemical weed control programme would be as follows:
a) Two weeks before planting, spray with glyphosate. The rate depends on the weeds. Young annual weeds are controlled with 2 litres/ha, but a dense cover of couch grass (Uqaqaqa (X); Ngwengwe (Z)) will need 8 litres/ha, preferably 2 sprays of 4 litres/ha.
b) Immediately after planting, apply a pre-emergent herbicide aimed at grass control. The cheapest is probably alachlor. Add a chemical for control of cutworms – one of the many pyrethroids is most cost-effective.
c) After about 4 weeks, apply a post-emergent herbicide. This will be determined by the weeds on the field as well as by the crop. The stalk-borer chemical can also be added at this stage, if required.
The 2 worst things we can do to the soil are to allow the sun to bake the surface, and to allow rain drops to strike the soil surface directly. To prevent this, retain a cover of organic matter on the soil.
Think of what the soil looks like in a forest and try to get the same effect on the surface of your land. Soil cover has a major effect on preventing weeds from germinating.
Never throw away any plant material; place it over the soil. In addition, when there is no crop in your field and there is moisture, grow a crop specifically to provide plant material to cover the soil.
These are known as green manure cover crops. You can use virtually any plant, but some of the more popular ones are maize, fodder sorghum, Saia oats, rye, vetch, sunhemp, dolichos beans and cowpeas.
It is best to limit the access your livestock has to your fields; preferably there should be no access at all.
If the plant material has to be used as animal feed, it is preferable to cut the plants and feed them to the animals off the fields.
The following are a guide:
1. Keep all animals out of the fields if the soil surface is wet.
2. Leave as much plant material as possible on the soil surface.
3. Remember that small stock compact soil more than large stock.
- This article was written by Werner Ristow and first appeared in Farming SA.