By MAKELI PHIRI
(Pastures Part 2)
IN pasture establishment and improvement, it is very important to choose or select species that would get established or get adapted to the area well.
Hence to get good results from such an activity, a farmer should look at how vigorous that pasture species is and how persistence they are, that is if they are able to withstand grazing. In Zambia two main pasture grass species are used and favoured by especially our dairy farmers, these are Star grass and Rhodes grass.
However, the two have their advantages and disadvantages.
(1) Star grass – Advantages;
– Runners that is the planting materials, these are readily available and can easily be got or collected from agricultural research stations dotted around the country and these are just given free to interested farmers.
– Runners can be planted by hand easily by farmers who do not have machinery. For those with machinery these can be dropped in a plough furrow and covered or disced in. Both hand planting and machinery planted is best carried out in the month of December when the rains are well established.
– Star grass withstands heavy grazing once it is well established and has good drought resistance.
– It grows well and vigorously and weeds are not a bother and also it is persistence once established as a permanent pasture.
– Problem is once established it is almost impossible to eradicate from the paddock if required for cropping.
– Much labour is required if a big field is to be planted by hand and if not adequately fertilised during planting it lacks vigour and is easily invaded by weeds. The material must be planted as soon as it is collected.
– Quick planting of collected material is very much encouraged to avoid accumulation of prussic acid (Hydrocyanic acid) which may cause death in cattle once such is grazed.
(2) Rhodes grass –
– Can grow on wide range of soils and responds well to fertility and is drought tolerant.
– Establishment is through planting seeds and is suitable for planting with machinery and large areas can be covered with little or less labour. Planting as for Star grass should also take place in December when the rains are well established. Broadcasting can also be done and then the surface covered.
– It combines well with pasture legumes and gives good soil cover.
– The grass after setting seed it has a lower digestibility than Star grass.
– It has to be allowed to set seed before grazing can be allowed so that the stand thickens into the following year.
– The cost of establishing is higher than Star grass as the seed has to be bought and sometimes in the initial stages of establishment can be poor due to poor quality seed coupled with unsuitable conditions.
Pasture establishment, this involves the choosing of high quality seed or planting material if good results are to be seen or realised. Under good conditions a high proportion of the seed should germinate. This entails getting good quality seed and material. Poorer – quality seed if it is to be planted this can be sown at a higher rate per given area than certified seed. Any farmer going into pasture establishment should take advantage of the December rains. Some legume seed may need “scarification” treatment this would make an even – germination of the plant stand.
The procedure can be done practically with the help of an agricultural extension officer. This is done by taking a porous bag which allows water, the seed then can be put in a drum of hot water (but not boiling) at 70°c for about ten minutes.
This softens the seed coat and allows the seeds to germinate quickly once planted. Other treatments of legumes seeds involve “inoculation” and also what is called “Dormancy” but this is left to the experts.
Good pasture establishment may not be obtained if the seed is planted too late in the rainy season. These, that is legumes are slow growing plants hence, should be planted as early as possible. For grasses these can be planted later as they grow faster. They should be planted in moist soil if good germination is to be obtained, emergence and establishment would be good as long as the soil does not suffer from dry spells due to periods of drought.
Pasture can be treated like any other crop grown on the farm. Therefore, some farming activities carried out on agricultural crops can also be done on pasture established land.
The land weed competition can be reduced by the use of herbicides although great care must be taken to choose the herbicides that do not affect the growth of pasture species. It would also be wise to plant at a high density of rapidly – establishing pasture plants which compete well with weeds.
It is worthy to note also that with a well-established, well fertilized and managed pasture, weeds are not much of a problem. The same with pests and diseases intervention should be taken as what is done to field crops.
When it comes to pasture establishment, there are many methods that can be applied which again depend on a number of factors such as the pasture species, the type of land that is cropping (this has to do with converting a cropping area to a permanent pasture, maize fields are easily converted to pasture land. The advantage of this is that the fertilised maize would supply the requirement of the pasture as it gets established, erosion would be controlled, moisture would be conserved due to the shading of the maize crop and this indeed favours the growing legumes and grasses underneath).
Apart from cropping land, veld or grassland can also be improved. The method of pasture improvement on such land is to use the lowest cost per given area that is through broadcasting of legume seed or even grass seed. Land or an area that is heavily grazed or burnt can be changed with good conditions being available such as good soil moisture.
However, with the help of agricultural extension workers the farmer can do more because other methods can also be introduced. Then the farmer can have a choice.
To be continued….