Prof Chris Dannhauser
Pasture seeds are normally small and do not geminate as easy and as quick as maize seed for example. In most cases farmers use old crop lands to plant the pastures or in some cases veld is replaced by planted pastures. According to the Law we are not allowed to replace veld with any crop or pasture without permission from the Department of Agriculture. In short, it is important to prepare a proper seed bed. The following factors should be considered:
Seedbed preparation and weed control:
Some people believe that grass germinate and grows naturally in the veld, thus if you buy seed you can just throw it out and it will germinate like in the veld. That is true but in nature only a very small percentage of the seeds germinate. Seed is too expensive to “throw it away” like that. A well prepared seedbed is important for successful establishment. The reason for poor establishment in an unprepared seedbed is that most grass seedlings are sensitive to weed competition and other grass seedlings. Good seedbed preparation and weed control is therefore important to get successful establishment.
To keep weeds out, some people plant in January, on a well prepared land, an annual pasture such as Hybrid pearl millet or a Sweet sorghum. The faster growing Millet or Sorghum will give competition to weed seeds that are still in the soil and they will then not develop in large plants. The Millet and/or Sorghum can supply good autumn and early winter grazing. In most cases the seedbed will then be clean to plant a perennial pasture the following season.
Other factors that can also influence establishment success.
- Soil moisture: The sub-soil should have enough moisture during establishment to ensure good seedling development. Although the top 5 cm should be dry. That means plant a week or two after a shower of rain.
- Time of establishment: Summer and winter species each have their own season of establishment. Plant the summer crops in October to December, depending on rainfall. In dry areas (western part of SA) the winter crops can only be planted under irrigation. On the Highveld (Eastern Free State, Gauteng, Mpmumalanga and KZN), where the average annual rainfall is higher than 650 mm/year, it can be planted without irrigation in February to Aprl, but only if there was good rain in January/February
- Poor seed: There are minimum requirements regarding purity and germination for grass seed. Buy from a reliable seed-dealer to ensure quality seed.
- Patience of the farmer: If you planted maize earlier, you know that you can see germinated seedlings a week or two after planting, In the case of perennial summer pastures it will show only 6 to 18 weeks after planting, sometimes even longer. Thus do not plough it out too early. All annual pastures (summer or winter) will germinate faster, 4 to 6 weeks, if there was enough rain.
Over the years, several planting techniques were developed. The oldest and the cheapest method is broad-cast the seed by hand. The disadvantage of this system is uneven spreading. A so called “Cyclone” hand spreader is available in the market that can do more even spreading. There are also planters available on the market for broadcast sowing such as the Teff planter. However broadcasting is only suggested in high rainfall areas or if irrigation is available. If seed is broadcasted the soil should compacted by a roller or you can use a herd of cattle, moving around on the land to trample it In this case the top soil should be dry
Under dry land conditions, row planting is highly recommended. Pasture plants in rows of 600 mm (60 cm) to 1500 mm apart, have a better chance for survival. Planting in rows can be done in several ways:
The Tractor wheel method is done by fixing drain pipes (plastic) or gutter pipes to the tractor as illustrated in Slides 1 and 2.
A person sitting on each mudguard let the seed drops though the pipe, into the track of the front wheel. The rear wheel then firmly compact the seed. Two tree branches, one behind each rear wheel, can also be dragged, in the same operation, to cover the seed.
The measurement between the two rear wheels (and front wheels) of the tractor is normally 120 cm. If you want to plant narrow rows (60 cm) it can be done by moving astride over the original two rows as indicated on Slide 3.
The question now is how much seed should be planted in a row by each person on a mud guard, if you plant by the tractor wheel method, in rows that are 60 cm apart. An indication is given in Table 1.
Table 1: Approximate gram (g) of seed per row of 10 m or 100 m long
|Suggested seeding rate (kg/ha)||Gram (g) in a 10 m long row||Gram (g) in a 100 m long row|
|4 kg/ha||2.5 g/10m||35 g/10m|
It is very important to start with a well prepared weed free land as mentioned on Page 1.
If there is a dense stand of grass and weeds on the land, it is better to plant the first year an annual pasture like Hybrid Pearl millet or Fodder sorghum.
It is further important to find out what is the best planting date for a specific pasture.
Last but not least, plant when the subsoil (5 to 30 cm deep) is wet, but the topsoil (top 5 – 10 cm) should be dry
Prof Chris S Dannhauser
Cel no (+27) 082 873 4736