How to plant pasture

Sowing should be done at the onset of the rains to ensure that the seed receives enough moisture for optimum germination.

There are two sowing methods — row spacing and broadcasting. The seeds are spread in the field while considering the direction of the wind for even distribution.

■ Sowing in swards or broadcasting has a disadvantage of using a higher seed rate. However, it has several advantages, including producing more pasture for livestock and controlling soil erosion.

■ Row planting involves drilling pasture seeds into furrows of about 2cm depth. Sowing in rows lowers seeding rates and enables weeds to be easily identified and controlled.

One of the most common causes of failure in establishment of small-seeded pasture grass species, such as Rhodes grass (chloris gayana), is sowing too deeply. Thus, the timing, rate and depth of sowing is critical. Since most pasture plant seeds are relatively small, they are generally sown on the surface of the soil or incorporated to not more than 1cm depth.

Fertiliser requirements

Adequate soil nutrients are required to promote plant growth, tillering and branching of pasture grasses.

Nitrogen is the main nutritional determinant of pasture grasses and split applications after one month of sowing and at flowering, 50kg/ha-100 kg/ha nitrogen are commonly used, based on the fertility of the soil.

This implies that after application of the two split doses, the total application rate of nitrogen will range between 100kg/ha- 200kg/ha. Single dose application of nitrogen is discouraged as the plant will not have adequately developed to effectively utilise all the applied nitrogen.

As such, much of the nitrogen is often wasted and is not channelled into vegetative and seed production. At times the grass benefits from application of phosphate fertilisers at sowing if phosphorus is limiting. However, a farmer is advised to consult local extension workers before such a decision is taken.

Pasture management

Pasture management is key to the profitability of dairy enterprises. Weed management strategy during pasture establishment is extremely important and needs to be developed and implemented long before the crop is seeded.

Effects of residual herbicides from previous crops must be considered.

Pest and disease control

Pests and diseases frequently cause damage to pastures.

Planted pastures should be monitored closely for any sign of insect attack, disease and germinating weeds. The major challenge to brachiaria mulato (signal grass) production is the red spider mite. The leaves become yellow and purple.

The symptoms are severe during the dry season, but disappear at the onset of the rains. The best way to eliminate red spider mites is to use brachiaria varieties that are tolerant.

Work to keep plants healthy and the areas around the plants free of debris and dust. Also, make sure plants have enough water since mites prefer dry environments.

Irrigation and Fertilisation

Pastures often become unproductive or dormant during the dry season due to lack of water.

With irrigation, comes the need for balanced and often increased fertilisation. Irrigating malnourished pastures is a waste.

Compiled by Joshua Kato (editor, Harvest Money) and Dr Jolly Kabirizi (agricultural development expert)