The second rainy season is expected to start early this month and as expected, it is time for farmers to plant maize and other crops.
The first step towards obtaining good maize harvest is ensuring that the farm is well-ploughed and ready for planting.
Ploughing should go a depth of at least 20cm and should be conducted two to three weeks before the onset of the rains.
James Mugerwa, an extension worker in Buvuma District says that maize is a heavy feeder that thrives in well-drained, well-aerated, deep warm loam soils. He explains that loam soils that make a ball which breaks on slight pressure are ideal for maize growing.
Ideal soils can be observed from the presence of indicator plants such as elephant grass, Guinea grass and Commelina sps. Sandy soils, clay and water-logged areas are not advisable for maize planting. Sloping areas, he advises digging contours and terraces to stabilise the soil and minimise run-off.
For commercial purposes, he recommends taking a soil test to assess soil health in as far as soil acidity and nutrient deficiency is concerned.
Tests can be done at the site while detailed analysis should be taken to recommended laboratories. “Always get advice on how to test soils from extension workers,” Mugerwa says.
Mugerwa says land preparation is extremely important. “Preparation of land to be used for the following season should always begin at the end of the harvesting period or at least three weeks before planting. This allows the breakdown of all organic matter,” he says.
New sites or those that are bushy should first be slashed before ploughing the residues into the soil.
This helps conserve moisture and improves water retention and infitration which adds to soil fertility. For fields that were previously covered with weeds that produce a lot of seeds such as Amaranthus spp, Mugerwa recommends earlier preparation.
“When the weeds germinate, the field can be tilled or sprayed with non-selective herbicides,” he says.
Some farmers burn plant residues but Mugerwa describes that approach as dangerous. “Burning the residues destroys plant nutrients which cannot be easily replaced,” he says.
Land can be tilled by either using the conventional tillage procedures or conservation. According to Mugerwa, conventional tillage involves use of hand hoes, animal traction, and walking tractors.
Hand hoes are convenient for smallholder farmers while use of oxen should not be used in sites with heavy soils ad steep terrain. Tractors and power tillers are the preferred means for commercial farmers. “In some instances, hiring a tractor at about Shs80,000 per acre, may be costly. A farmer should use appropriate technology that minimises costs of production,” he says.
Mugerwa advises farmers with little land such as two acres to use hand hoe for tilling. In Conservation Tillage (CT), Mugerwa explains that when it is applied, tree stumps and other barriers including ant-hills and thickets should be removed.
Maize should be planted on the onset of rains to take advantage of the nitrogen flush effect which is the release of accumulated nitrogen in the soil during the dry season. Normally the first season planting is in March and harvesting is in July, while the second season starts in August and ends in November. Farmers should avoid late planting since it leads to increased incidences of pests and disease attacks hence reduced yields.
“Planting requires proper management practices to attain potential yields,” says Mugerwa. He explains that making a decision on the variety of maize to be planted is an important aspect. That goes along with determining the purpose, acreage and planting time. After weeds germinate, herbicides like Round-up, Weedmaster, Mamba and Weedall can then be applied.
He cautions farmers must follow adequate planting depth rule because “seeds need more energy to penetrate the sub-soil unlike in a ploughed field”.
As a standard procedure, he recommends the application of compost or animal manure after the first cultivation to allow for adequate composting. The manure is churned into the soil at second ploughing at a recommended rate of 4-6 tonnes per acre.
Hybrid or OPV seeds?
One of the biggest challenges to farmers is poor seeds. Mugerwa says that seeds should be selected depending on the adaptability to production conditions, resistance to pests and diseases and length of the growing season. The growing season in particular, is important when there is unpredictable rainfall calling for early maturing and drought tolerant varieties.
There are two maize seed varieties; Open Pollinated Varieties (OPVs) and hybrids. OPVs can be recycled up to two years but the selected plants are marked before harvesting and stored separately. Hybrids, which normally yield more than OPVs, have to be bought every season because recycling reduces yield potential.
Mugerwa says that farmers can subject seeds to a germination test by putting a sample of about 100 seeds into a container with sand and wait for seven days to examine root, stem and leaf development.
“This helps the farmer to report any inconsistencies to the seed supplier in case of germination failure,” he says.
For optimum plant population Mugerwa recommends planting in lines which eases weeding, spraying and harvesting.
The recommended spacing for maize as a monocrop is 75cm between rows and 60cm between holes. By using two seeds per hole, this requires 10 kilogrammes of seed per acre and an optimum population of 21,000 plants. Alternatively, a farmer can use a space of 75cm (2.5ft) by 30cm (1ft) and plant one seed to achieve similar results.
When maize is to be intercropped, legumes such as beans, soybeans and peas are recommended. In such a case, inter-row spacing needs to be adjusted.