• Primary tillage for corn is better carried out at fall.
- Research discovered that reducing both clod and valley sizes in the fall can dramatically
reduce the risk of emergence problems in spring.
- Ideal Clod Size:
Prairie Soils: 15 cm (6 in) or less
Forest Soils: 12 cm (4.5 in) or less
- Action of frost on tilled soil during the winter helps in reaching a proper seed bed texture in spring.
• Timeframe: Primary tillage should begin behind the combine.
• A wide array of tools are available for primary tillage, such as
- Moldboard plow
- Chisel plows
- Disk rippers
- Offset disk.
• Disk rippers can be used for aggressive residue handling up front, more clearance, and an array of seedbed attachments on the back. This reduces field leveling and moisture losses in spring when
soils are recharged with water.
• Secondary tillage is carried out before planting in spring. The goal is to achieve a proper seedbed, which means soil particles of right size for good contact between seeds and soil.
• Soil with a rough surface hinders proper seed germination and plant growth, ultimately leading
to lost potential yield.
• A good seed bed is important, because plant roots require water and oxygen from the soil roots pore
space for sprouting.
• The right soil-air-water balance helps in limiting plant stress during drought periods and enables the
plant to fully explore the soil profile for nutrients. Plants are able to use water efficiently and grow
strong roots for good anchorage.
• Research carried out showed that many as 7000 plants per hectare, or up to 10 percent of the net
effective stand, could be lost due to poor seed bed conditions. Most of those lost plants were recovered,
simply by focusing on delivering level output, both clod and valley free, following primary tillage.
• In APAC Region, ploughing (moulboard plough) is still very common as primary tillage for corn. On average, working depth is between 28 and 35 centimetres. Nevertheless, more and more customers are realizing
that disk rippers are an outstanding alternative to moulboard plough. Disk rippers allows for good
soil structure, consistent soil tilth, sufficient residue management and seedbed finishing in one pass, with
evident economic advantages when compared with ploughing. More, existing hard pans are broken, with
advantages for root growth, plant nutrition and water management.
• Seedbed finishing is performed with an array of implements, as tine harrows, disk harrows, rototills
and many others. The goal is to get a firm seedbed beneath a layer of loose soil on surface, allowing
for uniform and quick germination of seeds. If the upper layer is too fine, crusting may happens.