Land is rolled primarily to improve harvest operations. Rollers level and smooth the soil surface by pushing down soil ridges. This makes silage and pulse harvesting faster and easier, with less wear and tear on equipment and better seed-to-soil contact.
Other benefits of land rolling:
- pushes stones and other debris into the soil, to reduce guard and sickle section breakage and expensive damage to cutter bars and combines
- allows the cutter bar to get closer to the base of plants to reduce yield losses
- allows for easier adjustment and operation of lifter fingers
- reduces potential for ‘earth tags’ or soil on the seed, which can affect crop quality and acceptability in some markets
- aids in the harvest of short stature crops; land rolling works especially well under drought conditions
- aids in the harvest of lodged pulse crops and pulse-cereal mixtures for silage
Although a land roller can firm soil and improve seed-soil contact, it should not be relied on as a seedbed finishing tool to provide the packing necessary to ensure even germination
For more information on land rolling, see: Land Rolling Guidelines for Pulse Crops in Western Canada.
Land rolling can have detrimental effects on soil properties and injure growing crops. Rolling pulverizes soil aggregates and leaves a smooth surface making the land susceptible to wind erosion.
Soil crusting can also occur if fine textured soils or low organic matter soils are wet when they are rolled.
Crops that are emerged or just below the soil surface can be broken or crushed by rolling. Damage to these crops often is not fatal but these injured plants probably will be set back by several days and are susceptible to diseases.
For rolling fields, the steel cylinder land roller is the most common roller used (Figure 1). However, if the land does not have rocks, a harrow packer (coil, spiral) draw bar is a viable option to the land roller. Harrows (tooth and tine) can break lumps and firm soil, but do not push rocks down and are not recommended for crops like pulses, which may lodge.
Figure 1. Roller used for land rolling crops
It is best to land roll soon after seeding, as long as soil erosion risks are low. Where land is prone to blowing, land rolling after peas or lentils have emerged is the best overall balance between what is best for the land and what is good for the crop.
Post-emergence rolling on peas should be done when the crop is at the 2- to 3-node stage. With lentils, the rolling should be completed before the crop passes the 7-node stage.
Land rolling does the least damage to crops if completed when soil and leaves are both dry. In most cases, rolling in the afternoon or when the crop is slightly wilted is the best time to roll after crop emergence.
For pushing rocks back into the soil and for smoothing out the soil surface, empty rollers are as effective as rollers that are half-full or full of water ballast.
Tips for success
- Delay land rolling if the crop is stressed by heat, drought, frost or herbicide application. Rolling is hard on an emerged crop so it is best to not add another stress to a crop that is already suffering from environmental conditions or other management practices.
- Minimize double rolling.
- Consider rolling a field round and round rather than back and forth to keep from over-packing turnaround areas.
- Slow down when turning and avoid sharp turns. Tractor tires potentially can do more damage to the crop than the land roller.