Harrow and rototill the field.
If weed population is high, make 1 pass using the flexi-tyne cultivator or spike-tooth harrow, then use the rotovator to till the soil.
When using the four-wheel tractor, make 2 passes across the field. If the power tiller is available, rototill the field for 1−3 times.
Make sure to perform all tillage operations within 2−3 days after each activity to prevent weed and volunteer seeds from germinating.
Level the field
Good land leveling is best achieved using laser-assisted leveling. Well maintained fields require laser leveling once every 3−4 years.
Between laser leveling operations, the field can be leveled using a drag bucket.
A level field allows planters or drills to place seed more precisely and enables more uniform irrigation. A level field reduces weed pressure and helps control water.
Implements: Bucket leveler with laser attachment, Hydraulically operated drag buckets
It takes approximately 8 hours to level 1 ha of land using the bucket leveler.
After land leveling, lightly till the soil at 1−3 cm to reduce compact.
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Allow weeds to emerge before planting
Allow weeds to emerge for at least 2 weeks, then kill them with a non-selective herbicide, such as glyphosate. Plant your crop within 1−2 days, then spray a pre-emergence herbicide.
If there is no time, plant your crop immediately after leveling and shallow tillage (Step 4) then apply a pre-emergence herbicide.
Other techniques in dry land preparation include:
Stale seedbed
This technique is effective in reducing the weed seedbank in the soil.
In this practice, the field is tilled and leveled, and then weeds are allowed to emerge before being killed by using a non-selective herbicide or light cultivation. Depending on weed population and soil condition, no further tillage may be required.
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Reduced tillage
Reduced tillage is a land preparation practice that minimizes soil disturbance by reducing the number of tillage passes.
This is best for fields that have no heavy weed pressure, particularly for perennial weeds.
Implements: Rotovator, Tractor-mounted drill seeders
- Make sure that the soil has optimum moisture for tilling.
- Rototill the soil for 1−2 times. Clod sizes should be at 2−3 cm maximum.
- Drill the seed.
For extremely dry conditions, irrigate the field for 5−7 days before tilling the soil.
With minimal tillage, farmers are able (1) to generate higher yields, (2) reduce production costs, and (3) reduce erosion and other forms of land degradation.
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You can use crop residues as mulches for reduced tillage
Seedbed with crop residues used as mulchesCrop residues are parts of plants left in the field after the crops have been harvested and threshed. These include stalks, stubbles or stems, and leaves.
When used as mulches, crop residues can help conserve soil moisture, improve soil fertility, and control weeds, especially in direct seeded systems.
To do this:
1. Clear the field.
2. Place all tall vegetation on the bunds.
3. Cut and mix the smaller vegetation with crop residues.
4. Spread the mulches on the field.
Zero tillage
The decision on whether or not to till the soil depends on site-specific factors, such as the need for leveling and the risk of rodent attack.
In zero tillage operations, existing weeds should be killed by a non-selective herbicide, such as glyphosate. In situations where weed infestation is not uniform, apply herbicide as a spot treatment rather than a blanket application.
Apply herbicide 2−3 days before sowing, when weeds are actively growing and not under stress. If weeds are under moisture stress, irrigate the field for 5−7 days before applying herbicide for better weed kill.
Read: (pdf)
Use clean water and a plastic container to make spray solution as herbicides bind with suspended soil particles and metal surfaces (e.g., iron bucket).
Use a multiple-nozzle boom fitted with flat-fan nozzles for full coverage