weeds; tillage; soil

Crop production: Improve soil through conservation tillage

Soil tillage is a costly business and intensive tillage can degrade the soil and impact the potential for crop production in the long term. New tillage systems, such as no-till and reduced tillage, were developed to slow down or stop the process of degradation.

These systems, which fall under the conservation tillage umbrella and aim to limit the mechanical manipulation of soil, can help restore soil to its original characteristics and potential over time.

The most notable problem with these systems – although it can be overcome – is the managerial component of production, especially with regard to the control of weeds, pests and diseases. The long-term advantages, including cost savings, are much more important in comparison to conventional tillage.

LIVING SOIL

  • After determination of environmental production potential and yield objective, the first production process is soil tillage or usage.
  • The primary objective of soil tillage should be to improve growing conditions, control weeds, loosen compacted soil layers, incorporate lime and fertiliser and manage water.
  • Tillage, however, can have a detrimental impact on the physical, chemical and biological status of the soil when used improperly.
  • Soil structure and factors such as filtration, aeration, soil fauna and organic matter are negatively affected by aggressive tillage over a protracted period.
  • This can negatively affect the potential of the soil to the extent that crop growth is negatively affected in the long run.
  • Soil tillage is therefore a sensitive activity that must be carried out cautiously and in harmony with the resource.

WATER

  • Water runoff and soil loss are two processes that are most likely to affect soil potential.
  • The long term effects of conventional tillage methods include the formation of compaction layers at the depth of tillage actions.
  • This is especially relevant for continuous ploughing and discing of sandy soil.

Rapid breakdown of organic matter caused by continuous overturning of soils by means of ploughing leads to lower water-holding characteristics, decreased soil fauna activities, increased possibility of compaction and other degradable characteristics.

Since soil is the natural resource in which plants are grown it should be used in a more resource-friendly manner, and with conservation as a long-term strategy. Conservation tillage, which includes reduced tillage and no-till are recommended ensuring cost savings and conservation.

All conservation tillage systems have specific advantages and and where problems are encountered it may be necessary to make use of conventional tillage methods. This includes, for example, mixing lime with soil, burying weeds and breaking up compaction layers.

FREQUENTLY ASKED QUESTIONS

What does it take to plant no-till?
Planters need 3 basic operations. They should:

  • Cut and separate the residue
  • Penetrate the soil to a desired depth
  • Establish proper seed to soil contact

What basic equipment is needed to begin no-till?

  • You will need a planter with heavy-duty slot openers and residue cutting facilities

What modifications are needed to traditional equipment to move to no-till?

  • No-till soil openers
  • Heavy duty residue cutters and movers
  • Added weight to ensure penetration

What factors influence whether or not no-till will work for me?

  • The production programme must fit the abilities and equipment of the manger
  • No-till requires a high management level
  • Clay content of the soil

What are the most important factors to make no-till work?

A. Getting a good stand

  • Do not plant too early (lower soil temperature due to residue)
  • Soil must not be too wet (closing of seed slot and soil contact)

B. Controlling weeds

  • Correct choice
  • Application rate and time must be correct
  • Periodic inspection of fields for species and occurrence

Also read: Conservation agriculture: No-till and controlling weeds

  • This information was originally compiled by the Agricultural Research Council’s Grain Crops Institute as published in its 2011 Maize Information Guide. 

Download the ARC’s 2016 Maize Information Guide in PDF-format here:
Agricultural Research Council – Maize Information Guide 2016

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