Diagnosing seedbed constraints in narrow-leafed lupins and field peas

Seedbed problems include poor seed-soil contact, poor depth of seeding, and soil crusting.

 

Poor growth within and between seeding rows
Plant that has germinated within embedded stubble

What to look for

    Paddock

  • Uneven germination and stunted plants that often occur along drill rows, heavy stubble areas, or specific soil types.

    Plant

  • Reduced and/or staggered germination.
  • Smaller or stunted plants.
  • Poorly covered seed. Seeds germinating near the surface are more susceptible to fungal root rot.
  • Hairpinned stubble or other organic matter may be close to the seed.
  • Surface crusting can cause damage to seedling cotyledons and growing point

What else could it be

Condition Similarities Differences
Diagnosing water repellence Reduced and staggered germination Restricted to water repellent areas and the problem is ongoing.
Diagnosing poor quality seed in narrow-leafed lupins Reduced and staggered germination The problem is more likely to be evenly distributed throughout the paddock; malformed seedlings.
Diagnosing allelopathy in narrow-leafed lupins Reduced and staggered germination Allellopathic affected plants remain pale, distorted and stunted and may be caused by toxins leaching into the seedbed or from contaminated seed.
Diagnosing waterlogging in narrow-leafed lupins and field peas Reduced and staggered germination Restricted to water gaining areas and the problem is ongoing.
Diagnosing salinity in narrow-leafed lupins Reduced and staggered germination Restricted to water gaining areas and the problem is ongoing.

Where did it come from?

  • Air around the sown seed prevents it from absorbing moisture from the soil. Examples include:

  • Seed sown on the soil surface.
  • 'Hairpinning', where straw is pinned in the seeding slot, leaving air voids and increasing the risk of allelopathy.
  • Poor seed-soil contact from insufficient soil firming or poor coverage of the seed in the seeding slot.

Management strategies

  • To ensure sufficient seed-soil contact it is important the sowing machinery is designed to seed at a uniform depth and provides uniform soil cover.
  • Systems such as harrows and prickle chains are subject to variation in the soil surface. Press wheels offer increased control.

Where to go for expert help

Page last updated: Wednesday, 6 May 2015 - 11:17am