W4 -L2 - Crop Establishment and Seedbed Preparation
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what can vary the yield potential of cereals crops
vary across soil types
what will happen when soils have good yield potential
Soils with ‘good’ yield potential will produce that yield if management, inputs and climate are optimal
what will happen when soils have poor yield potential
Soils with ‘poor’ yield potential will have a limit to yield irrespective of the level of management, inputs and nature of the climate
pH of soils for : Wheat: Oats: Barley:
Wheat: 6.0+ is best (problems if <5.4) Oats: 4.7-6.0 (optimum) Barley: 6.2-6.5 (problems <6.0)
soil type/ texture for: Wheat: Oats: Barley:
Wheat: medium- heavy - good % clay Oats: medium- heavy - lodging risk Barley: light-medium - well drained
Objectives of Cultivations (6)
• germination • facilitate root development • aid drainage • control weeds • bury thrash • control pests
definition of conventional tillage
Intensive primary soil inversion to 200 -300mm followed by intensive secondary tillage and subsequent seeding
def of direct drilling
seed placement without tillage.
in between conventional tillage and direct drilling
A complete range of systems: Deep or shallow reduced tillage, Strip tillage etc.
what is an excellent method of crop establishment
plough - till - sow
what the key component of crop establishment
good ploughing
describe ploughing
• inversion of the soil (20-25cm depth) • loosening of the soil layer • consolidation of the ‘new’ surface • burying of the previous crop trash
what are the advantages of ploughing (2)
• Yield security – crop residue / surface thrash is buried so facilitates ease of sowing • Disease control / weed control / (pest control)
what are the disadvantages of ploughing (5)
• Effect of soil biology – earthworms / beneficial insects • Soil compaction / soil structure damage • Soil erosion – very big problem on fragile topsoils worldwide • High energy (fuel) and time requirements • All of these disadvantages strongly support the search for alternative tillage techniques
what sort of seedbed is vital
fine firm and level
describe a fine seed bed
Fine - good soil seed contact - Residual weed control chemicals (herbicides) are more effective - too fine : surface capping and reduced emergence
describe a firm seedbed (3)
Firm - Good soil / seed contact - More even sowing depth - Better emergence
describe a level seedbed
Level - More even sowing depth - Uniform emergence
advantages of direct drilling/ No Till (4)
• time and energy saving • minimises moisture losses • organic matter retention (in top 5cm) • reduction of erosion
what are the requirements for success for Direct Drilling/ No till
in high rainfall areas (Ireland) remove the straw and avoid surface compaction after wet harvests the move was to ‘rotational’ ploughing
what is reduced tillage/ Minimum tillage
cultivate the top 8-15 cm (+/- 80 mm ) of the soil layer Non-inversion - soil is ‘mixed’
how much (%) is cost reduced using RT/MT But what is increased?
lower costs (40-60%) increased work rates
Advantages of MT/RT (3)
soil organic matter (soil carbon) soil structure more biological activity
what sort of seedbed is important for RT/MT
stale seedbed is very important and also minimum surface compaction