Challenges of no-till cropping and livestock on the same paddocks

(Ken Flower)

Moisture is the most limiting factor in our farming systemMoisture is the most limiting factor in our farming system

Our farming systems must aim to maximise moisture conservation

•Permanent vegetation

•Perennial pastures

•Annual pastures and cropping

Sustainability

Profit

D. Carter, 1999

High quality no-till system

Diverse crop rotationsIntegrated weed managementMinimal soil disturbance (i.e. no tillage)Minimal soil compactionPermanent soil cover

High quality no-till system:

1. Diverse rotationsIntegrated crop and livestock systems can

be very complementary - Diversity of pastures, vary length of phases, perennials, nitrogen fixation, weed control from ‘spraying out’ etc.

1. Diverse rotations

An alternative that is being tested in 100% cropping systems is cover crops –can provide many of the pasture benefits – Diversity of pastures, nitrogen fixation, weed control from ‘spraying out’etc.× Cannot have frequent cover cropsbecause of the economics

2. Integrated Weed Management

Effect of livestock gazing as an IWM tool• Grazing weeds• Spraying out pastures• Decrease in herbicide resistance• Grazing management

× Effect of livestock hooves on weed seed burial, germination uniformity, spreading weeds

2. Integrated Weed Management

The benefit of sheep in the system:more to do with the options available in the pasture system?

× Less to do with the effect of sheep grazing per se?

2. Integrated Weed ManagementResearch question

• Can sheep can overcome the problem of herbicide resistance?

• If yes, does this apply to all weeds?

3. Minimal soil disturbance

• No-till seeders with tynes and knife-points

• Have limits to the level of residue handing

• Zero-till seeders with disc openers have least disturbance

• These seeders can handle higher levels of crop residue

3. Minimal soil disturbanceResearch questionWhat is the most appropriate seeding machinery for a high quality no-till / livestock system? (One that can handle crop residues and penetrate the soil after livestock)

4. Minimal soil compaction

• There is no tillage in the system so compaction of the soil must be minimised

Controlled traffic× Impact of livestock hooves on soilphysical properties – timing of grazing winter increases impact significantly

• Decreased infiltration• Decreased water stable aggregates• Increased soil strength

4. Minimal Soil Compaction• Livestock trampling results in soil

structural decline/compaction (Proffitt et al., 1995)

• Impact can be reduced if soil surface is covered with vegetation (Hamza and Anderson, 2005)

Research question• How much vegetation?

5. Permanent soil cover

Full residue retention is a commonrecommendation of no-till systems

throughout the world• “… keeping the soil covered is afundamental principal of conservationagriculture” - FAO

No-till with no cover is poor quality

(derived from Wall, 1999)

5. Permanent soil cover• Full residue retention is one of the

major constrains to adoption of no-till by small-scale farmers who also maintain livestock (Govaerts, B. 2007)

5. Permanent soil cover

Erosion control 30 - 50% cover1, 2 and 3 t/ha for cereal, lupin and canolarespectively (Leonard, 2003)× Not enough data on soil cover vssoil ‘quality’ – soil organic matter?× Not enough long term data the

effect of soil cover/grazing on crop yield?

5. Permanent soil coverSoil moisture is the most limiting factor in our farming system

Research question• What is the optimal level of soil cover

required when crops and livestock utilise the same paddocks?

• What is the optimal grazing management?

Successful crop and livestock integration comes from a SYSTEM approach - maximising the positives and minimising the negatives

The End