Processing Tomato Industry: Soil Priorities for Moving towards 200 - - PowerPoint PPT Presentation

Processing Tomato Industry: Soil Priorities for Moving towards 200 t/Ha Yield.

• Ba Ag (Hons). University of Melbourne, Dookie College.
• Soils of the Riverine Plain.
• Soil formation (Butler 1950; Butler 1956; Butler & Hutton, 1956; Butler, 1958).
• Soil catenas – sequences
• Soil type and variability
• Land use capability & suitability
• Preferred crop types
• Engineering of soils to increase productivity.
• Focus primarily on soil physical properties.

Cockroft – Orchard Soils (Not Tomatoes)

Soil Physical Properties – Breakdown into Two Groups.

Cockroft & Dillon, 2006.

Inherent: Those that are fixed, difficult to change or modify (without engineering):

• A horizon topsoil depth
• Horizon texture
• Depth to hostile or constraining subsoil

Set and limit yield potential. Must have a rootzone to support growth. Dynamic: Those that can be modified or changed.

• Soil structure
• Bulk density, slaking, dispersion
• Others previously mentioned.

Can be modified to increase yield potential.

Soil Requirements for High Yield Potential in Horticulture:

1. Field drainage. 2. Deep topsoil, or engineer deeper topsoil – mound.

• Horsepower
• Drainage

3. Full amelioration of the ‘effective’ rootzone

• Mound
• All topsoil
• Upper B horizon

4. Improve water stability – control dispersion, slaking and reduce coalescence (Cockroft & Olsson 2000). 5. Maintain and improve aggregation (structure) by adding and growing organic matter / use management techniques to maintain structure (Tisdall & Oades 1979; 1980a; 1980b).

• Ryegrass
• Other cover crops
• Crop rotations
• Cultivation

6. Adequate supply of nutrition to meet yield potential, optimal cycling of nitrogen from organic matter. 7. Irrigation – method, placement, volume.

YIELD POTENTIAL OF 200 t/Ha…???

• We have seen 200 t/Ha yields before in patches.
• YES, potential is possible.
• Short-medium term (5 years), average yield potential on subsurface

drip irrigation:

• NO.
• Why? - Short term issues:
• Soils are too expensive or difficult to ameliorate.
• Poor compatibility between irrigation system application rates, placement

and soil properties.

• Industry does not focus on the ‘key’ factors which drive high yield potential.
• How will we get there?

2016 GRDC Conference.

Inherent soil properties - what we have to work with Dynamic soil properties – those we can change. 200 t/Ha

2018 study tour – December New Zealand.

• 17 t/Ha cereal crops, chasing

20 t/Ha.

• Reduce crop stress
• Perfect field drainage
• Deep rootzone, large area to

draw water

• Rainfall
• Irrigation – light, soft

application.

• Crop rotation critical.
• Several crops in rotation, both

summer and winter – more than 1 crop per year.

What this means for processing tomatoes:

• Starting conditions is critical. More due diligence on land.
• Irrigation system compatibility – must be studied.
• Knowing how soils behave and change under irrigation will support

hypothesis on yield decline – research required.

• Know yield potential before we start.
• Must understand and set benchmark parameters around soil physical

properties to support desired yields

• Use these benchmarks for:
• Land selection
• Soil amelioration.
• May already be achieving maximum yield potential from some soils

for the irrigation system that is employed.

Soil physical properties & other measures of soil physical conditions impacting plant growth and yield potential:

1. Horizon depths (cm): Visual assessment of the layers of soil in a profile with similar physical and chemical properties (Butler, 1955; Cockroft & Dillon, 2004) 2. Horizon texture: Texture of each horizon or layer in the profile, understand drainage (McDonald et al 1990; FAO, 2006). 3. Topsoil depth (cm): Zone where crop nutrients are accessed, zone of the profile which can rapidly drain, including the A1 & A2 Horizons, bleached layers (Cockroft & Dillon, 2006). 4. Soil colour: Assess internal and surface drainage, waterlogging potential and impedance to water flow (McDonald et al, 1990, Munsell Colour Charts, 1975). 5. Soil structure & porosity: Level of aggregation, surface tilth, hard panning, water movement and root movement (Freebairn et al, 1997; McDonald et al. 1990; US Dept. Ag, 1951). 6. Bulk density (t/m3): Calculation of the density of a soil, including volume of soil and air space for roots (Brady, 1990; White, 1979) 7. Slaking Class: Breakdown of aggregation and associated consolidation and compaction (Herrick et al 2001; Tisdall & Oades, 1982). 8. Dispersion Class: Clay colloid dispersion and associated consolidation and compaction. (Emerson, 1967; Charman, 1978; Charman & Murphy, 1991; Naudu et al. 1995)

9. Consistence: Field strength, cohesion and plasticity. (Butler, 1955; McDonald et al. 1990).

• 10. Effective root zone depth (cm):

Zone where soil can be efficiently accessed by plants. (Kramer & Boyer, 1995; Schaetzl & Anderson, 2005).

• 11. Calcium carbonate (free limestone), type of lime (nodules, powder or rubble), the depth to lime: Naturally occurring lime that

can impact root growth or influence soil pH rendering nutrients of low availability. (Brady & Weil; 2008; Weatherby, 1992; Cockroft & Dillon, 2004)

• 12. Calcium sulphate (gypsum) content and depth:

Visual inspection, influences soil electrical conductivity, less impact than lime, less impact than NaCl (FAO, 1990).

• 13. Plant root score, volume and distribution of the plant root system:

Scoring the root system in each horizon for available water (McDonald et al, 1990; personal observation).

• 14. Self-mulching processes in clay dominant soils and subsoils:

The influence of shrink-swell process on plant root zone depth, available water and soil chemistry. Discuss dryland and irrigation. (Churchman et al. 1995; McGarity et al, 1984).

• 15. Crusting and restricted infiltration:

Surfaces prone to crusting with restricted water infiltration. Closely related to texture, behaviour when wet and organic matter.

Processing Tomatoes: Summary of Field Observations Limiting Yield Potential:

• Germination and poor early growth.
• Crusting – slaking, dispersion, intense rainfall.
• Paddock variability – variable water use.
• Poor profile drainage – heavy sodic clay subsoils.
• Poor rooting depth, moisture drawn mostly from the surface.
• Soil structural, lack of aggregation.
• Soil moisture management – too wet, watered from the bottom up,

perched water table development, capillary rise of water.

• Amplified irrigation volume
• Consolidation around the tape
• Poor structure
• Limited roots where nutrition is being applied.

Early Growth.

Many problems relating to yield are caused from poor early growth and management.

• Crop struggles to get established
• Mis-match between irrigation requirement and application
• ET increases, shallow rootzone, irrigation becomes difficult.
• Crop does not flourish in peak ET period.

Early growth must secure:

• Effective rootzone depth – as deep as possible.
• Deeper than tape.
• Readily available water – as high as possible, big bucket.
• Wetting front from irrigation that takes soil from deficit to moist (field

capacity) over a large area, rather than deficit to saturated (small area). Ayres & Westcot, 1989. FAO Irrigation & Drainage Paper No. 29.

Kagome – 2014 Land Development.

• Crops on these soils yielded up to 140-160 t/Ha.
• Effect short term only – follow up work is required.

Kilter – Soil Physics & Chemistry Around Tape.

Kilter – Soil Physics & Chemistry Around Tape.

FINAL NOTE

• Several aspects of soil physics that can be studied to move towards

200 t/Ha.

• Major shift in R & D priorities.
• Water stability – major focus.