Allyl Isothiocyanate Release and the Allelopthic Potential of Brassica Napus
Balanced nutrition in Brassica napus production with emphasis...
Transcript of Balanced nutrition in Brassica napus production with emphasis...
Balanced nutrition in Brassica
napus production with emphasis
on S fertilizer requirements
Better Crops, Better Environment … through Science
Rob Norton.
Regional Director ANZ
Thomas Jensen, IPNI Northern Great Plains
Vladimir Nosov, IPNI Southern & Eastern Russia
ARAB 17, Wagga Wagga, August 2011
Why S and why now?
• Less use of high S fuels so less S from atmosphere.
• Use of high analysis fertilizers containing little incidental S
• Increased crop yields creating a higher S offtake.
• Slower organic matter turnover with conservation tillage
• Fewer S-containing pesticides
McNeill et al, 2005, Soil Use & Managementt/km2
S deficiency in Australia
• History of S deficiency in
pastures.
• Deficiencies in canola first seen
in NSW at Lockhart.
• Soils naturally low in S & OM.
• Since 1990, reduced use of
single super – clear trend to
AP’s
• High demand for S by canola.
• Sulphate is mobile – leachable.
S removals and S balances
Crop N P K S S %
Canola 2 t/ha 60 10 14 10 0.50
Wheat 3 t/ha 63 9 11 4 0.14
• Current fertilizer rates would indicate input of 1-5 kg S
per ha
• Offtakes differ among crops (Reuter & Robinson)
Crop S content Cv% Data
Canola 0.37 13% Khan et al., IPL Dahlen
Wheat 0.17 12% NVT SE Aust.
Grain Nitrogen to Sulphur Ratios – a
retrospective for balanced nutrition
Randell et al, 1981, AJAR, 32, 203-212.
S RESPONSIVE
S UNRESPONSIVE
Inadequate N
N & S CO-LIMITED –
ADDED N OR S WILL
CORRECT TO 17:1
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400
N %
S %
Slope ~7:1
Soil S levels – ANRA Audit 2001
• Nationally
11% < 5 mg/kg
• New South Wales
25% < 5 mg/kg
• Victoria
3% < 5 mg/kg
Draws on data from mid-1990’s
Requires revision and review – current IPNI ANZ project
KCl-40
(mg/kg)
Crop Pasture
<8 52% 43%
8-12 20% 30%
>12 28% 27%
2010 Soil S test values (top 10 cm) for Victoria, South
Australia, New South Wales (~1200 tests)
Soil S levels KCl40 – 2010 (Pre-sowing ie before May 2010)
Location and Soil Type
KCl 40 Wheat
(mg/kg)
KCl 40 Canola
(mg/kg)
<3 3 to 5 >5 <12 >12
Harden Red & Brown Loams 11% 33% 56% 80% 20%
Horsham Grey & Brown Clay Loams 23% 18% 59% 68% 32%
Maryborough Red & Brown Clay Loams 0% 8% 92% 74% 26%
Cummins Red & Brown Sandy Loams 12% 44% 44% 74% 26%
Moree Gray &Brown Clay/Clay Loams 17% 20% 63%
Dalby Gray &Brown Clay/Clay Loams 15% 23% 62%
Emerald Gray &Brown Clay Loams 27% 19% 54%
Gunnedah Gray &Brown Clay Loams 10% 26% 63%
Soil depth 0-10 – mobility of S in profiles, maybe need a deeper soil
test as routine – when request nitrate, also request sulphate.
Role of organic sulphur – should the budget include mineralised S.
Improving S nutrition
To apply 20 kg S/ha
• Gypsum (~200 kg/ha)
• Surface applied
• Variable quality
• Cheap (?)
• Ammonium sulphate (100 kg/ha)
• Fertilizer damage to seedlings (machinery)
• See http://anz.ipni.net/anz0042-en
Opener type and row spacing (cm)
Inverted T or similar narrow point/opener (2.5 cm spread)
Share or similar mixing point(7.5 cm spread)
15 22.5 30 15 22.5 30
Light (sandy loam) texture 40 20 10 175 90 75
Medium (loam/clay loam) texture 75 55 40 245 150 125
Heavy (clay) texture 125 95 80 325 210 180
R Gelderman, SDSU
J Laycock, IPL
C Dowling, Backpaddock P/L
Strategies for S
• Spread out the need through the whole rotation
– Higher S rates in the cereal phase (more tolerant of seed placed
fertilizer)
– Canola/Wheat/Barley – use 10/15/15 to meet total demand.
– Depends on soil type/S mobility
– Use high rates up front (eg gypsum)
– Elemental S
• +Bentonite
Banding fertilizer away from seedrow
• Particularly important for N and S
• (includes MAP)
• Band fertilizer away from seed
– Band 2-3 cm away
– Side or Side & Below
– Mid-row band
• P/K source in seed row.
Topdress S in-crop
• ammonium sulphate, potassium sulphate, ATS
• Where the plant can get it –
– Root zone – control release rates to avoid leaching
• In synchrony with plant demand – canola can recover
from nutrient stress – eg Canola
S
applied
Kg/ha
Sowing 5-6
Leaf
Buds
Visible
Stem
Elongati
on
10 1.73 1.62 1.56 1.41 LSD
40 2.15 2.26 2.11 2.19 0.43
Hocking et al., 1996
Alternative sources of SParticle Size µ % S oxidised
2 weeks 4 weeks
<75 80 82
75-125 61 81
125-175 36 68
175-400 15 36
400-840 5 14
840-2000 2 5
2000-4000 1 2
• S0 oxidation rapid with fine
particles
– Good for sulphate release
– Bad for handling
• Two new processes that
incorporate S0 into existing
products at manufacture
12:18:0:10
N:P:K:S
Up to 14% S
50:50 S0:SO4
Summary
• Care with S and N in-furrow with canola – especially light
soils, dry conditions, wide rows.
• Compared to cereal crops, canola requires a greater
supply of S – N:S 7:1 canola; 15:1 wheat
• Applying all the required S in the seed-row for canola is
difficult because of excess N coming from the ammonium
phosphate and ammonium sulphate portion of a possible
seed-row blend.
• There are alternative ways to supply sufficient S and
avoid excess N in the seed-row.