nitrate n residues, soil mineral n balance and n ... · n fertilizer recommendation in vegetable...

Nitrate-N residues, soil mineral N balance and N fertilizer recommendation

in vegetable fields in Flanders

Mia Tits, Annemie Elsen,

Hilde Vandendriessche and Jan Bries

Soil Service of Belgium W. de Croylaan 48,

3001 Heverlee, Belgium

www.bdb.be

Soil Service of Belgium Nutrihort, September 16-18, 2013, Ghent, Belgium

http://www.bdb.be/

Nitrate-N residues, soil mineral N balance and N fertilizer recommendation

in vegetable fields in Flanders

Definition:

Nitrate-N residue

= residual nitrate-N in the soil (0-90 cm) in autumn

= measured during the period from 1/10 – 15/11

= expressed as kg nitrate-N per hectare

= direct link with risk of nitrate leaching to ground- and surface water during winter

Nutrihort, September 16-18, 2013, Ghent, Belgium Soil Service of Belgium


Evolution of the weighted average nitrate-N-residue in Flanders based on the results of control measurements performed by the Manure Bank (VLM 2012)

kg n

itra

te-N

.ha-1

Evolution of the nitrate N residues in agricultural

crops in Flanders

Evolution of the nitrate N residues in vegetable crops in Flanders

Soil Service of Belgium Nutrihort, September 16-18, 2013, Ghent, Belgium

0

20

40

60

80

100

120

140

160

180

2009 2010 2011 2012

nit

rate

-N (

kg N

.ha-1

)

Average nitrate-N residues per year for cauliflower and leek

cauliflower

leek

source: Soil Service of Belgium

Distribution of nitrate-N residues in the soil profile

Nutrihort, September 16-18, 2013, Ghent, Belgium 5Soil Service of Belgium

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0-30

30-60

60-90

Distribution of the residual nitrate-N in the soil profile, per crop (VLM 2010)

Nitrate residue, influenced by many factors


nitrate stock spring

nitrate residue (1/10 – 15/11)

N leaching

organic fertilization

mineral fertilization

volatilization and denitrification

N mineralization spring

N uptake by crops

harvest

N mineralization autumn

N mineralization from crop residues

N uptake by catch crops

N leaching

N-fertilization using the N-index method


2. N-index N-availability during cropping season,

depending on crop and parcel characteristics

1. N-requirements

crop residue product

N-index

- effect soil texture/structure, low pH

- leaching during cropping season

+ N-stock (~rooting depth)

+ mineralization:

- OM (%C)

- green manure

- crop residue

- organic fertilizer

N-fertilization using the N-index method


2. N-index N-availability during cropping season,

depending on crop and parcel characteristics

1. N-requirements

3. N-advice

crop residue product

N-advice N-index

Calculation of the soil mineral N balance


N inputs N outputs

Mineral N stock in the soil profile (0-90 cm) N uptake by crops

Expected N mineralization from soil organic matter N uptake by catch crops

Expected N mineralization from crop residues N losses through leaching

Applied mineral N fertilization

N supply from applied organic fertilization

Total input (incl. N stock) Total output

Expected residue (input-output)

Nitrate-N residue

Balance deviation

Soil mineral N balance – case 1

Nutrihort, September 16-18, 2013, Ghent, Belgium 10

N inputs kg N.ha-1 N outputs kg N.ha-1

Mineral N stock in the soil profile (April) 88 N uptake by crops 250

Expected N mineralization from soil organic matter 165 N uptake by catch crops 0

Expected N mineralization from crop residues 40 N losses through leaching 0

Applied mineral N fertilization 190

N supply from applied organic fertilization 16

Total input (incl. N stock) 499 Total output 561

Expected residue (input-output) 249

Nitrate-N residue (September 27th) 311

Balance deviation -62

-100

0

100

200

300

400

1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10

(cauliflower-)cauliflower(-rye-grass)

balance

crop uptake

crop residues

fertilization

mineralization

stock

planting harvest



-100

0

100

200

300

400

1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10

(cauliflower-)cauliflower(-rye-grass)

balance

crop uptake

crop residues

fertilization

mineralization

stock

excessive N fertilization of 190 kg N.ha-1 (advice: 145 kg N.ha-1)

mineralization of N-rich crop residues in september

late N-uptake by catch crop rye-grass

high nitrate-N residue




Mineral N stock in the soil profile (April) 138 N uptake by crops (292+180) 472



Applied mineral N fertilization (169+140) 309


Total input (incl. N stock) 762 Total output 739


Nitrate-N residue (September 27th) 224

Balance deviation 23

-100

0

100

200

300

400

500

1/3 16/3 1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10 16/10 1/11

(carrots-)cauliflower-cauliflower

balance

leaching

crop uptake

crop residues

fertilization

mineralization

stock

planting 1 harvest 1

planting 2

harvest 2



-100

0

100

200

300

400

500

1/3 16/3 1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10 16/10 1/11

(carrots-)cauliflower-cauliflower

balance

leaching

crop uptake

crop residues

fertilization

mineralization

stock

excessive N fertilization for both crops (81+169 & 140 kg N.ha-1) (advice: 169 & 112 kg N.ha-1)

important N-supply from residues of first crop

lower N-uptake by second crop (unfavourable conditions)

late harvest, no catch crop





Mineral N stock in the soil profile (April) 132 N uptake by crops 110



Applied mineral N fertilization 21 Nitrate-N residue (September 27th) 147


Total input (incl. N stock) 296 Total output (incl. residue) 293


Balance deviation 2

-100

-50

0

50

100

150

200

250

1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10 16/10

(cabbage-)leek

balance

leaching

crop uptake

crop residues

fertilization

mineralization

stock

planting



-100

-50

0

50

100

150

200

250

1/4 16/4 1/5 16/5 1/6 16/6 1/7 16/7 1/8 16/8 1/9 16/9 1/10 16/10

(cabbage-)leek

balance

leaching

crop uptake

crop residues

fertilization

mineralization

stock

high N stock in spring

supplementary late N fertilization to improve yield (quality)

low N-uptake due to slow initial growth, shallow root system and N leached to deeper soil layers


early application of organic fertilizer leached to deeper soil layers by the time of crop growth

Conclusions


Major bottlenecks of vegetable growing in terms of nitrate residue:

- considerable amount of rapidly degradable crop residues

high N mineralization in a short period after harvest

- shallow root systems, N in deeper soil layers is not absorbed

N distribution in soil profile very important

N availability at right time very important

N uptake seriously affected by weather conditions

- late harvest in vegetative stage requires sufficient N supply

- sowing of catch crop often practically impossible

Importance of accurate N-fertilization (dose and timing)

N fertilization recommendations based on crop requirements,

soil analysis,

knowledge about mineral N becoming available during the growing season.

Soil mineral N balance = helpful tool

nitrate n residues, soil mineral n balance and n ... · n fertilizer recommendation in vegetable...

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