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Environmental Science > Cereals 2024 Week 9 Lecture Nitrogen Nutrition > Flashcards

Cereals 2024 Week 9 Lecture Nitrogen Nutrition Flashcards

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1
Q

Whats the important to get a cereal crop moderate-high yielding

A

Nitrogen uptake

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2
Q

When the crop receives nitrogen what % of N is “efficiency N recovery”
and
“what is the soil N uptake already in the soil?

A
  • Efficiency of fertilizer N recovery = 0.58, 58%

-Soil N uptake = 95kg/ha

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3
Q

Whats the fertiliser N rate (kg/ha) from previous question in terms of formula?

A

Crop N uptake (kg/ha)=
95(kg) + 0.58 = Fert N rate

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4
Q

What is used in Ireland and UK as a basis for fertiliser N Recommendations?

A

Nitrogen Index system for cereals

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5
Q

What does the N index take onto account for each tillage crop? (3)

A

– the previous crop
– manuring history of the field
– soil type

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6
Q

What does the N index scale go from?

A

1-4

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7
Q

Explain Index 1:

A

small release of soil N
The fifth tillage crop following permanent
pasture. For subsequent tillage crops
use the continuous tillage table

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8
Q

Explain Index 2:

A

medium release of soil N
The 3rd or 4th tillage crop following
permanent pasture. If original permanent
pasture was cut only, use index 1

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9
Q

Explain Index 3:

A

large release of soil N
The 1st or 2nd tillage crop following
permanent pasture (see also index 4). If
original permanent pasture was cut only,
use index 2

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10
Q

Explain Index 4:

A

very large release of soil N
The 1st or 2nd tillage crop following very
good permanent pasture which was
grazed only.

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11
Q

In sort of protein do you want in Barley?

A

Moderate

The more N you apply, the higher protein you get so apply a moderate N value

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12
Q

The more N you apply the greater the risk of what?

A

lodging

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13
Q

What does the N Index system for cereals require ?

A

requires that nutrient supply be
matched to crop demand, both in terms of
the quantity applied and the time of
application relative to the crop yield, soil
and climatic conditions

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14
Q

Index:
1
2
3
4
W. Wheat kg/N/Ha?
Winter Cereals

A

1- 210
2-180
3-120
4-80

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15
Q

Index:
1
2
3
4
W. Barley kg/N/Ha?
Winter Cereals

A

1- 180
2-155
3-120
4-80

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16
Q

Index:
1
2
3
4
W. Oats kg/N/Ha?
Winter Cereals

A

1- 145
2- 120
3- 85
4- 45

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17
Q

Index:
1
2
3
4
S.Wheat kg/N/Ha?
Spring Cereals

A

1-160
2-130
3-95
4-60

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18
Q

Index:
1
2
3
4
S.Barley kg/N/Ha?
Spring Cereals

A

1- 135
2- 100
3- 75
4- 40

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19
Q

Index:
1
2
3
4
S.Oats kg/N/Ha?
Spring Cereals

A

1- 110
2- 90
3- 60
4- 30

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20
Q

Increase use of N fertiliser will…

A

Increase yield

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21
Q

If i apply 120-135 kg/ha on malting barley what grain yield will i receive ?

A

7.5 t/ha grain yield

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22
Q

What type of N% is required for high quality malt for making beer?

A

Moderate grain N% is required

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23
Q

To avoid low grain protein in matling barley how much extra should you apply ?

A

20kg/ha

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24
Q

Malting Barley : Effect of +40 kg N on
Grain Protein % - Trends over 3 Years - whats the outcome?

A

10% increase in yields with +40 kg N

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25
Fertiliser Nitrogen use will increase yield e.g. apply 180-210 kg/ha what extra t/ha grain yield on milling wheat?
9 t/ha grain yield
26
What is required during grain fill for high grain protein % for good breadmaking quality
High N uptake
27
What is allowed extra for milling wheat grown on contract?
30kg/ha extra in late - N
28
Why is there interest in slurry use on cereal crops ??
High chemical fertiliser prices * Organic manures becoming a viable option for tillage farmers * Attitudes are changing for a cheaper alternative * Pig manure could replace at least one split of nitrogen in a crop fertilisation programme * Pig manure may also reduce P/K and trace element costs (P/K costs doubled since 2007)
29
What are practical Issues of N? (2)
1- Method and timing of application * Splash Plate, Band Spreader, Trailing Shoe * Winter/Spring Application * Growth Stages 2- Efficiency uptake and gaseous losses * Nitrogen Efficiency * Ammonia & Nitrous Oxide Emissions * Leaching
30
Whats the biggest % of N losses?
Dont want fallow
31
What sort of trials happened in 2007/2008
* Evaluation of separated liquid pig manure (LPM) as a nutrient source for winter wheat * Evaluation of separated solid pig manure (SPM) as a nutrient source for winter wheat, * Measurement of ammonia and nitrous oxide emissions from pig manure applied to the growing winter wheat crop
32
What are the 3 benefits to separation of pig manure?
1- Reduce manure dry matter * Easily absorbed into soil surface * Reduced risk of scorch 2- Reduce manure P level * Higher application levels without reaching P limit 3- Increased manure uniformity
33
What's the DM% of 1- Pig Manure 2- Separated Liquid 3- Separated Solid
1- 2-10% 2- <2% 3- 20-30%
34
What's the N% of 1- Pig Manure 2- Separated Liquid 3- Separated Solid
1- 0.42% 2- 0.40% 3- 0.772%
35
What's the P% of 1- Pig Manure 2- Separated Liquid 3- Separated Solid
1- 0.08% 2- 0.018% 3- 0.600%
36
2007 Solid Slurry Trial Grain Yield (t/ha) 4 treatments
0 t/ha Solid 4t/ha Solid 8t/ha Solid 12t/ha Solid
37
Whats the problems with N loss?(6)
1* Economic loss to production 2* Environmental implications of nitrate: – Eutrophication of waterways: depletion of O2 – Overgrowth of plants on waterways 3* Health implications of nitrate: – Inconclusive evidence of cause of Blue Baby syndrome/ stomach cancers. Evidence suggests no risk from Nitrate 4* Gaseous losses: NH3; N2O; N2; NO2- 5* N2O is a greenhouse gas, 300 times more potent than methane 6* Implications of Kyoto Protocol
38
What crop is very prown to lodging?
Barley -too much nutrient -too dense, too heavy
39
Whats the characteristics of a good wheat variety?
Strong strawed Short strawed
40
The two biggest sources of GHG from agriculture are: Together these are %? of global GHG emissions
the release of N20 from soils and the release of Methane from livestock and manure 5%
41
In crop production what is the most important part of the carbon footprint What % does fertiliser production account for? What % does fertiliser induced emissions account for?
nitrogen fertilise 50 + 33% = 80% plus of all emissions in crop production
42
W Oilseed Rape (500 kg CO2e/t) Sp Malting Barley (220 kg CO2e/t) Winter Wheat (300 kg CO2e/t) What one has the most fertiliser induced field emissions?
W Oilseed Rape (500 kg CO2e/t)
43
What is the use efficiency of Nitrogen and Phosphorus use ? (slide 27)
Nitrogen 65% Phosphorus 90% They are the most efficient when it comes to efficiency
44
Tillage farms emitted how much tonne/farm GHG equivalent in 2017 but only what % of this was from crop production
125 tonne/farm 23%
45
What % of the Ammonia emitted on tillage farms was from non-tillage activity (cattle)
83%
46
N Use Efficiency on tillage farms was what %?
70%
47
P Use Efficiency was what % on tillage farms?
91%
48
Volatilisation : definition in terms of cropping systems
volatised in gaseous form * NH3; N2O; N2; NO2 and environmental risk associated with greenhouse gas
49
How is Volatilisation measured?
Measured using controlled environments / N15
50
With more efficient N use there is....
less available for N loss in this form
51
What is the Kyoto Protocol :
Reduction in Gaseous emissions
52
Name the 2 ways nitrogen is lost from cropping systems :
1- Volatilisation 2- Leaching
53
Leaching information: how is it lost? How is nitrate loss measured?
* Leaching : N leached in groundwater * Currently receiving attention, especially in continental Europe / Nitrates Directive * Environmental implications * Nitrate loss measured using lysimeters
54
How much N losses to fallow on grass based rotation: Effect of applied N rate on post harvest nitrate Loss:
1.5 kg/n/ha
55
Effect of applied N rate on post harvest nitrate Loss: Grass based rotation: on 240 N treatment (kg N/ha)
1.6 kg N/Ha
56
Effect of applied N rate on post harvest nitrate Loss: Continuous cereal: Spring cropping -Fallow: -200 -240 -280 (slide 32)
-0.75 kg N/Ha -0/8 kg/N/Ha -1.0 kg/n/Ha -2kg/N/Ha
57
list 6 GHG:
* Nitrous Oxide (N2O) * Carbon Dioxide (CO2) * Methane (CH4) * Sulphur Hexafluoride (SF6) * Perfluorocarbons (PFCs) F Gases * Hydrofluorocarbons (HFCs)
58
What are the 3 F GHG?
* Sulphur Hexafluoride (SF6) * Perfluorocarbons (PFCs) F Gases *Hydrofluorocarbons (HFCs) F Gases more potent than the 3 naturally occurring GHG’s
59
N loss Studies : Conclusions: Spring vs Winter
Winter cropping * Acts as cover crop * Mops up autumn mineralised N * Well developed root structure to trap N vs Spring cropping: * Lower N requirement * Poor root structure then poor trapping and recovery * Over winter fallow * Winter ploughing can lead to flush of mineralisation
60
What are practices to reduce N losses? (8)
* Continuous winter cereal production where possible * Avoid rotation cropping : build up of soil organic N level * Where rotations practiced: * Harvest as early as possible: Including Sugar beet and Potatoes ! * Controlled by variety selection, planting date etc. * Establish winter crop soon after harvest * Reduce applied N rate to take mineralised N into account * Where late harvest, leave until spring : mineralisation flush
61
What are the issues related to reducing nitrate loss in spring cropping ? (5)
* Avoid winter ploughing * Establish cover crop to avoid winter fallow – Dedicated cover crops are problematic: subsequent establishment , moisture retention etc * Consider autumn cultivation which germinates weeds and volunteer seeds these act as cover crop * Constraints reduce recovery: increase N not taken into crop – Compaction – Disease: Take all; early season disease – Deficiency of other inputs : P, K, Lime etc * When deciding the N Application rates take crop requirements over season into consideration

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