AARHUS UNIVERSITY

Optimal application of slurry –use of implements Tavs Nyord - Aarhus University, Denmark

Background as a farmer Agronomist Ph.D. at DIAS Assistant professor at AU

p R TÆ A T SI EO N N

AARHUS UNIVERSITY

Da nish a griculture › 62 % of the la nd is fa rmed › Very intensive a nima l production › Vulnera ble wa ter bodies: Ba ltic Sea a nd inner Da nish wa ters

2

AARHUS UNIVERSITY

Legisla tion › NPO -a ction pla n ~1985 › W a ter Environment Action Pla n 1 ~ 1987 › W a ter Environment Action Pla n 4 ~ 2012? › Ma in focus on lea ching of Nitra te 3

AARHUS UNIVERSITY

Nitra te lea ching C la y soils

Sa ndy soils

4

AARHUS UNIVERSITY

How wa s nitra te lea ching reduced? › Reduced N a pplica tion ~ 10 (20? ) % under economica lly optimum › Timing of a pplica tion of a nima l ma nure

› Increa sed stora ge ca pa city for a nima l ma nure › a pplica tion when the crops need the fertilizer › Required ca pa city for stora ge of a nima l ma nure - 9 month

› W inter sown crops a nd pa rtly ca tch crops 5

AARHUS UNIVERSITY

Effect of timing of la ndsprea ding on nitra te lea ching

6

(Misselbrook et a l 2004)

AARHUS UNIVERSITY

Ammonia deposition

7

AARHUS UNIVERSITY

Legisla tion focussing on a mmonia › Ammonia emission a ction pla n – 2001 › required covering of stora ge fa cilities

› Broa d sprea ding ba nned › Incorpora tion ba nned (direct injection ha s to be used) - 2011 › O bliga tion to use soil injection or a cidifica tion of slurry when slurry is a pplied to gra ss or ba re soil 2011

8

AARHUS UNIVERSITY

Applica tion techniques Splash plate ~ 20-50 % loss Splash plate

Incorporation 5-10 % loss Incorporation

Unless slurry pH is reduced < 6.4 Trialing hose ~ 5-30 % loss Trailing hose ~ 75 %

Injection loss Injection0-5 ~ 25%%

Ma nda tory from 2011!

9

AARHUS UNIVERSITY

W hy soil injection/ incorpora tion? › Legisla tion › C ommon pra ctise before the legisla tion! › The reduced N-quota system gives fa rmers economica lly incitement to reduce a mmonia emission

10

AARHUS UNIVERSITY

Ba re soil injection of a nima l slurry

Before sowing in the spring 1 st Februa ry to 1 st Ma y 11

AARHUS UNIVERSITY

Ba re soil injection of a nima l slurry with spring tine (deep injection)

12

W a gner et a l. 2015)

AARHUS UNIVERSITY

Ba re soil injection with spring tine injectors (reference) › W ith out a ny spill – reduction of a mmonia emission by 90-100 % (C hen 2002; W a gner et a l. 2015) › Extra cost: energy, ma intena nce, reduced ca pa city compa red to tra iling hoses ~ 1 Euro/ m 3

13

AARHUS UNIVERSITY

Alterna tives

AARHUS UNIVERSITY

AARHUS UNIVERSITY

AARHUS UNIVERSITY

Experiment design › Va ria bles: › Injection tool (Reference, W ing tine, Discs) › Tra vel speed (2, 6, 10 km/ h) › O pera tions depth: Treatment \ Operation depth Deep (mm)

Medium (mm)

Shallow (mm)

150

110

80

80

55

30

100

70

40

Reference Disc Wing tine

17

AARHUS UNIVERSITY

AARHUS UNIVERSITY

Q ua ntifica tion of hea ted a rea

AARHUS UNIVERSITY

Results Medium o

Average temperature of defined area ( C)

18

Deep

Sha llow

16 14 12 10 8 6 4 2 0 Reference

Discs

Speed

Wing tine 20

AARHUS UNIVERSITY

C onclusion a bout soil injection implements › If there is a correla tion between a rea of hea ted soil a nd NH3 emission – this method could be va lua ble

› disc coulters a t a sufficiently forwa rd speed ca n ensure the incorpora tion of slurry into soil › injection of slurry with a wing tine should be done by a minimum of 6 km/ h. › At a forwa rd speed of 10 km/ h slurry ca n be injected into soil with a ll three methods

22

AARHUS UNIVERSITY

Ba re soil injection/ incirpora tion with disc coulter

23

AARHUS UNIVERSITY

Experiments ca rried out in Denma rk 2014 a nd 2015  Experiment on sa ndy soil  Dyna mic emission cha mbers (wind tunnels) used a s mea suring technique  Experiment rea peted two times (2*2 replica tions per trea tment)  Experiment ca rried out November 2014  Air tempera ture va ried between 1 a nd 12 degrees celcius 24

AARHUS UNIVERSITY

Two types of disc coulters

Slurry

Slurry pla ced in front of the discs

25

AARHUS UNIVERSITY

Two types of disc coulters

Slurry pla ced behind the discs

26

AARHUS UNIVERSITY

Loss of ammonia (% of applied NH4-N)

Experiments ca rried out in Denma rk 2014 a nd 2015 12

100 10

8

55

45

6

4

16 2

0

ai Tr

l

se ho

rfa u s (

ce

)

tb

e etw

I

n ro f n

e

is nd

cs nt

I

ro nf

is fd

cs

o

Be

d hin

is ed

cs

th

27

AARHUS UNIVERSITY

C onclusion › Direct injection of a nima l slurry into ba re soil ca n be done in severa l wa ys with “good” results › Injection with disc coulter ca n be done, a s long the tra vel speed exceeds 6 km/ h a nd the a pplica tion ra te is below 45 ton/ ha › Using disc injector, slurry ha s to be pla ced behind the discs – reducing the a mmonia emission with more tha n 50 %

28