Fertilising grass-clover swards for pasture-based milk production - - PowerPoint PPT Presentation

Fertilising grass-clover swards for pasture-based milk production systems

Brian McCarthy, Michael Egan, Daniel Enriquez-Hidalgo, Stephen McAuliffe, Clare Guy, Michael Dineen, Fergal Coughlan and Deirdre Hennessy Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland

Introduction

 Post milk quota abolition: need to maximise Ireland’s comparative advantage in pasture-based systems  Renewed interest in forage legumes – white clover (WC)

• Animal performance
• Grass DM production
• Environmental sustainability

 How to incorporate white clover into intensive pasture- based production systems ?

N fertiliser application and sward type

0 N 60 N 120 N 180 N 240 N Clover content (%) 33.3 30.6 27.0 21.7 19.6 N fixation (kg N/ha; 2011 - 2013)1 220 205 148 122 112 4 8 12 16 0 N 60 N 120 N 180 N 240 N Grass Production (t DM/ha) N application rate (kg N/ha)

Grass production – 4 year average

Grass only Grass clover

1 Calculated using the N difference method, Enriquez-Hidalgo et al., Grass Forage Science, In Press

4.2 t DM/ha 1.8 t DM/ha

Farm systems experiments with WC

 Clonakilty experiment – The effect of tetraploid and diploid swards sown with and without white clover on spring milk production systems

• 4 treatments: Tetraploid only sward, diploid only sward, tetraploid +

clover sward, diploid + clover sward

• 30 cows per treatment stocked at 2.75 LU/ha, each treatment

receiving 250 kg N/ha annually

 Moorepark experiment – Comparison of animal and sward production from grass-only sward receiving 250 kg N/ha and grass-clover swards receiving either 150 or 250 kg N/ha

• 3 treatments: Grass only 250 kg N/ha/year, grass + white clover

250 kg N/ha/year, grass + white clover 150 kg N/ha/year

• Stocked at 2.74 LU/ha

Fertiliser application on grass-clover swards

Moorepark & Clonakilty Moorepark only Rotation/Date Grass-only 250 kg N/ha Grass-clover 250 kg N/ha Grass - clover 150 kg N/ha Mid-late January 28 28 28 Mid March 28 28 28 April (2nd rot) 33 33 33 May (3rd & 4th rot) 60 60 18 June (5th rot) 17 17 9 July (6th & 7th rot) 34 34 18 August (8th rot) 17 17 9 Mid September 33 33 12

 Slurry applied to all treatments at same rate  Chemical P and K applied as per soil P and K index status

Daily pasture growth – Clonakilty 2014

10 20 30 40 50 60 70 80 90 100 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Daily grass growth (kg DM/ha per day) Month

Grass only Grass clover

20 kg DM/ha per day

2.5 t extra DM/ha 15.0 t DM/ha vs. 17.5 t DM/ha

39 % average clover content

Moorepark - Grass production & sward clover content

(2013 & 2014)

Treatment Grass 250 Clover 250 Clover 150 Annual Grass production (t DM/ha) 14.2 14.3 14.4 10 20 30 40 50 1 2 3 4 5 6 7 8 9 Sward clover content (%) Rotation Clover 150 Clover 250

Clover 150 = 27% Clover 250 = 24%

Clonakilty - Milk Production 2014

0.00 0.50 1.00 1.50 2.00 2.50 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 Milk solids (kg/cow per day) Lactation week

TO DO TC DC

+ 55 kg MS/cow

1TO = tetraploid only; DO = diploid only; TC = tetraploid + clover; DC = diploid + clover

Summary

 As N fertiliser rate increases clover content and N fixation decreases  Pasture DM Production response (0 to 2.5 t DM/ha)  Milk Production response (+ 55 kg milk solids/cow)  Initial results promising, further research required

Thank you & Questions?