Grassland yield and nitrogen uptake as influenced … 4/Session IV - Syndicate 2...of urea for temperate Grassland. Fertilizer Research, 26, 341–357. Thank you Title Slide 1 Author

Grassland yield and nitrogen uptake as influenced

by urea or ammonium nitrate based fertilisers

Forrestal, P.J.1*, Harty, M.1, Krol, D.1, Lanigan, G.1, Hennessy, D.2,

Wall, D.1, Carolan, R.3, Watson, C.3, Richards, K.G.3

*[email protected] 1Teagasc, Johnstown Castle, Co. Wexford, Ireland 2Teagasc, Moorepark, Fermoy, Co. Cork, Ireland 3Agrifood and Biosciences Institute, Newforge Lane, Belfast, U.K.

Experimental design

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 2

Randomised complete block experimental design with 5 replications

Three experimental sites over two years = Six site-years

N rates 0 – 500 kg N/ha

Five applications per year

P, K, S separately

Five N fertilisers

• Calcium ammonium nitrate (CAN)

• 4 Urea based N w/wo urease and/or nitrification inhibitors

Data presented collates 30 separate applications

Yield? CAN, Urea, Urea+NBPT

Six site-years 30 N applications

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 3

Forrestal et al. (2017) Soil Use & Management 33: 243-251

Effect of fertiliser formulation on yield

at 200 kg N/ha?

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 4

Adapted from Harty et al. (2017) Agronomy Journal 109: 1-9

N recovery efficiency?

CAN vs Urea vs Urea+NBPT

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 5

Forrestal et al. (2017) Soil Use & Management 33: 243-251

Effect of fertiliser formulation on apparent

fertilizer N recovery?

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 6

Adapted from Harty et al. (2017) Agronomy Journal 109: 1-9

Individual harvest, was there a yield

difference?

Repeated measures analysis of the 30

harvests showed no significant

difference (P ≤ 0.05) in yield between

CAN, urea and urea+NBPT

Collating the spring and summer data:

• Spring cuts urea at 103.5% of CAN yield

• Summer cuts urea at 98.4% of CAN yield

Trend towards small urea yield

advantage in spring and small penalty

in summer

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 7

Summary No significant yield difference in annual

yield between: CAN, Urea and Urea + NBPT

• Keane et al. (1974) n.s. between CAN and urea

• Murphy (1983), Watson et al. (1990) n.s. for early season

Slight trend towards spring advantage urea

Slight trend for summer advantage CAN / urea+NBPT

Use of a nitrification inhibitor on urea without also using a urease inhibitor decreased yields

BUT WAIT! Urea looses ammonia and has reduced N recovery efficiency

• Shouldn’t yields suffer over the long term?

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 8

Forrestal et al. (2016)

Soil Use and Management. 32: 92-100.

Long-term fertiliser N test facility

at Teagasc Johnstown Castle

Forrestal, P.J. et al. (2018) European Grassland Federation International Conference, Co. Cork, Ireland 9

Plots now in their fifth year receiving the same nitrogen source

e.g. CAN, urea or urea+NBPT, products on the market and new

products not yet on the market in Europe or Ireland

Is the urea story different?

Evidence emerging of

declining yield as well as N

recovery by urea over time

Watch this space!

Acknowledgements Funding support from the Irish

Department of Agriculture, Food and the Marine through the Research Stimulus Fund (Grant numbers RSF10-/RD/SC/716 and RSF11S138),

The Department of Agriculture, Environment and Rural Affairs in Northern Ireland,

The Teagasc Walsh Fellowship Scheme

Technical and laboratory staff at Teagasc Johnstown Castle, Moorepark and at the Agri-Food and Biosciences Institute

Teagasc Presentation Footer 10

References Forrestal, P.J., Harty, M.A., Carolan, R., Watson, C.J.,

Lanigan, G.J., Wall, D.P., Hennessy, D., Richards, K.G. 2017. Can the agronomic performance of urea equal calcium ammonium nitrate across nitrogen rates in temperate grassland? Soil Use and Management 33:243-251. doi: 10.1111/sum.12341.

Forrestal, P.J., Harty, M., Carolan, R., Lanigan, G.J., Watson, C.J., Laughlin, R.J., McNeill, G., Chambers, B. and Richards, K.G. 2016. Ammonia emissions from urea, stabilised urea and calcium ammonium nitrate: insights into loss abatement in temperate grassland. Soil Use and Management. 32: 92-100. doi: 10.1111/sum.12232

Harty, M.A., Forrestal, P.J., Carolan, R., Watson, C.J., Hennessy, D., Lanigan, G.J., Wall, D.P and Richards, K.G. 2017. Temperate grassland yields and nitrogen uptake are influenced by fertilizer nitrogen source. Agronomy Journal. 109: 1-9. doi:10.2134/agronj2016.06.0362.

Keane, G.P., Griffith, J.A. & O’Reilly, J.O. 1974. A comparison of calcium ammonium nitrate, urea and sulphate of ammonia as nitrogen sources for grass. Irish Journal of Agricultural Science, 13, 293–300.

Watson, C.J., Stevens, R.J., Garrett, M.K. & Mcmurray, C.H. 1990. Efficiency and future potential of urea for temperate Grassland. Fertilizer Research, 26, 341–357.

Thank you