Dahlen Long-term Nitrogen and Phosphorus Recovery Experiment

Long term crop responses to applied N and P.

IPNI-2010-AUS-08

The Dahlen Long Term Fertilizer Experiment was established by Incitec Pivot Fertilizers in 1996. It has four rates of P (0, 9, 18 and 36 kg P/ha) combined factorially with 5 rates of N (0, 20, 40, 80, 160 kg N/ha), with the N applied at either sowing or split between sowing and early growth. The crops are selected as part of a normal cropping rotation in this region which takes the general form of canola, wheat, barley and then a pulse (chickpea, lentil or field pea). Read more


Year of initiation:2010
Year of completion:2015
Map:

Articles

18 Dec 2015

Phosphorus after the dry
Experience from the past

18 Sep 2014

IPF Dahlen Long Term Fertilizer Experiment - 2014
What are we seeing 18 years on?

30 May 2014

Balanced nutrition yields benefits
Results from the Dahlen long term fertilizer experiment

23 Jul 2013

Will N fertilizer run down soil organic matter
Presentation at Agronomy Community Meetings

12 Dec 2012

Trends and surprises
Outcomes from the long term trial

12 Dec 2012

Returns for different nutrient strategies

12 Dec 2012

Efficiency of resource use
recovery efficiency for different strategies

12 Dec 2012

Effect on soils, Dahlen Long term experiment

12 Dec 2012

Crop Yields at Dahlen
Crop yields and main effects, 1996-2010

12 Dec 2012

Dahlen Long Term Experiment
Outline of the experiment

16 Feb 2012

Oaten Hay yields at the Dahlen Long-term N*P experiment
An Incitec Pivot research project, managed by IPNI ANZ Regional Director Rob Norton

13 Feb 2011

Dahlen Long Term Fertilizer Experiment
Results of canola grown on the long term N*P experiment at Dahlen, 10 km west of Horsham.

01 Jul 2010

Learning from long term experiments - what do they teach us?
R Norton, R Perris and R Armstrong


Interpretive Summary

The Dahlen N and P experiment was established in 1996 in the medium rainfall cropping zone of Victoria, Australia, and has been in a canola, wheat, barley, and pulse rotation each year since then. The experiment has four rates of P (0, 9, 18, 36 kg P/ha) applied at sowing, and five rates of N (0, 20, 40, 80, 160 kg N/ha) either all at sowing or split. Crop and soil data has been collected for each crop year, which included two years where crops were sown, but not harvested, due to drought.

The Dahlen nutrition experiment was established by Incitec Pivot Fertilizers in 1996 to investigate the interaction of different rates of N and P within a modern cropping system (i. e. , retain stubble, no-till) on a Vertisol. Since establishment, the site has been in a canola, wheat, barley, pulse rotation (with oaten hay in 2011) on factorial combinations of annual applications of N (0, 20, 40, 80, and 160 kg N/ha as urea) and P (0, 9, 18, and 36 kg P/ha as triple superphosphate).

The long-term profitability of N and P use has been assessed at the Dahlen field experiment established in 1996. In 2012, the site was sown to wheat. The addition of 9 kg P/ha gave about a 1 t/ha yield increase (30%) while extra P gave no further significant responses. The first 20 kg N/ha gave a 0. 6 t/ha yield increase (14%) and the highest yields occurred with 80 kg N/ha. The high N rate increased grain protein, but had no effect on grain test weights.

The Dahlen long-term N and P experiment was established in 1996, and has been sown to a canola, wheat, barley, and pulse rotation each year since then. Treatments included four rates of P (0, 9, 18, 36) applied at sowing and 5 rates of N (0, 20, 40, 80, 160) applied either all at sowing or as a 50:50 split between sowing and the start of reproductive growth.

Established in 1996, this long-term site at Dahlen, 10 km west of Horsham, has had five rates of N (0, 20, 40, 80, 160 kg as urea) and four rates of P (0, 9, 18, 36 kg as triple superphosphate) applied annually over the past 16 years. The site has been direct drilled and no stubble has been removed or burned. In 2011, the site was sown to oats in mid-May as a hay crop and the standing crop cut on 20 September when the plants were still in the flag leaf growth stage.

Since establishment, crops planted included barley (1996, 2000, 2004, 2008), chickpeas (1997), canola (1998, 2002, 2006), wheat (1999, 2003, 2007), and lentils (2001, 2005). Canola was chosen as the 2010 crop, following lentils in 2009, and barley in 2008. With good seasonal conditions, canola showed a strong response to P with the first 9 kg P/ha doubling yields and the next 18 kg P/ha plots raising yields to over 3 t/ha.

Since its establishment, crops planted included barley (1996, 2000, 2004, 2008) , chickpeas (1997), canola (1998, 2002, 2006), wheat (1999, 2003, 2007) and lentils (2001, 2005). Canola was chosen as the 2010 crop, following lentils in 2009 and barley in 2008. With the good seasonal conditions, canola showed a strong response to phosphorus with the first 9 kg P/ha doubling yields and the next 18 kg P/ha plots raising yields to over 3 t/ha (see Figure 1).

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Updates & Reports

2013

2012 Soil test values and nutrient balances from a long term fertilizer experiment

2011

Project Description


Dahlen Long Term Field Experimentmore photos

Project Leader

Craig Farlow, Incitec Pivot Fertilizers


Project Cooperators

Rohan Davies, Incitec Pivot
Peter Howie, University of Melbourne


IPNI Staff

R. M. Norton


Location

Oceania \ Australia and New Zealand \ AUS \ Victoria \ Wimmera


Topics

4r rate, 4r source, crop rotations, nutrient management

barley, chickpea, lentil, rapeseed (canola), wheat

Nitrogen (N), Phosphorus (P)