Identifying the causes of unreliable N fixation by medic based pastures

2015

Research organisaton
Funding source

Trial details

Researcher(s) Brian Dzoma (SARDI)
Year(s) 2015
Contributor SARDI Minnipa Agricultural Centre
Trial location(s) Piednippie, SA
Pingbong, SA
Related trials
Identifying the causes of unreliable N fixation by medic based pastures locations
Aims

To assess the impact of soil nutrition, current herbicides, adjuvants and rhizobial inoculants on nitrogen (N) fixation by medics under field conditions typical of the upper Eyre Peninsula. 

Key messages
  • Nodulation and shoot dry matter in medics is depressed by poor phosphorus (P) nutrition and in-crop application of certain herbicides.
  • Applying P when establishing a medic pasture boosts shoot and root dry matter and improves root health.
  • The timing of application of certain herbicides can have an important effect on maximum shoot dry matter.
  • High soil nitrogen levels can reduce nodulation in medic pastures.
Lead research organisation SARDI Minnipa Agricultural Centre
Host research organisation N/A
Trial funding source SAGIT SARDI515
Related program N/A
Acknowledgments

Thanks to Greg Scholz and Brent Cronin for allowing us to have the trials at their properties, and Andy Bates for his input in this project. This project is funded from SAGIT (SARDI 1515: Identifying the causes of unreliable N fixation by medic based pastures).


Other trial partners Not specified
Download the trial report to view additional trial information

Method

Crop type Pasture: Medic
Treatment type(s)
  • Crop: Type
  • Fertiliser: Rate
  • Herbicide: Timing
  • Herbicide: Type
Trial type
Trial design

Piednippie 2015

Sowing machinery Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Pingbong 2015

Sowing machinery

Two replicated field trials were established in different biophysical regions of the Eyre Peninsula; one representative of typical mallee environments in SE Australia (Greg Scholz - Pinbong) and an extreme scenario, on a grey highly calcareous sandy soil (Brent Cronin - Piednippie). Background rhizobia populations, soil moisture and soil fertility were determined prior to seeding. Treatments to simulate herbicide residues (Table 1) were imposed on 28 April 2015 and the trials were later sown on 13 May 2015 (Pinbong) and 14 May 2015 (Piednippie) with all nutrition treatments applied at sowing. Both trials were sown as a split plot design with the main plots being two contrasting and commercially popular medic varieties (Angel and Herald), and management options (nutrition, herbicides and inoculants) applied to both varieties. Post emergence herbicide treatments were applied after the third trifoliate leaf stage on 8 July 2015 (Pinbong) and on 30 July 2015 (Piednippie) at a wate

Sow date 13 May 2015
Harvest date Not specified
Plot size 1.5m x 10m
Plot replication 3
Fertiliser

Nutrition

Delivered as.

 

 

Nitrogen

Urea

100 kg

Phosphorous

Herbicide

Treatment

Active ingredient

Chemical group

Application rate (units/ha)

Post-emergence

 

 

 

Agritone 750

750 g/L MCPA (as dimethylamine salt)

I

330 ml

Broadstrike

800 g/kg Flumetsulam

B

25 g + Uptake oil

Ecopar

20 g/L Pyraflufen-ethyl

G

400 ml

Agritone 750

750 g/L MCPA

I

330 ml

Propyzamide 500 WP

500 g/kg Propyzamide

K

1000 ml

Verdict*

520 g/L Haloxyfop

A

75 ml + uptake oil

Clethodim

240 g/L Clethodim

A

375 ml + uptake oil

Agritone 750 - Late^

750 g/L MCPA (as dimethylamine salt)

I

330 ml

Chemical residues

 

 

 

Intervix

33 g/L Imazamox; 15 g/L Imazapyr

B

5 ml

Logran

750 g/kg Triasulfuron

B

0.125 g

2,4-D Amine

625 g/L 2,4-D (as dimethylamine salt)

I

10 ml

Control

No inoculum, no fertiliser, no herbicide

 

Delivered as.

 

 

Nitrogen

Urea

100 kg

Phosphorous

Phosphoric acid

10 kg

Sulphur

Gypsum

100 kg

Zinc

Zinc sulphate

2 kg

Manganese

Manganese sulphate

3 kg

Download the trial report to view additional method/treatment information
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Piednippie, SA Not specified
Pingbong, SA Red sandy loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Piednippie, SA Calcarosol
Pingbong, SA Calcarosol
Soil Moisture Source: BOM/ANU
Average amount of water stored in the soil profile during the year, estimated by the OzWALD model-data fusion system.
Year Piednippie SA Pingbong SA
2015 138.7mm355.6mm
2014 162.0mm418.8mm
2013 130.5mm339.4mm
2012 128.2mm392.1mm
2011 159.1mm402.6mm
2010 146.5mm397.2mm
2009 162.3mm391.9mm
2008 137.7mm318.6mm
2007 115.4mm339.2mm
2006 139.5mm339.2mm
2005 132.4mm312.3mm
2004 133.5mm305.0mm
2003 137.1mm323.1mm
2002 127.4mm332.8mm
2001 143.0mm396.6mm
2000 145.7mm424.6mm
National soil grid Source: CSIRO/TERN
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties

Loading

Climate

Pingbong SA 2015


Observed climate information

Rainfall avg ann (mm) 320mm
Rainfall avg gsr (mm) 225mm
Rainfall trial total (mm) 286mm
Rainfall trial gsr (mm) 260mm

Derived climate information

Piednippie SA

Pingbong SA

Piednippie SA

NOTE: Exact trial site locality unknown - Climate data may not be accurate
Loading
Loading
Loading

Pingbong SA

NOTE: Exact trial site locality unknown - Climate data may not be accurate
Loading
Loading
Loading

Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.

Trial report and links

2015 trial report



Trial last modified: 08-10-2019 11:55am AEST