Comparison of different green manure crops as tools for renovation cropping and evaluating economic benefits at Mullewa on a heavy soil

1998 - 2002

Research organisatons
Funding source

Trial details

Researcher(s) Frances Hoyle
Leanne Schulz
Contact email fhoyle.consult@gmail.com
Year(s) 1998 - 2002
Contributor SoilsWest
Trial location(s) Site 2, Mullewa, WA
Comparison of different green manure crops as tools for renovation cropping and evaluating economic benefits at Mullewa on a heavy soil locations
Aims

This research determines to assess the benefits (economic and environmental) of a green manure phase under current cropping systems in areas with a poor nutritional status. 

To evaluate crop types and incorporation techniques to rejuvenate poor performing soils using a green manure phase, as well as to identify and evaluate the potential longevity of benefits on a heavy loam soil in Mullewa, Western Australia over five years.

Key messages

Study Conclusions

Potential nitrogen contributions are assumed to be 40% of the total nitrogen contribution, assessed from the dry weight and nitrogen content (N% tissue) of the green manure crops measured at anthesis. Legume crops provided the most potential nitrogen of all treatments, due to high tissue nitrogen and moderate to high biomass production. Oats had the highest biomass but were low in tissue nitrogen and potential nitrogen benefits were therefore negligible. Any benefits from this type of crop, would be largely associated with the contribution of organic carbon to the soil. Emergence of both canola and mustard was poor, whilst the lathyrus and vetch competed poorly with weeds due to slow initial growth.

The percentage of undecomposed material remaining on the soil surface at seeding in 1999, varied from approximately 35% for oats down to 10% for lathyrus. The general pattern was that the crops with higher tissue nitrogen content broke down quicker. This indicates the microbial degradation of legume crops is likely to be faster than for brassica or cereal crops.

Differences in water infiltration observed may indicate the potential for treatments to increase the initial sorptivity of soil (ability for more rapid entry of rainfall) and decrease the flow rate through the soil (effectively increasing moisture retention). This may allow earlier sowing after summer rains, increased moisture availability during the growing season and potentially longer availability under dry finishing conditions. These results are variable and subject to trial/operator error. Further evaluation of these attributes is required prior to evaluation of renovation techniques.

The high cost of seeding and maintenance of the green manure crop, can significantly influence the gains or losses experienced over this three year period. It may be most economic, to green manure legume crops in seasons with low potential returns (poor yield potential or price).  The cost of harvesting a lupin crop for example may prove less beneficial than using it as a green manure to improve wheat yield and quality, where prices are depressed or where disease/season has reduced yield potential. Strategic use of green manure crops as a tool in integrated weed management or potential productivity gains through addressing specific problems may result in little or no short term economic gain where employed in better performing paddocks and must be viewed as a long term strategy to overcome yield constraints. However, strategic use of these techniques for poor performing paddocks, or paddock that would have otherwise been ‘rested’, are likely to result in economic responses, particularly where using low cost crops or pasture has been employed as there is no requirement to recover the cost of foregone yield – only those associated with growing a crop and the implementation of techniques.

Data supports the hypothesis that a green manuring:wheat:wheat rotation, may be as profitable as a legume:wheat:wheat rotation using either a field pea or Lathyrus crop. Given this assessment does not include any additional benefits that may be gained from green or brown manuring in terms of additional weed control and potential improvement of soil characteristics such as the addition of organic material, improved soil structure and longer term productivity gains, these techniques are likely to prove both economical and sustainable by providing additional benefits that may be observed in lower herbicide costs through better weed management, improved soil health and a more flexible farming system.

Lead research organisation Department of Agriculture and Food WA
Host research organisation Department of Agriculture and Food WA
Trial funding source GRDC DAW628
Related program N/A
Acknowledgments N/A
Other trial partners Not specified
Download the trial report to view additional trial information

Method

Crop types Oats
Wheat
Fallow
Mustard
Field peas
Vetch
Canola
Treatment type(s)
  • Crop: Type
Trial type
Trial design

Mullewa 1998 Oats

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Wheat

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Fallow

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Mustard

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Field peas

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Vetch

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1998 Canola

Sow rate or Target density Mustard (347.6.3.1.3) @ 6 kg ha Canola (Narendra) @ 6 kg ha Vetch (Languedoc) @ 65 kg ha Oats (Pallinup) @ 80 kg ha Vetch (75%):Oats (25%) @ 65kg ha Field peas (Dundale) @ 110 kg ha Lathyrus (Chalus) @ 60 kg ha Fallow (chemical)
Sow date 29 May 1998
Harvest date Not specified
Plot size 10m x 1.8m
Plot replication 3
Fertiliser

120kg/ha Super at seeding and 50kg/ha Urea topdressed

Herbicide

Sprayseed applied twice prior to seeding at 1L ha

Oat, mustard and canola received 500mL Dicamba + 200mL Lontrel

Vetch, lathyrus and oat/vetch received 40g

Broadstrike Field peas received 250g Lexone

Roundup @ 2L ha on 7th Spetember on renovation treatments

Mullewa 1999 Oats

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Wheat

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Canola

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Fallow

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Mustard

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Field peas

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 1999 Vetch

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Oats

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Wheat

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Canola

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Fallow

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Mustard

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Field peas

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2000 Vetch

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Oats

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Wheat

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Canola

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Fallow

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Mustard

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Field peas

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2001 Vetch

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Oats

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Wheat

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Canola

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Fallow

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Mustard

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Field peas

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified

Mullewa 2002 Vetch

Sow rate or Target density Not specified
Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Herbicide Not specified
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
Site 2, Mullewa, WA Red clay loam
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Site 2, Mullewa, WA Tenosol
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

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Climate

Site 2, Mullewa WA 1998


Observed climate information

Rainfall avg ann (mm) 341mm
Rainfall trial gsr (mm) 323mm

Derived climate information

Site 2, Mullewa WA

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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 last modified: 28-04-2021 20:22pm AEST