Abstract
ABSTRACT The effects of summer cover crops on cash crop yields and soil health in semi‐arid cropping systems in southern Australia remain largely unexplored. A study was conducted in Western Australia to investigate cover crop impacts on soil carbon and nitrogen cycling, soil water, and mineral nitrogen (N) and cash crop yield. A range of monoculture and mixed‐species cover crops were grown over summer between a lupin hay crop (terminated in October) and a canola cash crop sown the following April, in addition to a chemical fallow control. Cover crops produced 50–1050 kg ha −1 and did not affect soil water or mineral N compared to the bare fallow control prior to sowing canola the following winter, 2022. As a result, there was no impact on canola yield. This lack of difference is consistent with high evaporative demand over summer in this climate and associated low fallow water use efficiency. Cover crops had no significant effect on soil health indicators – soil organic carbon (C), total N, C:N ratio, permanganate‐oxidisable C (POXC) and soil respiration – measured in early autumn prior to canola (cash crop) seeding. However, POXC and soil respiration increased by 50% in response to cash crop biomass production, while soil C:N increased over the cash crop growing season as soil N declined from peak canola biomass to harvest. The lack of impact of cover crops on soil function at the Western Australian site likely reflects low C inputs into the soil (cover crop biomass < 1 t ha −1 ). While the cover crops did not impact subsequent cash crop yields, the lack of impact on soil function and the costs associated with sowing cover crops need to be considered in any management decisions.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Summer cover crops produced 50–1050 kg ha −1 biomass.
Verbatim
e0“Cover crops produced 50–1050 kg ha −1”
Claim · model-written summary
Cover crops did not affect soil water or mineral N versus bare fallow before canola sowing.
Verbatim
e0“did not affect soil water or mineral N compared to the bare fallow control prior to sowing canola the following winter, 2022”
t0“Summer Cover Cropping”
Claim · model-written summary
Summer cover crops did not affect subsequent canola yield.
- Taxon
- canola
.jpg?width=60)
Brassica napus var. napuse0 - Treatment
- Summer Cover Croppingt0
- Outcome
- canola yielde0
- Direction
- no impacte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“As a result, there was no impact on canola yield.”
t0“Summer Cover Cropping”
Claim · model-written summary
Cover crops had no significant effect on soil carbon and nitrogen indicators or respiration before canola seeding.
- Taxon
- canolaBrassica napus var. napuse0
- Treatment
- Cover cropse0
- Outcome
- soil organic carbon (C), total N, C:N ratio, permanganate‐oxidisable C (POXC) and soil respiratione0
- Direction
- no significant effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cover crops had no significant effect on soil health indicators – soil organic carbon (C), total N, C:N ratio, permanganate‐oxidisable C (POXC) and soil respiration – measured in early autumn prior to canola (cash crop) seeding.”
Claim · model-written summary
POXC and soil respiration increased by 50% with cash crop biomass production.
Verbatim
e0“POXC and soil respiration increased by 50% in response to cash crop biomass production”
Claim · model-written summary
Soil C:N increased over the cash crop growing season as soil N declined.
- Taxon
- canolaBrassica napus var. napuse0
- Outcome
- soil C:Ne0
- Direction
- increasede0
- Setting
- cash crop growing seasone0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soil C:N increased over the cash crop growing season as soil N declined from peak canola biomass to harvest”
Claim · model-written summary
Soil N declined from peak canola biomass to harvest.
- Taxon
- canolaBrassica napus var. napuse0
- Outcome
- soil Ne0
- Direction
- declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soil N declined from peak canola biomass to harvest”
Claim · model-written summary
Management decisions should consider cover crop sowing costs alongside the lack of soil function and yield benefits.
Verbatim
e0“the lack of impact on soil function and the costs associated with sowing cover crops need to be considered in any management decisions”
t0“Summer Cover Cropping”
The same questions in other papers
cover crop · yield · Brassica napus (oilseed rape)Results differ
2 papers in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
3 papers more in this group
See all 7 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.