Abstract
Current fertiliser guidelines for nitrogen (N) application for canola under conservation agriculture (CA) in South Africa, may result in over-fertilisation. This study aimed to evaluate the effects of N rates and foliar applied N on biomass, seed and oil yield of canola grown under CA. Trials took place from 2016 to 2019 at Darling, Porterville, Moorreesburg, Riviersonderend and Riversdale in the Western Cape, South Africa, representing diverse soil and climatic conditions. The study evaluated the application of 0, 25, 50, 75, 105, 135, 160 and 190 kg N ha−1 N rates using limestone ammonium nitrate followed by a urea ammonium nitrate foliar application of 20 kg N ha−1 vs a control (no foliar). The responses of biomass, seed and oil yield to top-dressed fertiliser N rate was site specific and varied with in-season rainfall. Foliar N application had no effect (p > 0.05) on biomass (all sites), seed yield (Darling, Porterville and Riversdale) and oil yield (Darling). At Moorreesburg (2016 and 2017) and Riviersonderend (2016, 2017 and 2019) foliar N increased seed yield. The lack of response by biomass, seed and oil yield to increased N application rates under different soil and rainfall conditions suggests lower fertiliser N demand under CA conditions.
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Claims 6
Claim · model-written summary
Biomass, seed and oil yield responses to top-dressed N rate were site specific and varied with in-season rainfall in canola.
- Taxon
- canola
.jpg?width=60)
Brassica napus var. napust0 - Treatment
- top-dressed fertiliser N ratee1
- Outcome
- biomass, seed and oil yielde1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“Nitrogen fertiliser demand of canola”
e1“The responses of biomass, seed and oil yield to top-dressed fertiliser N rate was site specific and varied with in-season rainfall”
Claim · model-written summary
Foliar N application had no effect on canola biomass at all sites.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- Foliar N applicatione2
- Outcome
- biomasse2
- Direction
- no effecte2
- Qualifier
- all sitese2
- Comparator
- control (no foliar)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Nitrogen fertiliser demand of canola”
e0“The study evaluated the application of 0, 25, 50, 75, 105, 135, 160 and 190 kg N ha−1 N rates using limestone ammonium nitrate followed by a urea ammonium nitrate foliar application of 20 kg N ha−1 vs a control (no foliar)”
e2“Foliar N application had no effect (p > 0.05) on biomass (all sites), seed yield (Darling, Porterville and Riversdale) and oil yield (Darling)”
Claim · model-written summary
Foliar N application had no effect on canola seed yield at Darling, Porterville and Riversdale.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- Foliar N applicatione2
- Outcome
- seed yielde2
- Direction
- no effecte2
- Comparator
- control (no foliar)e0
- Setting
- Darling, Porterville and Riversdalee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Nitrogen fertiliser demand of canola”
e0“The study evaluated the application of 0, 25, 50, 75, 105, 135, 160 and 190 kg N ha−1 N rates using limestone ammonium nitrate followed by a urea ammonium nitrate foliar application of 20 kg N ha−1 vs a control (no foliar)”
e2“Foliar N application had no effect (p > 0.05) on biomass (all sites), seed yield (Darling, Porterville and Riversdale) and oil yield (Darling)”
Claim · model-written summary
Foliar N application had no effect on canola oil yield at Darling.
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- Foliar N applicatione2
- Outcome
- oil yielde2
- Direction
- no effecte2
- Comparator
- control (no foliar)e0
- Setting
- Darlinge2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Nitrogen fertiliser demand of canola”
e0“The study evaluated the application of 0, 25, 50, 75, 105, 135, 160 and 190 kg N ha−1 N rates using limestone ammonium nitrate followed by a urea ammonium nitrate foliar application of 20 kg N ha−1 vs a control (no foliar)”
e2“Foliar N application had no effect (p > 0.05) on biomass (all sites), seed yield (Darling, Porterville and Riversdale) and oil yield (Darling)”
Claim · model-written summary
Foliar N increased canola seed yield at Moorreesburg (2016 and 2017) and Riviersonderend (2016, 2017 and 2019).
- Taxon
- canolaBrassica napus var. napust0
- Treatment
- foliar Ne3
- Outcome
- seed yielde3
- Direction
- increasede3
- Comparator
- control (no foliar)e0
- Setting
- Moorreesburg (2016 and 2017) and Riviersonderend (2016, 2017 and 2019)e3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Nitrogen fertiliser demand of canola”
e0“The study evaluated the application of 0, 25, 50, 75, 105, 135, 160 and 190 kg N ha−1 N rates using limestone ammonium nitrate followed by a urea ammonium nitrate foliar application of 20 kg N ha−1 vs a control (no foliar)”
e3“At Moorreesburg (2016 and 2017) and Riviersonderend (2016, 2017 and 2019) foliar N increased seed yield”
Claim · model-written summary
Canola needs lower fertiliser N under conservation agriculture conditions.
- Taxon
- canolaBrassica napus var. napust0
- Outcome
- lower fertiliser N demand under CA conditionse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Nitrogen fertiliser demand of canola”
e4“The lack of response by biomass, seed and oil yield to increased N application rates under different soil and rainfall conditions suggests lower fertiliser N demand under CA conditions”
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