Abstract
Fertigation with liquid sources of nitrogen (N) fertilizers, including ammonium sulfate and urea, were compared with granular applications of the fertilizers in northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’) during the first 5 years of fruit production (2008–12). The planting was established in Apr. 2006 at a field site located in western Oregon. The plants were grown on raised beds and mulched every 2 years with sawdust. Liquid fertilizers were injected through a drip system in equal weekly applications from mid-April to early August. Granular fertilizers were applied on each side of the plants, in three split applications from mid-April to mid-June, and washed into the soil using microsprinklers. Each fertilizer was applied at three N rates, which were increased each year as the plants matured (63 to 93, 133 to 187, and 200 to 280 kg·ha −1 N) and compared with non-fertilized treatments (0 kg·ha −1 N). Canopy cover, which was measured in 2008 only, and fresh pruning weight were greater with fertigation than with granular fertilizer and often increased with N rate when the plants were fertigated but decreased at the highest rate when granular fertilizer was applied. Yield also increased with N fertilizer and was 12% to 40% greater with fertigation than with granular fertilizer each year as well as 17% greater with ammonium sulfate than with urea in 2011. The response of berry weight to the treatments was variable but decreased with higher N rates during the first 3 years of fruit production. Leaf N concentration was greater with fertigation in 4 of 5 years and averaged 1.68% with fertigation and 1.61% with granular fertilizer. Leaf N was also often greater with ammonium sulfate than with urea and increased as more N was applied. Soil pH declined with increasing N rates and was lower with granular fertilizer than with fertigation during the first 3 years of fruit production and lower with ammonium sulfate than with urea in every year but 2010. Soil electrical conductivity (EC) was less than 1 dS·m −1 in each treatment but was an average of two to three times greater with granular fertilizer than with fertigation and 1.4 to 1.8 times greater with ammonium sulfate than with urea. Overall, total yield averaged 32 to 63 t·ha −1 in each treatment over the first 5 years of fruit production and was greatest when plants were fertigated with ammonium sulfate or urea at rates of at least 63 to 93 kg·ha −1 N per year.
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Claims 18
Claim · model-written summary
Canopy cover and fresh pruning weight were greater with fertigation than with granular fertilizer.
- Taxon
- northern highbush blueberry
Vaccinium corymbosume0 - Treatment
- fertigatione1
- Outcome
- fresh pruning weighte1
- Direction
- greatere1
- Qualifier
- measured in 2008 onlye1
- Comparator
- granular fertilizere1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Canopy cover, which was measured in 2008 only, and fresh pruning weight were greater with fertigation than with granular fertilizer”
Claim · model-written summary
Fresh pruning weight often increased with N rate when plants were fertigated.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- N ratee2
- Outcome
- fresh pruning weighte1
- Direction
- increasede2
- Qualifier
- when the plants were fertigatede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Canopy cover, which was measured in 2008 only, and fresh pruning weight were greater with fertigation than with granular fertilizer”
e2“often increased with N rate when the plants were fertigated but decreased at the highest rate when granular fertilizer was applied”
Claim · model-written summary
Fresh pruning weight decreased at the highest N rate when granular fertilizer was applied.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- highest ratee2
- Outcome
- fresh pruning weighte1
- Direction
- decreasede2
- Qualifier
- when granular fertilizer was appliede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Canopy cover, which was measured in 2008 only, and fresh pruning weight were greater with fertigation than with granular fertilizer”
e2“often increased with N rate when the plants were fertigated but decreased at the highest rate when granular fertilizer was applied”
Claim · model-written summary
Yield increased with N fertilizer in highbush blueberry.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- N fertilizere3
- Outcome
- Yielde3
- Direction
- increasede3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e3“Yield also increased with N fertilizer”
Claim · model-written summary
Yield was 12% to 40% greater with fertigation than with granular fertilizer each year.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- fertigatione4
- Outcome
- Yielde3
- Direction
- greatere4
- Value
- 12% to 40%e4
- Qualifier
- each yeare4
- Comparator
- granular fertilizere4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e3“Yield also increased with N fertilizer”
e4“was 12% to 40% greater with fertigation than with granular fertilizer each year”
Claim · model-written summary
Yield was 17% greater with ammonium sulfate than with urea in 2011.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- ammonium sulfatee5
- Outcome
- Yielde3
- Direction
- greatere5
- Value
- 17%e5
- Qualifier
- in 2011e5
- Comparator
- ureae5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e3“Yield also increased with N fertilizer”
e5“17% greater with ammonium sulfate than with urea in 2011”
Claim · model-written summary
Berry weight was variable but decreased with higher N rates during the first 3 years of fruit production.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- higher N ratese6
- Outcome
- berry weighte6
- Direction
- decreasede6
- Qualifier
- during the first 3 years of fruit productione6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e6“The response of berry weight to the treatments was variable but decreased with higher N rates during the first 3 years of fruit production”
Claim · model-written summary
Leaf N concentration was greater with fertigation in 4 of 5 years, averaging 1.68% with fertigation versus 1.61% with granular fertilizer.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- fertigatione7
- Outcome
- Leaf N concentratione7
- Direction
- greatere7
- Value
- 1.68%e7
- Qualifier
- 4 of 5 yearse7
- Comparator
- granular fertilizere7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e7“Leaf N concentration was greater with fertigation in 4 of 5 years and averaged 1.68% with fertigation and 1.61% with granular fertilizer”
Claim · model-written summary
Leaf N was often greater with ammonium sulfate than with urea.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- ammonium sulfatee1
- Outcome
- Leaf Ne1
- Direction
- greatere1
- Qualifier
- oftene1
- Comparator
- ureae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Leaf N was also often greater with ammonium sulfate than with urea and increased as more N was applied”
Claim · model-written summary
Leaf N increased as more N was applied.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- as more N was appliede1
- Outcome
- Leaf Ne1
- Direction
- increasede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Leaf N was also often greater with ammonium sulfate than with urea and increased as more N was applied”
Claim · model-written summary
Soil pH declined with increasing N rates.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- increasing N ratese1
- Outcome
- Soil pHe1
- Direction
- declinede1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Soil pH declined with increasing N rates and was lower with granular fertilizer than with fertigation during the first 3 years of fruit production and lower with ammonium sulfate than with urea in every year but 2010”
Claim · model-written summary
Soil pH was lower with granular fertilizer than with fertigation during the first 3 years of fruit production.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- granular fertilizere1
- Outcome
- Soil pHe1
- Direction
- lowere1
- Qualifier
- during the first 3 years of fruit productione1
- Comparator
- fertigatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Soil pH declined with increasing N rates and was lower with granular fertilizer than with fertigation during the first 3 years of fruit production and lower with ammonium sulfate than with urea in every year but 2010”
Claim · model-written summary
Soil pH was lower with ammonium sulfate than with urea in every year but 2010.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- ammonium sulfatee1
- Outcome
- Soil pHe1
- Direction
- lowere1
- Qualifier
- in every year but 2010e1
- Comparator
- ureae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Soil pH declined with increasing N rates and was lower with granular fertilizer than with fertigation during the first 3 years of fruit production and lower with ammonium sulfate than with urea in every year but 2010”
Claim · model-written summary
Soil electrical conductivity was an average of two to three times greater with granular fertilizer than with fertigation.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- granular fertilizere1
- Outcome
- Soil electrical conductivity (EC)e2
- Direction
- greatere1
- Value
- two to three timese1
- Comparator
- fertigatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“was an average of two to three times greater with granular fertilizer than with fertigation”
e2“Soil electrical conductivity (EC) was less than 1”
Claim · model-written summary
Soil electrical conductivity was 1.4 to 1.8 times greater with ammonium sulfate than with urea.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- ammonium sulfatee1
- Outcome
- Soil electrical conductivity (EC)e2
- Direction
- greatere1
- Value
- 1.4 to 1.8 timese1
- Comparator
- ureae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“1.4 to 1.8 times greater with ammonium sulfate than with urea”
e2“Soil electrical conductivity (EC) was less than 1”
Claim · model-written summary
Soil electrical conductivity was less than 1 dS·m −1 in each treatment.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Outcome
- Soil electrical conductivity (EC)e1
- Value
- less than 1e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Soil electrical conductivity (EC) was less than 1”
Claim · model-written summary
Total yield averaged 32 to 63 t·ha −1 in each treatment over the first 5 years of fruit production.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Outcome
- total yielde1
- Value
- 32 to 63e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Overall, total yield averaged 32 to 63”
Claim · model-written summary
Total yield was greatest when plants were fertigated with ammonium sulfate or urea at rates of at least 63 to 93 kg N per year.
- Taxon
- northern highbush blueberryVaccinium corymbosume0
- Treatment
- at rates of at least 63 to 93e2
- Outcome
- total yielde1
- Direction
- greateste2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“northern highbush blueberry ( Vaccinium corymbosum L. ‘Bluecrop’)”
e1“Overall, total yield averaged 32 to 63”
e2“was greatest when plants were fertigated with ammonium sulfate or urea at rates of at least 63 to 93”
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See all 24 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.