Abstract
The results of an incubation method for measuring the capacity of Ontario soils to accumulate nitrate were extremely variable. Placement of the soil sample between two layers of vermiculite in the incubation tube and addition of sufficient distilled water to moisten the top layer of vermiculite, the soil and a portion of the bottom layer of vermiculite resulted in satisfactory reproducibility of results. Wide fluctuations in results, due to prolonged air-dry storage before analysis or to time of sampling during the growing season, were reduced by storing all samples in the moist state at 10 °C. for 2 weeks before analysis.The correlation between the logarithm of the percentage yield decrement, which is a measure of crop response, and nitrate-supplying power as measured by the modified incubation method was highly significant for winter wheat (r = −0.437), oats (r = −0.411) and potatoes (r = −0.651). Soils having a nitrate-supplying power of 50 p.p.m. of N or more by the proposed modified method gave little or no increase in yield of wheat, oats, or potatoes when additional nitrogen was applied as fertilizer.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 9
Claim · model-written summary
Original incubation results for Ontario soils were extremely variable.
Not reportedTaxonComparator
Verbatim
e0“The results of an incubation method for measuring the capacity of Ontario soils to accumulate nitrate were extremely variable”
Claim · model-written summary
Vermiculite placement and moistening produced satisfactory reproducibility.
- Outcome
- reproducibility of resultse0
- Qualifier
- Placement of the soil sample between two layers of vermiculitee0
Not reportedTaxonComparator
Verbatim
e0“Placement of the soil sample between two layers of vermiculite in the incubation tube and addition of sufficient distilled water to moisten the top layer of vermiculite, the soil and a portion of the bottom layer of vermiculite resulted in satisfactory reproducibility of results”
Claim · model-written summary
Moist storage at 10 °C for two weeks reduced fluctuations due to air-dry storage or sampling time.
Not reportedTaxonComparator
Verbatim
e0“Wide fluctuations in results, due to prolonged air-dry storage before analysis or to time of sampling during the growing season, were reduced by storing all samples in the moist state at 10 °C. for 2 weeks before analysis”
Claim · model-written summary
Winter wheat yield decrement correlated with nitrate-supplying power at r = −0.437.
- Taxon
- winter wheat
Triticum aestivume0 - Outcome
- percentage yield decremente0
- Value
- r = −0.437e0
- Comparator
- nitrate-supplying powere0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“correlation between the logarithm of the percentage yield decrement, which is a measure of crop response, and nitrate-supplying power as measured by the modified incubation method was highly significant for winter wheat (r = −0.437)”
Claim · model-written summary
Oat yield decrement correlated with nitrate-supplying power at r = −0.411.
- Taxon
- oats
Avena sativae0 - Outcome
- yield decrementt0
- Value
- r = −0.411e0
- Comparator
- nitrate-supplying powert0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“winter wheat (r = −0.437), oats (r = −0.411) and potatoes (r = −0.651)”
t0“percentage yield decrement, which is a measure of crop response, and nitrate-supplying power”
Claim · model-written summary
Potato yield decrement correlated with nitrate-supplying power at r = −0.651.
- Taxon
- potatoes
Solanum tuberosume0 - Outcome
- yield decrementt0
- Value
- r = −0.651e0
- Comparator
- nitrate-supplying powert0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“winter wheat (r = −0.437), oats (r = −0.411) and potatoes (r = −0.651)”
t0“percentage yield decrement, which is a measure of crop response, and nitrate-supplying power”
Claim · model-written summary
At soil nitrate-supplying power of at least 50 p.p.m. N, added nitrogen gave little or no wheat yield increase.
- Taxon
- wheatTriticum aestivume0
- Treatment
- additional nitrogene0
- Outcome
- yield of wheate0
- Direction
- little or no increasee0
- Qualifier
- 50 p.p.m. of N or moree0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soils having a nitrate-supplying power of 50 p.p.m. of N or more by the proposed modified method gave little or no increase in yield of wheat, oats, or potatoes when additional nitrogen was applied as fertilizer”
Claim · model-written summary
At soil nitrate-supplying power of at least 50 p.p.m. N, added nitrogen gave little or no oat yield increase.
- Taxon
- oatsAvena sativae0
- Treatment
- additional nitrogene0
- Outcome
- yielde0
- Direction
- little or no increasee0
- Qualifier
- 50 p.p.m. of N or moree0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soils having a nitrate-supplying power of 50 p.p.m. of N or more by the proposed modified method gave little or no increase in yield of wheat, oats, or potatoes when additional nitrogen was applied as fertilizer”
Claim · model-written summary
At soil nitrate-supplying power of at least 50 p.p.m. N, added nitrogen gave little or no potato yield increase.
- Taxon
- potatoesSolanum tuberosume0
- Treatment
- additional nitrogene0
- Outcome
- yielde0
- Direction
- little or no increasee0
- Qualifier
- 50 p.p.m. of N or moree0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soils having a nitrate-supplying power of 50 p.p.m. of N or more by the proposed modified method gave little or no increase in yield of wheat, oats, or potatoes when additional nitrogen was applied as fertilizer”
The same questions in other papers
nitrogen · yield · Solanum tuberosum (potato)Results differ
22 papers in the same direction as this paper · 109 in the opposite direction
- positive
- positive
- positive
128 papers more in this group
See all 132 papers →nitrogen · yield · Avena sativa (oats)Positive and negative results
10 papers in the same direction as this paper · 105 in the opposite direction
- positive
- positive
- positive
112 papers more in this group
See all 116 papers →nitrogen · yield · Triticum aestivum (wheat)Positive and negative results
323 papers in the same direction as this paper · 1,737 in the opposite direction
- positive
- positive
- positive
2,057 papers more in this group
See all 2,061 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.