Abstract
Abstract Potassium chloride (KCl) was applied at 0, 150, 450, and 750 kg ha −1 in May 2000 and April 2001 to an allophanic soil (Egmont brown loam) in South Taranaki to generate a range of soil and pasture potassium (K) levels typical of grazed dairy pastures. Initial mean soil quick test (QT) K levels of 7.0 increased to 7.3, 9.2, 13.6, and 18.5 respectively for each rate of K at the March 2001 sampling. In the March 2002 sampling, soil QT K decreased to 5.5, 7.8, 8.1, and 8.5 for each rate of K. There was only a small effect of rate of K on initial soil magnesium (Mg), calcium (Ca), and sodium (Na) soil QT levels of 30.8, 8.6, and 8.4. Pasture K content was significantly higher ( P < 0.05) at the highest rate of K compared with control from July to December in Year 1 (July 2000‐May 2001) and January‐March in Year 2 (July 2001‐May 2002). Increasing rate of K did not significantly change pasture Mg and Ca in most months but significantly decreased pasture Na. Leachate collected at 1 m soil depth showed that with increasing rate of KCl there was a significant increase ( P < 0.10) in the amount of leached K in Year 1 ((July‐August 2001) (7.0 kg ha −1 for control to 17.5 kg ha −1 for highest rate of K)), chloride (64.6–146.6 kg ha −1 in Year 1 ( P < 0.01), 104.1–202.5 kg ha– 1 in Year 2 (June‐August 2002) ( P < 0.05)), Ca (30.4–60.1 kg ha −1 in Year 1 ( P < 0.05), 34.1–74.3 kg ha −1 in Year 2 ( P < 0.10)), and Na (59.4–74.1 kg ha −1 in Year 2 ( P < 0.10)). There was no measured significant K effect ( P > 0.10) on the amount of Mg, nitrate‐nitrogen and sulphate‐sulphur leached in either year. Therefore, application of excess K fertiliser on allophanic soils to elevate soil QT K >7 will reduce pasture uptake and the availability of Na to animals. If the leached Na and Ca is not replaced, pasture Na and Ca could become deficient for dairy cow requirements.
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 12
Claim · model-written summary
Soil quick-test K increased with KCl rate at the March 2001 sampling, to 7.3, 9.2, 13.6 and 18.5 from an initial level of 7.0.
Verbatim
t0“pasture”
e0“Potassium chloride (KCl) was applied at 0, 150, 450, and 750 kg ha −1”
e1“Initial mean soil quick test (QT) K levels of 7.0 increased to 7.3, 9.2, 13.6, and 18.5 respectively for each rate of K”
Claim · model-written summary
Soil QT K decreased with KCl rate at the March 2002 sampling, to 5.5, 7.8, 8.1 and 8.5.
- Taxon
- pasturet0
- Treatment
- Potassium chloride (KCl)e0
- Outcome
- soil QT Ke2
- Direction
- decreasede2
- Value
- 5.5, 7.8, 8.1, and 8.5e2
Not reportedComparator
Verbatim
t0“pasture”
e0“Potassium chloride (KCl) was applied at 0, 150, 450, and 750 kg ha −1”
e2“In the March 2002 sampling, soil QT K decreased to 5.5, 7.8, 8.1, and 8.5 for each rate of K”
Claim · model-written summary
The rate of K had only a small effect on initial soil Mg, Ca and Na QT levels.
- Taxon
- pasturet0
- Treatment
- rate of Ke3
- Outcome
- soil magnesium (Mg), calcium (Ca), and sodium (Na)e3
- Qualifier
- only a small effecte3
Not reportedComparatorDirection
Verbatim
t0“pasture”
e3“There was only a small effect of rate of K on initial soil magnesium (Mg), calcium (Ca), and sodium (Na) soil QT levels”
Claim · model-written summary
Pasture K content was significantly higher at the highest K rate than in the control.
Verbatim
t0“pasture”
e4“Pasture K content was significantly higher ( P < 0.05) at the highest rate of K compared with control”
Claim · model-written summary
Increasing K rate did not significantly change pasture Mg and Ca in most months.
- Taxon
- pasturet0
- Treatment
- Increasing rate of Ke5
- Outcome
- pasture Mg and Cae5
- Direction
- did not significantly changee5
- Qualifier
- in most monthse5
Not reportedComparator
Verbatim
t0“pasture”
e5“Increasing rate of K did not significantly change pasture Mg and Ca in most months but significantly decreased pasture Na”
Claim · model-written summary
Increasing K rate significantly decreased pasture Na.
Not reportedComparator
Verbatim
t0“pasture”
e5“Increasing rate of K did not significantly change pasture Mg and Ca in most months but significantly decreased pasture Na”
Claim · model-written summary
Increasing KCl rate significantly increased the amount of leached K in Year 1, to 17.5 kg ha −1 at the highest rate versus 7.0 kg ha −1 in the control.
Verbatim
t0“pasture”
e6“with increasing rate of KCl there was a significant increase ( P < 0.10) in the amount of leached K in Year 1”
e7“7.0 kg ha −1 for control to 17.5 kg ha −1 for highest rate of K”
Claim · model-written summary
Increasing KCl rate significantly increased leached chloride in Year 1, to 64.6–146.6 kg ha −1.
- Taxon
- pasturet0
- Treatment
- increasing rate of KCle6
- Outcome
- chloridee7
- Direction
- increasee6
- Value
- 64.6–146.6 kg ha −1e7
Not reportedComparator
Verbatim
t0“pasture”
e6“with increasing rate of KCl there was a significant increase ( P < 0.10) in the amount of leached K in Year 1”
e7“chloride (64.6–146.6 kg ha −1 in Year 1 ( P < 0.01)”
Claim · model-written summary
Increasing KCl rate significantly increased leached Ca in Year 1, to 30.4–60.1 kg ha −1.
- Taxon
- pasturet0
- Treatment
- increasing rate of KCle6
- Outcome
- Cae7
- Direction
- increasee6
- Value
- 30.4–60.1 kg ha −1e7
Not reportedComparator
Verbatim
t0“pasture”
e6“with increasing rate of KCl there was a significant increase ( P < 0.10) in the amount of leached K in Year 1”
e7“Ca (30.4–60.1 kg ha −1 in Year 1 ( P < 0.05)”
Claim · model-written summary
Increasing KCl rate significantly increased leached Na in Year 2, to 59.4–74.1 kg ha −1.
- Taxon
- pasturet0
- Treatment
- increasing rate of KCle6
- Outcome
- Nae7
- Direction
- increasee6
- Value
- 59.4–74.1 kg ha −1e7
Not reportedComparator
Verbatim
t0“pasture”
e6“with increasing rate of KCl there was a significant increase ( P < 0.10) in the amount of leached K in Year 1”
e7“Na (59.4–74.1 kg ha −1 in Year 2 ( P < 0.10)”
Claim · model-written summary
K rate had no significant effect on leached Mg, nitrate-nitrogen or sulphate-sulphur.
Not reportedComparator
Verbatim
t0“pasture”
e7“There was no measured significant K effect ( P > 0.10) on the amount of Mg, nitrate‐nitrogen and sulphate‐sulphur leached in either year”
Claim · model-written summary
Applying excess K fertiliser on allophanic soils to raise soil QT K above 7 is expected to reduce pasture uptake and the availability of Na to animals.
Verbatim
t0“pasture”
e7“application of excess K fertiliser on allophanic soils to elevate soil QT K >7 will reduce pasture uptake and the availability of Na to animals”