Abstract
A series of 10 field experiments conducted over a 4-yr period (1973–1976) on three of the most important Brown Chernozemic soils in the irrigated area of southern Alberta gave no significant yield responses to applied K (at rates of 0, 50, 100 and 150 kg ha −1 in 1973 and 0, 127, 254 and 508 kg ha −1 in the other years), using potato (Solanum tuberosum L.) as the test crop. The experiments included several cultivars, a variety of growing conditions, and diverse cropping histories. In addition, the K concentration of uppermost mature leaf blades obtained at the 10%-bloom stage were only slightly affected by K treatments, except in 1 yr (1975). The increased K uptake in 1975 was related to greater precipitation before irrigation was applied (66, 99 and 94 mm, respectively) during April, May and June in comparison with the long-term average of 32, 54 and 76 mm. The effects of early-season soil moisture stress were partially confirmed in a controlled environment (CE) experiment in which maintenance of soil water potentials between −30 and −20 kPa throughout the season caused greater uptake of added K in comparison with soil moisture stress in the 0–15 cm zone prior to the 10%-bloom stage. Yields of tubers were depressed with the stressed treatment, but there was no yield response to added K. Leaf analyses from the field experiments indicate that the critical K level of 43 g kg −1 , which was established earlier for the Russet Burbank cultivar growing on Podzol soils is too high for irrigated Chernozemic soils, and that 30 g kg −1 would be a more valid tentative value. In a second CE experiment, designed to quantify the fate of applied K during intensive cropping, no yield responses to K applications were obtained with alfalfa on a coarse-textured Cavendish sandy loam during a 2-yr period. With no applied K, crop uptake reduced exchangeable K levels throughout the entire profile (66 cm) by about 20%. Thirty percent of the K removed by the crop originated from nonexchangeable soil K. With the highest K rate (450 kg ha −1 applied twice), 50% could be attributed to plant uptake, 15% to increased exchangeable K, and 35% to fixation in the nonexchangeable form. It is concluded that response to applied K on irrigated Brown and Dark Brown Chernozemic soils of southern Alberta is unlikely, even with intensive cropping, for some time in the future. A practical strategy for producers could be to apply moderate rates of K as a conservation measure when economic conditions are favorable and to rely on soil reserves in times of financial pressures. Key words: K-release, K-fixation, leaf analysis, fertilizer K requirements, soil water stress, K deficiency
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Claims 15
Claim · model-written summary
Applied K produced no significant potato yield response across field experiments.
- Taxon
- potato
Solanum tuberosume0 - Treatment
- applied Ke0
- Outcome
- yield responsese0
- Direction
- no significante0
- Setting
- SOUTHERN ALBERTAt0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“gave no significant yield responses to applied K (at rates of 0, 50, 100 and 150 kg ha −1 in 1973 and 0, 127, 254 and 508 kg ha −1 in the other years), using potato (Solanum tuberosum L.) as the test crop”
t0“SOUTHERN ALBERTA”
Claim · model-written summary
Potassium treatment only slightly affected potato leaf K concentration except in 1975.
- Taxon
- potatoSolanum tuberosume1
- Organ / stage
- uppermost mature leaf bladese0
- Treatment
- K treatmentse0
- Outcome
- K concentratione0
- Qualifier
- except in 1 yr (1975)e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the K concentration of uppermost mature leaf blades obtained at the 10%-bloom stage were only slightly affected by K treatments, except in 1 yr (1975)”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Greater precipitation before irrigation in 1975 was related to increased potato K uptake.
- Taxon
- potatoSolanum tuberosume1
- Outcome
- K uptakee0
- Direction
- increasede0
- Qualifier
- greater precipitation before irrigation was appliede0
- Setting
- 1975e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increased K uptake in 1975 was related to greater precipitation before irrigation was applied”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Maintaining soil water potential throughout the season caused greater potato uptake of added K than early soil moisture stress.
- Taxon
- potatoSolanum tuberosume1
- Treatment
- maintenance of soil water potentials between −30 and −20 kPa throughout the seasone0
- Outcome
- uptake of added Ke0
- Direction
- greatere0
- Comparator
- soil moisture stress in the 0–15 cm zone prior to the 10%-bloom stagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maintenance of soil water potentials between −30 and −20 kPa throughout the season caused greater uptake of added K in comparison with soil moisture stress in the 0–15 cm zone prior to the 10%-bloom stage”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Early soil moisture stress depressed potato tuber yield.
- Taxon
- potatoSolanum tuberosume1
- Treatment
- stressed treatmente0
- Outcome
- Yields of tuberse0
- Direction
- depressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yields of tubers were depressed with the stressed treatment”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Added K did not increase potato tuber yield in the controlled environment experiment.
- Taxon
- potatoSolanum tuberosume1
- Treatment
- added Ke0
- Outcome
- yield responsee0
- Direction
- noe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there was no yield response to added K”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Leaf analyses indicate that the earlier potato critical K level is too high for irrigated Chernozemic soils and suggest a lower tentative level.
- Taxon
- potatoSolanum tuberosume1
- Material
- Russet Burbanke0
- Outcome
- critical K levele0
- Direction
- too highe0
- Value
- 30 g kg −1e0
- Qualifier
- 43 g kg −1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“critical K level of 43 g kg −1 , which was established earlier for the Russet Burbank cultivar growing on Podzol soils is too high for irrigated Chernozemic soils, and that 30 g kg −1 would be a more valid tentative value”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
Applied K produced no alfalfa yield response during two years.
- Taxon
- alfalfa
Medicago sativae0 - Treatment
- K applicationse0
- Outcome
- yield responsese0
- Direction
- noe0
- Setting
- Cavendish sandy loame0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“no yield responses to K applications were obtained with alfalfa on a coarse-textured Cavendish sandy loam during a 2-yr period”
Claim · model-written summary
Without applied K, alfalfa uptake reduced exchangeable K throughout the soil profile by about 20%.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- exchangeable K levelse0
- Direction
- reducede0
- Value
- about 20%e0
- Qualifier
- With no applied Ke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With no applied K, crop uptake reduced exchangeable K levels throughout the entire profile (66 cm) by about 20%”
e1“no yield responses to K applications were obtained with alfalfa”
Claim · model-written summary
Thirty percent of K removed by alfalfa came from nonexchangeable soil K.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- K removed by the crop originated from nonexchangeable soil Ke0
- Value
- Thirty percente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Thirty percent of the K removed by the crop originated from nonexchangeable soil K”
e1“no yield responses to K applications were obtained with alfalfa”
Claim · model-written summary
At the highest K rate, plant uptake accounted for 50% of applied K.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- 450 kg ha −1 applied twicee0
- Outcome
- plant uptakee0
- Value
- 50%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With the highest K rate (450 kg ha −1 applied twice), 50% could be attributed to plant uptake”
e1“no yield responses to K applications were obtained with alfalfa”
Claim · model-written summary
At the highest K rate, 15% was attributed to increased exchangeable K.
- Taxon
- alfalfaMedicago sativae2
- Treatment
- 450 kg ha −1 applied twicee1
- Outcome
- increased exchangeable Ke0
- Value
- 15%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“15% to increased exchangeable K”
e1“With the highest K rate (450 kg ha −1 applied twice), 50% could be attributed to plant uptake, 15% to increased exchangeable K, and 35% to fixation in the nonexchangeable form”
e2“no yield responses to K applications were obtained with alfalfa”
Claim · model-written summary
At the highest K rate, 35% was attributed to fixation in nonexchangeable form.
- Taxon
- alfalfaMedicago sativae2
- Treatment
- 450 kg ha −1 applied twicee1
- Outcome
- fixation in the nonexchangeable forme0
- Value
- 35%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“35% to fixation in the nonexchangeable form”
e1“With the highest K rate (450 kg ha −1 applied twice), 50% could be attributed to plant uptake, 15% to increased exchangeable K, and 35% to fixation in the nonexchangeable form”
e2“no yield responses to K applications were obtained with alfalfa”
Claim · model-written summary
The authors conclude that applied K responses on irrigated Brown and Dark Brown Chernozemic soils of southern Alberta are unlikely for some time.
- Taxon
- potatoSolanum tuberosume1
- Outcome
- response to applied Ke0
- Setting
- southern Albertae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“response to applied K on irrigated Brown and Dark Brown Chernozemic soils of southern Alberta is unlikely, even with intensive cropping, for some time in the future”
e1“using potato (Solanum tuberosum L.) as the test crop”
Claim · model-written summary
The authors recommend moderate K application when economic conditions favor it and reliance on soil reserves under financial pressure.
- Taxon
- potatoSolanum tuberosume1
- Outcome
- apply moderate rates of K as a conservation measuree0
- Qualifier
- when economic conditions are favorablee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“apply moderate rates of K as a conservation measure when economic conditions are favorable and to rely on soil reserves in times of financial pressures”
e1“using potato (Solanum tuberosum L.) as the test crop”
The same questions in other papers
potassium · yield · Solanum tuberosum (potato)Results differ
7 papers in the same direction as this paper · 61 in the opposite direction
- positive
- positive
- positive
65 papers more in this group
See all 69 papers →soil water · nutrient: content · Solanum tuberosum (potato)Results agree
1 paper in the same direction as this paper
- positive
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.