Abstract
Exchangeable Al in subsoils of Ultisols in the southeastern USA can restrict rooting depth. Downward movement of basic cations (Ca, Mg, and K), applied as lime and fertilizer, may diminish that restriction over time. Materials from the argillic horizon were collected from three paired sites, having managed (long-term cropping) and nonmanaged topsoils (Typic Paleudults and Hapludults). One managed site was cropped continuously for 15 yr while the others were cultivated for more than 30 yr. Concentrations of extractable cations and other nutrients from the paired sites were compared to determine the magnitude of change due to management. The ability of the subsoils to support plant growth was evaluated in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]. Subsoils of managed sites had greater effective cation-exchange capacity (CEC) and base saturation than those of non-managed sites. While availabilities of Ca, Mg, and K in subsoils of nonmanaged sites were inadequate to support maximal plant growth, they were adequate in subsoils of managed sites. Compared with nonmanaged sites, KCl-exchangeable Al in subsoils of managed sites was 23% lower at the 15-yr location and 65 and 100% lower at the two other locations. In the absence of lime, sorghum growth was almost totally inhibited on nonmanaged subsoils amended with optimum nutrients. On the managed subsoils, where 100, 65, and 23% of the nonmanaged exchangeable Al had been neutralized by topsoil fertilization and liming, growth reductions under the same conditions were 0, 50, and 100%, respectively. Thus, relatively long-term management had improved these Ultisol subsoils for root growth and development.
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Claims 6
Claim · model-written summary
Managed Ultisol subsoils had greater effective CEC and base saturation than non-managed subsoils.
- Treatment
- managed sitese0
- Outcome
- effective cation-exchange capacity (CEC) and base saturatione0
- Direction
- greatere0
- Comparator
- non-managed sitese0
- Setting
- southeastern USAe7
SorghumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Subsoils of managed sites had greater effective cation-exchange capacity (CEC) and base saturation than those of non-managed sites”
e6“in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]”
e7“Exchangeable Al in subsoils of Ultisols in the southeastern USA can restrict rooting depth”
Claim · model-written summary
KCl-exchangeable Al in managed subsoils was 23% lower at the 15-year location than in non-managed subsoils.
- Treatment
- managed sitese1
- Outcome
- KCl-exchangeable Al in subsoilse1
- Direction
- lowere1
- Value
- 23%e1
- Comparator
- non-managed sitese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Subsoils of managed sites had greater effective cation-exchange capacity (CEC) and base saturation than those of non-managed sites”
e1“KCl-exchangeable Al in subsoils of managed sites was 23% lower at the 15-yr location”
e6“in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]”
Claim · model-written summary
KCl-exchangeable Al in managed subsoils was 65 and 100% lower at the two other locations than in non-managed subsoils.
- Treatment
- managed sitese1
- Outcome
- KCl-exchangeable Al in subsoilse1
- Direction
- lowere2
- Value
- 65 and 100%e2
- Qualifier
- at the two other locationse2
- Comparator
- non-managed sitese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Subsoils of managed sites had greater effective cation-exchange capacity (CEC) and base saturation than those of non-managed sites”
e1“KCl-exchangeable Al in subsoils of managed sites was 23% lower at the 15-yr location”
e2“65 and 100% lower at the two other locations”
e6“in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]”
Claim · model-written summary
Sorghum growth was almost totally inhibited on non-managed subsoils amended with optimum nutrients when lime was absent.
- Treatment
- optimum nutrientse3
- Outcome
- sorghum growthe3
- Direction
- inhibitede3
- Qualifier
- In the absence of limee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“In the absence of lime, sorghum growth was almost totally inhibited on nonmanaged subsoils amended with optimum nutrients”
Claim · model-written summary
Growth reductions of sorghum on managed subsoils were 0, 50, and 100% for the three sites.
- Treatment
- topsoil fertilization and liminge7
- Outcome
- growth reductionse4
- Direction
- decreaseinferrede4
- Value
- 0, 50, and 100%e4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“growth reductions under the same conditions were 0, 50, and 100%, respectively”
e7“On the managed subsoils, where 100, 65, and 23% of the nonmanaged exchangeable Al had been neutralized by topsoil fertilization and liming”
e6“in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]”
Claim · model-written summary
Long-term management improved Ultisol subsoils for sorghum root growth and development.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“relatively long-term management had improved these Ultisol subsoils for root growth and development”
e6“in a missing-nutrient greenhouse experiment with sorghum [Sorghum bicolor (L.) Moench]”
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See all 8 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.