Abstract
A series of field, greenhouse and laboratory experiments were conducted to examine the influence of soil acidity and liming on the growth of Rhizobium and the nodulation, nitrogen fixation, and yield of alfalfa and red clover. In the greenhouse, from soil pH 5.0 to 5.6, nitrogen fixation was shown to be more correlated to Al saturation than pH or available P. Once Al saturation was reduced to less than 5 percent by liming, the application of P was more beneficial to yield and nodulation than further application of lime. Lime pelleted alfalfa seed sown at a soil pH of 5.0 increased nodule weight and number but did not improve nitrogen fixation or yield. Increasing the soil pH by soil-incorporation of lime eliminated the advantage of pelleting. The growth response of red clover to liming was less than for alfalfa. Work with ('32)P in hydroponics showed that red clover was capable of mobilizing P under acidic conditions in the presence of Al to a greater degree than alfalfa. The ratio of Al/P in the nodules was significantly less in red clover than alfalfa as measured by electron dispersive analysis by X-ray. Using an aeroponic culture, nitrogen fixation by red clover was more tolerant than alfalfa to Al stress at pH 5.0. The addition of nitrogen, however, reduced nitrogen fixation in both legumes by over 90 percent after four weeks. Nitrate reductase activity in red clover was shown to be four to five times that in alfalfa when the plants were grown at pH 5.6. The addition of fertilizer nitrogen to the soil increased nitrate reductase activity in both legumes with a compensatory decrease in nitrogen fixation such that yields were not affected. The growth of Rhizobium meliloti in acidic media was shown to be influenced by Al. At pH 5.0, the addition of the element severely reduced growth in the three strains tested. At pH 5.5, there was an increase in growth lag, but the strains demonstrated a differential adaptation to the toxicity. In order to test the effectiveness of these strains in soil, three alfalfa varieties were inoculated and seeded into sterile soil at pH 5.0, 5.5, and 6.0. No single combination of strain-variety gave the highest yield, nodule number, or nitrogen fixation for all three soil pH's. Two field experiments were established to study the influence of banded/broadcast lime and phosphorus on the growth of alfalfa and red clover established by minimum tillage in an acidic soil. In the Harmony Hill experiment, lime rate from 4.6 to 13.8 t/ha had no influence in the soil pH of the top 5 cm of the profile. At greater depths, the higher lime rates raised pH and significantly increased yields. Banded lime did not improve yields, percent legume, or stand persistence. One year after establishment, red clover averaged less than 25 percent of the stand; inspection indicated severe internal breakdown and secondary infection by Fusarium solani. The effects of low P and high Al saturation in the subsoil on alfalfa stand persistance is not known. In the Demerit experiment, hydrated lime increased the soil pH from 5.6 to over 6.5 in the top 5 cm of the soil one month after liming but actually reduced yield and nodulation of the legume. The application of broadcast P decreased the Al saturation in the unlimed plots in the top 5 cm of the soil to levels comparable to the dolomitic and hydrated lime plots. The yields of alfalfa in the unlimed plots equaled those in the limed plots when both sites received a single addition of banded monoammonium phosphate. These higher yields in the banded plots occurred in the first spring harvest following the August 1978 seeding and may have resulted from the presence of both N and P in the band. Results from the two field experiments indicated that good yields of alfalfa can be achieved in the year following establishment in the acidity is reduced in the top 10 cm of the soil profile and adequate P is present; longevity of the stand remains undetermined.
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 20
Claim · model-written summary
In the greenhouse, nitrogen fixation was more correlated with Al saturation than with pH or available P in soils at pH 5.0 to 5.6.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- Al saturatione1
- Outcome
- nitrogen fixatione1
- Setting
- greenhousee1
Not reportedDirection
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“In the greenhouse, from soil pH 5.0 to 5.6, nitrogen fixation was shown to be more correlated to Al saturation than pH or available P”
Claim · model-written summary
Once Al saturation was reduced below 5% by liming, applied P was more beneficial to yield and nodulation than further lime.
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“Once Al saturation was reduced to less than 5 percent by liming, the application of P was more beneficial to yield and nodulation than further application of lime”
Claim · model-written summary
Lime pelleting of alfalfa seed sown at soil pH 5.0 increased nodule weight and number.
- Taxon
- alfalfa
Medicago sativae1 - Treatment
- Lime pelleted alfalfa seede1
- Outcome
- nodule weight and numbere1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Lime pelleted alfalfa seed sown at a soil pH of 5.0 increased nodule weight and number but did not improve nitrogen fixation or yield”
Claim · model-written summary
Lime pelleting of alfalfa seed did not improve nitrogen fixation or yield.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- Lime pelleted alfalfa seede1
- Outcome
- nitrogen fixation or yielde1
- Direction
- did not improvee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Lime pelleted alfalfa seed sown at a soil pH of 5.0 increased nodule weight and number but did not improve nitrogen fixation or yield”
Claim · model-written summary
The growth response of red clover to liming was less than that of alfalfa.
- Taxon
- red clover
Trifolium pratensee1 - Treatment
- liminge1
- Outcome
- growth responsee1
- Direction
- lesse1
- Comparator
- alfalfae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The growth response of red clover to liming was less than for alfalfa”
Claim · model-written summary
Red clover mobilized P under acidic conditions with Al to a greater degree than alfalfa in hydroponics.
- Taxon
- red cloverTrifolium pratensee1
- Treatment
- acidic conditions in the presence of Ale1
- Outcome
- mobilizing Pe1
- Direction
- to a greater degreee1
- Comparator
- alfalfae1
- Setting
- hydroponicse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Work with ('32)P in hydroponics showed that red clover was capable of mobilizing P under acidic conditions in the presence of Al to a greater degree than alfalfa”
Claim · model-written summary
The Al/P ratio in red clover nodules was significantly lower than in alfalfa nodules.
- Taxon
- red cloverTrifolium pratensee1
- Outcome
- ratio of Al/P in the nodulese1
- Direction
- significantly lesse1
- Comparator
- alfalfae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The ratio of Al/P in the nodules was significantly less in red clover than alfalfa”
Claim · model-written summary
Nitrogen fixation by red clover was more tolerant to Al stress at pH 5.0 than that of alfalfa in an aeroponic culture.
- Taxon
- red cloverTrifolium pratensee1
- Treatment
- Al stresse1
- Outcome
- nitrogen fixatione1
- Direction
- more tolerante1
- Comparator
- alfalfae1
- Setting
- aeroponic culturee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Using an aeroponic culture, nitrogen fixation by red clover was more tolerant than alfalfa to Al stress at pH 5.0”
Claim · model-written summary
Adding nitrogen reduced nitrogen fixation in both legumes by over 90% after four weeks.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- The addition of nitrogene1
- Outcome
- nitrogen fixatione1
- Direction
- reducede1
- Value
- over 90 percente1
- Qualifier
- after four weekse1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“The addition of nitrogen, however, reduced nitrogen fixation in both legumes by over 90 percent after four weeks”
Claim · model-written summary
Nitrate reductase activity in red clover was about four to five times that in alfalfa when grown at pH 5.6.
- Taxon
- red cloverTrifolium pratensee1
- Outcome
- Nitrate reductase activitye1
- Direction
- higherinferrede1
- Value
- four to five timese1
- Qualifier
- when the plants were grown at pH 5.6e1
- Comparator
- alfalfae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrate reductase activity in red clover was shown to be four to five times that in alfalfa when the plants were grown at pH 5.6”
Claim · model-written summary
Adding fertilizer nitrogen to the soil increased nitrate reductase activity in both legumes.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- The addition of fertilizer nitrogen to the soile1
- Outcome
- nitrate reductase activitye1
- Direction
- increasede1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“The addition of fertilizer nitrogen to the soil increased nitrate reductase activity in both legumes with a compensatory decrease in nitrogen fixation such that yields were not affected”
Claim · model-written summary
Adding fertilizer nitrogen to the soil caused a compensatory decrease in nitrogen fixation in both legumes, with yields not affected.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- The addition of fertilizer nitrogen to the soile1
- Outcome
- nitrogen fixatione1
- Direction
- compensatory decreasee1
- Qualifier
- yields were not affectede1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“The addition of fertilizer nitrogen to the soil increased nitrate reductase activity in both legumes with a compensatory decrease in nitrogen fixation such that yields were not affected”
Claim · model-written summary
At pH 5.0, the addition of the element severely reduced growth of Rhizobium meliloti strains.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- the addition of the elemente1
- Interactor
- Rhizobium meliloti
Sinorhizobium melilotie2symbiont - Outcome
- growth of Rhizobium melilotie2
- Direction
- severely reducede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“At pH 5.0, the addition of the element severely reduced growth in the three strains tested”
e2“The growth of Rhizobium meliloti in acidic media was shown to be influenced by Al”
Claim · model-written summary
No single alfalfa or red clover strain-variety combination gave the highest yield, nodule number or nitrogen fixation across the three soil pH levels.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Outcome
- yield, nodule number, or nitrogen fixatione1
- Qualifier
- for all three soil pH'se1
Not reportedDirection
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“No single combination of strain-variety gave the highest yield, nodule number, or nitrogen fixation for all three soil pH's”
Claim · model-written summary
At greater depths, higher lime rates significantly increased yields.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- the higher lime ratese1
- Outcome
- yieldse1
- Direction
- significantly increasede1
- Qualifier
- At greater depthse1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“At greater depths, the higher lime rates raised pH and significantly increased yields”
Claim · model-written summary
Banded lime did not improve yields, percent legume or stand persistence.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- Banded limee1
- Outcome
- yields, percent legume, or stand persistencee1
- Direction
- did not improvee1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“Banded lime did not improve yields, percent legume, or stand persistence”
Claim · model-written summary
One year after establishment, red clover averaged less than 25% of the stand, with severe internal breakdown and secondary infection by Fusarium solani.
- Taxon
- red cloverTrifolium pratensee1
- Interactor
- Fusarium solani
_Sacc._5393379.jpg?width=60)
Fusarium solanie1pathogen - Outcome
- the stande1
- Value
- less than 25 percente1
- Qualifier
- One year after establishmente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Sacc._5393379.jpg?width=500)
Verbatim
e1“One year after establishment, red clover averaged less than 25 percent of the stand; inspection indicated severe internal breakdown and secondary infection by Fusarium solani”
Claim · model-written summary
Hydrated lime raised soil pH but reduced yield and nodulation of the legume in the Demerit experiment.
- Taxon
- ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)t0
- Treatment
- hydrated limee1
- Outcome
- yield and nodulation of the legumee1
- Direction
- reducede1
- Qualifier
- from 5.6 to over 6.5e1
- Setting
- Demerit experimente1
Not reportedComparator
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“In the Demerit experiment, hydrated lime increased the soil pH from 5.6 to over 6.5 in the top 5 cm of the soil one month after liming but actually reduced yield and nodulation of the legume”
Claim · model-written summary
Broadcast P decreased Al saturation in the unlimed plots to levels comparable to the dolomitic and hydrated lime plots.
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“The application of broadcast P decreased the Al saturation in the unlimed plots in the top 5 cm of the soil to levels comparable to the dolomitic and hydrated lime plots”
Claim · model-written summary
Alfalfa yields in the unlimed plots equaled those in the limed plots when banded monoammonium phosphate was applied once.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- banded monoammonium phosphatee1
- Outcome
- yields of alfalfae1
- Direction
- equalede1
- Comparator
- limed plotse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“ALFALFA (MEDICAGO SATIVA L) AND RED CLOVER (TRIFOLIUM PRATENSE L)”
e1“The yields of alfalfa in the unlimed plots equaled those in the limed plots when both sites received a single addition of banded monoammonium phosphate”
The same questions in other papers
ammonium dihydrogen phosphate · yield · Medicago sativa (alfalfa)Positive and negative results
3 reporting no difference from an alternative
- positive
- positive
- positive
lime · yield · Trifolium pratense (red clover)Results differ
10 papers in the same direction as this paper
- positive
- positive
- positive
7 papers more in this group
See all 11 papers →nitrogen · symbiosis · Medicago sativa (alfalfa)Results differ
10 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
14 papers more in this group
See all 18 papers →lime · yield · Medicago sativa (alfalfa)Results differ
40 papers in the same direction as this paper · 9 in the opposite direction
- no effect
- no effect
- no effect
46 papers more in this group
See all 50 papers →nitrogen · symbiosis · Trifolium pratense (red clover)Positive and negative results
1 in the opposite direction
- positive
lime · symbiosis · Medicago sativa (alfalfa)Positive and negative results
9 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
7 papers more in this group
See all 11 papers →phosphorus · symbiosis · Medicago sativa (alfalfa)Results agree
3 papers in the same direction as this paper
- positive
- positive
- 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.