Abstract
Studies with four‐year‐old ‘Vernal’ alfalfa ( Medicago saliva L.) fertilized yearly from planting with 673 kg/ha K as K 2 SO 4 or KC1 and 448 kg/ha K as K 2 SO 4 were made to determine the effects of K on nodulation, acetylene reduction, and nodule enzyme activities. The high rates of K fertilization increased nodule number and acetylene reduction rates over control plants, although the greatest increase in nodule mass and acetylene reduction rates was with the 673 kg/ha K as K 2 SO 4 treatment. This indicates that Cl and/or S may alter or mask the effects of K fertilization. Increases in acetylene reduction rates on a plant basis with K fertilization were due to increases in nodule mass and not increases in activity per unit weight of nodule tissue. With all treatments a positive linear correlation (P <0.01, r = 0.854) was found between nodule number and acetylene reduction rate. The greatest increase in shoot weight per plant over control plants was with the 673 kg/ha K as KC1 treatment. Positive linear correlations were found between rates of acetylene reduction and the activities of enzymes involved in ammonia assimilation (NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenase), amino acid interconversions (glutamate oxaloacetate transaminase), C supply (NADP‐isocitrate dehydrogenase) and energy transduction (glucose‐6‐phosphate dehydrogenase, malate dehydrogenase). Due to lower nodule protein concentrations and higher nodule masses in the K treatments, specific activities and, in general, activities on a per plant basis of enzymes assayed from K treatments were much higher than those of the control treatment. Malate dehydrogenase and NADP‐glutamate dehydrogenase specific activities were significantly higher than control plants for both 673 kg/ha K treatments. There were few differences between treatments for enzyme data calculated on a gram fresh‐weight basis. Yields of the two 673 kg/ha K treatments were nearly equal at third cut and were significantly higher than those of control plants. These data suggest that K fertilization increases alfalfa yields by increasing nodulation and N 2 ‐fixation.
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Claims 16
Claim · model-written summary
High rates of K fertilization increased nodule number and acetylene reduction rates over control plants.
- Taxon
- alfalfa
Medicago sativae1 - Material
- Vernale1
- Treatment
- high rates of K fertilizatione2
- Outcome
- nodule number and acetylene reduction ratese2
- Direction
- increasede2
- Comparator
- control plantse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“The high rates of K fertilization increased nodule number and acetylene reduction rates over control plants”
Claim · model-written summary
The 673 kg/ha K as K2SO4 treatment gave the greatest increase in nodule mass and acetylene reduction rates.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- 673 kg/ha K as K 2 SO 4e3
- Outcome
- nodule mass and acetylene reduction ratese3
- Direction
- increasee3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e3“the greatest increase in nodule mass and acetylene reduction rates was with the 673 kg/ha K as K 2 SO 4 treatment”
Claim · model-written summary
Acetylene reduction rates on a plant basis rose with K fertilization because nodule mass increased, not because activity per unit nodule tissue increased.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- K fertilizatione4
- Outcome
- acetylene reduction rates on a plant basise4
- Qualifier
- due to increases in nodule mass and not increases in activity per unit weight of nodule tissuee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e4“Increases in acetylene reduction rates on a plant basis with K fertilization were due to increases in nodule mass and not increases in activity per unit weight of nodule tissue”
Claim · model-written summary
Nodule number and acetylene reduction rate are positively and linearly correlated across all treatments (r = 0.854, P < 0.01).
- Taxon
- alfalfaMedicago sativae1
- Treatment
- all treatmentse5
- Outcome
- acetylene reduction ratee5
- Direction
- positivee5
- Value
- r = 0.854e5
- Qualifier
- nodule numbere5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e5“With all treatments a positive linear correlation (P <0.01, r = 0.854) was found between nodule number and acetylene reduction rate”
Claim · model-written summary
Acetylene reduction rates are positively correlated with ammonia-assimilation enzymes NAD-glutamate dehydrogenase, glutamine synthetase and NADP-glutamate dehydrogenase.
- Taxon
- alfalfaMedicago sativae1
- Gene
- NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenasee6
- Outcome
- rates of acetylene reductione6
- Direction
- Positivee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e6“Positive linear correlations were found between rates of acetylene reduction and the activities of enzymes involved in ammonia assimilation (NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenase)”
Claim · model-written summary
Acetylene reduction rates are positively correlated with glutamate oxaloacetate transaminase.
- Taxon
- alfalfaMedicago sativae1
- Gene
- glutamate oxaloacetate transaminasee7
- Outcome
- rates of acetylene reductione6
- Direction
- Positivee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e6“Positive linear correlations were found between rates of acetylene reduction and the activities of enzymes involved in ammonia assimilation (NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenase)”
e7“amino acid interconversions (glutamate oxaloacetate transaminase), C supply (NADP‐isocitrate dehydrogenase) and energy transduction (glucose‐6‐phosphate dehydrogenase, malate dehydrogenase)”
Claim · model-written summary
Acetylene reduction rates are positively correlated with NADP-isocitrate dehydrogenase.
- Taxon
- alfalfaMedicago sativae1
- Gene
- NADP‐isocitrate dehydrogenasee7
- Outcome
- rates of acetylene reductione6
- Direction
- Positivee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e6“Positive linear correlations were found between rates of acetylene reduction and the activities of enzymes involved in ammonia assimilation (NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenase)”
e7“amino acid interconversions (glutamate oxaloacetate transaminase), C supply (NADP‐isocitrate dehydrogenase) and energy transduction (glucose‐6‐phosphate dehydrogenase, malate dehydrogenase)”
Claim · model-written summary
Acetylene reduction rates are positively correlated with glucose-6-phosphate dehydrogenase and malate dehydrogenase.
- Taxon
- alfalfaMedicago sativae1
- Gene
- glucose‐6‐phosphate dehydrogenase, malate dehydrogenasee7
- Outcome
- rates of acetylene reductione6
- Direction
- Positivee6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e6“Positive linear correlations were found between rates of acetylene reduction and the activities of enzymes involved in ammonia assimilation (NAD‐glutamate dehydrogenase, glutamine synthetase, NADP‐glutamate dehydrogenase)”
e7“amino acid interconversions (glutamate oxaloacetate transaminase), C supply (NADP‐isocitrate dehydrogenase) and energy transduction (glucose‐6‐phosphate dehydrogenase, malate dehydrogenase)”
Claim · model-written summary
Specific activities of nodule enzymes were much higher in K treatments than in the control, because nodule protein concentrations were lower and nodule masses higher.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- K treatmentse2
- Outcome
- specific activitiese2
- Direction
- much highere2
- Qualifier
- lower nodule protein concentrations and higher nodule massese2
- Comparator
- control treatmente2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“Due to lower nodule protein concentrations and higher nodule masses in the K treatments, specific activities and, in general, activities on a per plant basis of enzymes assayed from K treatments were much higher than those of the control treatment”
Claim · model-written summary
Malate dehydrogenase and NADP-glutamate dehydrogenase specific activities were significantly higher than in control plants for both 673 kg/ha K treatments.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- both 673 kg/ha K treatmentse2
- Gene
- Malate dehydrogenase and NADP‐glutamate dehydrogenasee2
- Outcome
- specific activitiese2
- Direction
- highere2
- Comparator
- control plantse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“Malate dehydrogenase and NADP‐glutamate dehydrogenase specific activities were significantly higher than control plants for both 673 kg/ha K treatments”
Claim · model-written summary
Enzyme data on a gram fresh-weight basis showed few differences between treatments.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- enzyme data calculated on a gram fresh‐weight basise2
- Qualifier
- few differences between treatmentse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“There were few differences between treatments for enzyme data calculated on a gram fresh‐weight basis”
Claim · model-written summary
Yields of the two 673 kg/ha K treatments were nearly equal at third cut.
- Taxon
- alfalfaMedicago sativae1
- Outcome
- Yieldse2
- Qualifier
- nearly equal at third cute2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“Yields of the two 673 kg/ha K treatments were nearly equal at third cut and were significantly higher than those of control plants”
Claim · model-written summary
Yields of the 673 kg/ha K treatments were significantly higher than those of control plants.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- 673 kg/ha K treatmentse2
- Outcome
- Yieldse2
- Direction
- highere2
- Comparator
- control plantse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“Yields of the two 673 kg/ha K treatments were nearly equal at third cut and were significantly higher than those of control plants”
Claim · model-written summary
The 673 kg/ha K as KC1 treatment gave the greatest increase in shoot weight per plant over control plants.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- 673 kg/ha K as KC1e2
- Outcome
- shoot weight per plante2
- Direction
- increasee2
- Comparator
- control plantse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“The greatest increase in shoot weight per plant over control plants was with the 673 kg/ha K as KC1 treatment”
Claim · model-written summary
K fertilization is proposed to increase alfalfa yields by increasing nodulation and N2 fixation.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- K fertilizatione1
- Outcome
- alfalfa yieldse1
- Qualifier
- by increasing nodulation and N 2 ‐fixatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“These data suggest that K fertilization increases alfalfa yields by increasing nodulation and N 2 ‐fixation”
Claim · model-written summary
Cl and/or S may alter or mask the effects of K fertilization on alfalfa.
- Taxon
- alfalfaMedicago sativae1
- Treatment
- K fertilizatione2
- Outcome
- effects of K fertilizatione2
- Qualifier
- Cl and/or S may alter or maske2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“‘Vernal’ alfalfa ( Medicago saliva L.)”
e2“This indicates that Cl and/or S may alter or mask the effects of K fertilization”
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fertilization · symbiosis · Medicago sativa (alfalfa)Results differ
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See all 38 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.