Abstract
Abstract Much of the nutritional research on soybean [ Glycine max (L.) Merrill] nodulation has been under greenhouse or laboratory conditions. Additional field data are needed on the influence of nutrients on nodulation and other plant characteristics. The purpose of this investigation was to determine under field conditions the effects of P and K fertilization on number and weight of soybean nodules; the chemical composition of leaves, nodules, and seed; the number of pods per plant; and seed yield. Annual P rates of 0, 15, 30, and 60 kg/ha were applied with 0 and 112 kg K/ha in one field experiment. In another, annual K rates of 0, 28, 56, and 112 kg/ha were applied with 0 and 60 kg P/ha. Either P or K applied alone increased the number of nodules per plant and per unit volume of soil. Applied K increased the number of nodules, total and individual weight of nodules, and the number of pods per plant more than P, but increases were largest when both P and K were applied. Applied K increased the K concentration of nodules, but had little influence on N, P, Ca, Cu, Fe, Mn, and Zn concentration, and decreased Mg; applied P without K increased the P concentration. There was a good correlation between the relative concentrations of P and K in leaves sampled for each of four different sampling dates and the concentration of these elements in the seed. Applied P in excess of 15 kg/ha did not increase soybean yields. Each additional increment of K up to the maximum used (112 kg/ha) resulted in seed yield increases when P was also applied, but with no added P seed yield responses to more than 28 kg K/ha were not significant. These results showed that application of both P and K individually increased nodulation and pod formation with more response from K than P. Maximum response was obtained when both elements were added. Even though the soil was very low in available P when the experiment was initiated there was no seed yield response to more than 15 kg P/ha. A good yield response was obtained from 28 kg K/ha and to increasing rates of K when 60 kg P/ha was added, thus indicating the higher requirement of soybeans for K than for P.
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Claims 12
Claim · model-written summary
Phosphorus alone increased soybean nodules per plant and per soil volume.
- Taxon
- soybean
Glycine maxt0 - Treatment
- Pe0
- Outcome
- number of nodules per plant and per unit volume of soile0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Either P or K applied alone increased the number of nodules per plant and per unit volume of soil”
t0“Soybean”
Claim · model-written summary
Potassium alone increased soybean nodules per plant and per soil volume.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Ke0
- Outcome
- number of nodules per plant and per unit volume of soile0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Either P or K applied alone increased the number of nodules per plant and per unit volume of soil”
t0“Soybean”
Claim · model-written summary
Potassium increased nodule number and weight and pods per plant more than phosphorus.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Ke0
- Outcome
- number of nodules, total and individual weight of nodules, and the number of pods per plante0
- Direction
- increasede0
- Comparator
- Pe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Applied K increased the number of nodules, total and individual weight of nodules, and the number of pods per plant more than P”
t0“Soybean”
Claim · model-written summary
Combined phosphorus and potassium gave the largest increases.
- Taxon
- soybeanGlycine maxt0
- Treatment
- both P and Ke0
- Outcome
- increasese0
- Direction
- largeste0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increases were largest when both P and K were applied”
t0“Soybean”
Claim · model-written summary
Potassium increased nodule potassium concentration.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Ke0
- Outcome
- K concentration of nodulese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Applied K increased the K concentration of nodules”
t0“Soybean”
Claim · model-written summary
Potassium had little influence on several other nodule nutrients.
- Taxon
- soybeanGlycine maxt0
- Outcome
- N, P, Ca, Cu, Fe, Mn, and Zn concentratione0
- Direction
- little influencee0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“had little influence on N, P, Ca, Cu, Fe, Mn, and Zn concentration”
t0“Soybean”
Claim · model-written summary
Potassium decreased nodule magnesium concentration.
- Taxon
- soybeanGlycine maxt0
- Outcome
- Mge0
- Direction
- decreasede0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and decreased Mg”
t0“Soybean”
Claim · model-written summary
Phosphorus without potassium increased nodule phosphorus concentration.
- Taxon
- soybeanGlycine maxt0
- Treatment
- P without Ke0
- Outcome
- P concentratione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“applied P without K increased the P concentration”
t0“Soybean”
Claim · model-written summary
Leaf and seed phosphorus and potassium concentrations were correlated.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- leavese0
- Outcome
- concentration of these elements in the seede0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was a good correlation between the relative concentrations of P and K in leaves sampled for each of four different sampling dates and the concentration of these elements in the seed”
t0“Soybean”
Claim · model-written summary
Phosphorus above 15 kg/ha did not increase soybean yield.
- Taxon
- soybeanGlycine maxe0
- Treatment
- P in excess of 15 kg/hae0
- Outcome
- soybean yieldse0
- Direction
- did not increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Applied P in excess of 15 kg/ha did not increase soybean yields”
Claim · model-written summary
Each potassium increment to 112 kg/ha increased seed yield when phosphorus was applied.
- Taxon
- soybeanGlycine maxt0
- Treatment
- K up to the maximum used (112 kg/ha)e0
- Outcome
- seed yielde0
- Direction
- increasese0
- Qualifier
- when P was also appliede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Each additional increment of K up to the maximum used (112 kg/ha) resulted in seed yield increases when P was also applied”
t0“Soybean”
Claim · model-written summary
Without added phosphorus, potassium above 28 kg/ha did not significantly increase yield.
- Taxon
- soybeanGlycine maxt0
- Treatment
- more than 28 kg K/hae0
- Outcome
- seed yield responsese0
- Qualifier
- with no added Pe0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with no added P seed yield responses to more than 28 kg K/ha were not significant”
t0“Soybean”
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See all 81 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.