Abstract
Abstract In the southeastern Coastal Plain, soybean [ Glycine max (L.) Merr.] is normally grown on soils that are often exposed to drought and leaching rains as well as being low in available N. A field study was conducted to evaluate the impact of water management on accumulation of soil and symbiotically fixed N by soybean grown on these type soils. Nodulating and nonnodulating isolines of ‘Lee’ cultivar soybean were grown under irrigated and nonirrigated conditions in 1979 and 1980 on a Norfolk loamy sand (fine‐loamy, mixed, mesic Typic Paleudults). A period of excessive rainfall occurred in 1979, while a major drought occurred in 1980. Irrigated treatments had lower soil‐NO ‐ 3 concentrations in the Ap horizon than nonirrigated treatments during 1979, but there was no effect of irrigation on soil NO ‐ 3 in 1980. Dinitrogen fixation, as estimated by the difference in N accumulation between nodulating and nonnodulating isolines, accounted for 76 to 91% of total plant N in the irrigated plots and 55 to 60% in the nonirrigated plots. Estimates of total plant N fixed exceeded 1100 mg/plant for the irrigated plots in 1979 and 1980. Maximum N accumulation for the nodulating isoline occurred in the nonirrigated plots in 1979 and in the irrigated plots in 1980. However, the nonnodulating isoline had maximum accumulations of both N and dry matter in the nonirrigated treatments in both 1979 and 1980. The number of nodules/plant and the C 2 H 2 ‐reducing activity were significantly higher in the irrigated plots during the pod growth stages in 1980. Irrigation did not significantly affect seed yield of nodulating Lee soybean in 1979, but did result in a twofold increase in 1980. The effects of irrigation on the Lee nonnodulating isoline resulted in a positive yield response in 1980, but a negative response in 1979. These findings show that a major portion of the N‐requirement for soybean in the southeastern Coastal Plain is met by fixation and that the relative importance of fixed N may vary substantially with rainfall patterns and irrigation.
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Claims 14
Claim · model-written summary
Irrigated treatments had lower soil NO3 concentrations in the Ap horizon than nonirrigated treatments in 1979.
- Taxon
- soybean
Glycine maxe0 - Treatment
- Irrigated treatmentse1
- Outcome
- soil‐NO ‐ 3 concentrations in the Ap horizone1
- Direction
- lowere1
- Qualifier
- during 1979e1
- Comparator
- nonirrigated treatmentse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Irrigated treatments had lower soil‐NO ‐ 3 concentrations in the Ap horizon than nonirrigated treatments during 1979”
Claim · model-written summary
Irrigation had no effect on soil NO3 in 1980.
- Taxon
- soybeanGlycine maxe0
- Treatment
- irrigatione1
- Outcome
- soil NO ‐ 3e1
- Direction
- no_changeinferrede1
- Qualifier
- in 1980e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“there was no effect of irrigation on soil NO ‐ 3 in 1980”
Claim · model-written summary
Dinitrogen fixation accounted for 76 to 91% of total plant N in the irrigated plots.
- Taxon
- soybeanGlycine maxe0
- Treatment
- irrigated plotse1
- Outcome
- Dinitrogen fixatione1
- Value
- 76 to 91%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Dinitrogen fixation, as estimated by the difference in N accumulation between nodulating and nonnodulating isolines, accounted for 76 to 91% of total plant N in the irrigated plots and 55 to 60% in the nonirrigated plots”
Claim · model-written summary
Dinitrogen fixation accounted for 55 to 60% of total plant N in the nonirrigated plots.
- Taxon
- soybeanGlycine maxe0
- Treatment
- nonirrigated plotse1
- Outcome
- Dinitrogen fixatione1
- Value
- 55 to 60%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Dinitrogen fixation, as estimated by the difference in N accumulation between nodulating and nonnodulating isolines, accounted for 76 to 91% of total plant N in the irrigated plots and 55 to 60% in the nonirrigated plots”
Claim · model-written summary
Estimates of total plant N fixed exceeded 1100 mg/plant in the irrigated plots in 1979 and 1980.
- Taxon
- soybeanGlycine maxe0
- Treatment
- the irrigated plotse1
- Outcome
- total plant N fixede1
- Direction
- exceedede1
- Value
- 1100 mg/plante1
- Qualifier
- in 1979 and 1980e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Estimates of total plant N fixed exceeded 1100 mg/plant for the irrigated plots in 1979 and 1980”
Claim · model-written summary
Maximum N accumulation for the nodulating isoline occurred in the nonirrigated plots in 1979 and in the irrigated plots in 1980.
- Taxon
- soybeanGlycine maxe0
- Material
- nodulating isolinee1
- Treatment
- nonirrigated plotse1
- Outcome
- Maximum N accumulatione1
- Qualifier
- in 1979 and in the irrigated plots in 1980e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Maximum N accumulation for the nodulating isoline occurred in the nonirrigated plots in 1979 and in the irrigated plots in 1980”
Claim · model-written summary
The nonnodulating isoline had maximum accumulations of both N and dry matter in the nonirrigated treatments in 1979 and 1980.
- Taxon
- soybeanGlycine maxe0
- Material
- nonnodulating isolinee1
- Treatment
- nonirrigated treatmentse1
- Outcome
- maximum accumulations of both N and dry mattere1
- Qualifier
- in both 1979 and 1980e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“the nonnodulating isoline had maximum accumulations of both N and dry matter in the nonirrigated treatments in both 1979 and 1980”
Claim · model-written summary
Nodules per plant and C2H2-reducing activity were significantly higher in the irrigated plots during the pod growth stages in 1980.
- Taxon
- soybeanGlycine maxe0
- Organ / stage
- pod growth stagese1
- Treatment
- irrigated plotse1
- Outcome
- The number of nodules/plant and the C 2 H 2 ‐reducing activitye1
- Direction
- highere1
- Qualifier
- in 1980e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“The number of nodules/plant and the C 2 H 2 ‐reducing activity were significantly higher in the irrigated plots during the pod growth stages in 1980”
Claim · model-written summary
Irrigation did not significantly affect seed yield of nodulating Lee soybean in 1979.
- Taxon
- soybeanGlycine maxe0
- Material
- nodulating Leee1
- Treatment
- Irrigatione1
- Outcome
- seed yielde1
- Direction
- no_changeinferrede1
- Qualifier
- in 1979e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Irrigation did not significantly affect seed yield of nodulating Lee soybean in 1979, but did result in a twofold increase in 1980”
Claim · model-written summary
Irrigation resulted in a twofold increase in seed yield of nodulating Lee soybean in 1980.
- Taxon
- soybeanGlycine maxe0
- Material
- nodulating Leee1
- Treatment
- Irrigatione1
- Outcome
- seed yielde1
- Direction
- increasee1
- Value
- twofolde1
- Qualifier
- in 1980e1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“Irrigation did not significantly affect seed yield of nodulating Lee soybean in 1979, but did result in a twofold increase in 1980”
Claim · model-written summary
Irrigation effects on the nonnodulating Lee isoline gave a positive yield response in 1980.
- Taxon
- soybeanGlycine maxe0
- Material
- Lee nonnodulating isolinee2
- Treatment
- effects of irrigatione2
- Outcome
- yield responsee2
- Direction
- increaseinferrede2
- Qualifier
- in 1980e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e2“The effects of irrigation on the Lee nonnodulating isoline resulted in a positive yield response in 1980, but a negative response in 1979”
Claim · model-written summary
Irrigation effects on the nonnodulating Lee isoline gave a negative yield response in 1979.
- Taxon
- soybeanGlycine maxe0
- Material
- Lee nonnodulating isolinee2
- Treatment
- effects of irrigatione2
- Outcome
- yield responsee2
- Direction
- decreaseinferrede2
- Qualifier
- in 1979e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e2“The effects of irrigation on the Lee nonnodulating isoline resulted in a positive yield response in 1980, but a negative response in 1979”
Claim · model-written summary
A major portion of the N-requirement for soybean in the southeastern Coastal Plain is met by fixation.
- Taxon
- soybeanGlycine maxe0
- Outcome
- a major portion of the N‐requiremente1
- Qualifier
- met by fixatione1
- Setting
- southeastern Coastal Plaine1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“These findings show that a major portion of the N‐requirement for soybean in the southeastern Coastal Plain is met by fixation”
Claim · model-written summary
The relative importance of fixed N may vary with rainfall patterns and irrigation.
- Taxon
- soybeanGlycine maxe0
- Treatment
- rainfall patterns and irrigatione1
- Outcome
- relative importance of fixed Ne1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [ Glycine max (L.) Merr.]”
e1“the relative importance of fixed N may vary substantially with rainfall patterns and irrigation”
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See all 343 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.