Abstract
It is well known that nodulation and nitrogen fixation of soybean are generally depressed by the application of N fertilizers. We previously reported that a new fertilization method consisting of deep placement of slow-release N fertilizers, such as coated urea and lime nitrogen (calcium cyanamide) at a 20 cm depth enhanced soybean growth and seed yield. In the present study, the effect of deep placement of various 15N-labeled N fertilizers (100 kg N ha−1) was compared in converted paddy fields located at Niigata Agricultural Research Institute, in Nagaoka. Fertilizers consisting of 15N-labeled ammonium sulfate (AS), urea (U), coated urea (CU) or lime nitrogen (LN) were applied at a 20 cm depth for nodulated soybean (cv. Enrei) and for a non-nodulated isogenic line (En1282). The plants without deep placement of N fertilizer were used as control (Cont) for both Enrei and En1282. Whole plants were sampled at maturing stage, and 15N abundance and N concentration in each part were determined. The evaluation of the amounts of Ndfa, Ndfs and Ndff was conducted by the 15N dilution method using En1282 as a reference plant. Also the amounts of Ndfa and Ndfs+Ndff were estimated by the N balance method for comparing Cont and the other treatments. In all the deep placement treatments, the non-nodulated line exhibited only 36–40% of total dry weight and 16-30% of total N accumulation compared with the nodulated line, due to N deficiency associated with the lack of nitrogen fixation. In both nodulated and non-nodulated soybeans, plant growth and the total amount of accumulated N showed the highest values by the application of LN, followed by CU, U, AS and Cont, respectively. The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments. The value of Ndfa estimated by the 15N dilution method was higher in the LN (3.6 g N plant−1) and CU (2.8 g N plant−1) treatments than in the U (2.3 g N plant−1) and AS (2.2 g N plant−1) treatments. In addition, the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1). The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment. These results indicate that deep placement of LN and CU is effective to improve soybean growth and seed yield. The combination of “deep placement” and “slow-release N fertilizers” is important to supply N until the maturation stage, resulting in the increase of seed yield.
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Claims 20
Claim · model-written summary
The nonnodulated line had 36–40% of the nodulated line total dry weight under deep placement.
- Taxon
- Soybean
Glycine maxt0 - Material
- non-nodulated linee0
- Treatment
- deep placement treatmentse0
- Outcome
- total dry weighte0
- Direction
- onlye0
- Value
- 36–40%e0
- Comparator
- nodulated linee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In all the deep placement treatments, the non-nodulated line exhibited only 36–40% of total dry weight and 16-30% of total N accumulation compared with the nodulated line”
t0“Soybean”
Claim · model-written summary
The nonnodulated line had 16-30% of the nodulated line total nitrogen accumulation.
- Taxon
- SoybeanGlycine maxt0
- Material
- non-nodulated linee0
- Treatment
- deep placement treatmentse0
- Outcome
- total N accumulatione0
- Direction
- onlye0
- Value
- 16-30%e0
- Comparator
- nodulated linee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In all the deep placement treatments, the non-nodulated line exhibited only 36–40% of total dry weight and 16-30% of total N accumulation compared with the nodulated line”
t0“Soybean”
Claim · model-written summary
For both lines, growth was ranked LN, CU, U, AS, then control.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- application of LNe0
- Outcome
- plant growthe0
- Direction
- higheste0
- Comparator
- CU, U, AS and Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In both nodulated and non-nodulated soybeans, plant growth and the total amount of accumulated N showed the highest values by the application of LN, followed by CU, U, AS and Cont, respectively.”
t0“Soybean”
Claim · model-written summary
For both lines, accumulated nitrogen was ranked LN, CU, U, AS, then control.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- application of LNe0
- Outcome
- total amount of accumulated Ne0
- Direction
- higheste0
- Comparator
- CU, U, AS and Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In both nodulated and non-nodulated soybeans, plant growth and the total amount of accumulated N showed the highest values by the application of LN, followed by CU, U, AS and Cont, respectively.”
t0“Soybean”
Claim · model-written summary
Enrei seed dry weight under LN was highest at 73 g per plant.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- LNe0
- Outcome
- seed dry weighte0
- Direction
- higheste0
- Value
- 73 g plant−1e0
- Comparator
- Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
Enrei seed dry weight under CU was 63 g per plant.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- CUe0
- Outcome
- seed dry weighte0
- Direction
- followed bye0
- Value
- 63 g plant−1e0
- Comparator
- Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
Enrei seed dry weight under U was 47 g per plant.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- Ue0
- Outcome
- seed dry weighte0
- Direction
- followed bye0
- Value
- 47 g plant−1e0
- Comparator
- Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
Enrei seed dry weight under AS was 37 g per plant.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- ASe0
- Outcome
- seed dry weighte0
- Direction
- followed bye0
- Value
- 37 g plant−1e0
- Comparator
- Conte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of the seed dry weight of Enrei was highest in the LN (73 g plant−1), followed by CU (63 g plant−1), U (47 g plant−1), AS (37 g plant−1) and Cont (26 g plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
The 15N dilution method estimated Ndfa of 3.6 g N per plant under LN.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- LNe0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 3.6 g N plant−1e0
- Qualifier
- 15N dilution methode0
- Comparator
- Ue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of Ndfa estimated by the 15N dilution method was higher in the LN (3.6 g N plant−1) and CU (2.8 g N plant−1) treatments than in the U (2.3 g N plant−1) and AS (2.2 g N plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
The 15N dilution method estimated Ndfa of 2.8 g N per plant under CU.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- CUe0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 2.8 g N plant−1e0
- Qualifier
- 15N dilution methode0
- Comparator
- Ue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The value of Ndfa estimated by the 15N dilution method was higher in the LN (3.6 g N plant−1) and CU (2.8 g N plant−1) treatments than in the U (2.3 g N plant−1) and AS (2.2 g N plant−1) treatments.”
t0“Soybean”
Claim · model-written summary
The N balance method estimated Ndfa of 4.1 g N per plant under LN.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- LNe0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 4.1 g N plant−1e0
- Qualifier
- N-balance methode0
- Comparator
- Cont treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1).”
t0“Soybean”
Claim · model-written summary
The N balance method estimated Ndfa of 3.9 g N per plant under CU.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- CUe0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 3.9 g N plant−1e0
- Qualifier
- N-balance methode0
- Comparator
- Cont treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1).”
t0“Soybean”
Claim · model-written summary
The N balance method estimated Ndfa of 2.8 g N per plant under U.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- Ue0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 2.8 g N plant−1e0
- Qualifier
- N-balance methode0
- Comparator
- Cont treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1).”
t0“Soybean”
Claim · model-written summary
The N balance method estimated Ndfa of 2.6 g N per plant under AS.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- ASe0
- Outcome
- Ndfae0
- Direction
- highere0
- Value
- 2.6 g N plant−1e0
- Qualifier
- N-balance methode0
- Comparator
- Cont treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the value of Ndfa estimated by the N-balance method was also higher in the LN (4.1 g N plant−1), CU (3.9 g N plant−1), U (2.8 g N plant−1) and AS (2.6 g N plant−1) treatments than in the Cont treatment (1.5 g N plant−1).”
t0“Soybean”
Claim · model-written summary
Nitrogen fertilizer recovery in Enrei under LN was 43%.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- LNe0
- Outcome
- recovery rate of N fertilizerse0
- Direction
- highere0
- Value
- 43%e0
- Comparator
- Ue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment.”
t0“Soybean”
Claim · model-written summary
Nitrogen fertilizer recovery in Enrei under CU was 36%.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- CUe0
- Outcome
- recovery rate of N fertilizerse0
- Direction
- highere0
- Value
- 36%e0
- Comparator
- Ue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment.”
t0“Soybean”
Claim · model-written summary
Nitrogen fertilizer recovery in Enrei under U was 21%.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- Ue0
- Outcome
- recovery rate of N fertilizerse0
- Direction
- highere0
- Value
- 21%e0
- Comparator
- ASe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment.”
t0“Soybean”
Claim · model-written summary
Nitrogen fertilizer recovery in Enrei under AS was lowest at 8.5%.
- Taxon
- SoybeanGlycine maxt0
- Material
- Enreie0
- Treatment
- ASe0
- Outcome
- recovery rate of N fertilizerse0
- Direction
- loweste0
- Value
- 8.5%e0
- Comparator
- Ue0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recovery rate of N fertilizers in Enrei was higher in the LN (43%) and CU (36%) treatments than in the U (21%) treatment and lowest in the AS (8.5%) treatment.”
t0“Soybean”
Claim · model-written summary
Deep placement of LN and CU was interpreted as effective for soybean growth and seed yield.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- deep placement of LN and CUe0
- Outcome
- soybean growth and seed yielde0
- Direction
- improvee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results indicate that deep placement of LN and CU is effective to improve soybean growth and seed yield.”
t0“Soybean”
Claim · model-written summary
Deep placement combined with slow release nitrogen fertilizer was considered important for supplying nitrogen through maturation and increasing seed yield.
- Taxon
- SoybeanGlycine maxt0
- Treatment
- “deep placement” and “slow-release N fertilizers”e0
- Outcome
- seed yielde0
- Direction
- increasee0
- Qualifier
- until the maturation stagee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The combination of “deep placement” and “slow-release N fertilizers” is important to supply N until the maturation stage, resulting in the increase of seed yield.”
t0“Soybean”
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