Abstract
The effect of different rotational systems on symbiotic N2 fixation by, and yield of, peanut (Arachis hypogaea L. cv. Virginia Bunch) was determined over two growing seasons in southern Queensland. Estimates of N2fixation were obtained with the 15N natural abundance procedure by using a non-nodulating peanut genotype as a non-N2-fixing reference plant. Three rotational treatments were compared in both years. Crops were rainfed and dependent solely upon indigenous rhizobia for nodulation in the first season, but in the second, supplementary irrigation was supplied and portions of the trial were inoculated with three different rhizobial strains. Dry matter, crop N and pod yield were greatest in both years following a period of grass ley and lowest in a continuous peanut system. However, the proportion of the crop N derived from N2 fixation (PN2) was the same across all rotational and inoculation treatments, despite pre-sowing differences in the levels of soil nitrate and numbers of native rhizobia, and despite seasonal differences in the amounts of N mineralized. Proportions and amounts of N2 fixed were lower (22-31% and 32-57 kg N/ha, respectively) during the first year than under the better moisture conditions and lower concentrations of soil nitrate that prevailed in following season (44-48s and 82-120 kg N/ha). A greater proportion of fixed N was located in the pods and kernels (PN2 62-70%) than in the supporting shoot (PN2 13-21%) in the second year. When estimates of N2 fixation were compared with N removal in the pods at harvest, the net N balance suggested that soil N reserves had been depleted by 27-37 kg N/ha as a result of that season's peanut cropping.
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Claims 6
Claim · model-written summary
Dry matter, crop N and pod yield of peanut were greatest in both years after a grass ley and lowest in continuous peanut.
- Taxon
- peanut
Arachis hypogaeae1 - Treatment
- a period of grass leye1
- Outcome
- Dry matter, crop N and pod yielde1
- Direction
- greateste1
- Comparator
- a continuous peanut systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Dry matter, crop N and pod yield were greatest in both years following a period of grass ley and lowest in a continuous peanut system”
Claim · model-written summary
The proportion of peanut crop N derived from N2 fixation was the same across all rotational and inoculation treatments.
- Taxon
- peanutArachis hypogaeat0
- Treatment
- rotational and inoculation treatmentse1
- Interactor
- Bradyrhizobium
Bradyrhizobiumt1symbiont - Outcome
- proportion of the crop N derived from N2 fixation (PN2)e1
- Direction
- the samee1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“peanut”
t1“Bradyrhizobium”
e1“the proportion of the crop N derived from N2 fixation (PN2) was the same across all rotational and inoculation treatments”
Claim · model-written summary
The proportion of N2 fixed by peanut was lower in the first year (22-31%) than in the following season (44-48%).
- Taxon
- peanutArachis hypogaeat0
- Outcome
- Proportions and amounts of N2 fixede1
- Direction
- lowere1
- Value
- 22-31%e1
- Qualifier
- 44-48se1
- Comparator
- following seasone1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“peanut”
e1“Proportions and amounts of N2 fixed were lower (22-31% and 32-57 kg N/ha, respectively) during the first year than under the better moisture conditions and lower concentrations of soil nitrate that prevailed in following season (44-48s and 82-120 kg N/ha)”
Claim · model-written summary
The amount of N2 fixed by peanut was lower in the first year (32-57 kg N/ha) than in the following season (82-120 kg N/ha).
- Taxon
- peanutArachis hypogaeat0
- Outcome
- Proportions and amounts of N2 fixede1
- Direction
- lowere1
- Value
- 32-57 kg N/hae1
- Qualifier
- 82-120 kg N/hae1
- Comparator
- following seasone1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“peanut”
e1“Proportions and amounts of N2 fixed were lower (22-31% and 32-57 kg N/ha, respectively) during the first year than under the better moisture conditions and lower concentrations of soil nitrate that prevailed in following season (44-48s and 82-120 kg N/ha)”
Claim · model-written summary
In the second year a greater proportion of fixed N was located in peanut pods and kernels (62-70%) than in the supporting shoot (13-21%).
- Taxon
- peanutArachis hypogaeat0
- Organ / stage
- pods and kernelse1
- Outcome
- proportion of fixed Ne1
- Direction
- greatere1
- Value
- 62-70%e1
- Qualifier
- 13-21%e1
- Comparator
- the supporting shoote1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“peanut”
e1“A greater proportion of fixed N was located in the pods and kernels (PN2 62-70%) than in the supporting shoot (PN2 13-21%) in the second year”
Claim · model-written summary
The net N balance suggested that peanut cropping depleted soil N reserves by 27-37 kg N/ha in that season.
- Taxon
- peanutArachis hypogaeae1
- Outcome
- soil N reservese1
- Direction
- depletede1
- Value
- 27-37 kg N/hae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“the net N balance suggested that soil N reserves had been depleted by 27-37 kg N/ha as a result of that season's peanut cropping”
The same questions in other papers
inoculation · Bradyrhizobium · Arachis hypogaea (peanut)Positive and negative results
11 in the opposite direction
- positive
- positive
- positive
8 papers more in this group
See all 12 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.