Abstract
Alternative management practices are needed to minimize the need for chemical fertilizer use in non-leguminous cropping systems. The use of biological agents that can fix atmospheric N has shown potential to improve nutrient availability in grass crops. This research was developed to investigate if inoculation with Azospirillum brasilense in combination with silicon (Si) can enhance N use efficiency (NUE) in maize. The study was set up in a Rhodic Hapludox under a no-till system, in a completely randomized block design with four replicates. Treatments were tested in a full factorial design and included: i) five side dress N rates (0 to 200 kg ha-1); ii) two liming sources (Ca and Mg silicate and dolomitic limestone); and iii) with and without seed inoculation with A. brasilense. Inoculation with A. brasilense was found to increase grain yield by 15% when N was omitted and up to 10% when N was applied. Inoculation also increased N accumulation in plant tissue. Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE. Inoculation increased harvest index and NUE by 9.5 and 19.3%, respectively, compared with non-inoculated plots. Silicon application increased leaf chlorophyll index and N-leaf concentration. The combination of Si and inoculation provided greater Si-shoot accumulation. This study showed positive improvements in maize growth production parameters as a result of inoculation, but the potential benefits of Si use were less evident. Further research should be conducted under growing conditions that provide some level of biotic or abiotic stress to study the true potential of Si application.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 11
Claim · model-written summary
Azospirillum inoculation increased grain yield by 15% without nitrogen.
- Treatment
- Inoculation with A. brasilensee0
- Interactor
- A. brasilense
Azospirillum brasilensee0symbiont - Outcome
- grain yielde0
- Direction
- increasee0
- Value
- 15%e0
- Qualifier
- when N was omittede0
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation with A. brasilense was found to increase grain yield by 15% when N was omitted”
e1“NUE) in maize”
Claim · model-written summary
Azospirillum inoculation increased grain yield by up to 10% with nitrogen.
- Treatment
- Inoculation with A. brasilensee1
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- grain yielde1
- Direction
- increasee1
- Value
- up to 10%e0
- Qualifier
- when N was appliede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“up to 10% when N was applied.”
e1“Inoculation with A. brasilense was found to increase grain yield”
e2“NUE) in maize”
Claim · model-written summary
Inoculation increased plant tissue nitrogen accumulation.
- Treatment
- seed inoculation with A. brasilensee1
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- N accumulation in plant tissuee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation also increased N accumulation in plant tissue.”
e1“with and without seed inoculation with A. brasilense.”
e2“NUE) in maize”
Claim · model-written summary
Inoculation increased leaf chlorophyll index and grains per ear.
- Treatment
- seed inoculation with A. brasilensee1
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- leaf chlorophyll index, number of grains per eare0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE.”
e1“with and without seed inoculation with A. brasilense.”
e2“NUE) in maize”
Claim · model-written summary
Limestone application increased leaf chlorophyll index and grains per ear.
- Treatment
- limestone applicatione0
- Outcome
- leaf chlorophyll index, number of grains per eare0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE.”
e1“NUE) in maize”
Claim · model-written summary
Inoculation increased harvest index by 9.5% versus non-inoculated plots.
- Treatment
- seed inoculation with A. brasilensee1
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- harvest indexe0
- Direction
- increasede0
- Value
- 9.5e0
- Comparator
- non-inoculated plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation increased harvest index and NUE by 9.5 and 19.3%, respectively, compared with non-inoculated plots.”
e1“with and without seed inoculation with A. brasilense.”
e2“NUE) in maize”
Claim · model-written summary
Inoculation increased nitrogen use efficiency by 19.3% versus non-inoculated plots.
- Treatment
- seed inoculation with A. brasilensee1
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- NUEe0
- Direction
- increasede0
- Value
- 19.3%e0
- Comparator
- non-inoculated plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation increased harvest index and NUE by 9.5 and 19.3%, respectively, compared with non-inoculated plots.”
e1“with and without seed inoculation with A. brasilense.”
e2“NUE) in maize”
Claim · model-written summary
Limestone application increased harvest index and nitrogen use efficiency.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE.”
e1“NUE) in maize”
Claim · model-written summary
Silicon application increased leaf chlorophyll index and leaf nitrogen concentration.
- Treatment
- Silicon applicatione0
- Outcome
- leaf chlorophyll index and N-leaf concentratione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Silicon application increased leaf chlorophyll index and N-leaf concentration.”
e1“NUE) in maize”
Claim · model-written summary
Combined silicon and inoculation increased shoot silicon accumulation.
- Treatment
- combination of Si and inoculatione0
- Interactor
- A. brasilenseAzospirillum brasilensee1symbiont
- Outcome
- Si-shoot accumulatione0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The combination of Si and inoculation provided greater Si-shoot accumulation.”
e1“with and without seed inoculation with A. brasilense.”
e2“NUE) in maize”
Claim · model-written summary
The authors recommend testing silicon under biotic or abiotic stress conditions.
- Outcome
- Further research should be conducted under growing conditions that provide some level of biotic or abiotic stresse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Further research should be conducted under growing conditions that provide some level of biotic or abiotic stress to study the true potential of Si application.”
e1“NUE) in maize”
The same questions in other papers
Azospirillum brasilense · physiology: pigments · Zea mays (maize)Results differ
8 papers in the same direction as this paper · 1 in the opposite direction
- positive
- positive
- no effect
6 papers more in this group
See all 10 papers →Azospirillum brasilense · yield · Zea mays (maize)Results differ
41 papers in the same direction as this paper · 11 in the opposite direction
- positive
- positive
- no effect
49 papers more in this group
See all 53 papers →Azospirillum brasilense · nutrient: content · Zea mays (maize)Positive and negative results
14 papers in the same direction as this paper · 1 in the opposite direction
- positive
- positive
- no effect
12 papers more in this group
See all 16 papers →silicon atom · physiology: pigments · Zea mays (maize)Positive and negative results
26 papers in the same direction as this paper · 1 in the opposite direction
- positive
- negative
- positive
24 papers more in this group
See all 28 papers →calcium oxide · nutrient: efficiency · Zea mays (maize)Results agree
1 paper in the same direction as this paper
- positive
Azospirillum brasilense · nutrient: efficiency · Zea mays (maize)Results agree
6 papers in the same direction as this paper
- positive
- positive
- positive
3 papers more in this group
See all 7 papers →inoculation · Azospirillum brasilense · Zea mays (maize)Results differ
29 papers in the same direction as this paper · 9 in the opposite direction
- positive
- positive
- positive
35 papers more in this group
See all 39 papers →inoculation · physiology: pigments · Zea mays (maize)Results differ
84 papers in the same direction as this paper · 9 in the opposite direction · 1 reporting no difference from an alternative
- positive
- positive
- negative
91 papers more in this group
See all 95 papers →8 of 11 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.