Abstract
Biofertilizers are becoming increasingly popular in many countries and for many crops, but very few studies on their effect on grain yield have been conducted in rice. Therefore, we evaluated three different biofertilizers (based on Azospirillum, Trichoderma, or unidentified rhizobacteria) in the Philippines during four cropping seasons between 2009 and 2011, using four different fertilizer rates (100% of the recommended rate [RR], 50% RR, 25% RR, and no fertilizer as Control). The experiments were conducted under fully irrigated conditions in a typical lowland rice environment. Significant yield increases due to biofertilizer use were observed in all experimental seasons with the exception of the 2008/09 DS. However, the effect on rice grain yield varied between biofertilizers, seasons, and fertilizer treatments. In relative terms, the seasonal yield increase across fertilizer treatments was between 5% and 18% for the best biofertilizer (Azospirillum-based), but went up to 24% in individual treatments. Absolute grain yield increases due to biofertilizer were usually below 0.5 t·ha−1, corresponding to an estimated additional N uptake of less than 7.5 kg N ha−1. The biofertilizer effect on yield did not significantly interact with the inorganic fertilizer rate used but the best effects on grain yield were achieved at low to medium fertilizer rates. Nevertheless, positive effects of the biofertilizers even occurred at grain yields up to 5 t·ha−1. However, the trends in our results seem to indicate that biofertilizers might be most helpful in rainfed environments with limited inorganic fertilizer input. However, for use in these target environments, biofertilizers need to be evaluated under conditions with abiotic stresses typical of such systems such as drought, soil acidity, or low soil fertility.
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 9
Claim · model-written summary
Biofertilizers significantly increased rice yield in all but the 2008/09 dry season.
- Taxon
- rice
Oryza sativat0 - Treatment
- biofertilizer usee0
- Outcome
- yielde0
- Direction
- increasese0
- Qualifier
- with the exception of the 2008/09 DSe0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Significant yield increases due to biofertilizer use were observed in all experimental seasons with the exception of the 2008/09 DS.”
t0“Irrigated Rice”
Claim · model-written summary
Azospirillum biofertilizer increased seasonal grain yield 5% to 18% across fertilizer treatments.
- Taxon
- riceOryza sativat0
- Treatment
- Azospirillum-basede0
- Interactor
- Azospirillum
Azospirillume0symbiont - Outcome
- seasonal yielde0
- Direction
- increasee0
- Value
- between 5% and 18%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the seasonal yield increase across fertilizer treatments was between 5% and 18% for the best biofertilizer (Azospirillum-based)”
t0“Irrigated Rice”
Claim · model-written summary
Azospirillum biofertilizer increased yield up to 24% in individual treatments.
- Taxon
- riceOryza sativat0
- Treatment
- Azospirillum-basede0
- Interactor
- AzospirillumAzospirillume0symbiont
- Outcome
- yielde0
- Direction
- increasee0
- Value
- 24%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the seasonal yield increase across fertilizer treatments was between 5% and 18% for the best biofertilizer (Azospirillum-based), but went up to 24% in individual treatments.”
t0“Irrigated Rice”
Claim · model-written summary
Absolute biofertilizer grain yield gains were usually below 0.5 t·ha−1.
- Taxon
- riceOryza sativat0
- Treatment
- biofertilizere0
- Outcome
- grain yielde0
- Direction
- increasese0
- Value
- below 0.5 t·ha−1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Absolute grain yield increases due to biofertilizer were usually below 0.5 t·ha−1”
t0“Irrigated Rice”
Claim · model-written summary
Yield gain corresponded to estimated additional nitrogen uptake under 7.5 kg N ha−1.
- Taxon
- riceOryza sativat0
- Outcome
- additional N uptakee0
- Direction
- additionale0
- Value
- less than 7.5 kg N ha−1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“corresponding to an estimated additional N uptake of less than 7.5 kg N ha−1”
t0“Irrigated Rice”
Claim · model-written summary
Biofertilizer yield effect did not significantly interact with inorganic fertilizer rate.
- Taxon
- riceOryza sativat0
- Treatment
- biofertilizere0
- Outcome
- effect on yielde0
- Comparator
- inorganic fertilizer ratee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The biofertilizer effect on yield did not significantly interact with the inorganic fertilizer rate used”
t0“Irrigated Rice”
Claim · model-written summary
The strongest grain yield effects occurred at low to medium fertilizer rates.
- Taxon
- riceOryza sativat0
- Outcome
- grain yielde0
- Direction
- beste0
- Qualifier
- low to medium fertilizer ratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the best effects on grain yield were achieved at low to medium fertilizer rates”
t0“Irrigated Rice”
Claim · model-written summary
Biofertilizer effects remained positive at grain yields up to 5 t·ha−1.
- Taxon
- riceOryza sativat0
- Treatment
- biofertilizerse0
- Outcome
- grain yieldse0
- Direction
- positivee0
- Value
- up to 5 t·ha−1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“positive effects of the biofertilizers even occurred at grain yields up to 5 t·ha−1”
t0“Irrigated Rice”
Claim · model-written summary
The authors recommend testing biofertilizers under typical rainfed abiotic stresses.
- Taxon
- riceOryza sativat0
- Outcome
- biofertilizers need to be evaluatede0
- Qualifier
- drought, soil acidity, or low soil fertilitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biofertilizers need to be evaluated under conditions with abiotic stresses typical of such systems such as drought, soil acidity, or low soil fertility”
t0“Irrigated Rice”
The same questions in other papers
Azospirillum · yield · Oryza sativa (rice)Results differ
51 papers in the same direction as this paper · 1 in the opposite direction
- positive
- positive
- positive
49 papers more in this group
See all 53 papers →inoculation · yield · Oryza sativa (rice)Positive and negative results
381 papers in the same direction as this paper · 31 in the opposite direction · 5 reporting no difference from an alternative
- no effect
- positive
- positive
414 papers more in this group
See all 418 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.