Abstract
Hydrogels have shown promise in improving soil quality and alleviating plant drought stress. This study investigated the effectiveness of four hydrogel composites composed of polyvinyl alcohol, sodium alginate, and pine or olive tree biochar in improving bean (Phaseolus vulgaris) plant growth and soil microbial activities. The experiment was conducted in natural soil, where biochar–hydrogel composites were applied at a concentration of 0.75% hydrogel per soil weight (w/w) for 35 days under two different moisture conditions: adequate moisture (70% of water holding capacity (WHC)) and drought stress (40% WHC). The results showed variation between hydrogel composites and, more importantly, between water regimes. Under water deficit conditions, biochar–hydrogel composites consistently caused a decrease in plant weight and in chlorophyll (CHL) CHLa/CHLb ratio. Furthermore, antioxidant enzyme activities and malondialdehyde and protein levels generally increased in contrast to the observations at 70% WHC. Regarding microbial activities, the composites reduced soil respiration (12–38%) while promoting phosphatase activity (42–65%) under both moisture regimes. Overall, the introduction of hydrogel composites did not show consistently positive effects on either plants or soil microorganisms. To thoroughly evaluate the efficacy of these hydrogels as soil amendments, further studies are needed, considering different soil types, plant species, and hydrogel application rates.
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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 6
Claim · model-written summary
Under water deficit, composites decreased bean plant weight.
- Taxon
- bean (Phaseolus vulgaris)
Phaseolus vulgarise1 - Treatment
- biochar–hydrogel compositese0
- Outcome
- plant weighte0
- Direction
- decreasee0
- Qualifier
- Under water deficit conditionse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under water deficit conditions, biochar–hydrogel composites consistently caused a decrease in plant weight”
e1“bean (Phaseolus vulgaris)”
Claim · model-written summary
Under water deficit, composites decreased the chlorophyll CHLa/CHLb ratio.
- Taxon
- bean (Phaseolus vulgaris)Phaseolus vulgarise1
- Treatment
- biochar–hydrogel compositese0
- Outcome
- chlorophyll (CHL) CHLa/CHLb ratioe0
- Direction
- decreasee0
- Qualifier
- Under water deficit conditionse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under water deficit conditions, biochar–hydrogel composites consistently caused a decrease in plant weight and in chlorophyll (CHL) CHLa/CHLb ratio.”
e1“bean (Phaseolus vulgaris)”
Claim · model-written summary
Antioxidant enzyme activities increased relative to 70% WHC.
- Taxon
- bean (Phaseolus vulgaris)Phaseolus vulgarise1
- Treatment
- water deficit conditionse2
- Outcome
- antioxidant enzyme activitiese0
- Direction
- increasede0
- Comparator
- 70% WHCe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“antioxidant enzyme activities and malondialdehyde and protein levels generally increased in contrast to the observations at 70% WHC”
e1“bean (Phaseolus vulgaris)”
e2“water deficit conditions”
Claim · model-written summary
Malondialdehyde and protein levels generally increased relative to 70% WHC.
- Taxon
- bean (Phaseolus vulgaris)Phaseolus vulgarise1
- Treatment
- water deficit conditionse2
- Outcome
- malondialdehyde and protein levelse0
- Direction
- increasede0
- Comparator
- 70% WHCe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“malondialdehyde and protein levels generally increased in contrast to the observations at 70% WHC”
e1“bean (Phaseolus vulgaris)”
e2“water deficit conditions”
Claim · model-written summary
Composites reduced soil respiration by 12–38% under both moisture regimes.
- Taxon
- bean (Phaseolus vulgaris)Phaseolus vulgarise1
- Treatment
- the compositese0
- Outcome
- soil respiratione0
- Direction
- reducede0
- Value
- 12–38%e0
- Qualifier
- under both moisture regimese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the composites reduced soil respiration (12–38%) while promoting phosphatase activity (42–65%) under both moisture regimes”
e1“bean (Phaseolus vulgaris)”
Claim · model-written summary
Composites promoted soil phosphatase activity by 42–65% under both moisture regimes.
- Taxon
- bean (Phaseolus vulgaris)Phaseolus vulgarise1
- Treatment
- the compositese0
- Outcome
- phosphatase activitye0
- Direction
- promotinge0
- Value
- 42–65%e0
- Qualifier
- under both moisture regimese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the composites reduced soil respiration (12–38%) while promoting phosphatase activity (42–65%) under both moisture regimes”
e1“bean (Phaseolus vulgaris)”
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