Optimizing Cucumis sativus seedling vigor: the role of pistachio wood vinegar and date palm compost in nutrient mobilization

BACKGROUND

The goal of this research is to enhance the quality of cucumber seedlings grown in greenhouses by experimenting with various soilless culture mediums (CMs) and the application of pistachio wood vinegar (WV). The experimental setup was designed as a factorial experiment within a randomized complete block design (RCBD), in greenhouse conditions featuring three replications to assess the effects of different culture media (CMs) and concentrations of pistachio wood vinegar (WV) on cucumber seedling growth. Cucumber seeds were planted in three CMs: coco peat-peat moss, coco peat-vermicompost, and date palm compost-vermicompost mixed in a 75:25 volume-to-volume ratio. These were then treated with pistachio WV at concentrations of 0, 0.5, and 1%, applied four times during irrigation following the emergence of the third leaf.

RESULTS

The study revealed that treating seedlings with 0.5% WV in the date palm compost-vermicompost CM significantly enhanced various growth parameters. Specifically, it resulted in a 90% increase in shoot fresh mass, a 59% increase in shoot dry mass, an 11% increase in root fresh mass, a 36% increase in root dry mass, a 65% increase in shoot length, a 62% increase in leaf area, a 25% increase in stem diameter, a 41% increase in relative water content (RWC), and a 6% improvement in membrane stability index (MSI), all in comparison to untreated seedlings grown in coco peat-peat moss CM. Furthermore, chlorophyll a, b, total chlorophyll, and carotenoid levels were 2.3, 2.7, 2.6, and 2.7 times higher, respectively, in seedlings treated with 0.5% WV and grown in the date palm compost-vermicompost CM, compared to those treated with the same concentration of WV but grown in coco peat-peat moss CM. Additionally, the Fv/Fm ratio saw a 52% increase. When plant nutrition was enhanced with the date palm compost-vermicompost CM and 1% WV, auxin content rose by 130% compared to seedlings grown in coco peat-peat moss CM and treated with 0.5% WV.

CONCLUSIONS

The study demonstrates that using 0.5% WV in conjunction with date palm compost-vermicompost CM significantly betters the quality of cucumber seedlings, outperforming other treatment combinations.

Effects of pyroligneous acid on acute, chronic, and cyto-genotoxicity to earthworms (Eisenia fetida)

The pyroligneous acid (PA), or wood vinegar, is a byproduct of wood carbonization during the slow pyrolysis process. PA is recognized globally as a safe compound for agriculture due to its various beneficial properties, such as antioxidant, antibacterial, antifungal, and termiticidal properties. However, the impact of different PA concentrations on beneficial soil organisms, such as earthworms has not been investigated. The present study aims to understand the effects of different PA concentrations on earthworm Eisenia fetida. The earthworms were exposed to nine different concentrations of PA in soils, including their control. The acute toxicity assay was performed after 14 days of exposure, and the chronic toxicity assay was performed up to 8 weeks after exposure. The results from the acute toxicity assay demonstrated no significant effect on earthworm mortality. The chronic toxicity assay showed that lower PA concentrations (0.01-0.2% of weight/weight PA in soil) promoted cocoon and juvenile production in soils, whereas higher PA concentrations (0.5 and 1%) had a negative effect. These findings highlight the potential of PA to enhance soil fertility at lower concentrations, up to 0.2%, by stimulating worm activity and subsequent manure production. The outcomes of this study have significant implications for the careful management of PA concentrations within agricultural operations.

Exploring sustainable alternatives: Wood distillate alleviates the impact of bioplastic in basil plants

The growing interest in bioplastics and bio-based crop management products in agriculture is driven by the Sustainable Development Goals of the 2030 Agenda. However, recent research has raised concerns about the sustainability of bioplastics due to their potential negative impact on crop growth and yield, with implications for the environment and human health. In this study, wood distillate (WD) was evaluated as a natural enhancer of plant growth and defence system to mitigate the negative impact of a starch-based bioplastic on basil (Ocimum basilicum L.) plants. The study analyzed physiological and biochemical changes in basil plants subjected for 35 days to single or combined treatments of WD and bioplastic by measuring biomarkers of healthy growth, such as soluble proteins, sugars, vitamin C, and malondialdehyde (MDA). The results showed that WD promoted basil development, whereas the presence of bioplastic hindered it. Interestingly, WD did not affect sugars but increased vitamin C by 12 %, which is considered a positive effect as changes in sugar levels could indicate plant stress. In contrast, bioplastic resulted in reduced sugars (-41 %) and increased (+17 %) MDA level, while vitamin C content remained unchanged. However, when WD was added to plants grown with bioplastic, it elevated the levels of all examined parameters, except for sugars and vitamin C, which experienced reductions (-66 % and 33 %, respectively). Intriguingly, despite this reduction, the observed direct correlation between sugar and vitamin C contents was maintained, indicating that the decrease in sugar content may have reached a critical threshold. This study suggests that the use of WD has the potential to alleviate the adverse effects of bioplastic on basil growth and development and highlights the importance of adopting sustainable practices in agriculture, as well as the need for a critical assessment of the environmental impact of new technologies and products.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptus grandis - clone I144) and bamboo (Bambusa vulgaris)

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Synthesis of an environmentally friendly binding material using pyrolysis by-products and modified starch binder for slow-release fertilizers

Biochar-based slow-release fertilizers (BSRFs) are vital for the development of eco-friendly and sustainable agriculture. Considerable attention has been given to enhancing the efficiency of fertilizers (EEFs) by appropriate modification or binding to reduce nutrient waste and improve the slow-release effect on the growth of plants. In this study, sustained binding materials were presented for BSRF synthesis, including pyroligneous acids (PA), bio-oil (BO), and modified starch binder (MSB). The results show that the release ratio of phosphorus from PA + BO+MSB was 4.7%, 15.2%, and 21.2% slower than that of PA, BO, and MSB alone, respectively. The BSRFs were characterized by SEM, XRD, FT-IR, XPS, and EDS, and the release kinetic outcome revealed that PA + BO+MSB contributed to the formation of a satisfactory structure in the BSRFs. The MSB viscosity significantly influences the slow-release performance and accumulation of N, P, and K nutrients. Moreover, economic assessments showed that PA + BO+MSB exhibited the lowest cost.

Effect of pyroligneous acid on soil urease, amidase, and nitrogen use efficiency by Chinese cabbage (Brassica campestris var. Pekinensis)

Urea is one of the most commonly used nitrogen fertilizers in agricultural soil and is easily decomposed by soil urease resulting in ammonium release. The produced ammonium can be volatilized or converted to nitrate, which is susceptible to leaching, leading to groundwater contamination unless used by plants. Hence, it is important to control the release of nitrogen from the urea. Pyroligneous acid inhibited the urease activity and decreased ammonium release up to 80% compared to the control. Amidase including asparaginase and glutaminase is an enzyme that catalyzes hydrolysis of amide group, similar to urease. Therefore, the effect of pyroligneous acid on the inhibition of soil amidase was also tested and the results showed that pyroligneous acid competitively inhibited asparaginase while glutaminase was not inhibited. However, inhibitory effect of pyroligneous acid on asparaginase was negligible compared to the urease. The application of pyroligneous acid with a smaller amount of urea for controlled nitrogen release during Chinese cabbage growth showed that dry biomass and nutrient contents of Chinese cabbage were similar to the case of the conventional urea application. The nitrogen utilization efficiency (NUE) was highest for 33% less amount of urea supply with pyroligneous acid (2.21) compared to conventional treatment (1.81). Consequently, the use of pyroligneous acid with urea enhances nitrogen use efficiency while also protecting environments from non-point source contamination.

Slow pyrolysis liquid in reducing NH3 emissions from cattle slurry - Impacts on plant growth and soil organisms

A substantial percentage of manure nitrogen (N) can be lost as gaseous ammonia (NH₃) during storage and field spreading. Lowering slurry pH is a simple and accepted method for preserving its N. Efficiency of slow pyrolysis liquid (PL) produced from birch (Betula sp.) as an acidifying agent, and its ability to reduce NH₃ emissions following surface application of cattle slurry, was studied in a field experiment. Untreated slurry (US) and slurries acidified with PL and sulfuric acid (SA) were applied to the second harvest of a grass ley. Immediate NH₃ emissions, grass biomass, N-yield and possible toxic impacts on soil nematodes and enchytraeids were examined. Furthermore, the effects on soil respiration, nitrogen dynamics and seed germination were studied in subsequent laboratory experiments. In the field, over one third of the water-extractable ammonium-N (NH₄-N) applied was lost through NH₃ volatilization from US. SA and PL acidified slurries reduced NH₃-N emission rate equally from 3.4 to <0.04 kg ha^-1 h^-1. Acidification with SA resulted in the highest and that with PL in the lowest grass dry matter (DM) and N yield. Neither SA nor PL acidification had negative effects on soil enchytraeids or nematodes. Reduced yield production, seed germination and delayed microbial activity after PL slurry application were most probably caused by the PL containing organic compounds. However, later increase in carbon dioxide (CO₂) production and improved seed germination suggest that these compounds were rapidly volatilized and/or degraded by soil microbes. Though PL efficiently cut NH₃ emission from surface-spread slurry, further studies on appropriate application methods and possible phytotoxicity are needed.

Characterization and antiinflammatory properties of fractionated pyroligneous acid from palm kernel shell

Pyroligneous acid (PA) obtained from slow pyrolysis of palm kernel shell (PKS) has high total phenolic contents and exhibits various biological activities including antioxidant, antibacterial and antifungal. In this study, PA obtained using slow pyrolysis method and fractionated using column chromatography was characterized (chemical and antioxidative properties) and investigated for its cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibition activities using the in vitro and in silico approaches. The F₉ PA fraction exhibited highest total phenolic content of 181.75 ± 17.0 μg/mL. Fraction F_21-25 showed ferric reducing antioxidant power (FRAP) (331.80 ± 4.60 mg TE/g) and IC₅₀ of 18.56 ± 0.01 μg/mL towards COX-2 and 5.25 ± 0.03 μg/mL towards the 5-LOX enzymes, respectively. Molecular docking analysis suggested favourable binding energy for all chemical compounds present in fraction F_21-25, notably 1-(2,4,6-trihydroxyphenyl)-2-pentanone, towards both COX-2 (- 6.9 kcal/mol) and 5-LOX (- 6.4 kcal/mol) enzymes. As a conclusion, PA from PKS has the potential to be used as an alternative antioxidant and antiinflammatory agents which is biodegradable and a more sustainable supply of raw materials.

Wood vinegar and biochar co-application mitigates nitrous oxide and methane emissions from rice paddy soil: A two-year experiment

Both biochar (BC) and wood vinegar (WV) influence the nitrous oxide (N₂O) and methane (CH₄) emissions from agricultural systems. However, the impacts of BC and WV co-application on rice production, N₂O and CH₄ emissions are not well documented. We here conducted a two-year soil columns experiment with four treatments: WV (5 t WV ha^-1), BC (7.5 t BC ha^-1), WV + BC (5 t WV ha^-1 +7.5 t BC ha^-1) and a control (no treatment). The results showed that BC and WV + BC produced higher rice grain yield than the control by 14.1-15.9% in 2016 and by 4.1-5.2% in 2017, respectively. While WV increased rice grain yield by 11.2% in 2016, it had no significant influence on yield in 2017. Both WV and BC significantly mitigated N₂O emissions by 22.4-41.8% in 2016 and 22.4-36.9% in 2017, respectively. Interestingly, WV + BC treatment showed the highest N₂O mitigation efficiency, with a 52.9-62.8% mitigations in 2016 and 2017. Furthermore, the co-application of WV and BC significantly mitigated CH₄ emissions by 42.6% in 2016 and 35.3% in 2017, respectively, while applying WV or BC alone had no annually-consistent mitigation effect on CH₄ emissions. Overall, GWPt of rice growth cycle was most significantly suppressed by WV + BC with a 48.7-56.1% reduction, followed by WV and BC with 20.4-28.0% and 19.7-35.7% reductions, respectively. Consequently, the WV + BC treatment had the highest GHGI mitigation effect, averaging with 56.7% over two consecutive rice growth cycles. In conclusion, co-application of WV and BC is recommended for rice cultivation, which can both improve rice yield and minimize GHG emissions.

A possible environmental-friendly removal of Microcystis aeruginosa by using pyroligneous acid

Cyanobacteria blooms are crucial environmental issues by threatening both aquatic ecosystem and human health. A biomass by-product with antimicrobial activity, pyroligneous acid (PA) was tested for its suitability for removal of the cyanobacteria Microcystis aeruginosa (M. aeruginosa) in this work. Results show that the removal efficiency could reach up to 90% in the presence of 0.45% of PA and the inhibition to M. aeruginosa growth could extend to at least 40 days. The removal mechanism was studied. Both organic acids and phenols are functional content in M. aeruginosa removal and acetic acid is the most important one. Zeta potential analysis and morphology study show that the damage of cells dominates the flocculation and sedimentation of M. aeruginosa under low PA concentration (<0.7%), and increasing PA (≥0.7%) resulted in a trend of zeta potential to zero, thus removing any "shield" and triggering flocculation. Finally, study on the phenols residual after M. aeruginosa treatment shows that it could be close to 0 in 70 h. Therefore, this work proposes a possible method for world-wide treatment of cyanobacteria bloom and a new way for further utilization of PA.

Cellulose before CELL: Historical themes

In 2020 the Cellulose and Renewable Materials Division (CELL) of the American Chemical (ACS) society celebrates its 100th anniversary. The following paper is based on a chapter from the book commissioned by the Division (Patterson, 2021). CELL is one of the most successful and dynamic Divisions in the ACS. It has evolved throughout its history to remain relevant and productive. One of its strengths is its diversity, while staying true to its founding vision. This perspective was present at its founding, and the following paper surveys the world of cellulose and renewable materials from the dawn of history to 1920. CELL has both industrial and scientific roots and has always welcomed the full range of participants from these communities. Rather than operating as separate tribes, the two groups have fostered innovations in each other. Many aspects of cellulose science and technology are discussed from antiquity to the early 20th century.

Evaluation of pyroligneous acid as a therapeutic agent against Salmonella in a simulated gastrointestinal tract of poultry

Pyroligneous acid (PA) was evaluated as a potential alternative to therapeutic antibiotics in poultry. Antimicrobial activity of PA was studied at acidic pH (2.0) and neutral pH (7.0) of the liquid against Salmonella enterica and Lactobacillus acidophilus. Acidic PA gave a MIC value of 0.8% (v/v) and 1.6% (v/v), and neutralized PA gave a MIC value of 1.6% (v/v) and 3.2% (v/v) against S. enterica and L. acidophilus respectively. Acidic PA was evaluated at different concentrations in a simulated poultry digestive tract and cecal fermentation to study its effect on the cecal microflora and fermentation profile. PA at a concentration of 1.6% (v/v) completely inhibited S. enterica and was also found to have a similar effect on lactobacilli count as compared with the control (p = 0.17). Additionally, PA at this concentration was found not to have a significant effect on acetic acid production after 24 h of cecal fermentation (p = 0.20). Graphical abstract.

Responses of ammonia volatilization from rice paddy soil to application of wood vinegar alone or combined with biochar

Wood vinegar (WV) was applied alone or combined with biochar (BC) to observe their efficiency on suppressing the ammonia (NH₃) volatilization from rice paddy soil. Five treatments, i.e., control (240 kg N ha^-1 applied in urea), WV-5 and WV-10 (240 kg N ha^-1 plus 5 and 10 t WV ha^-1, respectively), and their counterparts WV-5-BC and WV-10-BC (WV-5 and WV-10 plus 7 t BC ha^-1), were evaluated by a soil columns experiment. The N fertilizer was split applied as basal and two supplementary fertilizations (named BF, SF1 and SF2, respectively). The results showed that WV-5 treatment increased rice grain yield up to 11.2% compared to the control. Compared with the control, four WV-amended treatments, exhibited lower pH values of the floodwater (7.94-8.18 vs 8.47 and 7.85-7.91 vs 7.98) and the topsoil (6.52-6.76 vs 6.82 and 6.82-6.92 vs 6.99) during the BF and SF1 periods. Both WV-5 and WV-10 increased the NH₄⁺-N contents of topsoil by 10.9-17.8% and 16.1-36.2% after BF and SF1, respectively, than control treatment. Additionally, the floodwater of the WV-amended treatments had higher NH₄⁺-N concentration than control during the first three days after N fertilization, which can be attributed to the stimulating effect of WV on soil urease enzyme activity. WV did not effectively reduce NH₃ volatilization as hypothesized. Interestingly, four WV-amended had relatively reduced the yield-scale NH₃ volatilization by 13.6% than the control. It is suggested that WV needs to be applied with BC at a moderate rate to achieve optimum rice yield and mitigate NH₃ volatilization.

The evaluation of the potential ecotoxicity of pyroligneous acid obtained from fast pyrolysis

Pyroligneous acid (PA) is a by-product of bio-oil, which is obtained by pyrolysis of the wood. This product has been tested for use in several areas, such as agriculture, as a promising green herbicide; however, there are few scientific data regarding its environmental impacts. For this study, an ecotoxicity testing battery, composed of Daphnia magna acute toxicity test, Allium cepa test and in vitro Comet assay with the rainbow trout gonad-2 cell fish line (RTG-2) were used to evaluate the acute toxicity and genotoxicity of PA obtained from fast pyrolysis of eucalyptus wood fines. The PA presented acute toxicity to D. magna (microcrustacea) with EC₅₀ of 26.12 mg/L, and inhibited the seed germination (EC₅₀ 5.556 g/L) and root development (EC₅₀ 3.436 g/L) of A. cepa (higher plant). No signs of genotoxicity (chromosomal aberrations and micronuclei in A. cepa and primary DNA lesions in RTG-2 cells) were detected to this product. The acute toxicity and absence of genotoxicity may relate to the molecules found in the PA, being the phenolic fraction the key chemical candidate responsible for the toxicity observed. In addition, daphnids seem to be more sensitivity to the toxicity of PA than higher plants based on their EC₅₀ values. This first ecotoxicological evaluation of PA from fast pyrolysis pointed out the need of determining environmental exposure limits to promote the safer agriculture use of this product, avoiding impacts to living organisms.