Soil Invertase Research Articles

Analysis of Tobacco Straw Return to the Field to Improve the Chemical, Physical, and Biological Soil Properties and Rice Yield

Straw incorporation into soil contributes significantly to the sustainable development of agriculture. To investigate the impact of tobacco straw returns on a tobacco–rice replanting system, we designed an experiment with two straw return levels and a control group: T1 (full return), T2 (root return), and CK (no straw return). Over a three-year field experiment in rice fields in South China, we assessed the effects of tobacco straw return on soil quality, microbial diversity, dry matter accumulation, and yield composition of rice. The results demonstrated that returning tobacco straw to the field effectively enhanced rice yield by positively influencing various soil physical, chemical, and biological properties. Compared to those in the CK treatment, as the soil porosity increased from 9.0% to 12.4%, the mean weight diameter of the soil aggregates substantially increased, ranging from 28.7% to 45.2%. There were significant increases in soil organic matter, total nitrogen, and alkaline dissolved nitrogen. Soil sucrase activity increased between 29.8% and 44.9%, and urease activity increased between 4.3% and 62.2% over the three consecutive years of straw return. The diversity index of soil fungi significantly increased. Additionally, rice yield increased markedly, ranging from 1.8% to 5.1%. Overall, the enhancement effect of T1 surpassed that of T2. According to our comprehensive analysis, the incorporation of tobacco straw into the field was found to enhance the physical properties of the soil, elevate soil enzyme activity, and increase the abundance of soil microorganisms. Consequently, this practice led to improved rice yield and a reduction in agricultural waste output. Overall, the return of tobacco straw to the field represents a clean and dependable approach in rice-cultivated tobacco areas to improve soil health and rice productivity.

The impact of continuous cultivation of Ganoderma lucidum on soil nutrients, enzyme activity, and fruiting body metabolites

To explore the impacts of continuous Ganoderma lucidum cultivation on soil physicochemical factors, soil enzyme activity, and the metabolome of Ganoderma lucidum fruiting bodies, this study conducted two consecutive years of cultivation on the same plot of land. Soil physicochemical factors and enzyme activity were assessed, alongside non-targeted metabolomic analysis of the Ganoderma lucidum fruiting bodies under continuous cultivation. The findings unveiled that in the surface soil layer (0–15 cm), there was a declining trend in organic matter, ammonium nitrogen, available phosphorus, available potassium, pH, polyphenol oxidase, peroxidase, alkaline phosphatase, and sucrase, whereas nitrate nitrogen, electrical conductivity (EC), and salt content exhibited an upward trend. Conversely, in the deeper soil layer (15–30 cm), organic matter, ammonium nitrogen, available potassium, alkaline phosphatase, and sucrase demonstrated a decreasing trend, while nitrate nitrogen, available phosphorus, pH, EC, salt content, polyphenol oxidase, and soil peroxidase showed an increasing trend. Metabolomic analysis of Ganoderma lucidum fruiting bodies distinguished 64 significantly different metabolites between the GCK and GT groups, with 39 components having markedly higher relative contents in GCK and 25 components having significantly lower relative contents in GCK compared to GT. Moreover, among these metabolites, there were more types with higher contents in the fruiting bodies harvested in the first year (GCK) compared to those harvested in the second year (GT), with pronounced differences. KEGG pathway analysis revealed that GCK exhibited more complex metabolic pathways compared to GT. The metabolites of Ganoderma lucidum fruiting bodies were predominantly influenced by soil physicochemical factors and soil enzyme activity. In the surface soil layer (0–15 cm), the metabolome was significantly affected by soil pH, soil organic matter, available phosphorus, and soil alkaline phosphatase, while in the deeper soil layer (15–30 cm), differences in the Ganoderma lucidum metabolome were more influenced by soil alkaline phosphatase, soil catalase, pH, nitrate nitrogen, and soil sucrase.

A Study of the Relationship between Initial Grape Yield and Soil Properties Based on Organic Fertilization

Increasing the use of organic fertilizers is an effective measure to improve, increase soil fertility and maintain crop yields. The aim of this study was to investigate the influence of different types of organic fertilizers on the early yield of grapes and soil parameters, as well as the relationship between soil parameters and grape yield under fertilization conditions. The ‘Shine Muscat’ grape was used as the material, with early maturing cultivation in the solar greenhouse. From the time of grape planting, three-year continuous fertilization management was carried out using five types of base fertilizers: chemical fertilizer (CK), fermented corn stalk residue (A1), mature sheep manure (A2) and two types of commercial organic fertilizers (B1 and B2). In the third year, berry and soil samples were collected to determine grape yield and evaluate soil physicochemical properties, nutrient status and changes in enzyme activity, studying the relationship between grape yield and soil indicators. The results show that compared to CK, the grape yields with B1 and B2 increased by 19.04% and 16.26%, respectively, while A1 and A2 decreased by 24.09% and 18.97%. Organic fertilizer application reduced soil bulk density, increased soil porosity, enhanced soil organic matter content and effectively buffered soil pH levels. Two types of commercial fertilizers (B1 and B2) improved soil total nitrogen, total phosphorus, total potassium, available nitrogen and available phosphorus content to varying degrees. All organic fertilizer treatments effectively increased soil enzyme activity, except for soil sucrase activity. Through correlation and regression analyses, it was found that in this study, the levels of available nitrogen, available potassium and soil saccharase activity were most closely related to early grape yield. Their influence on grape yield was in the order of available nitrogen > soil saccharase activity > available potassium. Therefore, with a combined organic and inorganic basal fertilization system, the fertilizer nutrients are more comprehensive and help to increase the productivity of grapes at the beginning of the fruiting period. Nitrogen and phosphorus are very important in the maintaining of grape yields and improving sucrose activity in the soil through the application of organic fertilizers cannot be ignored when increasing yields.

Effects of antimony on the soil enzymes, microbial, and rhizobial activity of legumes

ABSTRACT Leguminous farmland in China is severely polluted by antimony. Here, to explore the effects of antimony stress on rhizobia and soil microorganisms in leguminous plants, mung beans, kidney beans, and peanuts were grown in soil with different concentrations of Sb3+, Sb5+, and Sb3++Sb5+. Antimony had a promotional effect on soil sucrase and catalase activities and an inhibitory effect on urease activity. The effects of Sb3+ on sucrase, catalase, and urease activities were 3.3–11.1, 1.27–1.29, and 1.24–3.05 times those of Sb5+, respectively. Antimony reduced the rhizobial activity by 20.63–57.84%, with the inhibitory effect positively related to the antimony content. Additionally, the inhibitory effect of Sb3+ was 1.10–2.22 times that of Sb5+. This inhibition decreased the total nitrogen and ammonia nitrogen content in the soil. However, the decrease in Sb3+ was 0.46–1.54 times that of Sb5+. Sb3+ significantly altered the microbial activity.

The role of microplastics in the process of Paraclostridium sp. DLY7-assisted phytoremediation of phenanthrene contaminated soil

Microplastics can absorb polycyclic aromatic hydrocarbons (PAHs), decrease the bioavailability of pollutants, alter the soil microbial community, and thus might affect the dissipation of soil pollutants. However, whether microplastics could alter the remediation efficiency of PGPR-assisted plants for PAHs-contaminated soil has not been studied. This study assessed the remediation potential of PGPR exhibiting phenanthrene (PHE) degradation ability in assisting maize for PHE-contaminated soil. Especially, the role of microplastics involved in this remediation process was also investigated. The results showed that strain Paraclostridium sp. DLY7 (DLY7) significantly increased the PHE removal efficiency (63.4%) from soil by maize and reduced the content of PHE in maize leaves and roots with no microplastics addition. However, the presence of microplastics significantly inhibited the PHE removal from soil and increased the PHE accumulation in maize issues, in comparison with PHE + DLY7 treatment. Microplastics also significantly reduced soil sucrase and alkaline phosphatase activities, and the content of soil nitrate nitrogen and ammonium nitrogen under non-inoculation with strain conditions. Inoculation with strain DLY7 also altered the rhizosphere soil microbial community, enriched some beneficial bacteria and increased activities of some crucial soil enzymes, thus facilitating PHE removal from soil. On the whole, compared with conventional soil contamination remediation studies, this study innovatively pointed out that microplastics significantly reduced the removal efficiency of soil PHE and increased the uptake of PHE by maize in the PGPR-assisted phytoremediation process. However, the effects of microplastics on microorganisms might be related to the particle size, concentration and type of microplastics in the environment, which would be studied in our future research. These findings proposed new perspectives for revealing the role of microplastics on the efficiency of microbe-assisted phytoremediation of PAHs-contaminated soil.

The Early Effects of an Agrivoltaic System within a Different Crop Cultivation on Soil Quality in Dry–Hot Valley Eco-Fragile Areas

The co-allocation of photovoltaic arrays with crops presents a promising strategy to mitigate the conflict between photovoltaics and agricultural land. However, there is a notable lack of quantitative research on the impact of agrivoltaic system on land quality in fragile areas. In this study, peanuts (Arachis hypogaea) and ryegrass (Lolium perenne) were cultivated in photovoltaic array in the dry–hot valley of southwest China, with an off-site native land serving as the control. Sixteen soil physicochemical and biochemical parameters were measured in the gap and under-panel and control area. Results demonstrated that the agrivoltaic system significantly enhanced soil moisture, organic carbon, nitrogen–phosphorus–potassium nutrients, microbial biomass, and urease activity. It also led to varying degrees of increase in soil pH and electrical conductivity, along with reduced soil sucrase and phosphatase activity. In comparison to the control, the agrivoltaic system notably improved soil quality and multifunctionality. Specially, gap cultivation had a more pronounced positive impact on soil quality than under-panel cultivation, and the cultivation of peanuts had a greater effect on soil quality and multifunctionality improvement than ryegrass. This study provides fundamental data to support the improvement of land quality in photovoltaic developed regions, and to alleviate the conflict between photovoltaics and agricultural land.

Effects of brackish water irrigation and biochar application on fertility, enzyme activity, and winter wheat yield in coastal saline‐alkali soils

AbstractSoil salinization is a common form of land degradation in coastal regions. The Yellow River Delta is a typical coastal saline‐alkali soils distribution region, with saline‐alkali soils accounting for nearly half of the total area of the region. In view of the lack of fresh water in the region, the use of brackish water and biochar made from agricultural waste to improve coastal saline‐alkali soils has a good application prospect, but there are fewer studies on this at present. To explore water conservation, fertilization, and yield enhancement solutions appropriate for saline‐alkali soils in the Yellow River Delta region, this study focused on investigating the impact of biochar addition on the fertility, enzyme activity, and winter wheat yield in saline‐alkali soils under brackish water irrigation conditions. The research was conducted through outdoor potting experiments, utilizing a local moderately saline‐alkali soil as the subject of study. The study design established three different irrigation water mineralization levels (0, 2, and 4 g L−1) during the research. Two types of biochar, wheat straw biochar (WB) and corn straw biochar (CB) were used with four different applications (0, 5, 10, and 20 t ha−1). There were 21 treatments; each replicated three times. The research findings indicated that brackish water irrigation adversely affected soil fertility and soil alkaline phosphatase activity and soil sucrase activity but increased soil urease activity and soil peroxidase activity. In contrast, biochar application improved soil fertility and enzyme activities. The soil fertility and enzyme activities of K2Y10 treatment was higher than that of CK (fresh water, no biochar application) except for soil total nitrogen, which increased by 5.5%–71.2%. While brackish water irrigation decreased winter wheat yield. Biochar application increased winter wheat yield, with the K2Y10 treatment showing the highest yield under brackish water irrigation conditions, and increased by 17.7% compared to CK. In conclusion, the study recommends a combination of water‐saving measures, fertilizer cultivation, and yield increase strategies to improve saline‐alkali soils in the Yellow River Delta region effectively. Specifically, irrigating with 2 g L−1 brackish water and application 10 t ha−1 of CB demonstrated greater efficacy in addressing the challenges of saline‐alkali soils in the region.

The cuticular wax on sorghum straw influenced soil microbial diversity and straw degradation in soil

The cuticular waxes cover living plant surface but the ecological significance of cuticular wax in crop straw returning to soil remains uncertain. This study focused on sorghum straw to investigate the bioactivity of cuticular waxes in the soil system. The surface of sorghum leaf, sheath and stem organs was covered with epicuticular wax crystals, which present a dull and glaucous wax layer. The leaf surface with wax exhibited an average contact angle of 83°, while after the wax removal the contact angle decreased to 53° on average, showing hydrophobic surface on the sorghum leaf. In total, six wax classes were identified across all organs, including aldehydes, alkanes, fatty acids, primary alcohols, sterols, and minor triterpenoids. The total wax coverage on leaves was 1.5 μg·cm−2, which was significantly lower than that on sheaths (20.6 μg·cm−2) and stems (6.3 μg·cm−2). The wax addition increased the proportions of Actinobacteria and Firmicutes by 24.42 % and 78.02 %, whereas decreased Proteobacteria and Acidobacteria by 16.32 % and 23.16 % on day 14 under higher wax rate. The microbial communities inhabiting returned straw surfaces also differed significantly between wax-retrained and wax-removed straw, as well as among leaf, stem, and sheath components, and at various decomposition stages. Wax addition increased soil microbial biomass carbon and nitrogen by 56.76 % and 25.60 % at higher rate, and soil enzyme activities (i.e., soil urease, soil acid phosphatase activity, soil sucrase activity). Wax removal significantly increased the decomposition rate of dry matter by 24.28 % and crude fiber by 27.22 % on day 154. These findings demonstrate that plant cuticular waxes maintain their bioactivities after entering the soil, which broadens our knowledge of the roles of plant cuticular waxes in ecosystems. Therefore, selecting efficient wax-degrading microorganisms would accelerate the nutrient cycling of crops in soil system.

Enhancing sugar beet yield and quality in Northeast China: Investigating the synergistic impact of sugar mill filter mud and biochar on black soil

In this study, different ratios of sugar beet sugar factory filter mud and biochar in different proportions were used to assess the effect of incorporating filter mud into the field on soil quality and its influence on two distinct sugar beet (Beta vulgaris) varieties: high-yielding KWS9147 and high-sugar KWS1176. The experiment was conducted in 2022 at the Hulan Campus of Heilongjiang University in Harbin City, Heilongjiang Province, China. Eight treatments were employed, including CK1 (no filter mud or biochar application), CK2 (20 t/ha biochar), T1 (16.67kg/ha filter mud), T2 (16.67 t/ha filter mud + 20 t/ha biochar), T3 (33.33 t/ha filter mud), T4 (33.33 t/ha filter mud + 20 t/ha biochar), and T5 (50kg/ha filter mud). For sugar beets, parameters such as the SPAD value(Soil and Plant Analyzer Development, represents the relative content of chlorophyll), disease resistance (root rot and brown spot), tuber yield, and sugar content were evaluated. Soil analysis included nitrogen content, available potassium content, available phosphorus content, and soil sucrase, urease, and phosphatase activities. Results indicated that the combined application of 16.67 t/ha filter mud and 20 t/ha biochar had a positive impact on the growth indices, tuber yield, sugar content, effective phosphorus, and quick-acting potassium content in KWS1176. In contrast, for KWS9147, the most favorable effect was achieved with the application of 16.67 t/ha filter mud. This treatment improved plant leaf growth, increased tuber yield and sugar content, reduced root rot incidence, elevated alkaline dissolved nitrogen content in the inter-root soil, and enhanced soil phosphatase activity. Biochar application did not contribute significantly to these improvements. Therefore, returning sugar mill sludge to the field demonstrated its potential to enhance soil quality, promote the yield of sugar beet varieties, and improve resistance to root rot while also providing an eco-friendly solution for managing environmental issues related to sludge accumulation.

Controlled-Release Nitrogen Mixed with Common Nitrogen Fertilizer Can Maintain High Yield of Rapeseed and Improve Nitrogen Utilization Efficiency.

Field experiments were conducted to study the effects of different proportions of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer on the yield and nitrogen utilization efficiency of direct-seeding rapeseed. Using a conventional nitrogen application rate of 180 kg ha-1 as a control, a total of 5 types of available nitrogen fertilizers and different proportions of controlled-release nitrogen fertilizers were mixed for fertilizer treatment. The proportion of available nitrogen fertilizer used was 135 kg ha-1, and the addition ratios of the five types of controlled-release nitrogen fertilizers were 0%, 30%, 50%, 70%, and 100%, respectively (i.e., the proportion of controlled-release nitrogen to the total nitrogen application amount). These ratios were represented as N135R0, N135R1, N135R2, N135R3, and N135R4, respectively. The results showed that there was no significant difference in the number of pods per plant, the number of seeds per pod, or the grain yield under the treatment of controlled-release nitrogen fertilizer mixed with quick-acting nitrogen fertilizer for proportions of 30-50% (N135R1~R3) when compared with the control, and a stable yield was achieved. Mixing controlled-release nitrogen fertilizer under reduced nitrogen application can significantly improve the apparent utilization rate of rapeseed nitrogen fertilizer, but it first increases and then decreases with the increase of the controlled-release nitrogen mixing ratio, reaching its highest under the N135R2 treatment. The agronomic utilization efficiency and partial productivity of nitrogen fertilizer first increased and then decreased with the increased proportion of controlled-release nitrogen, and both reached their highest utilization with the N135R2 treatment. The mixed treatment of controlled-release nitrogen did not affect soil urease activity, but significantly increased soil sucrase activity. The mixed treatment of controlled-release nitrogen also increased soil microbial biomass nitrogen and carbon content. Especially in the flowering stage, the soil microbial biomass nitrogen and carbon content was significantly higher under a controlled-release nitrogen mixing ratio of 30-50%. At the same time, it had a similar effect on soil inorganic nitrogen content. Therefore, a controlled-release nitrogen mixing treatment provided sufficient nitrogen for the key growth period of rapeseed. Under the condition of reducing the amount of nitrogen fertilizer by 25% based on the amount of nitrogen fertilizer applied to conventional rapeseed, the application of controlled-release urea mixed with common nitrogen fertilizer mixed at a ratio of 30-50% can be an effective way to maintain grain yield levels and improve nitrogen utilization efficiency.

The Ameliorating Effect of Alkaline Industrial Byproducts in the Presence of Exogenous Low-Molecular-Weight Organic Acids on an Acidic Brown Soil from Jiaodong Peninsula of China

ABSTRACT It has been proposed that the quality of acidic soils can be improved in the presence of alkaline byproduct amendments containing silicon (Si), calcium (Ca), magnesium (Mg), and potassium (K). In the present study, we aimed to explore the effect of byproduct amendments on ameliorating acidic soil in Jiaodong Peninsula of China in the existence of different types of low-molecular-weight organic acids (LOAs, such as malic acid, citric acid, oxalic acid, and succinic acid) that are usually excreted by plant roots. Therefore, a 60-day incubation test was carried out to assess the effect of byproduct amendments and LOAs on soil physicochemical properties, soil available Mg and Ca, cation exchange capacity (CEC), soil respiration, and enzyme activities. The results showed that in the presence of LOAs, the byproduct amendments could still increased the soil pH and decreased the soil exchangeable acid and exchangeable Al3+. Compared with the control group (CK), all byproduct amendment-containing treatments could increase soil available Mg and Ca, soil CEC, soil respiration, and soil sucrase (S-SC) activity. The addition of byproduct amendments could significantly improve the chemical and biological properties of the acidic brown soils in Jiaodong Peninsula of China. However, LOAs, especially the LOAs that could precipitate with Ca in byproduct amendments, negatively impair the ameliorating effect on acidic soil compared with byproduct amendments alone treatment. When using byproduct amendments to ameliorate acidic soil, the type of LOAs secreted by plant roots was an influencing factor that must be considered.

Ammonium bicarbonate alleviates apple replant disease: Inhibiting Fusarium and improving soil environment

Providing nitrogen is the core of increasing production in modern agricultural systems, as well as in the production of fruit trees. The rational application of nitrogen is an important measure to increase production and sustainably utilize agricultural ecosystems. Greenhouse, pot and field experiments were conducted to study the effects of different nitrogen forms on the antifungal effect in vitro, apple growth status and the soil environment under replant condition, aims to provide a basis for scientific fertilization and alleviates apple replant disease during orchard construction. We investigated the growth of apple in replant soil treated with different forms of nitrogen, including ammonium nitrogen (NH4N), nitrate nitrogen (NO3N) and amide nitrogen (CO(NH2)2). The results showed that ammonium bicarbonate can inhibit the mycelial growth, spore germination and toxins synthesis of soil-borne pathogens in vitro. The addition of ammonium bicarbonate significantly promoted the replanted apple growth. The activities of soil sucrase, urease, phosphatase and catalase were higher following treatment with ammonium bicarbonate than in the control soil. The qPCR analysis showed that the bacterial, fungal biomass differed distinctly between the different nitrogen forms and the control. These results suggest that ammonium bicarbonate can inhibit the mycelial growth, spore germination and toxins synthesis of soil-borne pathogens, improve the activities of soil enzymes and change soil microbial biomass. These changes can promote growth ofreplanted apple, thereby, ammonium bicarbonate can be used to alleviate apple replant disease as a new control measure.

Microplastics reduced bioavailability and altered toxicity of phenanthrene to maize (Zea mays L.) through modulating rhizosphere microbial community and maize growth

Due to its large specific surface area and great hydrophobicity, microplastics can adsorb polycyclic aromatic hydrocarbons (PAHs), affecting the bioavailability and the toxicity of PAHs to plants. This study aimed to evaluate the effects of D550 and D250 (with diameters of 550 μm and 250 μm) microplastics on phenanthrene (PHE) removal from soil and PHE accumulation in maize (Zea mays L.). Moreover, the effects of microplastics on rhizosphere microbial community of maize grown in PHE-contaminated soil would also be determined. The results showed that D550 and D250 microplastics decreased the removal of PHE from soil by 6.5% and 2.7% and significantly reduced the accumulation of PHE in maize leaves by 64.9% and 88.5%. Interestingly, D550 microplastics promoted the growth of maize and enhanced the activities of soil protease and alkaline phosphatase, while D250 microplastics significantly inhibited the growth of maize and decreased the activities of soil invertase, alkaline phosphatase and catalase, in comparison with PHE treatment. In addition, microplastics changed the rhizosphere soil microbial community and reduced the relative abundance of PAHs degrading bacteria (Pseudomonas, Massilia, Proteobacteria), which might further inhibit the removal of PHE from soil. This study provided a new perspective for evaluating the role of microplastics on the bioavailability of PHE to plants and revealing the combined toxicity of microplastics and PHE to soil microcosm and plant growth.

Effects of Supplementation of Different Amendments on Soil Heavy Metals and Enzyme Activities in Coastal Saline Land

The supplementation of soil amendments may not only improve the soil physical and chemical properties but also lead to the accumulation of heavy metals in soil. This experiment included six treatments:control (CK), organic manure (OM), polyacrylamide+organic manure (PAM+OM), straw mulching+organic manure (SM+OM), buried straw+organic manure (BS+OM), and bio-organic manure+organic manure (BM+OM) to explore the effects of different soil amendments on heavy metals and soil enzyme activities in coastal saline land and the relationship between them. The results revealed that compared with that in the CK treatment, the contents of soil Cr, Cu, Ni, and Pb exhibited an upward trend after the supplementation of soil amendments, among which the SM+OM and PAM+OM treatments had the most significant effects on the contents of soil Cr and Cu, respectively, whereas the BM+OM treatment had the most significant effects on the contents of soil Ni and Pb. Compared with those in the CK treatment, the activities of soil invertase and urease increased significantly following supplementation of soil amendments, and the BM+OM treatment had the best effect. The alkaline phosphatase activity exhibited a slightly upward trend after the supplementation of soil amendments, whereas the catalase activity did not change significantly. The redundancy analysis revealed that the first two axes cumulatively accounted for 70.3% of the variability in enzyme activities, and the importance of single soil heavy metals on soil enzyme activity was as follows:Ni>Cu>Cr>Pb.

Response of Nicandra physalodes (Linn.) Gaertn. and Its Rhizospheric Organisms to the Selective Pressures of High-Concentration Oxytetracycline, Ciprofloxacin, and Tobramycin

Antibiotics play an essential role in the treatment of infectious diseases in humans and animals. Despite their benefits, the release of an increasing amount of various antibiotics into the environment poses a potential threat to plants, soils, animals, and microorganisms. Here, an outdoor pot experiment was conducted to preliminarily evaluate high concentrations of three antibiotics (oxytetracycline, ciprofloxacin, and tobramycin) on Nicandra physalodes (Linn.) Gaertn. and its rhizospheric organisms. The results showed that the three antibiotics had different effects on the growth behavior (germination uniformity, average growing height gain per week, and thousand seed weight) and biomass (aboveground biomass and belowground biomass) of Nicandra physalodes (Linn.) Gaertn. After adding high concentrations of the three antibiotics to the soil of each test group, the earthworm extract in group A (oxytetracycline) significantly increased the coagulation parameters prothrombin time (PT) and thrombin time (TT). The PT significantly decreased (p < 0.01), while the TT was not affected in group B (ciprofloxacin). For group C (tobramycin), the TT significantly decreased (p < 0.01) and the PT was not affected compared to the CK group (control group). The application of the three antibiotics caused alterations in the general activity of enzymes, such as soil sucrase (SC), urease (UE), acid phosphatase (ACP), alkaline phosphatase (AKP), and nitrate reductase (NR). Different antibiotic groups influenced the rhizosphere bacterial diversity and community structure of Nicandra physalodes (Linn.) Gaertn. At the phylum level, Ignavibacteriae was only found in group C, and Parcubacteria and Ignavibacteriae were not present in the CK group. At the genus level, Parcubacteria_norank was not present in the CK group, and BSV40_norank was found in group C. Ultimately, the results suggested that high concentrations of oxytetracycline, ciprofloxacin, and tobramycin could affect the growth behavior and biomass of Nicandra physalodes (Linn.) Gaertn. and alter its rhizobacterial community structure, providing the scientific basis for the rational use of antibiotics in animal husbandry and veterinary science.

Enzymatic fermentation of rapeseed cake significantly improved the soil environment of tea rhizosphere

BackgroundRapeseed cake is an important agricultural waste. After enzymatic fermentation, rapeseed cake not only has specific microbial diversity but also contains a lot of fatty acids, organic acids, amino acids and their derivatives, which has potential value as a high-quality organic fertilizer. However, the effects of fermented rapeseed cake on tea rhizosphere microorganisms and soil metabolites have not been reported. In this study, we aimed to elucidate the effect of enzymatic rapeseed cake fertilizer on the soil of tea tree, and to reveal the correlation between rhizosphere soil microorganisms and nutrients/metabolites.ResultsThe results showed that: (1) The application of enzymatic rapeseed cake increased the contents of soil organic matter (OM), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), and available phosphorus (AP); increased the activities of soil urease (S-UE), soil catalase (S-CAT), soil acid phosphatase (S-ACP) and soil sucrase (S-SC); (2) The application of enzymatic rapeseed cake increased the relative abundance of beneficial rhizosphere microorganisms such as Chaetomium, Inocybe, Pseudoxanthomonas, Pseudomonas, Sphingomonas, and Stenotrophomonas; (3) The application of enzymatic rapeseed cake increased the contents of sugar, organic acid, and fatty acid in soil, and the key metabolic pathways were concentrated in sugar and fatty acid metabolisms; (4) The application of enzymatic rapeseed cake promoted the metabolism of sugar, organic acid, and fatty acid in soil by key rhizosphere microorganisms; enzymes and microorganisms jointly regulated the metabolic pathways of sugar and fatty acids in soil.ConclusionsEnzymatic rapeseed cake fertilizer improved the nutrient status and microbial structure of tea rhizosphere soil, which was beneficial for enhancing soil productivity in tea plantations. These findings provide new insights into the use of enzymatic rapeseed cake as an efficient organic fertilizer and expand its potential for application in tea plantations.

EFFECTS OF MIXING ADDITION OF THE GREENERY WASTES ON THEIR REMEDIATING EFFECTS ON PETROLEUM POLLUTED SOIL

In this study, greenery wastes of Platycladus orientalis (Po) and the other 5 species which are commonly used in urban landscaping were collected. Monospecific greenery wastes and their 1:1 mixtures containing Po waste were used to treat contaminated soil with a petroleum content of 15.00 g/kg, to conduct a 150-day laboratory remediating experiment at 20-25℃, under a soil moisture of 50% of the saturated water holding capacity. The effects of mixed addition of greenery wastes on their re-mediating effects on contaminated soil were detected, to provide scientific basis for the reasonable utilization of greenery waste in contaminated soil remediation. The results indicated that: (1) Mixed addition of Po waste with Picea asperata (Pa), Acer truncatum (At), Ginkgo biloba (Gb) or Juniperus formosana (Jf) waste significantly enhanced their effect of removing petroleum contaminants, espe-cially for removing aromatic and non-hydrocarbon substances; while the mixed addition of Po waste with Pinus tabuliformis (Pt) waste significantly weakened their remediating effects. The mixed addition of Po waste with Gb or Jf waste significantly enhanced their effects of replenishing soil available N and P; the mixed addition of it with Pa, Pt, Gb or Jf waste tended to enhance their effects of stimulating the activities of soil invertase, urease, phosphatase and dehydrogenase, while the mixed of it with At waste tended to weaken their simulating effects. (2) Mixed litters with high contents of C, N, terpenoids and amino acids, and chemical dispersion facilitated the degradation of petroleum contaminants, while those with high contents of soluble saccharides and total organic acids/terpenoids led to contrast effects; mixed litters with high N content facilitated the increment of soil enzymatic activities, while those with high contents of total organic acids and terpenoids led to contrast effects. In conclusion, mixed addition of Po and Jf, Po and Gb, and Po and Pa wastes might enhance their overall remediating effects on petroleum contaminated soil, while mixed addition of Po and Pt wastes might weaken their ability of removing the contaminants, and this mixing form of greenery wastes should be avoided.

Effects of drip irrigation on yield, soil fertility and soil enzyme activity of different potato varieties in Northwest China.

The effects of different irrigation and fertilization on potato yield, soil fertility and soil enzyme activity of different varieties under drip irrigation fertilization mode were studied, which could provide support for selecting the best varieties in Northwest China. Three factors and three levels orthogonal experimental design method, a total of nine treatments. The three irrigation levels were W1 (100% crop evapotranspiration (ETC)), W2 (80% ETC) and W3 (60% ETC). The three fertilization levels were F1 (N-P2O5-K2O, 240-120-300 kg ha-1), F2 (180-90-225 kg ha-1) and F3 (120-60-150 kg ha-1). The three varieties were V1 (Feiuritar), V2 (Longshu7) and V3 (Qingshu 9). The results showed that different irrigation and fertilization had significant effects on potato yield, soil fertility and soil enzyme activity in root zone. The highest yield of T5 (80%ETC, 180-90-225 kg ha-1, Qingshu 9) was 49,222.3 kg ha-1. With the increase of fertilizer application rate, potato yield and soil enzyme activity in root zone increased first and then decreased, but soil electrical conductivity (SEC), soil nitrate-N content (SNNC), soil alkali-hydrolyzable nitrogen content (SAHC), soil available potassium (AK), soil available phosphorus (AP), soil ammonium-N content (SANC) and soil organic matter (SOM) in root zone increased continuously. The yield, soil catalase activity, soil urease activity and soil sucrase activity at W2 were 2.81% and 22.2%, 1.84% and 7.04%, 8.26% and 9.62%, 5.34% and 13.36% higher than those at W1 and W3, respectively. The overall trend of soil water content, soil nutrient content and enzyme activity in root zone was 0-20 cm >20-40 cm >40-60 cm soil layer. There were many soil factors affecting tuber yield, among which soil enzyme activity, pH value and root zone conductivity were the key factors. The results showed that T5 (80%ETC, 180-90-225 kg ha-1, Qingshu 9) was the best treatment to improve soil enzyme activity and yield.

Responses of soil biochemical and microbial properties to vegetation combinations of quarry restoration strategies in mountainous areas in China

The growing concern about the effectiveness of restoration strategies has spurred an evaluation of soil properties under different vegetation combinations. The restoration of underground microbial communities is critical to the success of restoration, however, the responses of biochemical and microbial properties to reclamation remain unknown. In this study, soil nutrients, enzyme activities and the characteristics of microbial communities of four restoration modes, CK1 (a non-restored mode) and CK2 (an original habitat mode) in a mining area of Sanhe City of Hebei Province were measured. Soil bacteria and fungi communities were analyzed by high-throughput sequencing of 16S rRNA gene fragment and internal transcribed spacer (ITS) to assess the recovery effects of different ecological restorations. Our results showed that: (1) The improved effect on soil available phosphorus (AP), available potassium (AK) and organic matter (OM) was obvious. Also, artificial and native plant combinations of Medicago sativa + local dominant natural vegetation (Nr) had the most obvious effect on soil nutrients. (2) The activities of soil urease, soil sucrase and soil phosphatase in Nr were considerably higher than those in other restoration modes (p < 0.05), while the soil catalase activity was the highest in the vegetation combinations of Medicago sativa + artificial miscellaneous grass (Mg) (p < 0.05). (3) Bacterial community structures in Nr were closest with those in CK2, whereas fungal community structures in Mg recovered the best. On the whole, the recovery rates of different indicators were ranked as follows: soil nutrients > bacteria > fungi. These results indicated that in the short term, native vegetation incorporating the planting of alfalfa significantly increased ecological restoration effects, however, a longer restoration history was required to restore the soil microbial diversity level similar to that of the original habitat.

Elevational changes in soil properties shaping fungal community assemblages in terrestrial forest

Environmental variables shifted by climate change act as driving factors in determining plant-associated microbial communities in terrestrial ecosystems. However, how elevation-induced changes in soil properties shape the microbial community in forest ecosystems remains less understood. Thus, the Pinus tabuliformis forests at elevations of 1500 m, 1900 m, and 2300 m above sea level were investigated to explore the effect of environmental factors on microbial assemblage. Significant changes in the soil physicochemical properties were found across the investigated elevations, such as soil moisture, temperature, pH, nitrogen (N), and phosphorus (P). Soil enzymatic activities, including soil sucrase, phosphatase, and dehydrogenase, were significantly affected by elevation, and sucrase showed a linear correlation with soil organic matter. Furthermore, the richness of fungal communities in the rhizosphere was decreased as elevation increased, while a humpback pattern was found for roots. Certain core microbiota members, such as Agaricomycetes, Leotiomycetes, and Pezizomycetes, were crucial in maintaining a stable ecological niche in both the root and rhizosphere. We also found that shifting of fungal communities in the rhizosphere were more related to physical properties (e.g., pH, soil moisture, and soil temperature), while changes in root fungal communities along elevation gradient were related mostly to soil nutrients (e.g., soil N and P). Overall, this study demonstrates that the assemblage of the root and rhizosphere fungal communities in P. tabuliformis forest primarily depends on elevation-induced changes in environmental variables and highlights the importance of predicting fungal responses to future climate change.