The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and...The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.展开更多
Treatment of peat soil foundation in Yunnan surrounding Dianchi and Erhai Lakes poses complex problems for engineering projects.It is insufficient to rely on ordinary cement to reinforce peat soil.In order to make the...Treatment of peat soil foundation in Yunnan surrounding Dianchi and Erhai Lakes poses complex problems for engineering projects.It is insufficient to rely on ordinary cement to reinforce peat soil.In order to make the reinforcement reliable,this experiment mixed(ultrafine cement)UFC into ordinary cement to form a composite solidify agent.This study aimed to analyze the influence of UFC proportion on the strength of cement-soil in the peat soil environment.Unconfined compressive strength(UCS)and scanning electron microscope(SEM)tests were conducted on samples soaked for 28 and 90 days,respectively.The test results show that without considering the effects of Humic Acid(HA)and Fulvic Acid(FA),incorporating UFC can significantly improve the UCS of cement-soil.The rapid hydration of the fine particles generates a large number of cementitious products,improves the cohesion of the soil skeleton,and fills the pores.However,when the proportion of UFC increases,the aggregate structure formed by a larger quantity of fine particles reduces the hydration rate and degree of cement hydration,making the UCS growth rate of cement-soil insignificant.In the peat soil environment,HA significantly weakened the UCS of cement-soil in both physical and chemical aspects.However,UFC can mitigate the adverse effect of HA on cement-soil by its small particle size,high surface energy,and solid binding ability.In addition,FA has a positive effect on the UCS of cement-soil soaked for 28 days and 90 days.The UFC addition could promote the enhancement effect of FA on cement-soil UCS.SEM test results showed that cement hydration products increased significantly with the increase of UFC proportion,and cementation between hydration products and soil particles was enhanced.The size and connectivity of cement-soil pores were significantly reduced,thereby improving cement-soil structural integrity.展开更多
Rice sheath blight is one of the serious rice diseases causing economic losses worldwide.Shenqinmycin,a broad-spectrum microbial metabolite pesticide,inhibits plant pathogens.This study investigated the sensitivity of...Rice sheath blight is one of the serious rice diseases causing economic losses worldwide.Shenqinmycin,a broad-spectrum microbial metabolite pesticide,inhibits plant pathogens.This study investigated the sensitivity of rice sheath blight pathogen to the biological pesticide by treating 45 strains isolated from three northeastern provinces with varying concentrations of Shenqinmycin.The effects on mycelial growth and sclerotial germination of the rice sheath blight pathogens were measured to determine the resistance levels.The results indicated that all tested strains were sensitive to Shenqinmycin,with EC50 values for Rhizoctonia solani ranging from 0.0487 mg·L^(-1) to 0.2348 mg·L^(-1),and a sensitivity baseline of 0.1292 mg·L^(-1).For Rhizoctonias oryzae-sativae,the EC50 values ranged from 0.0517 mg·L^(-1) to 0.1697 mg·L^(-1),with a sensitivity baseline of 0.1163 mg·L^(-1).Shenqinmycin had no effect on the sclerotial germination of either pathogen,suggesting its potential as an effective agent for controlling rice sheath blight.展开更多
Soil DNA extraction,such as microbial community analysis and gene drift detection,is an important basis for multiple analyses in different fields.Nevertheless,the soil DNA extraction methods for field detection are st...Soil DNA extraction,such as microbial community analysis and gene drift detection,is an important basis for multiple analyses in different fields.Nevertheless,the soil DNA extraction methods for field detection are still lacking.This study established a rapid soil DNA extraction(RSDE)method that can be used in field detection.In this method,we first utilized the optimized lysate to isolate DNA from soil and then used a filtration membrane and a DNA adsorption membrane to purify the DNA via the column method.Moreover,we used the pressure from the syringe instead of the conventional centrifugal force of the centrifuge to assist the sample filtration,resulting in very low requirements for this method,with an extraction time of less than 20 min.Furthermore,we demonstrated that the RSDE method was applicable for DNA extraction from different types of soils,with the demand for soil samples as low as 0.1 g and that the amount of obtained DNA was,to some extent,greater than that obtained by a commercial kit.Further analysis revealed that this extracted genomic DNA can be used directly for polymerase chain reaction(PCR)analysis,including ordinary PCR,real-time fluorescent quantitative PCR,and recombinase polymerase amplification(RPA)-CRISPR/Cas12a visual assays.In addition,we demonstrated that this method can be used to extract DNA from residual plant roots in addition to soil microbes,which lays a foundation for the comprehensive analysis of soil plants and microorganisms.In summary,the RSDE method proposed in this study may have wide application prospects.展开更多
In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel m...In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.展开更多
Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or C...Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.展开更多
Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influenc...Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.展开更多
During the operation of the rice combine harvester,the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational reliability.Aiming at the problem of leveling due to the ti...During the operation of the rice combine harvester,the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational reliability.Aiming at the problem of leveling due to the tilt of the field surface,this research developed an innovative dual-parallelogram chassis lifting mechanism for rice harvesters designed a hydraulic system to adjust the chassis height by extending the cylinder.Using Adams simulation software,a detailed model of the lifting chassis was constructed to analyze its performance,revealing a direct correlation between the hydraulic cylinder extension and chassis elevation.Notably,the mechanism could achieve leveling on slopes with inclination angles of up to 7.5°.Comprehensive evaluations of the liftable chassis system were conducted under both static and dynamic conditions.In the static tests,the system exhibited the capacity for comprehensive or unilateral auto-leveling contingent upon the tilt,with leveling times and angular variations confined to 3.6 s and±0.4°,respectively.In dynamic tests conducted on sloped fields and paddy soils,the system reduced post-leveling mean tilt angles and standard deviations remained below 1.2°and 0.6°,respectively.These results demonstrated a substantial improvement in the stability and reliability of the chassis during operations.This research provides valuable insights into the design and optimization of automatic leveling mechanisms and structural innovations for harvester chassis.展开更多
Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium ...Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.展开更多
Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to t...Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to the emergence of the thermal contact resistance effect.In this paper,four thermal contact models were developed to predict the thermal contact resistance at the interface of multilayered saturated soils.Based on the theory of thermal-hydro-mechanical coupling,semi-analytical solutions of thermal consolidation subjected to time-dependent heating and loading were obtained by employing Laplace transform and its inverse transformation.Thermal consolidation characteristics of multilayered saturated soils under four different thermal contact models were discussed,and the effects of thermal resistance coefficient,partition thermal contact coefficient,and temperature amplitude on the thermal consolidation process were investigated.The outcomes indicate that the general thermal contact model results in the most pronounced thermal gradient at the interface,which can be degenerated to the other three thermal contact models.The perfect thermal contact model overestimates the deformation of the saturated soil during the thermal consolidation.Moreover,the effect of temperature on consolidation properties decreases gradually with increasing interfacial contact thermal resistance.展开更多
This study was designed to enhance the soft clayey soil treatment effects using an innovative mechanochemically activated geopolymer(GP)through the optimized inclusion of nano-metakaolin(NM)and polypropylene fiber.The...This study was designed to enhance the soft clayey soil treatment effects using an innovative mechanochemically activated geopolymer(GP)through the optimized inclusion of nano-metakaolin(NM)and polypropylene fiber.The study also investigated the possible improvements in the binding ability of GP stabilization under different curing regimes.To this end,binders including lime alone,LG(slag-based geopolymer),LGNM(nano-modified LG with NM)and LGNMF(LGNM/fiber)mixture were separately added to soft soil samples.The fabricated composites were then subjected to a set of macro and micro level tests.The results indicated that,adding LG binary with a 20%NM replacement can lead to a significant increase(by nearly 21 times)in soil strength and a remarkable decline(about 70%)in the compression index.In fact,NM can play a great role in accelerating the rate of hydration reactions and forming a densely packed fabric,which staggeringly improve the soil hydromechanical attributes.It was also observed that raising the curing temperature will effectively augment the polymerization kinetics,leading to a substantial increase(~2 times)in the soil solidification process.However,the stabilized composites containing NM may reveal a brittle nature under more intense stress.Such a potential drawback seems to be resolved by the integration of fibers within the matrix.LGNM combined with fiber would boost(≥10 times)the energy absorption capacity of the soil,notably enhancing its residual strength.Overall,LGNMF may not only feature a broader range of benefits(inc.economic,technical,environmental)compared to traditional binders but also promote the ductility of the GP materials.展开更多
Bauxite tailing(BT)slurry has been generated and accumulated in large quantities,posing a threat to the green and sustainable development of the alumina industry.The regression equation between the actual water conten...Bauxite tailing(BT)slurry has been generated and accumulated in large quantities,posing a threat to the green and sustainable development of the alumina industry.The regression equation between the actual water content and mud water separation rate was established to achieve efficient resource utilization,and the feasibility of foam lightweight soil(FLS)prepared from BT was investigated.The effects of industrial waste residues(fly ash and slag powder)on the properties of FLS were studied.Meanwhile,the micro-mechanisms were revealed by XRD,SEM-EDS,and TG-DSC.The results revealed that fly ash reduced the workability and compressive strength of FLS.Slag powder can significantly enhance the compressive strength of FLS,which increased by 18.60%-23.26%,17.07%-58.54% and 12.12%-52.12%,respectively.Besides,slag powder can improve the long-term water stability performance and enhance carbonation resistance.XRD and thermal analyses showed that adding fly ash decreased the hydration degree of FLS,leading to a decrease in the hydration products.Slag powder improved the pore structure and compacted the skeleton structure of FLS.This study would provide an effective way to realize the resource utilization of BT,fly ash,and slag powder,with certain socio-economic and environmental benefits.展开更多
Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils...Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China's maximum permission level(MPL)for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi(XY)Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery>lactuca sativa L>Chinese cabbage>Romaine lettuce>asparagus lettuce>mustard>cabbage mustard>cabbage.The mean hazard quotient(HQ)of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA(2009)threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents.展开更多
How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical mode...How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical model with N,P,K,irrigation water( W) and water use efficiency( WUE),which was set up under the condition of controlled irrigation with quadratic D- 416 optimized saturation design. The results show that the decending order of single factor' s influence on the WUE was N,K,P and W. All the interactions between N&P,N&K,N&W,K&P,P&W and K&W on the WUE were raised initially,and when reached a certain value,they began to decline. The decending order of each interaction on the WUE was K&P,K&W,N&K,N&P,P&W and N&W. When the WUE was targeted within 1. 8- 2. 5 kg / km^3,an optimized proportion plan was obtained in the 95% confidence interval,i. e. N 87. 76- 103. 32 kg / hm^2,K_2 O 52. 37- 66. 53 kg / hm^2 and P_2O_536. 80- 46. 71 kg / hm^2. Furthermore,the late tillering of the soil moisture content was 70. 07%- 72. 57% of the saturated moisture content.展开更多
Using hybrid rice Yixiang1577 as the material, the mid-season and ratooning hybrid rice yield variation was studied in Southem Sichuan at different levels of nitrogen fertilizer. The results showed that rice yield by ...Using hybrid rice Yixiang1577 as the material, the mid-season and ratooning hybrid rice yield variation was studied in Southem Sichuan at different levels of nitrogen fertilizer. The results showed that rice yield by using N fertilizer increased to the most significant level than no fertilizer ones, and the mid-season rice and rice yield by using more N fertilizer increased to the significant level than less fertilizer ones. The rice yield by using no fertilizer ones increased to the most significant level than some used fertilizer, and the ratooning rice and rice yield by using more N fertilizer decreased to the most significant level than less fertilizer ones. The rice yield by using some fertilizer increased to the most significant level than no fertilizer ones for mid-season＋rationing rice and rice yield by using some fertilizer had no obvious differences at different nitrogen levels. Therefore, application of fertilizer can improve yield of mid-season rice and mid-season＋rationing rice. Soil test results showed that nutrient contents in rice field in South Sichuan were very rich in nitrogen, which could provide more adequate crop growth potential soil nitrogen nutrition. The crops with a deep root system had stronger ability of utilization on soil nitrogen. Therefore, the ratooning rice used no or little N fertilizer had a high yield performance because they made full use of soil nitrogen with deep root system.展开更多
The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw retur...The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.展开更多
Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice sy...Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.展开更多
Rice is a typical silicon-loving crop,known as"representative of silicic acid plant".Southeast Asia and other rice-producing countries have listed silicon fertilizer as the fourth most elemental fertilizer a...Rice is a typical silicon-loving crop,known as"representative of silicic acid plant".Southeast Asia and other rice-producing countries have listed silicon fertilizer as the fourth most elemental fertilizer after nitrogen,phosphorus and potassium.Therefore,improving the utilization of soil silicon and promoting the transformation of soil silicon form is of great significance to the growth of rice and the development of agriculture.In order to investigate the effects of silicon preparations on different forms of silicon in soil and silicon contenst in rice plants,a pot experiment with Dongnong 427 was carried out,spraying on rice leaves at the booting stage,and three treatment groups(Si-TG,Si-EG and Si-60G)and a control group(CK)were set up.The contents of available silicon,water-soluble silicon,amorphous silicon,active silicon in soil and plant silicon were measured at the heading stage and the maturity stage of rice,then the effect of silicon preparation on the silicon content of rice soil and plant was analyzed.The results showed that spraying silicon preparation could significantly improve the silicon content of rice plants,promote the transformation of silicon forms in soil to varying degrees,and improve the silicon supply capacity of soil.Compared with CK,the soil available silicon content increased by 7.42%-8.26%at the heading stage and 6.70%at the maturity stage.The Si-EG treatment at the heading stage had the best effect on increasing the available silicon content of the soil,which was 8.26%higher than that of CK,reaching a significant level;the Si-TG treatment at the maturity stage had the best effect on increasing the silicon content of the plant,and the silicon content of the plant was 27.17%higher than that of CK,reaching a significant level.展开更多
文摘The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.
基金National Natural Science Foundation of China(No.41967035)。
文摘Treatment of peat soil foundation in Yunnan surrounding Dianchi and Erhai Lakes poses complex problems for engineering projects.It is insufficient to rely on ordinary cement to reinforce peat soil.In order to make the reinforcement reliable,this experiment mixed(ultrafine cement)UFC into ordinary cement to form a composite solidify agent.This study aimed to analyze the influence of UFC proportion on the strength of cement-soil in the peat soil environment.Unconfined compressive strength(UCS)and scanning electron microscope(SEM)tests were conducted on samples soaked for 28 and 90 days,respectively.The test results show that without considering the effects of Humic Acid(HA)and Fulvic Acid(FA),incorporating UFC can significantly improve the UCS of cement-soil.The rapid hydration of the fine particles generates a large number of cementitious products,improves the cohesion of the soil skeleton,and fills the pores.However,when the proportion of UFC increases,the aggregate structure formed by a larger quantity of fine particles reduces the hydration rate and degree of cement hydration,making the UCS growth rate of cement-soil insignificant.In the peat soil environment,HA significantly weakened the UCS of cement-soil in both physical and chemical aspects.However,UFC can mitigate the adverse effect of HA on cement-soil by its small particle size,high surface energy,and solid binding ability.In addition,FA has a positive effect on the UCS of cement-soil soaked for 28 days and 90 days.The UFC addition could promote the enhancement effect of FA on cement-soil UCS.SEM test results showed that cement hydration products increased significantly with the increase of UFC proportion,and cementation between hydration products and soil particles was enhanced.The size and connectivity of cement-soil pores were significantly reduced,thereby improving cement-soil structural integrity.
基金Supported by the Green Plant Protection Project(213010801)the Heilongjiang Provincial Key R&D Program Projects(20232X02B0502)。
文摘Rice sheath blight is one of the serious rice diseases causing economic losses worldwide.Shenqinmycin,a broad-spectrum microbial metabolite pesticide,inhibits plant pathogens.This study investigated the sensitivity of rice sheath blight pathogen to the biological pesticide by treating 45 strains isolated from three northeastern provinces with varying concentrations of Shenqinmycin.The effects on mycelial growth and sclerotial germination of the rice sheath blight pathogens were measured to determine the resistance levels.The results indicated that all tested strains were sensitive to Shenqinmycin,with EC50 values for Rhizoctonia solani ranging from 0.0487 mg·L^(-1) to 0.2348 mg·L^(-1),and a sensitivity baseline of 0.1292 mg·L^(-1).For Rhizoctonias oryzae-sativae,the EC50 values ranged from 0.0517 mg·L^(-1) to 0.1697 mg·L^(-1),with a sensitivity baseline of 0.1163 mg·L^(-1).Shenqinmycin had no effect on the sclerotial germination of either pathogen,suggesting its potential as an effective agent for controlling rice sheath blight.
基金the Experimental Technology Research Project of Zhejiang University(SYB202138)National Natural Science Foundation of China(32000195).
文摘Soil DNA extraction,such as microbial community analysis and gene drift detection,is an important basis for multiple analyses in different fields.Nevertheless,the soil DNA extraction methods for field detection are still lacking.This study established a rapid soil DNA extraction(RSDE)method that can be used in field detection.In this method,we first utilized the optimized lysate to isolate DNA from soil and then used a filtration membrane and a DNA adsorption membrane to purify the DNA via the column method.Moreover,we used the pressure from the syringe instead of the conventional centrifugal force of the centrifuge to assist the sample filtration,resulting in very low requirements for this method,with an extraction time of less than 20 min.Furthermore,we demonstrated that the RSDE method was applicable for DNA extraction from different types of soils,with the demand for soil samples as low as 0.1 g and that the amount of obtained DNA was,to some extent,greater than that obtained by a commercial kit.Further analysis revealed that this extracted genomic DNA can be used directly for polymerase chain reaction(PCR)analysis,including ordinary PCR,real-time fluorescent quantitative PCR,and recombinase polymerase amplification(RPA)-CRISPR/Cas12a visual assays.In addition,we demonstrated that this method can be used to extract DNA from residual plant roots in addition to soil microbes,which lays a foundation for the comprehensive analysis of soil plants and microorganisms.In summary,the RSDE method proposed in this study may have wide application prospects.
基金Supported by the Green Plant Protection Project(213010801)the Heilongjiang Province Key Research and Development Plan Project(20232X02 B0502)the Natural Science Foundation of Heilongjiang Province(LH2022C022)。
文摘In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.
基金Supported by the Joint Funds of the National Natural Science Foundation of China(U2340219)。
文摘Cadmium(Cd)or excess copper(Cu)has a great impact in terms of toxicity on living organisms as it severely affects crop growth,yield and food security;thus,warranting appropriate measures for the remediation of Cd or Cu polluted soils.Phytoextraction of heavy metal(HM)using tolerant plants along with organic chelators has gained global attention,and this study provided further insights into this issue.Pot experiments were performed to evaluate the effects of different types of chelators[ethylenediamine tetraacetic acid(EDTA),ethylenediamine disuccinic acid(EDDS)and citric acid(CA)]to improve the phytoextraction capacity of Ricinus communis L.for the metals Cd and Cu.Contaminated soil from a copper smelter was used in this study.A rhizon soil sampler was used to determine the metal concentrations in soil pore water.The results indicated that R.communis was an adequate candidate for chelator induced phytoextraction under the experimental conditions and that EDDS would be a good candidate chelator for the phytoextraction of Cu in soils.EDTA addition obviously improved the uptake of Cd and Cu in R.communis;however,it posed the greatest risk because the concentration of HMs in soil pore water was very high even after 40 days.Compared with EDTA and EDDS,CA had few effects on Cd or Cu uptake in R.communis.Linear relationships between the metal uptake in R.communis shoots and the maximum HM concentrations in soil pore water under HM,2.5,5,and 10 mmol·kg^(-1) treatments were typically observed.From the results of this study,it could be concluded that EDDS treatments played a promising role in increasing the uptake of Cd or Cu and reducing its phytotoxicity.EDDS application could be an effective approach for the phytoextraction of Cd or Cu from polluted soils by growing Ricinus communis L.
基金Project(2020YFC1908802)supported by the National Key Research and Development Project of China。
文摘Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms.
基金Sichuan Science and Technology Program(2022YFG0077)。
文摘During the operation of the rice combine harvester,the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational reliability.Aiming at the problem of leveling due to the tilt of the field surface,this research developed an innovative dual-parallelogram chassis lifting mechanism for rice harvesters designed a hydraulic system to adjust the chassis height by extending the cylinder.Using Adams simulation software,a detailed model of the lifting chassis was constructed to analyze its performance,revealing a direct correlation between the hydraulic cylinder extension and chassis elevation.Notably,the mechanism could achieve leveling on slopes with inclination angles of up to 7.5°.Comprehensive evaluations of the liftable chassis system were conducted under both static and dynamic conditions.In the static tests,the system exhibited the capacity for comprehensive or unilateral auto-leveling contingent upon the tilt,with leveling times and angular variations confined to 3.6 s and±0.4°,respectively.In dynamic tests conducted on sloped fields and paddy soils,the system reduced post-leveling mean tilt angles and standard deviations remained below 1.2°and 0.6°,respectively.These results demonstrated a substantial improvement in the stability and reliability of the chassis during operations.This research provides valuable insights into the design and optimization of automatic leveling mechanisms and structural innovations for harvester chassis.
基金Project(22376221)supported by the National Natural Science Foundation of ChinaProject(2024JJ2074)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST。
文摘Understanding the adsorption behavior of heavy metals and metalloids on clay minerals is essential for remediating heavy metal-contaminated soils.The adsorption of heavy metals and metalloids on illite(001)and sodium montmorillonite(Na-MMT)(001)surfaces was investigated using first-principles calculations in this study,especially As atom and H_(3)AsO_(3) molecule.The adsorption energies of the As atom were−1.94 eV on the illite(001)and−0.56 eV on the Na-MMT(001),whereas,the adsorption energies of the H_(3)AsO_(3) molecule were−1.40 eV on illite(001)and−1.01 eV on Na-MMT(001).The above results indicate that the adsorption was more energetically favorable on illite(001).Additionally,compared to Na-MMT(001),there were more significant interactions between the atoms/molecules on the illite(001).After As atom and H_(3)AsO_(3) molecule adsorption,the electrons were transferred from mineral surface atoms to the adsorbates on both illite(001)and Na-MMT(001)surfaces.Moreover,the adsorption of As atom on illite(001)and Na-MMT(001)surfaces were more energy favorable compared to Hg,Cd,and Cr atoms.Overall,this work provides new insights into the adsorption behavior of As atoms and As molecules on illite and Na-MMT.The results indicate that illite rich soils are more prone to contamination by arsenic compared to soils primarily composed of Na-MMT minerals.
基金Projects(U24B20113,42477162) supported by the National Natural Science Foundation of ChinaProject(2025C02228) supported by the Primary Research and Development Plan of Zhejiang Province,China。
文摘Heat transfers at the interface of adjacent saturated soil primarily through the soil particles and the water in the voids.The presence of water induces the contraction of heat flow lines at the interface,leading to the emergence of the thermal contact resistance effect.In this paper,four thermal contact models were developed to predict the thermal contact resistance at the interface of multilayered saturated soils.Based on the theory of thermal-hydro-mechanical coupling,semi-analytical solutions of thermal consolidation subjected to time-dependent heating and loading were obtained by employing Laplace transform and its inverse transformation.Thermal consolidation characteristics of multilayered saturated soils under four different thermal contact models were discussed,and the effects of thermal resistance coefficient,partition thermal contact coefficient,and temperature amplitude on the thermal consolidation process were investigated.The outcomes indicate that the general thermal contact model results in the most pronounced thermal gradient at the interface,which can be degenerated to the other three thermal contact models.The perfect thermal contact model overestimates the deformation of the saturated soil during the thermal consolidation.Moreover,the effect of temperature on consolidation properties decreases gradually with increasing interfacial contact thermal resistance.
文摘This study was designed to enhance the soft clayey soil treatment effects using an innovative mechanochemically activated geopolymer(GP)through the optimized inclusion of nano-metakaolin(NM)and polypropylene fiber.The study also investigated the possible improvements in the binding ability of GP stabilization under different curing regimes.To this end,binders including lime alone,LG(slag-based geopolymer),LGNM(nano-modified LG with NM)and LGNMF(LGNM/fiber)mixture were separately added to soft soil samples.The fabricated composites were then subjected to a set of macro and micro level tests.The results indicated that,adding LG binary with a 20%NM replacement can lead to a significant increase(by nearly 21 times)in soil strength and a remarkable decline(about 70%)in the compression index.In fact,NM can play a great role in accelerating the rate of hydration reactions and forming a densely packed fabric,which staggeringly improve the soil hydromechanical attributes.It was also observed that raising the curing temperature will effectively augment the polymerization kinetics,leading to a substantial increase(~2 times)in the soil solidification process.However,the stabilized composites containing NM may reveal a brittle nature under more intense stress.Such a potential drawback seems to be resolved by the integration of fibers within the matrix.LGNM combined with fiber would boost(≥10 times)the energy absorption capacity of the soil,notably enhancing its residual strength.Overall,LGNMF may not only feature a broader range of benefits(inc.economic,technical,environmental)compared to traditional binders but also promote the ductility of the GP materials.
基金Project(5206800)supported by the National Natural Science Foundation of ChinaProject(2024JJA160096)supported by the Natural Science Foundation of Guangxi Province,China。
文摘Bauxite tailing(BT)slurry has been generated and accumulated in large quantities,posing a threat to the green and sustainable development of the alumina industry.The regression equation between the actual water content and mud water separation rate was established to achieve efficient resource utilization,and the feasibility of foam lightweight soil(FLS)prepared from BT was investigated.The effects of industrial waste residues(fly ash and slag powder)on the properties of FLS were studied.Meanwhile,the micro-mechanisms were revealed by XRD,SEM-EDS,and TG-DSC.The results revealed that fly ash reduced the workability and compressive strength of FLS.Slag powder can significantly enhance the compressive strength of FLS,which increased by 18.60%-23.26%,17.07%-58.54% and 12.12%-52.12%,respectively.Besides,slag powder can improve the long-term water stability performance and enhance carbonation resistance.XRD and thermal analyses showed that adding fly ash decreased the hydration degree of FLS,leading to a decrease in the hydration products.Slag powder improved the pore structure and compacted the skeleton structure of FLS.This study would provide an effective way to realize the resource utilization of BT,fly ash,and slag powder,with certain socio-economic and environmental benefits.
基金Project(51204074)supported by the National Natural Science Foundation of ChinaProjects(2010009017,201209048,ZX021-201106-031)supported by the National Environmental Protection Public Welfare Industry Targeted Research Fund,China
文摘Soil cadmium(Cd)contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China's maximum permission level(MPL)for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi(XY)Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery>lactuca sativa L>Chinese cabbage>Romaine lettuce>asparagus lettuce>mustard>cabbage mustard>cabbage.The mean hazard quotient(HQ)of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA(2009)threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents.
文摘How to improve the water use efficiency of rice in black soil regions was studied. The black soil region in paddy fields was chosen as the research object. The research showed the fertilizer coupling mathematical model with N,P,K,irrigation water( W) and water use efficiency( WUE),which was set up under the condition of controlled irrigation with quadratic D- 416 optimized saturation design. The results show that the decending order of single factor' s influence on the WUE was N,K,P and W. All the interactions between N&P,N&K,N&W,K&P,P&W and K&W on the WUE were raised initially,and when reached a certain value,they began to decline. The decending order of each interaction on the WUE was K&P,K&W,N&K,N&P,P&W and N&W. When the WUE was targeted within 1. 8- 2. 5 kg / km^3,an optimized proportion plan was obtained in the 95% confidence interval,i. e. N 87. 76- 103. 32 kg / hm^2,K_2 O 52. 37- 66. 53 kg / hm^2 and P_2O_536. 80- 46. 71 kg / hm^2. Furthermore,the late tillering of the soil moisture content was 70. 07%- 72. 57% of the saturated moisture content.
基金Supported by Rice Industry Technical System Construction Project from the Ministry of Agriculture
文摘Using hybrid rice Yixiang1577 as the material, the mid-season and ratooning hybrid rice yield variation was studied in Southem Sichuan at different levels of nitrogen fertilizer. The results showed that rice yield by using N fertilizer increased to the most significant level than no fertilizer ones, and the mid-season rice and rice yield by using more N fertilizer increased to the significant level than less fertilizer ones. The rice yield by using no fertilizer ones increased to the most significant level than some used fertilizer, and the ratooning rice and rice yield by using more N fertilizer decreased to the most significant level than less fertilizer ones. The rice yield by using some fertilizer increased to the most significant level than no fertilizer ones for mid-season＋rationing rice and rice yield by using some fertilizer had no obvious differences at different nitrogen levels. Therefore, application of fertilizer can improve yield of mid-season rice and mid-season＋rationing rice. Soil test results showed that nutrient contents in rice field in South Sichuan were very rich in nitrogen, which could provide more adequate crop growth potential soil nitrogen nutrition. The crops with a deep root system had stronger ability of utilization on soil nitrogen. Therefore, the ratooning rice used no or little N fertilizer had a high yield performance because they made full use of soil nitrogen with deep root system.
基金Supported by the National Key Research and Development Plan Project(2016YFD0300909-04)。
文摘The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China。
文摘Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
基金Supported by the New Ideas Team and the Doctoral Research Foundation of Northeast Agricultural University(Topic CXZ003,20082010)the Scientific Research Fund of Heilongjiang Provincial Education Department(11551067)。
文摘Rice is a typical silicon-loving crop,known as"representative of silicic acid plant".Southeast Asia and other rice-producing countries have listed silicon fertilizer as the fourth most elemental fertilizer after nitrogen,phosphorus and potassium.Therefore,improving the utilization of soil silicon and promoting the transformation of soil silicon form is of great significance to the growth of rice and the development of agriculture.In order to investigate the effects of silicon preparations on different forms of silicon in soil and silicon contenst in rice plants,a pot experiment with Dongnong 427 was carried out,spraying on rice leaves at the booting stage,and three treatment groups(Si-TG,Si-EG and Si-60G)and a control group(CK)were set up.The contents of available silicon,water-soluble silicon,amorphous silicon,active silicon in soil and plant silicon were measured at the heading stage and the maturity stage of rice,then the effect of silicon preparation on the silicon content of rice soil and plant was analyzed.The results showed that spraying silicon preparation could significantly improve the silicon content of rice plants,promote the transformation of silicon forms in soil to varying degrees,and improve the silicon supply capacity of soil.Compared with CK,the soil available silicon content increased by 7.42%-8.26%at the heading stage and 6.70%at the maturity stage.The Si-EG treatment at the heading stage had the best effect on increasing the available silicon content of the soil,which was 8.26%higher than that of CK,reaching a significant level;the Si-TG treatment at the maturity stage had the best effect on increasing the silicon content of the plant,and the silicon content of the plant was 27.17%higher than that of CK,reaching a significant level.
