This study employed thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to characterize and provide insights into the pyrolysis behaviors and by-products of rice husk (RH) and rice straw (RS). The primary pyrolysis range is partitioned into three stages, designated as pseudo-hemicellulose, pseudo-cellulose, and pseudo-lignin pyrolysis, by an asymmetric bi-Gaussian function. The average activation energies of the three pseudo-components of RH were estimated by the Flynn–Wall–Ozawa and Starink methods to be 179.1 kJ/mol, 187.4 kJ/mol, and 239.3 kJ/mol, respectively. The corresponding values for RS were 171.8 kJ/mol, 185.8 kJ/mol, and 203.2 kJ/mol. The results of the model-fitting method indicated that the diffusion model is the most appropriate for describing the pseudo-hemicellulose reaction. The reaction of pseudo-cellulose and pseudo-lignin is most accurately described by a nucleation mechanism. An accelerated heating rate resulted in enhanced pyrolysis performance, with RS exhibiting superior performance to that of RH. RH produces 107 condensable pyrolysis by-products, with ketones, acids, and phenols representing the largest proportion; RS produces 135 species, with ketones, phenols, and alcohols as the main condensable by-products. These high-value added by-products have the potential to be utilized in a variety of applications within the agricultural, bioenergy, and chemical industries.

Biochar application to soil has proven to be an excellent approach for decreasing the concentration of auto-toxic compounds and promoting plant growth in continuous-cropping fields. However, the mechanisms underlying the action pathway among biochars, auto-toxic compounds and tobacco remain unknown. In this study, we conducted an experiment tracking the incidence rate of black rot and auto-toxic compounds for a 3-year continuous-cropping tobacco pot trial in response to biochar treatment intensity compared with that of non-biochar treatment. Biochar inhibited the incidence of black rot. Using ultra-high-performance liquid chromatography–mass spectrometry (UPLC‒MS/MS), we revealed that biochar can effectively decrease the concentration of p-hydroxybenzoic acid (PHA), which is associated with the incidence rate of black rot (R2 = 0.890, p < 0.05). The sorption kinetics and isotherm of PHA sorption on biochar indicate that the coexistence of heterogeneous and monolayer sorption plays an important role in the adsorption process. Using Molecular dynamics (MD), Density functional theory (DFT) and Independent gradient model (IGM) analyses, we provide evidence that van der Waals force (vdW), π–π bonds and H-bonds between biochar and PHAs are the dominant factors that affect adsorption capacity. Moreover, the molecular adsorption rate (Nbiochar: NPHAs = 1:4) was theoretically calculated. In contrast, biochar dramatically increased nutrient retention capacity and improved soil properties, further enhancing tobacco quality, including its agronomic and physiological traits. Therefore, we considered that biochar not only relieved continuous cropping but also improved soil properties suitable for tobacco growth. Together, we demonstrate that the action of biochar in continuously cropped soil improves soil traits and alleviates auto-toxic compound toxicity. These data contribute to the direction of modified biochar application to improve continuous-cropping soil.

Introduction:Biochar has been shown to be an effective soil amendment for promoting plant growth and improving nitrogen (N) utilization. However, the physiological and molecular mechanisms behind such stimulation remain unclear.Methods:In this study, we investigated whether biochar-extracted liquor including 21 organic molecules enhance the nitrogen use efficiency (NUE) of rice plants using two N forms (NH4 +-N and NO3 --N). A hydroponic experiment was conducted, and biochar-extracted liquor (between 1 and 3% by weight) was applied to rice seedlings.Results:The results showed that biochar-extracted liquor significantly improved phenotypic and physiological traits of rice seedlings. Biochar-extracted liquor dramatically upregulated the expression of rice N metabolism-related genes such as OsAMT1.1, OsGS1.1, and OsGS2. Rice seedlings preferentially absorbed NH4 +-N than NO3 --N (p < 0.05), and the uptake of NH4 +-N by rice seedlings was significantly increased by 33.60% under the treatment of biochar-extracted liquor. The results from molecular docking showed that OsAMT1.1protein can theoretically interact with 2-Acetyl-5-methylfuran, trans-2,4-Dimethylthiane, S, S-dioxide, 2,2-Diethylacetamide, and 1,2-Dimethylaziridine in the biochar-extracted liquor. These four organic compounds have similar biological function as the OsAMT1.1 protein ligand in driving NH4 +-N uptakes by rice plants.Discussion:This study highlights the importance of biochar-extracted liquor in promoting plant growth and NUE. The use of low doses of biochar-extracted liquor could be an important way to reduce N input in order to achieve the purpose of reducing fertilizer use and increasing efficiency in agricultural production.

Biochar is a potential amendment for the remediation of Cd-contaminated soils. Although the immobilization effect of biochar on soil Cd has been studied under indoor laboratory conditions, the effect of biochar on rice Cd uptake and soil Cd fractions under field conditions is still poorly understood. Here, the Cd content of the different organs of rice and the Cd fractions in soil were characterized for three years after the application of different amounts of biochar (0, 7.5, 15, 30 t ha−1, and 3 t ha−1 year−1). The Cd content of brown rice, husk, leaf, stem and sheath, and root under biochar treatment could be maximally reduced by up to 26.25%, 20.16%, 20.74%, 33.2%, and 26.89%, respectively. Biochar altered the Cd fractions in soil, including the decrease in exchangeable Cd content and the increase in Fe-Mn oxide bound Cd and organic bound Cd. The concentration factor of Cd uptake by rice was reduced by 32% under biochar application, while biochar had little influence on the transfer factor and distribution factor. The immobilization effect of biochar on soil Cd lasted for at least three years, but the trend of Cd immobilization efficiency over time for different amounts of biochar treatment was different. The Risk Assessment Code (RAC) of Cd in soil with biochar amendment could be reduced to a medium risk level from a high risk level. Redundancy analysis (RDA) revealed that changes in soil pH and Fe-Mn oxide bound Cd content caused by biochar application contributed most to the reduction in the Cd content of rice organs. These findings would enhance our understanding of the immobilization effect of biochar on Cd in paddy soil under field conditions.

Biochar and sulfur are considered useful amendments for soil cadmium (Cd) contamination remediation. However, there is still a gap in the understanding of how combined biochar and sulfur application affects Cd resistance in rice, and the role of the accumulation of iron plaque and the expression of Cd efflux transporter-related genes are still unclear in this type of treatment. In this study, we screened an effective combination of biochar and sulfur (0.75 % biochar, 60 mg/kg sulfur) that significantly reduced the Cd content of rice roots (32.9 %) and shoots (12.3 %); significantly reduced the accumulation of amino acids and their derivatives, organic acids and their derivatives and flavonoids in rice roots; and altered secondary metabolite production and release. This combined biochar and sulfur application alleviated the toxicity of Cd to rice, in which the enhancement of iron plaque (24.8 %) formation and upregulated expression of heavy metal effector genes (NRAMP3, MTP3, ZIP1) were important factors. These findings show that iron plaque and heavy metal transport genes are involved in the detoxification of rice under the combined application of biochar and sulfur, which provides useful information for the combined treatment of soil Cd pollution.

Biochar has been considered an effective approach as soil amendment for decreasing incidences of disease and regulating microbial populations in continuous-cropping soil. Although researches have extensively focused on changes of soil microbes and unbalance of nutrition in continuous-cropping soil, the relationship between soil properties and pathogens by biochar application remains poorly understood. In this study, we applied ITS ribosomal RNA gene profiling to analyze tobacco root microbiota of biochar and non-biochar treatment in a 3-year continuous-cropping tobacco field, comparing firstly planting tobacco as control. We found that biochar application decreased the relative abundance of the soil fungal pathogens (Ceratobasidium and Monosporascus), which are the prime pathogens of tobacco root rot in continuous-cropping soil. Using RDA, co-occurrence and PLS-PM approaches, we provided evidence that there was a negative correlation between fungal genera (especially for Ceratobasidium and Monosporascus) and soil polyphenol oxidase (PPO) activity (R2incidence rate = − 0.930, R2disease index = − 0.905, both p < 0.001). The PPO was up-regulated by different biochar treatment intensities. Together, we demonstrated that biochar in continuous-cropping soil regulated the soil PPO activity to suppress pathogens, and further decrease incidence of root rot. Notably, biochar application forward continuous cropping was more effective for the continuous-cropping soil improvement than the other treatments. The data should help in appropriate timing of biochar application for alleviating continuous-cropping obstacle.

辣椒碱具有抗癌、抗菌、抗炎、抗氧化及调节机体糖脂代谢等生物学功能.辣椒碱可作为生物驱虫剂、防霉剂、色素、促生长添加剂等在畜禽生产中应用,对动物疾病防治也具有重要作用.文章阐述辣椒碱的生物学功能,结合其在动物生产中的研究成果,旨在为辣椒碱在动物生产中的进一步推广使用提供参考.

生物炭是生物质在缺氧环境下热解而得到的富碳固体材料,具有发达的孔隙结构、较强的吸附能力及丰富的官能团,其作为一种绿色、可再生的新型功能材料,在土壤改良、污染修复和碳封存等方面具有巨大潜力.近年来,有关生物炭应用于农田土壤改良的研究中发现,植物土传病害的发生情况受生物炭影响显著,生物炭对植物土传病害的影响研究逐渐成为农用生物炭研究的热点方向.由土壤病原真菌和细菌引起的土传病害经常给农作物生产造成无可挽回的损失,以往的化学防治方法又常常给生态环境带来沉重负担,且随着病原微生物的不断演化,常规化学药剂防治效果越来越难以令人满意.植物土传病害严重威胁土壤-植物系统健康和农业可持续发展,过量使用化学药品防控病害存在污染风险,也是病原体产生耐药性的主要原因.本研究从生物炭影响病原微生物的数量和生长代谢、诱导增强植物全系统防御能力以及改善土壤环境等方面,探讨了生物炭抑制土传病害病原微生物的机理.生物炭能够增强植物养分吸收,提高寄主系统抗性,改变土壤微生物群落和功能,减少对抗性和植物毒性化合物,建立健康的植物根际-土壤防御系统,进而减少病原体种群,降低土传病害发病率.生物炭与土壤、植物和病原微生物之间相互作用,很难确定一个单独的因子来解释生物炭对土传病害的影响,还需要更多的实验数据支撑.上述生物炭抗病机制间是否相互独立或者存在协同效应,亟待进一步研究.

It is widely recommended that enhanced efficiency nitrogen fertilizers (EENFs; urease inhibitors, nitrification inhibitors, urease and nitrification inhibitors combined, coated controlled-release urea) be applied to croplands to improve N use efficiency and crop yield via regulating N transformations. However, EENFs may inevitably affect soil C dynamics for the coupled relationship between soil carbon (C) and N biogeochemical cycles. Yet, a comprehensive assessment of the effects of EENFs on soil C dynamics is lacking. Here, we conducted a global meta-analysis using 67 publications to assess the overall effects of EENFs on soil CH4 production, CO2 emission, organic C (SOC) content, dissolved organic C (DOC) content, microbial biomass C (MBC) content under different environmental and management conditions (climate conditions, soil properties and fertilizer management practices). Our results showed that on average, compared to conventional N fertilizer, EENFs with the same amount of N fertilizer have a non-significant impact on CH4 emission, which further depended on environmental and management conditions. Best scenarios for CH4 reduction included: paddy field (25.8%), urease inhibitor (26.9%) and medium N application rate (150-300 kgN ha-1; 23.6%), mainly due to the decreased stimulation of NH4+ on CH4 production; acid soil (33.7%), which was attributed to the enhanced methanotrophic communities' activities. The positive effect was also amplified by the increased mean annual precipitation and soil clay content that facilitated CH4 production. Contrarily, EENFs significantly reduced CO2 emission by 9.3%. The greater reduction was observed for the conditions producing more CO2 after fertilization, i.e. field experiment, alkaline soils, low soil inorganic N content and high N application rate (>= 300 kgN ha-1). Nitrification inhibitors and coated N fertilizer were the best available options as they can reduce inorganic C dissolution in calcareous soil and SOC mineralization, respectively. Besides, EENFs application did not significantly alter SOC, DOC and MBC contents. Our findings highlighted the role of EENFs played in decreasing soil C emission in agroecosystems.

The organic compounds from biochar play a role of hormone analogs, stimulating the expression of metabolites by controlling related gene and protein. In this experiment, we reported the L-histidine biosysthesis was promoted by biochar treatment in E. coli unlike genetic engineering of the traditional method. The related results indicated the most optimal concentration was found to be 3%, and 7% is the lethal dose. E. coli was inhibited in the high-concentration treatment. On the other hand, docking technology was usually used as drug screening, basing on Lock-and-key model of protein in order to better understand mechanisms. So the organic compounds of biochar from GC-MS analysis that acted as ligands were connected to HisG protein controlling L-histidine biosysthesis in E. coli. The result showed that the three organic molecules interacted with HisG protein by hydrogen bond. So we considered that these three compounds play regulatory roles in L-histidine biosysthesis, and the hisG gene expression fully supports this conclusion.

Organic molecules of biochar’s leacheates are known to increase the cold resistance of rice seedlings. Yet, it remains unclear whether the organic molecules of biochar leacheates can interact with the abscisic acid (ABA) signaling pathway associated with low temperature. This study used experiments and bioinformatics (molecular docking) to determine which of the organic molecules of biochar’s leacheates could influence the ABA signaling pathway. Specifically, we investigated whether these molecules affected ABA, a plant hormone linked to cold resistance. The contents of endogenous ABA and its precursor carotenoids were determined under low-temperature stress (10°C) and treatment with different concentrations of biochar leacheates. With increased leacheate concentrations, the endogenous ABA and carotenoid contents also increased, as did the expression of ABA- and cold-related genes. When rice seedlings were instead treated with exogenous ABA, it also affected the above-measured indexes; hence, we surmised that certain water-soluble organic molecules of biochar could exert a similar effect as ABA. We first used gas chromatography/mass spectrometry (GC/MS) to identify the organic molecules in the biochar extract, and then we used molecular docking software Autodock to show how they interact. We found that the molecule (1R, 2R, 4S)-2-(6-chloropyridin-3-yl)-7-azabicyclo(2.2.1)heptane was simplified, as Cyah could dock with the ABA receptor protein OsPYL2 in rice, which shows Cyah in biochar is probably an analog of ABA, with a similar function. Based on these results, we conclude that organic molecules of biochar’s leacheates could enter into rice plants and interact with ABA-related proteins to affect the ABA signaling pathway, thereby improving the cold stress resistance of plants.

Natural colloidal particles (NCPs), which are ubiquitous and abundant in surfacewaters, may play a crucial role in the sunlight-driven transformation of organic contaminants. This research focused on the effects of NCPs on the photodegradation of two fluoroquinolone antibiotics (FQs), ofloxacin (OFL) and ciprofloxacin (CIP), and assessed the photosensitivity of colloidal organicmatter (COM). Results showed that the photodegradation rate constants (kobs) of OFL and CIP in NCP solutions ranged from 9.28 x 10(-2) h(-1) to 15.98 x 10(-2) h(-1) and 63.88 x 10(-2) h(-1) to 196.59 x 10(-2) h(-1), respectively, and NCPs can significantly accelerate the photodegradation rate of OFL and CIP. Indirect photodegradation (IP) accounted for >50% of the overall observed degradation in most treatments and was the dominant degradation pathway for the two FQs, especially for CIP, for which IP reached 82%-94%. In the IP process, the contributions of triplet states of colloidal organicmatter ((COM)-C-3*) to the photolysis of OFL and CIP were close to 42% and 46%, respectively. The compositions of COM played an important role in the IP of the FQs, amongwhich terrestrial sources of COM tended to have higher photoreactivity than biological sources. This study is essential in predicting the photochemical effect of FQs and also allows for a better understanding of the real environmental fate of antibiotic contaminants. (C) 2021 Elsevier B.V. All rights reserved.

"太湖蓝藻"、"泰晤士河大恶臭"、"塞纳河生态系统崩溃"、"美国伊利湖爆发大规模蓝藻"等多起国内外水体富营养化事件引起人们对水体环境、生态保护的重视.水体富营养化给农业生产、生态环境、经济产业文化发展造成很大负面影响,而水体富营养化的一大原因就是农田养分排放.我国农业生产施肥多用氮肥、磷肥,这两类肥料的利用率都不及2/5,未被利用的肥料养分会随径流进入河流、湖泊,造成河、湖总氮量和总磷量升高.从源头上减少化肥投入是农业面源污染治理公认的控制治理办法,但由于大部分农民对环境保护、化肥减量的认识不足,该方法施行难度较大.那么如何降低农田养分流失?经过多年研究和实践经验来看,通过水生植物富集后进行资源化再利用无疑是一种十分有效、环保、可行性高的治理措施.

试验研究不同处理方法对高粱秸秆营养成分及消化率的影响.试验选择辽杂37号(LZ37)、辽杂19号(LZ19)和辽粘3号(LN3)3种高粱品种,分别对其秸秆以物理、化学、生物3种方式进行处理.结果显示,生物处理方式对LZ37、LZ19、LN3高粱秸秆的营养成分和消化率的影响均优于其他两种处理.研究表明,对高粱秸秆进行适当处理能够提升高粱秸秆的饲用价值,其中生物处理对提高高粱秸秆的饲用价值最有效.

Abstract This study investigated the effect of corn straw biochar on the decomposition, nutrient transformation, and bacterial community characteristics in the corn straw decomposition process. A 90-day microcosm incubation experiment was performed to assess the effects of corn straw biochar (500 °C, 1 h) on the corn straw decomposition process and the resulting product. Four biochar amendment rates (0%, 5, 10, and 15%, as mass fractions of biochar) and three different addition times (1st day, 30th day, and 60th day) were set in total. The results showed that corn straw biochar significantly increased the pH of the corn straw decomposition process by 0.71–0.73 and increased the electrical conductivity value by 0.64–1.07 μS/cm over that of the controls. In addition, biochar was shown to increase the temperature rise rate and temperature peak of the straw maturation system, and advance the process of straw maturation by 10 days. Thus, treatment with corn straw biochar could accelerate the corn straw decomposition process and change the conditions for microorganisms involved in the process. Furthermore, biochar additions significantly decreased the organic matter content by 9.67% under B3 and T1 treatment, and enhanced the N, P2O5, and K2O contents of the straw decomposition product by 0.36, 0.19, and 0.88% under B3 and T1 treatment. Biochar additions could increase the abundance of several effective bacteria closely related to the N, P2O5, and K2O contents of the straw maturation product. The growth of these bacteria was likely to be affected by the increase in pH with biochar addition, which enabled the improvement of the nutrient mineralization process.

Biochar has unique physicochemical properties of being rich in carbon, being alkaline, and exhibiting a highly porous structure, which can adjust features of different systems. A 90-day microcosm incubation experiment was performed to investigate the effects of corn straw biochar on the process, properties, nutrient contents, and CO2 emissions during corn straw composting. There were four treatments, including control (CK), 5% biochar addition (B1, as mass fractions of biochar), 10% biochar addition (B2), and 20% biochar addition (B3). The results showed that biochar significantly increased the temperature rise rate and temperature peak of the straw maturation system, and promoted straw decomposition. Biochar increased the pH of the microbial active period, and the electrical conductivity (EC) value of the straw decomposition system, which provided a more suitable environment for microbial degradation of the organics. Further more, biochar decreased the organic matter content, increased the total nutrient content of the straw decomposition system, and improved the quality of the straw decomposition products. In addition, nitrogen (N) content was not changed by increasing amount of biochar; however, both phosphorus (P2O5) and potassium (K2O) content were significantly increased. Compared to control, the content of P2O5 and K2O in B3 treatment was increased by 0.2% and 0.9%, respectively. Biochar addition could improve CO2 emission of the straw decomposition system. The CO2 emission was consistent with the trend of temperature change, which provided solid evidence that biochar improve the degradation of organic matter by microbes in the system.

为提高秸秆热解气的净化率,防止装置堵塞,该研究设计了旋风分离器与回转指杆轮相结合的两级净化装置,I级旋风分离器主要分离热解气中大粒径杂质,II级指杆轮使小粒径灰尘、焦油等杂质与锥形指杆碰撞、聚集、并在高速回转作用下离心分离,实现热解气高效净化.研究确定了I级净化装置的结构参数,设计了II级净化装置,确定了指杆轮与锥形指杆的参数及排列方式.以指杆轮转速、热解气的进口速度和芯筒入筒体深度为影响因素,以热解气的净化率和压力损失为指标,进行了二次通用旋转组合样机性能试验.利用Design-Expert8.0.6软件对试验数据进行方差和响应面分析,建立了影响因素与指标之间的数学模型,采用多指标优化法确定最优组合并进行了试验验证.试验得到最优组合参数:指杆轮转速为3030 r/min,进口速度为19.5 m/s,芯筒入筒体深度为210 mm,此时的压力损失为1971.73 Pa,热解气总净化率为84.2％,达到了净化要求.研究结果可为秸秆热解气净化装置研究提供理论依据.

以丹玉402、丹玉405、沈玉21和先玉335四个生态适应性不同的春玉米品种为试验材料,研究在50％遮荫条件下,不同春玉米品种根系发育、营养生长及产量形成的变化规律.结果表明:遮荫处理后,不同春玉米的根长、根表面积、根系体积、根系直径及根干重等均呈下降趋势,且穗期遮荫处理较花粒期更为敏感.遮荫处理后,茎秆所占比重呈增加趋势,而雌穗的重量则明显降低,各品种产量均表现为明显的下降趋势;品种间对遮荫生态适应性的比较表明,生长发育前期遮荫,丹玉402、沈玉21较先玉335和丹玉402适应性强,而生长发育后期则相反.

为校园绿化植物的药用功能及应用开发提供参考,通过实地勘察、资料查阅及专家咨询等方法对校园植物的药用部位、药用功能等进行全面调查.结果 表明:遵义师范学院校园内现有绿化植物90种,隶属6纲,49科,84属,其中具有药用价值的植物共计72种,占所有绿化植物的80.0％.调查研究填补了遵义师范学院校园绿化药用植物信息的空白,丰富了校园绿化药用植物资源数据,为校园绿化植物的药用功能及应用开发提供必要条件.

高等农业教育是农业教育系统中教育理论与教育实践的研究成果、实践经验及发展动态的紧密结合,是为中国特色社会主义现代化农业培养优秀人才和农业接班人的教育机构.本文从中国农业高等教育教学法的发展现状出发,剖析了农业高等教育教学法在实际运用过程中存在的问题,并以此为基础着重探讨了中国农业高等教育教学法未来的发展方向.为改进中国农业高等教育教学法,提高农业高等教育教学效果提供一定的理论依据.