As the fundamental unit of soil, aggregates exhibit significant variations in their abilities to adsorb and desorb trace elements, depending on their size. Batch experiments were conducted to investigate the characteristics of adsorption and desorption of cadmium (Cd), copper (Cu), and lead (Pb) on and from soil aggregate fractions from three layers of a calcareous soil profile in Changxing County, Zhejiang Prvince, China. The results showed that both Langmuir and Freundlich models successfully described the isothermal adsorption processes of single Cd, Cu, and Pb on different soil aggregates. Additionally, aggregates from the bottom soil layer showed the highest maximum adsorption capacity and required the lowest energy for Cd, Cu, and Pb adsorption compared to aggregates from upper soil layers. The physicochemical properties of soil aggregates were found to govern the adsorption and desorption processes of heavy metals rather than the aggregate size, wherein the contents of iron/aluminum oxides and organic matter were the most crucial influencing factors. Cadmium displayed higher mobility than Cu and Pb in different soil aggregates, and the maximum adsorption capacities of the metal ions followed the order of Pb > Cu > Cd, while their desorption rates followed the order of Cd > Cu > Pb. Additionally, the < 0.053 mm microaggregates presented the lowest desorption rates for Cd, Cu, and Pb compared to other soil aggregate fractions in each soil layer. Furthermore, the orthogonal experiment results demonstrated that the competitive adsorption between metals occurred on soil aggregates in the ternary heavy metal system, but only the desorption of Pb was significantly affected by the coexistence of Cd and Cu.

[Objective]Black rock series contain high amounts of cadmium(Cd)and selenium(Se).During weathering and soil formation on the rocks,the chemical form transformation and release of Cd and Se from the rocks can have an impact on the surrounding ecological environment.[Methods]In this study,a black rock series distribution area of Hetang formation of the Lower Cambrian was selected in northwest Zhejiang.By collecting horizonal soil samples from soil profiles along different parts of the terrain(hill upslope,hill middle slope,hill downslope,inter hill valley bottom and valley terrace),the quantity and chemical form transformation patterns of Cd and Se during the process of weathering soil formation and weathering material migration of the black rock series were discussed.[Results]The results showed that total Cd and total Se in the soil decreased from parent rock to soil.The loss of Cd and Se in the weathered matter of black rock series increased with the increasing of transportation distance along the hilly slope,and the loss of Cd and Se in the process of evolution from slope deposit to diluvium was greater than that from residual to slope deposit.The Cd and Se lost from the weathered materials could affect the contents of Cd and Se in the topsoil derived from the alluvial of the downstream river in the way of water diffusion,but the degree of influence decreased with the increasing of distance.With the increasing of the transportation distance of weathered materials and the evolution of soil,the transformation of carbonate bound Cd and residual Cd to water-soluble Cd,exchangeable Cd,organic matter bound Cd and oxide bound Cd occurred.The residual Se gradually activated and transformed into exchangeable Se,organic matter bound Se and oxide bound Se.The results also showed that soil water-soluble Cd,exchangeable Cd(Se)and organic matter bound Cd(Se)showed an increasing trend toward the surface.The organic enrichment and topsoil enrichment of Se were more obvious than those of Cd.[Conclusion]The results indicated that the weathering of black rock series could not only directly affect the contents of soil Cd and Se in their distribution area through residue,but also affect the contents of soil Cd and Se in the surrounding areas through water diffusion.

Biochars, produced from different feedstocks, modify soils differently which in turn affect the growth of plants. To this end, comparing the characteristics of oak wood and bamboo biochars, evaluating their effect on soil properties and growth of ryegass (Lolium perenne L.) is crucial. Oak wood (WB) and bamboo biochars (BB) were used to fill pot with soil with 0.5, 1.0 and 2% levels each and control (0%) as treatment. After one week of incubation, rye grass seeds were sown in each pot and allowed to grow for 120 days in a climate controlled glass house. Characteristics of WB and BB, the amended soil quality, the shoots and roots biomass, and nutrient uptake of rye grass were measured and analyzed. Application of WB and BB increased nutrient content, organic C, soil pH, cation exchange capacity (CEC), water holding capacity (WHC), but decreased bulk density (BD) of the soil. As compared to BB, the WB had higher surface properties such as surface area, pore volume and oxygen containing functional groups which modified the soil pH, CEC, BD, WHC, and microbial biomass C of the amended soils. The BB had higher ash content and nutritional properties, thus it increased shoot and root biomass, and the uptake of nutrients in ryegrass. Due to its innate nutrient, BB enhanced plant growth more than WB. While WB improved the soil quality as it had better surface properties than BB. It is suggested that the biochar's properties contribute in determining soil productivity.

As the fundamental unit of soil, aggregates exhibit significant variations in their ability to adsorb or desorb trace elements, depending on their size. Batch experiments were conducted to investigate the characteristics of adsorption and desorption of Cd, Cu and Pb on different sizes of soil aggregates from each genetic horizon of calcareous soil profiles. The results showed that both Langmuir and Freundlich models were successfully fitted to describe the isothermal adsorption process of single Cd, Cu, and Pb on different soil aggregates. Additionally, soil aggregates at the bottom layer showed the highest maximum adsorption capacity and required the lowest energy for Cd, Cu and Pb adsorption compared to aggregates from upper soil horizon. The physical-chemical properties of various soil aggregates were found to govern the adsorption and desorption process of heavy metals rather than aggregate sizes, wherein the content of Fe/Al oxides and organic matter were the most crucial influencing factors accounted for this process. Cd displayed higher mobility than Cu and Pb among the different soil aggregates, and the maximum adsorption capacity of the metal ions studied followed the order: Pb > Cu > Cd, while their desorption rate followed the order: Cd > Cu > Pb. Additionally, the < 0.053 mm size of soil microaggregates presented the lowest desorption rate for Cd, Cu, and Pb compared to other sizes of soil aggregates in each soil horizon. Furthermore, Orthogonal experiment results demonstrated the competition for metal adsorption occurred on soil aggregates in ternary heavy metal ions system, however, only the desorption of Pb was significantly affected by the coexistence of Cd and Cu.

Information about the temperature dependence of soil organic carbon (SOC) mineralization is important to predict the possible carbon (C) release from the terrestrial ecosystem facing global warming. However, the way in which SOC quality and mineral protection of SOC affects mineralization rates and their response to increasing temperature remains poorly understood. Here, we focused on investigating thermal stability and chemical composition of soils which differed greatly with the type and extent of organo-mineral associations, and revealing their implications for SOC mineralization. Chemical composition and thermal stability of SOC were analyzed with 13C nuclear magnetic resonance spectroscopy (13C NMR) and simultaneous thermogravimeteric analysis and differential scanning calorimetry (TG-DSC), respectively. Soil mineralization and its temperature sensitivity (Q10) were assessed by incubating soils at 15 and 25 degrees C for 90 days.Our results showed that SOC of subsoil was more biologically stable, but exhibited higher temperature sensitivity than those of topsoil. Significant differences in chemical composition and thermal stability of SOC were detected across soils developed from four parent materials but not between two soil layers, and indicators obtained from the two techniques showed apparent associations with depth-specific SOC mineralization rates. Increase in SOC mineralization rates at two incubation temperatures and two soil layers were observed when the soils were characterized by higher percentage of labile SOC fractions (i.e., O-alkyl C and organic carbon oxidized during exothermic reactions). The Q10 values of topsoil were positively and mostly related to the percentage of Alkyl C. In addition to notable relationships with chemical composition, the Q10 values of subsoil were positively correlated with Exo1/Exo2 ratios and Energy density values, and negatively correlated with TG-50. It was interesting to note that thermal stability was possibly as a function of soil texture and total oxides. Results from VPA analysis further revealed that SOC mineralization rates at two soil layers and Q10 of topsoil were mainly driven by SOC quality, while it was related to both SOC quality and chemical protection for subsoil, implying that factors controlling the temperature sensitivity of SOC mineralization were depth-specific. Altogether, substrate accessibility as a function of chemical composition and chemical protection would play vital role in determining the feedbacks of the subsoil SOC pool to the future climate warming.

钙是植物必需的中量元素,土壤中钙的数量与形态直接影响植物对钙的吸收和土壤性状.为了解浙江省农田土壤钙素状况,本研究从滨海平原、水网平原、河谷平原和丘陵山地共采集了70个代表性蔬菜地表土,分析了其钙含量及其形态(水溶态、吸附态、酸溶态和矿物结合态)组成.结果表明,全省蔬菜地土壤钙含量在3.24～28.45 g·kg-1,平均为7.19 g·kg-1;土壤全钙平均含量依次为滨海平原>水网平原>丘陵山地、 河谷平原;土壤中各形态的钙占比依次为矿物结合态>酸溶态>吸附态>水溶态;钙全量、矿物结合态、酸溶态、交换态均随土壤酸化而下降;水溶态钙随pH值下降呈现先增加后下降的变化特征.分析认为,当土壤pH值下降至5.5以下时,土壤因钙贮量下降发生缺钙的概率将会明显增加.

为了解由红层坡地改成梯田后,在稳定的成土环境与施肥条件下土壤酸碱度的变化特点,从浙江省采集了240个不同利用方式和利用时间的红层母质发育的农地土壤样本,探讨了不同类型红层母质发育土壤的酸缓冲性,分析了在水耕和旱耕条件下红层母质发育土壤酸碱度随利用时间的变化特点.结果表明,研究土壤酸缓冲曲线可分为pH值＞6.5、pH值介于3.5～6.5之间和pH值＜3.5等3个阶段,pH值＞6.5和＜3.5时,土壤pH值随酸加入量的变化较缓慢,对酸具有较强的缓冲性;pH值介于3.5～6.5时,土壤pH值随酸量增加呈现快速下降的趋势,容易发生土壤酸化.红层母质发育土壤的酸缓冲容量与缓冲强度有很大的变化,分别介于65.09～663.31、38.98～160.61 mmol/kg之间,平均值分别为232.64、81.60 mmol/kg;其酸缓冲容量明显高于自然红壤.土壤酸缓冲容量和土壤酸缓冲强度主要与土壤初始pH值、CaCO3含量、CEC和盐基饱和度有关.水耕和旱耕后的红层母质发育土壤均随利用时间的延长而发生酸化,红紫砂土的pH值下降主要发生在利用时间25 a内,紫砂土的pH值下降主要发生在利用时间25 a后;而酸性紫砂土的pH值持续缓慢地下降,水耕对紫砂土的酸化作用较旱耕更明显,但对红紫砂土和酸性紫砂土的酸化作用比旱耕弱.

【Objective】 Reclaiming the saline coastal soils in eastern China is crucial for ensuring food security. Given the significance of soil carbon in soil quality, this paper investigates the change in soil organic carbon and phosphorus in the soil following initiation of reclamation. 【Method】 The experiment was conducted in the northern regions of Hangzhou Bay and Yueqing Bay in eastern Zhejiang province. Soil samples were collected from vegetable fields, orchards, and paddy fields to measure their organic carbon, phosphorus, and other soil properties, from which we analyzed the relationship between soil organic carbon, phosphorus composition, reclamation duration, and land usage. A non-reclaimed soil was taken as the control. 【Result】 As reclamation time elapsed, soil pH decreased while total organic carbon (TOC), total phosphorus (TOP), and available phosphorus increased. Fifty years of reclamation led to a reduction in soil pH in Hangzhou Bay and Yueqing Bay by 1.72 to 2.36 and 1.14 to 2.24, respectively. This was accompanied by significant increases in organic carbon and TOP by 126.46% to 294.97% and 130.37% to 266.14%, and available phosphorus by 17.66% to 100.00% and 39.31% to 87.20%, respectively. The decrease in soil pH among different land usages was ranked in the order of wasteland > paddy field > orchard > vegetable field; the increase in soil organic carbon followed the order of paddy field > orchard > vegetable field > wasteland; and the increase in TOP and available phosphorus followed the order of wasteland < paddy field < orchard < vegetable land. Reclamation also significantly increased different forms of soil organic carbon. Over time, the ratio of free particulate organic carbon to organic carbon (fPOC/TOC) in micro-aggregates decreased initially and then gradually increased, while the ratio of occluded particulate organic carbon to organic carbon (oPOC/TOC) increased gradually. The ratio of mineral-associated organic carbon to organic carbon (MOC/TOC) initially increased significantly and then decreased slowly. Land usage had a notable impact on the MOC/TOC ratio, with paddy fields showing the highest influence, followed by orchards and vegetable fields. The impact of land usage on TOP and available phosphorus was more significant than reclamation time. Except for residual phosphorus and HCl-P, other forms of phosphorus increased with reclamation time. It was also found that with the increase in reclamation time, the fraction of residual phosphorus and HCl-P decreased, while the fraction of phosphorus in other forms increased. TOC and organic carbon in different forms exhibited a strong correlation, but no correlation was found between TOP and phosphorus. 【Conclusion】 Reclamation of the coastal saline soils results in continuous changes in composition and content of organic carbon and phosphorus, characterized by decreasing pH, increasing organic carbon and phosphorus. Land usage has a more substantial impact on the change in organic carbon and phosphorus than reclamation history. Growing rice promotes organic carbon sequestration, whereas vegetable cultivation enhances phosphorus accumulation.

设置了对照(清园)、秸秆覆盖、自然生草和人工种草4个处理,比较了不同覆盖方式对丘陵红壤区柑橘土壤有机质、养分、水分、地表径流量、地表径流中泥沙和养分流失量以及柑橘产量和品质等的影响,以期为南方果园科学管理提供依据.结果表明:3种不同处理方式促进了表土不同形态的有机质积累,提高了水稳定性团聚体含量和土壤水分贮量并降低了表层的土壤容重.3种覆盖方式的综合效果以秸秆覆盖最佳,秸秆覆盖后的土壤碳库管理指数较对照提高了55.00%,年累计径流量、泥沙流失量、全氮和全磷流失量较对照分别降低了61.27%、89.31%、79.24%和87.50%.秸秆覆盖处理可小幅提高柑橘产量,显著提高柑橘的糖度,降低其可滴定酸含量.综上所述,低丘果园行间覆盖农作物秸秆具有良好的生态效应,能够有效减少养分流失,改善土壤理化性质和生态环境,可作为南方丘陵果园生态优化的水保措施.

为了解不同来源有机废弃物在提升新围涂地土壤有机碳库和生物活性的作用,采用盆栽试验方法开展了为期30周的施用等有机碳量猪粪、鸡粪、水稻秸秆、蔬菜收获残留物、厨余垃圾堆肥、沼渣、猪粪/稻草秸秆堆肥和生活垃圾堆肥等8种有机废弃物后涂地土壤有机碳、易氧化有机碳、稳定态有机碳、水溶性有机碳、微生物生物量碳及土壤酶活性的动态观察.结果表明:施用各种有机废弃物对改善土壤性状均有明显的效果,在提升土壤有机碳库、生物活性及农田碳库管理指数方面以经过生物发酵处理的猪粪/水稻秸秆堆肥、生活垃圾堆肥、餐厨垃圾堆肥和沼渣为佳;其次为猪粪、鸡粪和水稻秸秆;蔬菜收获残留物因主要由新鲜有机物质组成,其稳定性较差,对提升土壤有机碳库和生物活性的效果较差.施用有机废弃物后,土壤碳库、土壤微生物生物量及其他土壤性状可随试验时间发生明显的变化.研究认为,从提升土壤有机碳库和生物活性考虑,在新围涂地改良中应优先施用猪粪/水稻秸秆堆肥、生活垃圾堆肥、餐厨垃圾堆肥和沼渣等有机废弃物.

为了解农业生产上石灰降酸措施对土壤碳循环的潜在影响,我们采用盆栽方法开展了连续 30 周的淹水与非淹水环境下及有机肥施用与不施用条件下石灰石粉施用量对土壤中有机碳、易氧化有机碳和稳定有机碳影响的动态观察研究.结果表明,石灰石粉的施用提高了土壤 pH值,改善了土壤微生物生境,提高了土壤微生物活性,加速了土壤有机碳的循环.在不施用有机肥的条件下,石灰石粉的施用可降低土壤本身有机碳、易氧化有机碳和稳定有机碳的数量,这种影响随石灰石粉用量的增加而增强.在有机肥施用的条件下,石灰石粉优先影响外源有机碳的循环,加快因有机肥引入的土壤中有机碳、易氧化有机碳的矿化,促进易氧化有机碳向稳定有机碳的转化,从而增加稳定态有机碳的数量.

植稻土壤是中国最为重要的农业土壤,它是被人类用于水稻生产、通过长期水耕熟化形成了具有特定土壤剖面特征的一类土壤.中国目前的"中国土壤分类系统"与"中国土壤系统分类"等2个土壤分类系统中都把其作为独立的土壤类型,分别称为水稻土和水耕人为土.该类土壤是周期性灌溉、排水、施肥、耕耘、轮作下逐步形成的,其主要的成土过程包括周期性的氧化还原交替与铁锰淋淀、盐基淋溶与复盐基作用和强烈的有机碳的固定与积累作用.当前对这类土壤的定量化研究已逐渐完善,对其在地理空间上的分布规律与特点及其受地形、成土母质的影响也有较为深入的了解.但有关这类土壤中氧化铁垂直分异的机理、某些土壤类别的设置、土壤定量鉴定标准、田间调查制图技术及因利用方式改变引起的土壤类型演化等问题还有待进一步研究完善.

Islands have special geographical landscapes and complex soil forming conditions, where the soil formation is different from that in mainland areas. To understand the genesis characteristics and taxonomic classification of island hilly soils in Zhejiang Province, 80 soil profiles were surveyed combining with historical literature data in this study. The results showed that the geomorphic structures, parent materials, climatic conditions, and vegetation types of the soils were relatively single, but the soils were frequently affected by the island scales, distances from land, tide, and human activities. The terrain slope was large; the lithification was obvious; the clayization was weak; the desilicification-allitization was changeable; the weathering-leaching coefficient was medium; the restoring base cations were obvious; the pH value and base saturation percentage were higher than those in the mainland at the same latitude; and the soil forming environment was affected by both ancient and modern factors. Four soil orders, namely Ferrosols, Argosols, Cambosols, and Primosols, were identified from the islands of Zhejiang Province, including 7 suborders of Ustic Ferrosols, Udic Ferrosols, Ustic Argosols, Udic Argosols, Ustic Cambosols, Udic Cambosols, and Orthic Primosols, as well as 10 soil groups, 11subgroups and 25 soil families. In conclusion, the direction of soil formation from the islands of Zhejiang Province is basically the same as that of mainland hilly soil at the same latitude, belonging to the traditional ‘red soil zone’.

The soils of four citrus orchards in western Zhejiang were studied in this research. In order to explore the effects of lime on soil chemical properties and bacterial communities, the incubation experiment was conducted with six different dosages of lime addition, 0, 0.6, 1.2, 2.4, 4.8, 7.2 g/kg, respectively. The results showed that soil pH increased significantly (p < 0.05) and the contents of exchangeable acid decreased significantly (p < 0.05) at the early stage of lime application. As time went by, the reacidification existed in the soil of each treatment, mainly reflected in a significant (p < 0.05) decrease in soil pH. Liming increased the nitrate nitrogen content and decreased the ammonium nitrogen content in the four soils. However, the responses of other nutrient indexes to lime varied in different soils, which might be due to the different degrees of soil acidification. In general, the addition of lime increased the soil integrated fertility index (IFI) and improved the soil nutrient status. The application of lime under 2.4 g/kg significantly improved the structure of bacterial community and increased the relative abundance of soil bacterial community species, while the application of lime above 4.8 g/kg might inhibit the growth and activity of microorganisms, resulting in the reduction of soil microbial biomass and diversity. Redundancy analysis (RDA) showed that lime affected the bacterial community mainly by reducing the content of soil active acid and exchangeable acid. At the same time, network analysis showed that the bacterial community had a stronger buffer capacity against external disturbances after lime application. In conclusion, the addition of lime with appropriate amount (2.4~4.8 g/kg, corresponding to a field application rate of 5.8~11.5 t/ha) in acid orchard soil could improve soil properties, soil integrated fertility, and the diversity and stability of the bacterial community.

Antibiotics are widely used in livestock and poultry farming for disease prevention and animal growth promotion. Due to the low absorption rate of antibiotics by animals, antibiotics can remain in livestock and poultry manure as parent or metabolites and enter the farm environment with the application of livestock and poultry manure, which has potential effects on crop growth. This study assessed the effects of single and combined contamination of antibiotics in soil on tomato plants. The accumulation of antibiotics in tomato plants and the impacts on crop growth were investigated. A pot experiment with sandy soil was conducted in a greenhouse, and a 100-day tomato growth experiment was conducted by adding different doses of tetracycline and sulfadiazine (0, 25, and 50 mg/kg). The antibiotic contents in various tissues and organs of the tomato were examined, and the changes in photosynthetic intensity and biomass of the tomato were observed to simulate the effects of exogenous antibiotic addition on the growth and quality of the tomato. The results indicated that tomato plants simultaneously absorbed tetracycline and sulfamethazine from soil. Antibiotics were primarily absorbed by tomato roots and were further delivered to plant leaves, stems, and fruits. Antibiotics exhibited the highest concentration in roots, followed by leaves, stems, and fruits. The contents of tetracycline and sulfamethazine in plant tissues elevated with the increase in soil antibiotics, which were higher in the vegetative growth stage than those in the late growth stage. At concentrations of 25 and 50 mg/kg, tetracycline and sulfamethazine combined pollution significantly reduced leaf photosynthetic rates and plant biomass. Notably, high levels of antibiotics led to decreases in tomato yield and quality. Additionally, high concentrations of antibiotic contamination elevated leaf nitrogen, phosphorus, and potassium, but reduced the leaf carbon/nitrogen ratio, as well as reduced the vitamin C content in the fruits. Overall, since antibiotics can accumulate in vegetables and enter the food chain, the findings are crucial for evaluating the impacts of soil antibiotic contamination on the production and food safety of tomato products, and will also add to our knowledge of antibiotic migration into the food chain.

对浙江省典型茭白种植区表层(0～20 cm)土壤中的磷素丰缺状况和磷库特征进行调查,分析茭白种植年限与土壤磷积累的关系.结果表明:样本茭白田土壤的全磷和有效磷(Olsen-P)含量平均值分别为876.73、63.30 mg·kg-1,土壤磷积累明显,有效磷水平达丰富级别的占比高达 81.05%.样本土壤的磷素以无机磷为主,平均占比达到79.91%,水提取态无机磷(H2O-Pi)、NaHCO3 提取态无机磷(NaHCO3-Pi)、NaOH提取态无机磷(NaOH-Pi)、HCl提取态无机磷(HCl-Pi)、NaHCO3 提取态有机磷(NaHCO3-Po)、NaOH提取态有机磷(NaOH-Po)和残余态磷的平均含量分别为 16.16、122.06、213.03、103.22、22.18、158.52、241.86 mg·kg-1.除残余态磷和HCl-Pi外,其他形态磷的含量均随茭白种植年限的增加而增加.土壤磷吸持饱和度随茭白种植年限延长逐渐增加,土壤磷素随种植年限延长呈向下迁移的特点.当样本土壤的有效磷含量大于60 mg·kg-1时,土壤磷素淋失风险增加,约48.37%的样本土壤处于磷高淋失风险状态.

To understand the spatial variability and influencing factors of soil properties developed from parent materials of red bed, taking Zhejiang Province as an example, the distribution, formation features and genetic characteristics of soils developed from parent materials of red bed in the subtropical region were examined, and the effects of paleoenvironment of red bed formation, modern topography and land-use mode on the physical and chemical properties of the soils were analyzed, and the classification of the soils was discussed. The results showed that the distribution of soils developed from parent materials of red bed was determined by the geological structure. The formation of the soils on red bed was a result of balance between physical weathering and surface erosion, while chemical weathering and decalcification led to soil acidification. The soils developed from parent materials of red bed tended to be juvenile, which was the common result of the special weathering characteristics of the parent material and the short soil forming time. The paleoenvironment of red bed formation had a profound impact on the material composition of the soils, and the modern topography affected the stage of soil development, and the land-use mode could change the vertical development of the soils. The color of soils developed from parent materials of red bed was not generally believed to always retain the color of the parent materials. In some cases, the former was different from the latter. Due to the complexity of red bed genesis and the diversity of material composition, the soils developed from parent materials of red bed were far more complex and changeable than generally believed. According to the “Chinese soil classification system”, the soils developed from parent materials of red bed in Zhejiang Province were only classified as purple soil group, and divided into calcareous purple soil and acid purple soil subgroups, which could not well reflect the changeable characteristics of soils developed from parent materials of red bed. According to the diagnostic horizons and diagnostic characteristics of “Chinese soil taxonomy”, the soils developed from parent materials of red bed in Zhejiang Province could be divided into two soil orders (Cambosols and Primosols), two suborders (Udic Cambosols and Orthic Primosols), seven soil groups and fourteen subgroups.

Abstract Food safety has raised immense concern globally. Due to the improper use of chemical fertilizers and pesticides, antibiotic pollution in vegetable land is becoming increasingly serious. In this study, the effects of single and combined pollution of tetracycline and sulfamethazine on tomato plants were studied. The results showed that tomato plants simultaneously absorbed tetracycline and sulfamethazine from soil and transferred them to leaves, stems and fruits. The contents of tetracycline and sulfamethazine in plant tissues elevated with the increase of soil antibiotics, which were higher in the growth stage than that in the late growth stage. Antibiotics exhibited the highest concentration in roots, followed by leaves, stems and fruits. At the concentrations of 25 and 50 mg/kg, both tetracycline and sulfamethazine hampered the growth and physiology of tomato in terms of photosynthetic rate, chlorophyll content, plant height and biomass. High concentration of antibiotic contamination led to the accumulation of nitrogen, phosphorus and potassium in leaves, reduced the carbon/nitrogen ratio in leaves, and reduced the vitamin C and sugar contents in fruits. Overall, our results indicated that the combined pollution of antibiotics can strengthen the impact on plant growth, physiological indicators and biomass.

为了解不同降镉措施对镉轻度污染农田土壤的治理及降低水稻糙米镉含量的效果,为污染农田安全利用提供技术支撑,在浙江省桐庐县江南镇和瑶琳镇各选择镉轻度污染农田开展了不同用量石灰调控pH降低水稻镉积累、施用腐殖质型土壤调理剂+钙镁磷肥降低水稻镉积累、施用等量不同土壤改良剂降低水稻镉积累、石灰与叶面阻控剂配合施用降低水稻镉积累和不同土壤改良剂+叶面阻控剂组合降低水稻镉积累等5个比较试验.结果表明,糙米Cd含量随石灰用量的增加而下降,以中量为宜(300 kg/667 m2);施用钙镁磷肥的降镉效果优于腐殖质型土壤调理剂;降酸—腐殖质型土壤调理剂和降酸—黏土矿物型土壤调理剂对降低糙米Cd含量均有明显的效果,但其效果略低于石灰或钙镁磷肥;仅喷施叶面阻控剂可降低糙米Cd含量,但糙米Cd含量仍超过食品卫生标准;叶面阻控剂与腐殖质型土壤调理剂、粘土型土壤改良剂、钙镁磷肥与石灰配合施用能有效降低糙米Cd含量,达到安全生产的目的.