Efficiently estimating the protein nitrogen content of rice leaves (LPN) is crucial for monitoring the nutritional health of rice and guiding precision fertilization based on requirements. Unmanned aerial vehicle (UAV)-acquired hyperspectral imagery is a key tool for estimating rice nitrogen content. Previous studies have demonstrated the potential of machine learning models for this task. However, these models typically require substantial data for supervised training to ensure high performance and generalizability. Acquiring a large sample size is challenging due to weather conditions, high collection costs, and other factors. Moreover, machine learning models have low interpretability. Enhancing it is vital for understanding the model’s decision-making. To address these issues, we utilized the Wasserstein-generative adversarial network (WGAN) algorithm to expand the sample dataset. This method employs statistical regression (multiple linear regression (MLR) and partial least squares regression (PLSR)) and machine learning (support vector machines (SVM) and K-nearest neighbor (KNN)) algorithms to establish an estimation model for the LPN. The Shapley Additive exPlanations (SHAP) method was used to analyze the contributions of the input features to LPN estimation. An experiment was conducted at the National Agricultural Science and Technology Park, Guangzhou, Baiyun District, Guangdong, China. The model based on the KNN provided the optimum estimation performance, and the model accuracy was improved by adding the augmented dataset, resulting in a 10.39% improvement in the R2 value. The SHAP values revealed that B775.6, double-peak canopy nitrogen index (DCNI), and MERIS terrestrial chlorophyll index (MTCI) were the core variables for LPN estimation. These findings provide significant references for precision fertilization and improving nitrogen use efficiency in rice cultivation.

Allelopathic stress induced by phenolic acids poses a significant challenge to sustainable agricultural development. To alleviate this stress in tomatoes, this study synthesized humic acid-based compounds with medium and trace elements, including calcium (HA-Ca), magnesium (HA-Mg), copper (HA-Cu), zinc (HA-Zn), iron (HA-Fe), and manganese (HA-Mn). Their potential to alleviate phenolic acid stress during tomato seed germination were evaluated. Among them, HA-Ca exhibited the most pronounced mitigation effect, followed by HA-Mg, HA-Mn, HA-Fe, HA-Zn, and HA-Cu. Compared with the p-coumaric acid (p-CA) stress treatment, HA-Ca application for 7 days significantly increased seed germination rate, germination index, root length, root surface area, and root volume by 15.4 %, 623.1 %, 530.4 %, 403.3 %, and 301.2 %, respectively. Additionally, HA-Ca enhanced root activity of tomato radicles by 105.8 %, elevated the activities of key antioxidant enzymes (SOD, POD, CAT, APX, GR) by 106.6 %–244.1 %, and raised the GSH/GSSG ratio by 185.5 %. Conversely, it reduced reactive oxygen species (H₂O₂, O₂·⁻, •OH) and malondialdehyde (MDA) levels by 55.8 %–90.3 %, and lowered osmotic adjustment substances (soluble sugar, soluble protein, proline) by 70.1 %–88.5 %. At the molecular level, HA-Ca down-regulated the expression of SlLOX2, SlFAD2–2, PAL and SlCBF1 by 44.0 %–96.8 %, while up-regulated SlMAPK3 and SlGRAS1 by 91.0 % and 31.0 %. Furthermore, the addition of HA-Ca facilitated a 99.9 % removal of p-CA from the culture medium, which was 62.1 % higher than that in the p-CA stress control, and increased the solution pH by 0.39 units. In conclusion, HA-Ca alleviates phenolic acid stress in germinating tomato seeds by improving the growth environment and enhancing physiological and antioxidant defenses.

The continuous-cropping obstacles of Pogostemon cablin (patchouli) is severely constrained by autotoxic phenolic acids accumulated in the rhizosphere soil. Biochar adsorption and chemical oxidation are common remediation strategies; they often fail to simultaneously and efficiently remove phenolic allelochemicals while improving the soil micro-ecological environment. To address this issue, this study developed a novel biochar–urea peroxide composite particle (BC-UP). Batch degradation experiments and electron paramagnetic resonance (EPR) analysis confirmed the synergistic adsorption-oxidation function of BC-UP. A pot experiment demonstrated that application of BC-UP (5.0 g/kg) significantly alleviated phenolic acid stress. Specifically, BC-UP application significantly enhanced shoot biomass by 28.8% and root surface area by 49.3% compared to the phenolic acid-stressed treatment and concurrently reduced the total phenolic acid content in the rhizosphere soil by 37.3%. This growth promotion was accompanied by the enhanced accumulation of key bioactive compounds (volatile oils, pogostone, and patchouli alcohol). BC-UP amendment also improved key soil physicochemical properties (e.g., pH, and organic matter) and enhanced the activities of critical enzymes. Furthermore, BC-UP reshaped the microbial community, notably reducing the fungi-to-bacteria OTU ratio by 49.7% and enriching the relative abundance of Firmicutes and Nitrospirota but suppressing the Ascomycota phylum abundance. Redundancy analysis identified soil sucrase and catalase activity, total phenolic acid content, and Ascomycota abundance as key factors influencing patchouli biomass. In conclusion, BC-UP effectively mitigates phenolic acid stress through combined adsorption and radical oxidation, subsequently improving soil properties and restructuring the rhizosphere microbiome, offering a promising soil remediation strategy for patchouli and other medicinal crops.

Pineapple, a vital tropical fruit worldwide, faces economic losses due to blackheart disorder, a complex physiological disorder influenced by various factors, including abrupt temperature changes. This study employed Ultra-Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (UPLC-ESI-MS/ MS) to investigate the metabolic alterations in pineapple fruits Ananas comosus L. Merr. cv. 'Comte de Paris' associated with different stages of blackheart disorder. A total of 268 metabolites were detected in pineapple pulp at varying blackheart disorder stages according to the metabolomic profiling. Twelve differentially accumulated metabolites (DAMs) (Cyclic AMP, Senecionine, 3 '-AMP, Cyclic GMP, 3 '-GMP, beta-Alanyl-L-arginine, gamma-Glutamylalanine, beta-Alanyl-L-lysine, GMP, R-b-aminoisobutyric acid, L-Homophenylalanine, L-Argi- nine) were significantly enriched in healthy pineapple fruit tissues, with their levels negatively correlated with the severity of internal blackheart disorder in pineapples. Additionally, four potential biomarkers such as pipecolic acid, chlorogenic acid, phenylethylamine, and stachyose were identified, due to their significantly enriched in the internal blackheart disorder pineapple tissues, with their levels positively correlated with the blackheart severity rate. This study provides valuable insights into the metabolic pathways involved in pineapple blackheart disorder. The identified metabolites offer potential biomarkers for understanding physiological disorder progression, laying the groundwork for future studies focused on the prevention and control of pineapple blackheart disorder, ultimately safeguarding the economic value of this tropical fruit.

Flooding intensity significantly alters the availability of iron (Fe), zinc (Zn), and cadmium (Cd) in paddy soil. However, the influence of arbuscular mycorrhizal fungi (AMF) on the uptake and transfer of Cd and micronutrients (Fe and Zn) under Cd stress in varying flooding conditions is not well understood. A pot experiment was conducted to investigate the micronutrient homeostasis and Cd uptake and transfer in rice cultivated in Cdcontaminated soil with AMF inoculation under continuous and intermittent flooding conditions. Compared to non-inoculation controls, mycorrhizal inoculation decreased Cd concentration in rice plants under continuous and intermittent flooding, and improved grain yield by 39.2 % for early season rice and 21.1 % for late season rice under continuous flooding. Mycorrhizal inoculation balanced the availability of Zn and Fe and decreased the availability of Cd in soil, lowering the ratios of soil-available Cd to both soil-available Zn and soil Fe2+. These changes led to a redistribution of Zn and Fe concentrations in rice, thereby reducing Cd acquisition in a soil-rice system. Structural equation model (SEM) analysis revealed that mycorrhizal inoculation had a strong direct negative effect on the expression of Zn and Fe-related genes OsNRAMP1, OsIRT1, and OsIRT2 in the roots of rice, which in turn directly affected root Cd concentration. Furthermore, mycorrhizal colonization decreased Cd transfer coefficients from leaves to grains under continuous flooding and from nodes and leaves to grains under intermittent flooding. In the nodes, the Fe concentration and the expression of genes OsIRT1 and OsHMA2 were associated with Cd transfer from the nodes to grains. Similarly, in the leaves, the expression of genes OsZIP1 and OsMTP1 corresponded with Cd transfer from leaves to grains. This study provides insights into the role of AMF in affecting micronutrient concentrations and Cd uptake in rice under varying flooding conditions.

Flooding is a critical factor that limits the establishment of a symbiosis between rice and arbuscular mycorrhizal fungi (AMF) in wetland ecosystems. The distribution of carbon resources in roots and the acclimation strategies of rice to flooding stress in the presence of AMF are poorly understood. We conducted a root box experiment, employing nylon sheets or nylon meshes to create separate fungal chambers that either prevented or allowed the roots and any molecules to pass through. We found that the mycorrhizal colonization rate and the expression of genes OsD14L and OsCERK1, which are involved in fungal perception during symbiosis, both increased in mycorrhizal rice roots following intermittent flooding compared to continuous flooding. Furthermore, AMF inoculation affected root morphological traits, facilitating both shallower and deeper soil exploration. Increased submergence intensity led to carbohydrate deprivation in roots, while high mycorrhizal colonization increased soil oxygen consumption and decreased the neutral lipid concentration in roots. However, mycorrhizal inoculation increased the rice photosynthesis rate and facilitated acclimation to submergence by mediating the expression of the genes OsCIPK15 and OsSUB1A to enhance rice shoot elongation and the sugar concentration in roots as a result of reduced competition for carbon between rice and AMF under different flooding conditions.

Efficiently obtaining leaf nitrogen content (LNC) in rice to monitor the nutritional health status is crucial in achieving precision fertilization on demand. Unmanned aerial vehicle (UAV)-based hyperspectral technology is an important tool for determining LNC. However, the intricate coupling between spectral information and nitrogen remains elusive. To address this, this study proposed an estimation method for LNC that integrates hybrid preferred features with deep learning modeling algorithms based on UAV hyperspectral imagery. The proposed approach leverages XGBoost, Pearson correlation coefficient (PCC), and a synergistic combination of both to identify the characteristic variables for LNC estimation. We then construct estimation models of LNC using statistical regression methods (partial least-squares regression (PLSR)) and machine learning algorithms (random forest (RF); deep neural networks (DNN)). The optimal model is utilized to map the spatial distribution of LNC at the field scale. The study was conducted at the National Agricultural Science and Technology Park, Guangzhou, located in Baiyun District of Guangdong, China. The results reveal that the combined PCC-XGBoost algorithm significantly enhances the accuracy of rice nitrogen inversion compared to the standalone screening approach. Notably, the model built with the DNN algorithm exhibits the highest predictive performance and demonstrates great potential in mapping the spatial distribution of LNC. This indicates the potential role of the proposed model in precision fertilization and the enhancement of nitrogen utilization efficiency in rice cultivation. The outcomes of this study offer a valuable reference for enhancing agricultural practices and sustainable crop management.

Phenolic acid is a well-known allelochemical, but also a pollutant in soil and water impeding crop production. Biochar is a multifunctional material widely used to mitigate the phenolic acids allelopathic effect. However, phenolic acid absorbed by biochar can still be released. In order to improve the removal efficiency of phenolic acids by biochar, the biochar-dual oxidant (BDO) composite particles were synthesized in this study, and the underlying mechanism of the BDO particles in ameliorating p-coumaric acid (p-CA) oxidative damage to tomato seed germination was revealed. Upon p-CA treatment, the BDO composite particles application increased the radical length, radical surface area, and germination index by 95.0%, 52.8%, and 114.6%, respectively. Compared to using biochar or oxidants alone, the BDO particles addition resulted in a higher removal rate of p-CA and produced more O2•−, HO•, SO4•− and 1O2 radicals via autocatalytic action, suggesting that BDO particles removed phenolic acid by both adsorption and free radical oxidation. The addition of BDO particles maintained the levels of the antioxidant enzyme activity close to the control, and reduced the malondialdehyde and H2O2 by 49.7% and 49.5%, compared to the p-CA treatment. Integrative metabolomic and transcriptomic analyses revealed that 14 key metabolites and 62 genes were involved in phenylalanine and linoleic acid metabolism, which increased dramatically under p-CA stress but down-regulated with the addition of BDO particles. This study proved that the use of BDO composite particles could alleviate the oxidative stress of phenolic acid on tomato seeds. The findings will provide unprecedented insights into the application and mechanism of such composite particles as continuous cropping soil conditioners.

Dissolved organic matter (DOM) is an active component of the soil organic carbon (SOC) and nitrogen (N) pool. However, the relationship between DOM chemodiversity and microbial communities, and their effects on the C and N in paddy fields under organic or inorganic fertilization, are poorly understood but important for sustainable agricultural production. We conducted a six-year experiment in paddy fields under the following different organic and inorganic fertilizer treatments: no fertilizer (CK), chemical fertilizer (150 kg·hm−2 N; CF), 50

PurposePoor structure, nutrient deficiency, and acidification are core factors restricting the reclamation of rare earth mining wasteland soil (REMWS). Sewage sludge, bagasse, and molybdenum tailings, all of which need proper disposal, have great potentials in REMWS reclamation. The goal of this study was to explore the remediation effect on rare earth mining wasteland soil with the combined application of sewage sludge compost (SSC), bagasse, and modified molybdenum tailings (MMT).Materials and methodsSSC (T1), SSC + bagasse (T2), and SSC + bagasse + MMT (T3) were applied in REMWS as amendments in a 4-month pot experiment, and their effects on REMWS properties and heavy metals (HMs) toxicity were tested with Eucalyptus urophylla, which grows fast, resists environment stress, and is a promising plant in REMWS reclamation.ResultsThe application of SSC (T1) improved REMWS fertility, but increased Cu, Zn, Cd, and Ni contents in soil and E. urophylla seedlings, and inhibited E. urophylla growth. Bagasse application (T2) alleviated growth inhibition and further addition of bagasse + MMT (T3) significantly improved E. urophylla growth. Moreover, T3 improved soil physical properties, organic carbon content, pH, and reduced soil HMs bioavailability and plant HMs content as compared to T1 and T2. Structural equation modeling results revealed that plant nutrient accumulation increased plant HMs accumulation, the latter inhibited plant nutrient accumulation in turn, and soil pH played a key role in retarding HMs uptake and improving E. urophylla growth and nutrients uptake.ConclusionThese results suggested that the combined application of SSC, bagasse, and MMT is an effective approach for REMWS amelioration and land disposal of solid waste resources.

[目的]酚酸胁迫是造成番茄连作障碍的主要因素之一.本研究探讨了生物炭-过氧化钙复合颗粒(简称复合颗粒)作为土壤改良剂缓解番茄酚酸胁迫的效果和机理.[方法]供试番茄品种为千禧圣女果,供试土壤为赤红壤.盆栽试验共设5个处理:常规栽培(CK),酚酸胁迫处理(T1),添加外源酚酸的同时分别添加生物炭-过氧化钙复合颗粒(T2)、生物炭颗粒(T3)、过氧化钙颗粒(T4),其中土壤酚酸胁迫浓度为140μg/g.在番茄移栽后30和120天,测定了番茄生长和生理指标.在收获期,调查果实产量与品质,分析根际土壤理化性状,并使用高通量测序技术解析番茄根际土壤中细菌和真菌的群落结构特征.[结果]施用复合颗粒(T2处理)能够增强番茄根系活力,促进植株生长发育;单株番茄果实产量、单果重和糖酸比分别比T1处理增加了 13.8％、20.1％和52.6％.与T1处理相比,T2处理番茄收获期根际土壤中残余总酚酸含量下降了 44.6％,电导体(EC)值下降17.7％,pH提高0.77个单位,有机质含量增加77.4％.复合颗粒处理能够改善酚酸胁迫下番茄根际土壤微生物群落结构,使细菌多样性提高,真菌多样性降低,并有效恢复微生物群落的均衡性.Spearman相关性热图分析和冗余分析结果显示,番茄产量和体现品质的糖酸比与土壤残余总酚酸含量和EC值呈负相关,与pH值和有机质含量正相关.生物炭-过氧化钙复合颗粒可通过去除土壤酚酸,降低EC值,提高土壤pH和有机质含量,并介导增加与番茄果实产量和糖酸比具有正相关关系的拟杆菌门和壶菌门的相对丰度,而对与番茄产量和糖酸比呈负相关的酸杆菌门和子囊菌门起抑制作用.[结论]土壤残留总酚酸、pH、有机质含量、EC值是驱动番茄根际土壤微生物群落变异,及影响番茄果实产量与品质的主要环境因子.生物炭-过氧化钙复合颗粒可通过对土壤理化性状、细菌和真菌群落的双重调控作用,改善番茄根际土壤微生态环境,从而有效缓解酚酸类物质对番茄生长的化感胁迫效应,实现番茄果实产量和品质的协同提升.

Ecological theories can be applied to improve agricultural sustainability. In our study, a core hypothesis behind this claim is that "selfish behaviour" of rice cultivars results in "aversion" to a toxic substance in a multi-cropping system. We studied Changliangyou 772, a low-cadmium rice cultivar, cultivated with 11 different rice cultivars in intercropping and mixed systems. Rice cultivars with medium grain yield, ranging from 25 to 45 g plant-1, had distinctly higher yields in mixtures. Rice varieties with lower grain cadmium concentrations in monocultures had greater reductions in grain cadmium in the mixtures. In the intercropping systems, the yields of Changliangyou 772 were positively correlated with those of the neighbouring rice cultivars, while the grain cadmium showed a negative correlation with the grain cadmium of intercrops in the monocultures. The neighbouring cultivars with low grain cadmium concentrations in the intercropping showed higher cadmium concentrations in the monocultures. The intercropping and mixtures reduced the grain cadmium in two ways: 1) they increased the soil pH, resulting in lower cadmium bioavailability; and 2) they enhanced the iron plaque (Ip). However, a high Ip or cadmium concentration that was too high in the Ip weakened the Ip to block cadmium uptake by the roots.

Excessive Cd in crop grains is toxic to humans. We conducted a field experiment to investigate the effects of intercropping on rice yield and grain Cd content as well as a pot experiment to compare the rhizosphere redox potentials of low-Cd 'Zhuliangyou 189' and the neighboring high-Cd 'Changxianggu' that mediated Cd uptake in a flooded or a ridge-furrow system. In the field experiment, Cd removal from contaminated soil in intercropping was 1.44 times higher than that in monoculture of Zhuliangyou 189. In both Zhuliangyou 189 and Changxianggu, intercropping improved the grain yield and decreased grain Cd content. In the pot experiment, Fe plaque amount was strongly and positively correlated with bulk soil Fe(II) content, root H2O2 concentration, and Fe(II)-oxidizing ability of root bacteria but negatively correlated with Fe(II)-oxidizing ability of bulk soil bacteria and root Cd content. In Zhuliangyou 189, intercropping increased root H2O2 concentration, rhizosphere redox potential, iron plaque amount but decreased Cd bioavailability, Fe(II)-oxidizing ability of bulk soil bacteria, and organ Cd content. In the flooded system, Zhuliangyou 189 showed higher bulk soil Fe(II) content than Changxianggu. In the ridge-furrow system, ridges decreased the Fe(II)-oxidizing ability of root and bulk soil bacteria, thereby decreasing Fe plaque amount and increasing organ Cd content of rice. In both monoculture and intercropping systems, rice cultivars planted on ridges showed higher Cd bioavailability and lower bulk boil Fe(II) content than those planted in furrows.

Root-released carboxylates enhance the availability of manganese (Mn), which enters roots through transporters with low substrate specificity. Leaf Mn concentration ([Mn]) has been proposed as a signature for phosphorus (P)-mobilising carboxylates in the rhizosphere. Here we test whether leaf [Mn] provides a signature for root functional types related to P acquisition. Across 727 species at 66 sites in Australia and New Zealand, we measured leaf [Mn] as related to root functional type, while also considering soil and climate variables. To further assess the specific situations under which leaf [Mn] is a suitable proxy for rhizosphere carboxylate concentration, we studied leaf [Mn] along a strong gradient in water availability on one representative site. In addition, we focused on two systems where a species produced unexpected results. Controlling for background site-specific variation in leaf [Mn] with soil pH and mean annual precipitation, we established that mycorrhizal species have significantly lower leaf [Mn] than non-mycorrhizal species with carboxylate-releasing root structures, e.g., cluster roots. In exception to the general tendency, leaf [Mn] did not provide information about root functional types under seasonally waterlogged conditions, which increase iron availability and thereby interfere with Mn-uptake capacity. Two further exceptions were scrutinised, leading to the conclusion that they were ‘anomalous’ in not functioning like typical species in their families, as expected according to the literature. Leaf [Mn] variation provides considerable insights on differences in belowground functioning among co-occurring species. Using this approach, we concluded that, within typical mycorrhizal families, some species actually depend on a carboxylate-releasing P-mobilising strategy. Likewise, within families that are known to produce carboxylate-releasing cluster roots, some do not produce functional cluster roots when mature. An analysis of leaf [Mn] can alert us to such ‘anomalous’ species.

收稿日期:2018-09-17 录用日期:2018-12-25 作者简介:黄志元(1980—),男,浙江绍兴人,高级工程师,从事电网基建项目管理工作。E-mail:huangzhiyuan@gd.csg.cn *通信作者:黎华寿 E-mail:lihuashou@scau.edu.cn 基金项目:广东省科技计划项目(2015B090903077);广东电网公司科技计划项目 Project supported: Project for Science and Technology of Guangdong Province(2015B090903077);Scientific and Technological Planning Project of Guangdong Power Grid Company 摘 要:输变电工程建设及其营运对变电站场和线路工程区及周边局部区域的水土资源产生一定影响,本文就输变电工程对土

输变电工程建设及其营运对变电站场和线路工程区及周边局部区域的水土资源产生一定影响,本文就输变电工程对土壤理化性质、土壤生物、水土保持的影响,工程活动可能带来的外来物种入侵生态风险等进行综述分析,并通过地处亚热带地区的广东沿海某500 kV输变电工程项目的实际案例,总结了防控输变电工程土壤侵蚀等环境影响的具体措施.

This study tests the hypotheses that whether environmental relevance of glyphosate would help control spread of the invasive snail Pomacea canaliculata, or benefit its population growth worldwide. Our results showed that glyphosate induced acute toxicity to the snail only at high concentrations (96h LC50 at 175mg/L) unlikely to occur in the environment. Long-term exposures to glyphosate at sublethal levels (20 and 120mg/L) caused inhibition of food intake, limitation of growth performance and alterations in metabolic profiles of the snail. It is worth noting that glyphosate at 2mg/L benefited growth performance in P. canaliculata. Chronic exposures of glyphosate significantly enhanced overall metabolic rate and altered catabolism from protein to carbohydrate/lipid mode. Cellular responses in enzyme activities showed that the exposed snails could increase tolerance by their defense system against glyphosate-induced oxidative stress, and adjustment of metabolism to mitigate energy crisis. Our study displayed that sublethal concentrations of glyphosate might be helpful in control of the invasive species by food intake, growth performance and metabolic interruption; whether environmental relevance of glyphosate (≤2mg/L) benefits population growth of P. canaliculata is still inconclusive, which requires further field study.

During 2015, we studied the temporal patterns of nutrient concentrations and turbidity in water bodies with different degrees of agricultural and urban pressures across Guangzhou and Foshan (China). Data and observations were made by trained citizen scientists and professional researchers. Our study shows that all monitored water bodies, with the exception of Qiandeng Lake and Fengjiang River, had elevated NO3−-N concentrations, which ranged from 0.10 to 6.83 mg/L and peaked in late winter and early spring and reached a minimum in summer and mid-autumn. PO43-P concentrations ranged from 0.01 to 0.25 mg/L and peaked during the winter, late-summer and late autumn. Turbidity values were highest at sites with agricultural activities, with maximums in the late winter and autumn, and the highest frequency (16% and 25%) of algae presence occurred in the spring and autumn. To better understand the characteristics and drivers of the algae occurrences, measurements of phytoplankton composition and physicochemical characteristics were conducted in three key seasons in the agricultural process, fallow, sowing and rainy season in 2016. Our focused study found that the occurrence of Bacillariophyta, Euglenophyta, Xanthophyta, Cryptophyta, Chrysophyta were positively correlated with dissolved oxygen and phosphorus concentrations, while Chlorophyta and Cyanophyta had positive correlations with turbidity, oxygen demand and nitrogen concentrations. Bacillariophyceae counted for the highest proportion of phytoplankton during the fallow season, comprising up to 60 +% of the phytoplankton among the sites. During the rainy season, Chlorophyceae species were the majority, comprising up to 90 +% of phytoplankton among the sampled sites. Our results pointed to the complexity of nutrient and phytoplankton dynamics in water bodies under multiple pressures, and to the value of using citizen scientists to determine contextual information to benefit more focused studies.

A pot experiment was conducted to investigate the effects of different fertilizers on the growth, cadmium(Cd)accumulation and distribution in Chinese Flowing Cabbage(Brassica campestris L. ssp.chinensis var.utilis)Cultivar Youlv- 80d- choy sum(Y80)and Teqing-60d-choy sum(T60)cultivated in Cd contaminated soil. Result showed that the increase of soil Cd content raised the concentration of Cd in rhizosphere soil, root, stem and leaf of the two cultivars. With the increase of soil Cd, the plant growth were also further inhibited. However, the biomass of Cultivar Y80 was significantly greater than that of T60. Under different fertilizer treatment, the range of Cd absorption in the edible part of these two cultivars from low to high was:chicken manure fertilizer>silicon magnesium fertilizer>bio-chicken manure fertilizer>compound fertilizer. The concentration of Cd in edible part was the lowest in the treatment of chicken manure fertilizer and then the second lowest was in treatment of silicon magnesium fertilizer. They both significantly lower than that in treatment of compound fertilizer. The concentration of Cd in stem and leaf was 46.19%lower in Cultivar Y80 than in Cultivar T60 on average. In chicken manure fertilizer treatments, the Cd content in stem and leaf was even 56.05%lower in Cultivar Y80 than in Cultivar T60. The biomass yields of Y80were 33.53%~61.49%more than Cultivar T60. In chicken manure fertilizer treatments, the enrichment rates were from 0.77 to 1.1 for Y80 and from 2.07 to 2.26 for T60 and the transfer rate of Cd were from 0.96 to 1.24 for Y80 and from 1.99 to 2.89 for T60 in the treatments of chicken manure fertilizer. So the Cultivar Y80 is more suitable than Cultivar T60 for production in Cd contaminated soil. Chicken manure fertilizer is important to control the vegetable contamination for these two cultivars in Cd contaminated soil.