Contribution of arbuscular mycorrhiza to soil quality in contrasting cropping systems

The aim of this study was to determine how the potential to rely on arbuscular mycorrhiza (AM) for plant nutrition differs between a conventional and a low-input cropping system in the long term. The roles of fertilisation rate, composting of recycled plant residues and stage of the rotations in the overall impact of the cropping systems on soil quality and AM were also identified. The conventional cropping system with a non-leguminous crop rotation (barley–barley–rye–oat–potato–oat) was fertilised at either full or half the recommended rate. In the low-input cropping system, one year with barley was replaced by clover, and oat was cultivated mixed with pea. Straw and clover were returned to the soil either with or without composting. In the low-input system, biotite and rock phosphate were used to compensate for K and P in the harvested yield, while animal manure was applied at the start only. After 15 years, crop growth and nutrition, AMF colonisation and soil quality were assessed in the field, while the AM contribution to growth and nutrient uptake were determined in a bioassay in a growth chamber. AM functioning made a higher contribution to soil quality in terms of crop performance and environmental benefits in the low-input cropping system than at either fertilisation rate in the conventional system. Halving fertilisation in the conventional system prevented some costs and enhanced some of the benefits of AM in comparison with full fertilisation. However, only the low-input system with composting conclusively favoured AM in comparison with the conventional system. It resulted in the highest percentage colonisation and, in a bioassay with flax and clover, gave a relative average contribution to growth of 27% and to P uptake of 68% in comparison with 4 and 36%, respectively, for the conventional cropping system with full fertilisation. Rye yield was in the low-input system without composting similar to that in the conventional system with full fertilisation, and with composting 87% of the latter one. Incorporation of clover green manure without composting inhibited AM functioning, leading to a temporary loss of AM contribution to crop performance. This effect draws attention to the impact of the form of recycled organic matter on supporting ecosystem services such as nutrient cycling.     

猪粪堆肥与化肥配施对水稻产量和氮效率的影响

采用大田试验方法研究猪粪堆肥与化肥配施对水稻产量和氮效率的影响.结果表明:在本试验条件下,猪眄粪堆肥与化肥配施能显著提高水稻籽粒产量,增加水稻每穗实粒数.尤其是1 500 kg·hm-2猪粪堆肥 化肥配施处理,稻谷产量达8 595 kg·hm-2,比未施氮处理和化肥处理分别增产57.8%和13.6%,差异达显著水平.猪粪堆肥与化肥配施处理水稻氮素养分效率均高于化肥处理.猪粪堆肥与化肥配施的氮肥回收率为35.3%～38.6%,而化肥处理仅为27.6%.     

小型畜牧养殖场废水处理工程实例

采用以人工湿地为主体的工艺处理小型养殖场产生的废水,先经稀释、混合调节对高浓度废水进行预处理,之后依次进入简易厌氧池、四级人工湿地和生物塘工序。实际运行结果表明:该工艺处理效果好,运行稳定,耐冲击负荷能力强,费用低廉,SS、COD、NH4+-N、TP去除率分别达到91%、89%、62%和88%,出水可达再生水回用于农业用水选择性标准。     

Heavy metal depuration in flat tree oysters isognomon alatus under field and laboratory conditions

Oysters Isognomon alatus containing high concentrations of Zn, Cu, Pb and Cd were collected from the Sepang Besar River, and transferred to the Sepang Kecil River where the native oysters contain low metal concentrations. Concentrations of heavy metals in oysters were measured monthly over six months. The concentrations of all metals decreased significantly (p<0.05) for Cd 87%, Pb 83%, Cu 78%, and Zn 59%. In addition, metal depuration in oysters was investigated under laboratory conditions. Oysters were exposed to 100?µg?g^?1 of metals for two weeks followed by one week of depuration. Our studies suggest that metals in oysters tend to be lost in the order, Cd>Pb>Cu>Zn. A comparison between laboratory and field data showed that depuration of metals under the laboratory conditions is significantly faster than in the field.     

Soil pollution by trace metals derived from animal feed and manure in the Bursa region of Turkey

The Bursa region of Turkey has important agricultural production areas. Animal producers use agricultural fields in this region for disposal of manure. Therefore, in this study the concentrations of the seven trace metals Zn, Mn, Cu, Ni, Cr, Pb, and Cd in 324 animal feed and manure samples from three dairy cattle, three laying hens farms, and three broiler farms have been determined. The average concentrations in dairy cattle manure were 130 (Zn), 150 (Mn), 4.2 (Cu), 6.8 (Ni), 44 (Cr), 0.8 (Pb), and 0.09 (Cd) mg kg^?1 dry weight; for laying hens manure 240 (Zn), 190 (Mn), 0.63 (Cu), 3.8 (Ni), 30 (Cr), 0.55 (Pb), and 0.12 (Cd) mg kg^?1 dry weight; and for broiler manure 240 (Zn), 280 (Mn), 1.4 (Cu), 3.8 (Ni), 35 (Cr), 3.4 (Pb), and 0.16 (Cd) mg kg^?1 dry weight. The calculated trace metal loading rate indicated that manure application might pose a potential risk to agricultural fields according to the current soil protection regulations of Turkey.     

林场经营管理的问题与对策分析

林场经营管理中需要坚持走科学发展的道路,发挥林场资源优势,提高林场经营管理的整体水平。当前林场经营管理中存在的基本问题是:林场性质定位不够明确、林场管理方式单一、林场经营管理中产权主体不够清晰、林场生产的产品结构单一等。需要在具体工作过程中发挥林场生产经营的自主权,采用多元化的经营模式,以提升整个林场的经济效益。     

粪肥和有机肥施用对稻田土壤微生物群落多样性影响

为探究典型粪肥施用对稻田土壤微生物的影响,开展崇明岛稻田粪肥施用现场实验.采用高通量测序技术分析对照组(CK)和鸡粪(CM)、猪粪(PM)和有机肥(OF)施用稻田土壤微生物群落组成及多样性.结果表明,与CK相比,施用有机肥可提高土壤有机质(SOM),施用鸡粪可显著提高土壤氨氮(NH⁺₄-N)和总氮(TN)含量(P<0.05).PM组土壤微生物多样性显著高于CK组(P<0.05),OF组土壤微生物群落丰富度显著高于CM组(P<0.05).pH值、总磷(TP)、总氮和Pb是影响稻田土壤微生物群落组成的重要因素,CM组微生物群落结构与其他3组差异较大.与CK相比,OF组增加了硝化螺菌属(Nitrospira)的相对丰度,CM组显著降低了反硝化细菌Ignavibacteriae的相对丰度(P<0.01),达40.56%,但显著增加了硝化细菌陶厄氏菌属(Thauera)的相对丰度(P<0.05),达203.00%; PM组显著增加了氨化细菌Armatimonadetes的相对丰度(P<0.05),达57.51%,还增...     

牛粪还田对土壤微生物群落特征的影响

畜禽粪便还田对土壤质量产生了深刻影响,而土壤微生物是反映土壤质量的敏感指标.基于稀释平板计数和高通量测序技术,研究了牛粪还田区土壤微生物群落特征及其影响因素.结果表明,与对照点相比,牛粪还田区土壤微生物群落β多样性发生了显著变化;牛粪还田增加了变形杆菌门(Proteobacteria)的相对丰度,而减少了放线菌门(Actinobacteria)和芽单胞菌门(Gemmatimonadetes)的相对丰度;牛粪还田显著改变了土壤微生物群落中的鞘氨醇单胞菌属(Sphingomonas)、PLTA13属、MSB-4B10属、盐单胞菌属(Halomonas)、CCD24属、Gaiella属、节杆菌属(Arthrobacter)、芽孢杆菌属(Bacillus)和Entotheonellaceae属的相对丰度;影响牛粪还田区土壤微生物群落组成的重要因素是土壤含水量和放线菌数量;牛粪还田增加了假单胞菌属(Pseudomonas)、梭状芽孢杆菌属(Clostridium)和链球菌属(Streptococcus)等病原菌的相对丰度,对土壤质量存在一定的生物污染风险.研究结果可为深入认识牛粪还田对土壤质量的...     

畜禽粪便生物处理与土地利用全过程中抗生素和重金属抗性基因的赋存与转归特征研究进展

抗生素抗性基因(antibiotic resistance gene,ARG)在全球范围内的传播已引起国际上的广泛关注.越来越多的证据显示抗生素和重金属对抗生素抗性基因在环境中的分布和传播起到了重要作用.畜禽粪便是环境中抗生素和重金属的主要污染源之一,并已成为抗生素抗性基因重要的蓄积库.生物处理(如厌氧发酵和好氧堆肥)和土地利用是畜禽粪便广泛应用的处理与处置方式.本文通过文献调研,综述国内外抗生素抗性基因和重金属抗性基因在畜禽粪便生物处理及土地利用全过程中的传播、分布及控制的研究进展,并对今后的研究重点和方向提出建议和展望,以期为我国畜禽养殖粪便的风险控制和资源化利用提供借鉴.针对畜禽粪便处理处置全过程中抗性基因的削减与控制,我们建议在以下方面开展深入研究:1抗生素抗性基因和重金属抗性基因在全过程中的赋存与转归特征;2生物处理工艺操作参数对畜禽粪便中抗性基因分布及其削减的影响;3加强综合管理研究,源头控制抗性基因;4研发适于全过程抗性基因的协同控制关键技术等.     

典型设施菜地土壤抗生素污染特征与积累规律研究

利用超声波提取,固相萃取-高效液相色谱-串联质谱分析方法,分析了山东省某典型设施菜地的20个蔬菜大棚土壤中14种抗生素的含量与分布特征.结果表明,在所有的土样中均检测出抗生素,其中4种四环素类抗生素(如四环素、土霉素、金霉素和强力霉素)是该地区主要的抗生素种类,单个化合物的检出率均为100%,其含量范围分别在2.11～139.16、6.06～332.02、1.82～391.31、2.20～248.56μg.kg-1之间.4种四环素类抗生素总含量Σ(TCs)为26.79～1 010.11μg.kg-1,平均含量为274μg.kg-1.磺胺类、喹诺酮类和大环内酯类抗生素也均有检出,其中喹诺酮类抗生素总含量Σ(QNs)在0～1 017.06μg.kg-1,平均含量73.05μg.kg-1,检出率为85%,而磺胺类和大环内酯类抗生素单个化合物的检出浓度很低,未检出氯霉素类抗生素.分析结果还发现,该设施菜地种植不同蔬菜的土壤中抗生素种类和含量差异很大.值得注意的是,个别大棚土壤诺氟沙星(QNC)和氧氟沙星(OFC)含量分别高达373.73和643.34μg.kg-1,均远远地超过抗生素生态毒害效应触发值(100μg.kg-1).可见,设施菜地土壤抗生素污染问题应引起关注.