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化肥过量使用与畜禽粪便的不合理处置是造成我国农村面源污染的主要原因,西部地区生态环境脆弱,为应对面源污染的风险,应及时控制化肥使用量,有效提高畜禽粪便利用率。本文在实地调研的基础上,对有机肥使用的农户行为进行研究,以农户提高有机肥使用比例的意愿为对象,结合计量分析得出,在有机肥使用比例提高到50%的水平上,影响农户意愿的主要因素有:是否加入合作社,收入水平、畜禽养殖量、目前有机肥使用比例、农户对当前环境感知及地区变量。文中以甘肃省定西和临夏地区为实证调研地点,通过比对分析发现,临夏地区比定西地区在提高有机肥施用比例方面有更强烈的意愿。两地农户不同的意愿感知主要源于当地生产经营方式、畜禽饲养数量的不同。两地总体来看,增加畜禽养殖数量,在有偿引导的条件下,可以促进有机肥使用。 相似文献
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农户是农业生产中生产要素的主要投资者,是施用化肥的主体,因此关注农户的施肥行为及其影响因素,对保护农业生态环境有很重要的意义。基于河南省驻马店地区的281份有效问卷,采用结构方程模型(SEM)探讨影响农户施肥行为的主要因素。结果表明:过量施用化肥的认识、有机肥施用效果认知和提高施肥技能对农家肥施用行为的影响是显著正向的,标准化路径系数分别为0.194 6、0.634、0.486,对商品有机肥施用行为的影响是显著正向的,标准化路径系数分别为0.102 8、0.335、0.568,而对化肥合理施用行为的影响不显著,标准化路径系数分别为0.142 6、-0.024、0.194,了解化肥信息对化肥合理施用行为的影响是不显著的,标准化路径系数为0.087。在此基础上提出建议:加强农户对化肥过量危害的负面认识,农户对有机肥施用效果的认知程度,完善农家肥补贴措施和重视施肥技术培训工作。 相似文献
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太湖地区肥料、农药过量施用调查研究 总被引：16，自引：1，他引：16
抽样选择毗邻太湖的常州市武进区雪堰镇3个村,调查当地种植结构及变化,肥料、农药过量施用情况,以及农民对农业面源污染的认识。结果显示,肥料投入总量依次为:蔬菜>水蜜桃>葡萄>稻麦轮作>稻油轮作>柑橘>茶叶;稻-麦轮作、水蜜桃和柑橘3种主要种植模式都存在肥料过量施用,稻-麦轮作N投入过量,水稻和小麦过量的比例分别为40.00%和53.57%,水蜜桃和柑橘则是P2O5投入过量,比例分别为85.71%和25.00%。因此,太湖地区减量施肥的潜力较大。农药投入近年来有所下降,但绝对投入量仍较大,远高于10~15年前的使用量,也有较大的减量空间。当地农民对农业面源污染缺乏认识,急需宣传提高。 相似文献
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我国农业生产中化肥等农用化学品的高强度、低效率使用所导致的面源污染,对农村生态环境构成了严重威胁。为此,必须改变传统的低效施肥方法,开展测土配方施肥,最大程度地减少化肥的使用量。以测土配方施肥为主要内容的化肥减量政策需要农化服务体系来承担技术服务和指导工作,而现行农业技术部门主导型农化服务模式缺乏化肥企业和农户的有效参与,制约了化肥减量政策的效果。因此,必须创新农化服务模式,建立合作社主导型农化服务模式,通过专业合作社组织分散的农户参与农化服务过程,有效协同农化服务各环节,使测土配方的成果真正被广大农户所采用,以实现化肥减量和减少面源污染的目标。 相似文献
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针对三峡库区农业面源污染风险评估指标体系不完善、个别指标计算时基础数据获取难度大的问题，该研究充分考虑农业面源污染产生、形成及调控全过程因素，构建了基于层次分析法的三峡库区面源污染风险评价指标体系，以更易获取的数据为基础参数、应用韦伯-费希纳定律克服个别风险指标过大的问题，给定了三峡库区面源污染风险评估指标计算方法，评估了三峡库区农业面源污染风险，并提出了三峡库区县域单元的纵向和横向污染治理清单。研究结果表明，三峡库区各县域农业面源污染总体处于中风险，库区内湖北省夷陵区、重庆市南岸区风险值最高，其次是重庆市大渡口区、沙坪坝区等市辖区、巫溪县以及湖北省兴山县和秭归区，之后是开州区、万州区、丰都县、云阳县等区域；化肥强度指数、畜禽养殖强度指数、降雨侵蚀指数、环保投资指数是三峡库区农业面源污染风险的主要影响指标；三峡库区各县域化肥强度指数以及畜禽养殖强度指数风险值之和占总压力指数风险值的比例平均为79%，巫溪县、巴东县、巫山县甚至达到90%；重庆市南岸区、大渡口区以及湖北省各县域化肥施用强度较高，建议开展茶果树施肥技术提升，畜禽养殖强度相对较大的区域主要集中在重庆市云阳县、开州区、巫溪县、巫山县以及湖北省各县区，建议更多开展猪和羊畜禽废污处理能力提升，此外还应加大环保投入以及合理调整种植结构；从纵向管控来看，三峡库区农业面源污染治理应以南岸区和夷陵区为优先管控区域，河流水质优先治理区域为大渡口区、九龙坡区以及湖北省的各县区，从横向管控来看，大部分县域的主要污染防控因素为化肥减量和畜禽养殖治理，其中三峡库区上游和下游地区应当更多关注化肥减量，中游则更多关注畜禽养殖的污染防控，该研究成果可为三峡库区农业面源污染政策制定提供有力参考。 相似文献
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控制化肥过量施用 保护农业生态环境 总被引：3，自引：0，他引：3
多年来由于盲目、过量施用化肥、施肥结构的不合理等,不仅造成土壤板结,耕地质量下降,资源浪费,农业环境污染,而且还增加生产成本,限制农作物产量和品质的提升,致使农民增收缓慢。本文通过对安阳市耕地化肥施用情况的深入调研,论述了化肥施用过程中存在的突出问题,并提出控制化肥过量施用、减少农业面源污染的主要对策。 相似文献
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中国粮食主产区化肥施用时空特征及生态经济合理性分析 总被引：4，自引：4，他引：4
研究粮食主产区化肥施用状况能够为化肥减量增效、防治化肥损失引起的面源污染、保障国家粮食安全提供决策参考。该研究在分析中国粮食主产区化肥施用强度的时空变化特征的基础上,根据大田粮食作物对氮磷钾的养分要求,提出化肥施用生态经济合理性评价方法,并对中国粮食主产区化肥施用生态经济合理性进行评价。研究表明:从1993到2017年,中国粮食主产区化肥施用强度从205.5 kg/hm~2增加到319.9 kg/hm~2,其中氮、磷、钾化肥的施用强度分别从133.8、48.0、23.7 kg/hm~2增加到162.6、84.2、73.2 kg/hm~2;总化肥及氮、磷、钾化肥施用生态经济适宜量分别从217.4、108.7、54.4、54.4 kg/hm~2增加到300.6、150.3、75.2、75.2 kg/hm~2;氮肥施用强度在1993年已经超过了其生态经济适宜量,磷肥从2001年开始超过了其生态经济适宜量,钾肥在2009年后逼近其生态经济适宜量;1993-2007年间,河南、山东、江苏一直是高强度施肥省份,其他次高强度施肥的省份由高强度施肥省份逐步向周围扩散。2017年,河南为化肥施用生态经济不合理区,化肥施用明显过量;河北、江苏、安徽、山东和湖北则属于经济合理生态不合理区,化肥施用有所过量;湖南、吉林、辽宁和内蒙古施肥适当,属于施肥生态经济合理区;黑龙江、四川和江西为施肥生态合理经济不合理区,化肥施用不足。因此,中国粮食主产区化肥施用强度及生态经济合理性差异较大,总体施肥过量,部分地区存在施肥不足的情况。节肥增效、防治农业面源污染要坚持分类指导、因地减量的原则,完善配方测土施肥政策和技术手段,大力推进信息技术和有机肥利用,走有机无机肥相结合道路。 相似文献
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明确当前安徽省的施肥现状和存在问题对于科学施肥具有十分重要的指导意义。对安徽省不同区域农户进行抽样调查,调查内容包括:肥料品种、肥料用量、施肥方式、种植面积。根据调查结果对当前安徽省区域间(皖北、皖中、皖南)和作物间肥料投入总量、强度、方式和品种进行统计分析。调查结果表明:(1)当前全省化肥施用总量和强度分别是312.8万t和342 kg/hm2。虽然全省化肥施用总量逐步降低,但是区域和作物间肥料投入差异较大。皖北化肥总投入量最大,其次是皖中,皖南最小。蔬菜、果树等经济作物过量施肥较为普遍,大田粮食作物化肥施用过量与不足并存;(2)目前全省机械化施肥普及率为55.5%,但是区域间差异较大,主要集中在皖北区域,皖中和皖南区域普及率较低;机械化施肥主要集中在粮食作物上,经济作物比例较低;(3)在施肥品种方面,全省粮食作物和油料作物存在重视化肥投入、有机替代施用不足等问题;而在水果、蔬菜、茶叶等经济作物有机肥投入主要以商品有机肥、粪肥和饼肥为主,但是施肥水平有待提高。综上所述,当前安徽省化肥总量和施肥强度相对于2014年已经有了较大幅度的降低,这说明全省已提前实现了2020年化肥零增长的目标,但是目前全省化肥施用不合理现象依然存在,因此应该加强宏观调控,实施合理的化肥资源区域布局,做到因地制宜,通过总量控制、增加有机替代比例、加强机械化施肥推广等途径实现化肥减施,提高经济效益和环境效益。 相似文献
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Asulam reaching the soil either directly as spray drift or as rain washings from bracken fronds would, due to its rapid mobility in soil, be expected to leach down the soil profile into the drainage water and thereby contaminate streams and water catchments. The mobility of asulam in soil is influenced by pH, where undissociated asulam will leach less rapidly than the associated form (asulam pKa 4·82). This is particularly relevant in the case of bracken as it can grow satisfactorily over a wide range of pH values (3·6 – 7·6). Adsorption coefficients expressed as Kd values [(μg asulam/g soil)/(μg asulam/ml solution)] were 2·54, 1·94 and 0·96 at pH readings of 4·0, 4·3 and 4·9 respectively. Another factor involved, the breakdown of asulam, was shown to be temperature dependent, 30·95, 7·65 and 2·50% remaining after 28 days at 5, 18 and 25°C respectively, thus underlining the influence of geographical regions and climatic conditions on asulam behaviour. 相似文献
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E.B. Roslycky 《Soil biology & biochemistry》1982,14(2):87-92
Limited information on the effect of glyphosate (N-phosphonomethylglycine) on soil microorganisms justified an inquiry into the response of soil actinomycetes, bacteria and fungi in terms of their respiration, and sensitivity of isolates. Low concentrations of glyphosate had little effect on total populations of these organisms during the 214-day experiment, while high concentrations initially increased actinomycete and bacterial numbers by 2 and 1 logs, respectively. The stimulation was followed by a decline and fluctuation showing a gradual increase in numbers. The respiration rates of the soil microbiota in soil suspensions, showed some irregular stimulation and retardation with up to 10 μg glyphosate ml?1. In contrast high doses suppressed O2 uptake by the microbiota. Fungi were the least affected. Pronounced inhibition of actinomycete and bacterial respiration was in agreement with the results from isolate replication. The results indicated both stimulation and inhibition of O2 uptake by some organisms within these groups. In contrast to some reports of limited, short-term inquiries these results showed considerable effects of glyphosate on soil microorganisms. 相似文献
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Stephen AC Marklevitz Elizabete Almeida Joanna Flemming Jocelyne Hellou 《Journal of Soils and Sediments》2008,8(2):92-97
Background, Aims and Scope
Our study determined if and when an avoidance or attraction behavioural response would be displayed by Ilyanassa obsoleta when presented with a choice between harbour and reference sediments. Our goal was to develop a non-lethal approach that could be used in future assessments of the environmental quality of field sediments. 相似文献14.
By measuring the isotopic signature of soil respiration, we seek to learn the isotopic composition of the carbon respired in the soil (δ13CR-s) so that we may draw inferences about ecosystem processes. Requisite to this goal is the need to understand how δ13CR-s is affected by both contributions of multiple carbon sources to respiration and fractionation due to soil gas transport. In this study, we measured potential isotopic sources to determine their contributions to δ13CR-s and we performed a series of experiments to investigate the impact of soil gas transport on δ13CR-s estimates. The objectives of these experiments were to: i) compare estimates of δ13CR-s derived from aboveground and belowground techniques, ii) evaluate the roles of diffusion and advection in a forest soil on the estimates of δ13CR-s, and iii) determine the contribution of new and old carbon sources to δ13CR-s for a Douglas-fir stand in the Pacific Northwest during our measurement period. We found a maximum difference of −2.36‰ between estimates of δ13CR-s based on aboveground vs. belowground measurements; the aboveground estimate was enriched relative to the belowground estimate. Soil gas transport during the experiment was primarily by diffusion and the average belowground estimate of δ13CR-s was enriched by 3.8-4.0‰ with respect to the source estimates from steady-state transport models. The affect of natural fluctuations in advective soil gas transport was little to non-existent; however, an advection-diffusion model was more accurate than a model based solely on diffusion in predicting the isotopic samples near the soil surface. Thus, estimates made from belowground gas samples will improve with an increase in samples near the soil surface. We measured a −1‰ difference in δ13CR-s as a result of an experiment where advection was induced, a value which may represent an upper limit in fractionation due to advective gas transport in forest ecosystems. We found that aboveground measurements of δ13CR-s may be particularly susceptible to atmospheric incursion, which may produce estimates that are enriched in 13C. The partitioning results attributed 69-98% of soil respiration to a source with a highly depleted isotopic signature similar to that of water-soluble carbon from foliage measured at our site. 相似文献
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M. V. Korneikova 《Eurasian Soil Science》2018,51(1):89-95
The number, biomass, length of fungal mycelium, and species diversity of microscopic fungi have been studied in soils of the tundra and taiga zones in the northern part of the Kola Peninsula: Al-Fe-humus podzols (Albic Podzols), podburs (Entic Podzols), dry peaty soils (Folic Histosols), low-moor peat soils (Sapric Histosols), and soils of frost bare spots (Cryosols). The number of cultivated microscopic fungi in tundra soils varied from 8 to 328 thousand CFU/g, their biomass averaged 1.81 ± 0.19 mg/g, and the length of fungal mycelium averaged 245 ± 25 m/g. The number of micromycetes in taiga soils varied from 80 to 350 thousand CFU/g, the number of fungal propagules in some years reached 600 thousand CFU/g; the fungal biomass varied from 0.23 to 6.2 mg/g, and the length of fungal mycelium varied from 32 to 3900 m/g. Overall, 36 species of fungi belonging to 16 genera, 13 families, and 8 orders were isolated from tundra soils. The species diversity of microscopic fungi in taiga soils was significantly higher: 87 species belonging to 31 genera, 21 families, and 11 orders. Fungi from the Penicillium genus predominated in both natural zones and constituted 38–50% of the total number of isolated species. The soils of tundra and taiga zones were characterized by their own complexes of micromycetes; the similarity of their species composition was about 40%. In soils of the tundra zone, Mortierella longicollis, Penicillium melinii, P. raistrickii, and P. simplicissimum predominated; dominant fungal species in soils of the taiga zone were represented by M. longicollis, P. decumbens, P. implicatum, and Umbelopsis isabellina. 相似文献
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Mitsuhiko A. Takahashi 《Biological conservation》2009,142(9):1958-1964
Japan has a variety of laws to conserve and manage wildlife and biodiversity. This article reviews Japanese laws from conservation of endangered species to the fish and game code, and indicates the issues and challenges they face. It then discusses the issues and challenges for management in the application of the laws.The Japanese statute for conservation of endangered species corresponds to the US Endangered Species Act in appearance, but is much more limited in application and scope. There is no legal channel, such as lawsuits, to assure citizens’ and experts’ input. With respect to general species, management of fish and animals are divided; the fish code’s scope is limited to fishery purposes. Control of wildlife damage is the biggest emphasis in the wildlife code. Reform to bring principles of scientific management into pest control has begun, but conventional culling is still the norm.Japan’ wildlife and fish management is distinctive in relying upon local resource users, instead of on a strong regulatory agency. This is a consequence of traditional communal management, and is apparent in coastal fisheries. The depopulation and exhaustion of rural communities, however, makes it difficult to rely on the community for management. In particular, wildlife management, which relies on aging hunters, is facing a turning point. To address these changes, agencies must be strengthened and lawmakers must enact a mechanism to assure sound science in wildlife policy, while working to revitalize rural communities. 相似文献
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Protozoan predation and the turnover of soil organic carbon and nitrogen in the presence of plants 总被引：5，自引：0，他引：5
Kuikman P. J. Jansen A. G. van Veen J. A. Zehnder A. J. B. 《Biology and Fertility of Soils》1990,10(1):22-28
Summary The impact of protozoan grazing on the dynamics and mineralization of 14C- and 15N-labelled soil organic material was investigated in a microcosm experiment. Sterilized soil was planted with wheat and either inoculated with bacteria alone or with bacteria and protozoa or with bacteria and a 1:10 diluted protozoan inoculum. 14C–CO2 formation was continuously monitored. It served as an indicator of microbial activity and the respiration of soil organic C. The activity of protozoa increased the turnover of 14C-labelled substrates compared to soil without protozoa. The accumulated 14C–CO2 evolved from the soils with protozoa was 36% and 53% higher for a 1:10 and for a 1:1 protozoan inoculum, respectively. Protozoa reduced the number of bacteria by a factor of 2. In the presence of protozoa, N uptake by plants increased by 9% and 17% for a 1:10 and a 1:1 protozoan inoculum, respectively. Both plant dry matter production and shoot: root ratios were higher in the presence of protozoa. The constant ratio of 15N: 14+15N in the plants for all treatments indicated that in the presence of protozoa more soil organic matter was mineralized. Bacteria and protozoa responded very rapidly to the addition of water to the microcosms. The rewetting response in terms of the 14C–CO2 respiration rate was significantly higher for 1 day in the absence and for 2 days in the presence of protozoa after the microcosms had been watered. It was concluded that protozoa improved the mineralization of N from soil organic matter by stimulating the turnover of bacterial biomass. Pulsed events like the addition of water seem to have a significant impact on the dynamics of food-chain reactions in soil in terms of C and N mineralization.Communication No. 19 of the Dutch Programme on Soil Ecology of Arable Farming Systems 相似文献
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The levels and distributions of petroleum hydrocarbons incoastal waters and sediments of the United Arab Emirates (U. A. E.) along theArabian Gulf and the Gulf of Oman were investigated. Oil concentrations in the waters ofthe U. A. E. were below the 15 μg L-1 and ranged from 1.6 to 13 μg L-1.Petroleum hydrocarbons showed different pattern of distribution in the Arabian Gulf and the Gulf of Oman withmore or less similar values. Horizontal distribution of petroleum hydrocarbons atthe Arabian Gulf showed significant differences between most sites. At the Gulf ofOman, similar oil concentrations were measured at different sites. Meanwhile,vertical distributions of petroleum hydrocarbons indicated higher concentrations atsurface layers of the Arabian Gulf compared to bottom layers. Whereas, more or less similarconcentrations were measured at the Gulf of Oman. The concentration of petroleum hydrocarbons in marinesediments varied from 2.5 to 8.2 μg g-1 (dry sediment weight), with higher concentrations at theArabian Gulf compared to the Gulf of Oman. The pattern of distribution for petroleumhydrocarbons in marine sediments resembled to some extent the distribution of organiccarbon in marine sediments. The study revealed that the concentrations ofpetroleum hydrocarbons in waters and sediments of the investigated area are not highcompared to other areas of the world. 相似文献
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Methane emission from natural mires in the middle and southern taiga zones of Tomsk oblast was studied in the summer and fall of 2006. Methane fluxes (mg C/m2 per h) from different types of mires and different microelements of the surface topography were characterized by the following median values: 0.67 for a forested bog; 4.06 and 2.67 for hollows and elevations (hillocks) of an open (nonforested) mire, respectively; and 0.74 and 2.13 for hollows and ridges of a ridged bog, respectively. Based on these and the literature data on the areas of different types of mires in Tomsk oblast, annual methane emission from mire ecosystems of Tomsk oblast was estimated at about 0.50 × 1012 Tg C. This value comprised 0.3–1.0% of the global emission of methane from wetlands or 0.1% of the global methane emission from all sources. 相似文献
20.
Chemical and microbiological parameters for the characterisation of the stability and maturity of pruning waste compost 总被引：1，自引：0，他引：1
Composting of pruning waste, leaves and grass clippings was monitored by different parameters. A windrow composting pile, having the dimensions 2.5 m (height) x 30 m (length) was establish. The maturation of pruning waste compost was accompanied by a decline in NH4 +-N concentration, water soluble C (WSC) and an increase in NO3 –-N content. Both organic matter (OM) content and total N (TN) losses during composting followed a first-order kinetic equation. These results were in agreement with the microbiological activity measured either by the CO2 respiration or dehydrogenase (DH-ase) activity during the process. Statistically significant correlations were found between DH-ase activity, easily biodegradable organic C forms, NH4 +-N and NO3 –-N concentrations and organic matter content and N losses. For this reason, DH-ase activity and the CO2 evolution could be used as good indicators of pruning waste compost maturity. In contrast, humification parameters data from the organic matter fractionation did not agree with the initially expected values and did not contribute to the assessment of compost maturity. Neither the cation exchange capacity nor the germination index showed a clear tendency during the composting time, suggesting that these parameters are not suitable for evaluating the dynamics of the process. 相似文献