我国循环农业发展理论与实践

发展循环农业是实现农业清洁生产、农业资源可持续利用的有效手段,也是解决现代农业发展困境的必然选择。文章系统地阐述了循环农业的内涵、特征、理论基础与遵循原则,指出其本质特征是资源节约和产业链条延伸,是遵循循环经济理念的生产方式、资源节约和高效利用的农业经济增长方式、产业链延伸的农业空间拓展路径和环境友好的新农村理念。分析了循环农业的发展动力与物质流程框架,指出循环农业的产业链循环包括农业生产过程中农产品的顺时针外循环路径和可再生资源的逆时针内循环路径,其发展动力主要是产业链内固有的价格机制和竞争机制产生的拉动作用和产业链外资金、技术、政策等对产业发展产生的推动作用。文章总结了国内发展循环农业的实践和相关的模式,提出了循环农业今后的研究重点包括循环农业的机理研究,循环农业发展的制度创新和补偿机制研究以及循环经济闭合循环链条体系的构建。     

区域农业循环经济能值评价的实证研究

本文将能值理论与区域农业循环经济理论相结合,提出一套包括经济社会发展、资源减量投入、资源循环利用和资源环境安全等方面指标体系的区域农业循环经济的能值评价方法,并以吉林省西部进行实证研究。结果表明,1985—2004年期间,吉林省西部农业生态经济系统的能值投入和产出均呈明显的增长趋势,系统中物质循环利用及有效能值的转化率明显提高,种植业与畜牧业耦合程度有所增强,农业循环经济发展趋势得到明显加强,2004年农业循环经济综合评价指数是1985年的1．257倍;但资源减量投入和资源环境安全仍是吉林省西部农业循环经济发展的主要障碍,必须因地制宜地制定相关政策和措施加强农业循环经济建设。     

江苏发展循环农业的探索与实践

为最终实现经济增长方式的转变,实现生态效益、社会效益、经济效益的统一,实现农业和农村经济的可持续发展,以现代循环经济理论和生态经济学理论为指导,坚持4R原则,阐述了循环农业的内涵及江苏省发展循环农业的总体目标、内容、主推技术和配套措施。     

安徽省循环农业发展典型案例研究

安徽省根据循环经济的理念和自身农业发展特点,建立循环农业模式,充分协调经济发展与生态环境之间的关系,以实现农业可持续发展。本文对安徽省发展循环农业的情况进行了系统研究,总结和分析了安徽省典型循环农业模式:淮南毛集实验区循环农业模式、砀山梨生产循环利用模式、临泉县"林-草-牧-沼-菌"模式,在此基础上提出了适合安徽省的循环农业发展模式:立体农业模式、生态链转换模式、农业产业链延伸模式和观光旅游模式。     

基于指标体系的河北省农业循环经济发展评价

在农业循环经济内涵基础上,构建了农业循环经济发展水平的综合评价指标体系,指标体系包括经济与社会发展、资源减量化投入、资源循环再利用及资源环境安全等4个类指标共18个操作化指标.并对河北省1991～2005年农业循环经济发展水平进行评价.结果表明,河北省农业循环经济整体水平逐年上升,主要是由于农业产出水平提高的拉动;农业投入水平是最主要制约因素;资源循环再利用水平多年徘徊不前;农业资源环境安全基本得到了保障.     

吉安市发展循环农业的实践与探讨

循环农业是一种以资源高效利用和循环利用为核心,以"减量化、再利用、资源化"为原则,以低消耗、低排放、高效率为基本特征的农业发展模式。本文分析了吉安市从构建支持循环农业发展的政策体系、扶持机制、发展模式入手,探索实践发展循环农业的情况,并提出了发展循环农业的对策建议。     

面向循环经济的生态农业现代化转型

循环经济是可持续发展的重要支撑,已得到世界上许多国家的认同和接受。中国是一个农业大国和人口大国,发展农业循环经济具有极其重要的现实意义。我国具有良好的发展农业循环经济的基础。农业循环经济的内容十分丰富,包括农业生产部门内部的物质与能量的耦合、农业产业部门之间的物质与能量的耦合、农业与工业之间的物质与能量的耦合、城乡资源利用之间的物质与能量的耦合等具体发展模式。生态农业是农业循环经济发展的重要形式和载体,但要达到循环经济的目标和要求,还必须实现向规模化、产业化、无害化、标准化、市场化与功能多元化的转型与提升。同时,必须采取相应的对策措施,包括加强农业循环经济的法制建设、生态农业产业化建设、工农业废弃物处理与资源化利用以及现代生态农业园区建设等内容。     

发展农业循环经济 推进农村节能减排——洛阳市发展循环农业的现状与对策

农业循环经济是以循环经济理论来发展农业生产,通过调整和优化农业生态系统内部结构及产业结构,提高农业生态系统物质和能量的多级循环利用,严格控制外部有害物质的投入和农业废弃物的产生,达到农业和农村节能减排的目的,实现生态保护与农业发展良性循环的农业经济发展模式。本文通过对洛阳市发展农业循环经济的成效、做法和存在问题分析,指出农业循环经济对节能减排的作用,提出了今后农业循环经济发展对策。     

面向循环经济的生态农业现代化转型

循环经济是可持续发展的重要支撑，已得到世界上许多国家的认同和接受。中国是一个农业大国和人口大国，发展农业循环经济具有极其重要的现实意义。我国具有良好的发展农业循环经济的基础。农业循环经济的内容十分丰富，包括农业生产部门内部的物质与能量的耦合、农业产业部门之间的物质与能量的耦合、农业与工业之间的 物质与能量的耦合、城乡资源利用之间的物质与能量的耦合等具体发展模式。生态农业是农业循环经济发展的重要形式和载体，但要达到循环经济的目标和要求，还必须实现向规模化、产业化、无害化、标准化、市场化与功能多元化的转型与提升。同时，必须采取相应的对策措施，包括加强农业循环经济的法制建设、生态农业产业化建设、工农业废弃物处理与资源化利用以及现代生态农业园区建设等内容。     

陕北农户“四位一体”生态农业循环经济模式实例分析

以米脂县对岔村一农户为研究对象,对该户的"四位一体"生态农业循环经济模式产生的经济效益、生态效益和社会效益进行了分析.结果认为,推广以沼气为纽带的生态农业循环经济,有利于解决农业生产中长期存在种养分离,能源利用与环境保护分离造成的农业效益低,农民收入低和环境污染等问题,为农村生态农业循环经济的发展提供有利借鉴.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

Aircraft operations near concentrations of birds in Antarctica: The development of practical guidelines

Aircraft operations have the potential to disturb and to impact negatively on bird life. A gradient of increasing behavioural response is evident in birds when exposed to increasing aircraft stimulus. The most major disturbance is likely to lead to impacts on the health, breeding performance and survival of individual birds, and perhaps bird colonies. A process of revision to policies on aircraft operations contained in management plans for a number of specially protected areas in Antarctica by the United Kingdom, accompanied by consultations made within the scientific community through the Scientific Committee on Antarctic Research (SCAR) and with operational interests through the Council of Managers of National Antarctic Programmes (COMNAP) resulted in new guidelines being adopted by the Antarctic Treaty Consultative Parties in June 2004. The principal recommendations of the guidelines are that bird colonies should not be overflown below 2000 ft (∼610 m) above ground level and landings within 1/2 nautical mile (∼930 m) of bird colonies should be avoided wherever possible. These guidelines are less stringent and less specific than those that were recommended by the SCAR specialist group on birds, and represent a compromise to accommodate operational needs. While the adoption of clear and consistent guidelines for the operation of aircraft in Antarctica is welcome in that this provides practical advice that is likely to reduce incidences of close aircraft/bird encounters, there remains insufficient knowledge of the interactions between aircraft and birds in Antarctica, and the consequent impacts on individual birds and on bird populations. It is important, therefore, that the guidelines adopted are considered interim, and should be kept under scrutiny with revisions made as new and improved research results appear.     

The abundance of heterocystous blue-green algae in rice soils and inocula used for application in rice fields

Summary Algal populations were quantified (as colony-forming units [CFU] per square centimetre) in 102 samples of rice soils from the Philippines, India, Malaysia and Portugal, and in 22 samples of soil-based inocula from four countries. Heterocystous blue-green algae (BGA) were present in all samples. Nostoc was the dominant genus in most samples, followed by Anabaena and Calothrix. In soils, heterocystous BGA occurred at densities ranging from 1.0 × 10² to 8.0 × 10⁶ CFU/cm² (median 6.4 × 10⁴) and comprised, on average, 9% of the total CFU of algae. Their abundance was positively correlated with the pH and the available P content of the soils. In soil-based inocula, heterocystous BGA occurred at densities ranging from 4.6 × 10⁴ to 2.8 × 10⁷ CFU/g dw (dry weight), comprising only a moderate fraction (average 13%) of the total algae. In most soils, the density of indigenous N₂-fixing BGA was usually higher than that attained by applying recommended rates of soil-based inoculum. Whereas research on the practical utilization of BGA has been mostly directed towards inoculation with foreign strains, our results suggest that attention should also be given to agricultural practices that enhance the growth of indigenous strains already adapted to local environmental conditions.Maître de Recherches ORSTOM (France), Visiting Scientist at IRRI