黄土高原集水农业研究进展

回顾了黄土高原集水农业理论与技术体系的研究成果．分析评价了集水农业的研究进展。随着黄土高原集水农业研究方法的改进、研究内容的深入、研究领域的扩充．提出了广义性集水农业研究范畴。在黄土高原集水农业理论研究的基础上．应加强微集雨微灌溉应用技术、现代集雨技术、计算机控制技术与集雨网络等高新技术手段的技术集成．以提高雨水汇集与利用效率。同时．黄土高原集水农业的研究已经从微生境条件下的农业生态系统延伸至区域生态环境保育。利用汇集雨水合理调配生态用水．进行小流域综合治理。农林牧综合发展。生态环境重建的集水型生态农业是黄土高原集水农业的发展趋势。     

禁牧政策对宁夏盐池县农业生态系统服务影响的能值分析

农牧交错区农业可持续发展问题一直是我国区域农业研究的重要课题,以典型北方农牧交错区宁夏盐池县为例,利用农业生态系统能值分析框架,评估盐池县1991—2016年农业生态系统正反服务,揭示禁牧政策对农业可持续发展的影响。研究结果表明:(1) 1991—2016年盐池县农业投入能值和农业生态系统正反服务能值一直处于增长的趋势,禁牧政策实施以后增长速度高于禁牧之前,其中农业投入能值的增加主要是由于经济反馈能值投入的增加。(2)根据Pearson相关性分析,盐池县农业生态系统服务和反服务在0.01水平(双侧)呈显著的强正相关,农业生态系统服务和反服务具有相同的变化趋势。(3)生态环境的改善、经济反馈能值和农业灌溉面积的增加,可以增强北方农牧交错区农业抵御气候波动的能力。(4)盐池县农业可持续性高于全国和典型农区的平均水平,禁牧政策实施之前盐池县农业可持续性表现出稳定的下降趋势,而禁牧政策实施以后其可持续性表现为上升的趋势,禁牧政策的实施已初步实现农业生产的生态经济效益。     

Changes in the Potential Multiple Cropping System in Response to Climate Change in China from 1960–2010

The multiple cropping practice is essential to agriculture because it has been shown to significantly increase the grain yield and promote agricultural economic development. In this study, potential multiple cropping systems in China are calculated based on meteorological observation data by using the Agricultural Ecology Zone (AEZ) model. Following this, the changes in the potential cropping systems in response to climate change between the 1960s and the 2010s were subsequently analyzed. The results indicate that the changes of potential multiple cropping systems show tremendous heterogeneity in respect to the spatial pattern in China. A key finding is that the magnitude of change of the potential cropping systems showed a pattern of increase both from northern China to southern China and from western China to eastern China. Furthermore, the area found to be suitable only for single cropping decreased, while the area suitable for triple cropping increased significantly from the 1960s to the 2000s. During the studied period, the potential multiple cropping index (PMCI) gap between rain-fed and irrigated scenarios increased from 18% to 24%, which indicated noticeable growth of water supply limitations under the rain-fed scenario. The most significant finding of this research was that from the 1960s to the 2000s climate change had led to a significant increase of PMCI by 13% under irrigated scenario and 7% under rain-fed scenario across the whole of China. Furthermore, the growth of the annual mean temperature is identified as the main reason underlying the increase of PMCI. It has also been noticed that across China the changes of potential multiple cropping systems under climate change were different from region to region.     

黄土高原旱地长期种植作物对土壤微量元素形态和有效性的影响

在长期定位试验的基础上,用连续浸提方法对土壤微量元素进行形态分级,研究了长期种植作物条件下黄土高原旱地土壤中微量元素的形态组成及其在不同土壤组分间的分配特征,探讨了种植系统对土壤微量元素有效性的影响。土壤中有效态微量元素含量的剖面分布除与土壤中微量元素的全量有关外,还与不同的种植系统有关。各种植系统有效锌和有效铜含量均低于休闲土壤,有效锌以小麦连作和苜蓿连作降低最多,有效铜以小麦连作和粮豆轮作降低最多。小麦连作系统40 cm以上土层土壤有效锰含量和休闲土壤接近,40~100cm土层低于休闲土壤,苜蓿连作和粮豆轮作整个剖面土壤有效锰含量均有所增加。各种植系统40cm以上土层土壤有效铁含量均高于休闲土壤,40~100cm土层土壤有效铁分布趋势相同,其含量均随土层深度的增加而增加,并且小麦连作低于休闲土壤,粮豆轮作高于休闲土壤,苜蓿连作与休闲相近,这些结果表明长期种植作物可以显著改善土壤锰素营养和铁素营养状况。苜蓿连作和小麦连作使锌和铁从矿物态向有机结合态转化,增加了土壤有效锌和有效铁的储备,粮豆轮作系统各形态锌低于休闲土壤,并且土壤中锌的总贮量有所减少;各种植系统土壤氧化物结合态铁在耕层增加,在古耕层降低,这也表明种植作物可以活化深层土壤难溶态铁。长期种植作物使耕层土壤各形态铜含量降低,粮豆轮作和小麦连作系统古耕层土壤各形态铜含量较休闲土壤有所增加。3种种植系统碳酸盐结合态、氧化物结合态和有机结合态锰含量均有不同程度的下降,且耕层土壤交换态、碳酸盐结合态和有机结合态锰高于古耕层,氧化物结合态和矿物态锰含量低于古耕层。     

Agricultural sustainability: concepts, principles and evidence

Concerns about sustainability in agricultural systems centre on the need to develop technologies and practices that do not have adverse effects on environmental goods and services, are accessible to and effective for farmers, and lead to improvements in food productivity. Despite great progress in agricultural productivity in the past half-century, with crop and livestock productivity strongly driven by increased use of fertilizers, irrigation water, agricultural machinery, pesticides and land, it would be over-optimistic to assume that these relationships will remain linear in the future. New approaches are needed that will integrate biological and ecological processes into food production, minimize the use of those non-renewable inputs that cause harm to the environment or to the health of farmers and consumers, make productive use of the knowledge and skills of farmers, so substituting human capital for costly external inputs, and make productive use of people's collective capacities to work together to solve common agricultural and natural resource problems, such as for pest, watershed, irrigation, forest and credit management. These principles help to build important capital assets for agricultural systems: natural; social; human; physical; and financial capital. Improving natural capital is a central aim, and dividends can come from making the best use of the genotypes of crops and animals and the ecological conditions under which they are grown or raised. Agricultural sustainability suggests a focus on both genotype improvements through the full range of modern biological approaches and improved understanding of the benefits of ecological and agronomic management, manipulation and redesign. The ecological management of agroecosystems that addresses energy flows, nutrient cycling, population-regulating mechanisms and system resilience can lead to the redesign of agriculture at a landscape scale. Sustainable agriculture outcomes can be positive for food productivity, reduced pesticide use and carbon balances. Significant challenges, however, remain to develop national and international policies to support the wider emergence of more sustainable forms of agricultural production across both industrialized and developing countries.     

Perceptions and Patterns of Human–elephant Conflict in Old and New Settlements in Sri Lanka: Insights for Mitigation and Management

Human–elephant conflict poses a major threat to elephants in many parts of Asia, including Sri Lanka. We studied human–elephant conflict in two areas with contrasting scenarios of landuse and conflict, Kahalle and Yala. Kahalle was developed and settled under the Mahaweli irrigation project and the main agricultural practice was irrigated agriculture, with two annual growing seasons. The area was a mosaic of settlements, agriculture, and small forest patches with ill defined human- and elephant-use areas. Elephants ranged within the habitat mosaic year round, occupying remnant forest patches and raiding adjacent crops at night. In contrast, Yala was dominated by a large protected area complex, and the main agricultural methods were slash-and-burn agriculture and rain-fed paddy cultivation. Human- and elephant-use areas were well defined and segregated. The protected area provided elephants with a refuge and food during the rainy season, when the single annual crop was grown. During the dry season, elephants moved into slash-and-burn areas and utilized leftover crops and pioneer vegetation in fallow fields. The landuse pattern and agricultural practices in Yala facilitated co-existence, whereas that in Kahalle led to year round conflict. We suggest that areas managed according to traditional landuse practices should be part of an elephant conservation strategy, where people and elephants have to share resources.     

Precision agriculture: a challenge for crop nutrition management

Precision agriculture was initiated in the mid 1980s, using newly available technologies, to improve the application of fertilizers by varying rates and blends as needed within fields. Presently, the concept has been adapted to a variety of practices, crops, and countries. Its adoption varies significantly by cropping system, regions, and countries but it is progressively introduced or evaluated around the world. Several types of challenges limit a broader adoption: socio-economical, agronomical, and technological. Socio-economical barriers are principally costs and lack of skills. Agronomical challenges are lack of basic information, inadequate sampling and scouting procedures, absence of site-specific fertilizer recommendations, misuse of information, and lack of qualified agronomic services. There are multiple technological barriers that relate to machinery, sensor, GPS, software, and remote sensing. However, these barriers will be progressively lifted and precision agriculture will be a significant component of the agricultural system of the future. It offers a variety of potential benefits in profitability, productivity, sustainability, crop quality, food safety, environmental protection, on-farm quality of life, and rural economic development.     

绿肥在我国旱地农业生态系统中的服务功能及其应用

旱地农业分布面积广、增产潜力大,在保障我国粮食安全方面占有重要地位,但也面临着水资源短缺、土壤贫瘠、水土流失严重和不可再生资源利用效率低等问题。绿肥不仅具有提高土壤质量、调节土壤养分和增强土壤水分蓄纳能力,从而改善作物生长环境,促进作物持续高产稳产的作用,而且在增加农田生态系统生物多样性、提高地表覆盖度、减少养分向环境中的无效损失、增强农田系统气体调节功能、提高病虫草害的生物防控等方面也具有显著的生态效益。在全球气候变化加剧、生态环境恶化和农产品需求改变等新形势下,以肥用为主要目的的传统绿肥种植应用技术已不能满足当前农业发展的需求,需要加强旱地绿肥种质资源的选育工作,通过研制新的适应新形势的全国绿肥区划,构建适应不同区域的绿肥种植模式,优化和研发适应现代化生产水平的耕作栽培技术,探究绿肥综合效益评价体系,为旱地农业区改善生态环境、提高经济效益,构建资源节约、生态保育型的绿肥应用模式,充分挖掘绿肥效益提供科学依据和技术支撑。     

Environmental and Socioeconomic Interactions in the Evolution of Traditional Irrigated Lands: A Dynamic System Model

The Huerta de Murcia is a traditionally irrigated land located in the middle lowland area of the Segura River around the city of Murcia, Southeast Spain. During the twentieth century several factors, such as the creation of new irrigated lands and the urbanization of traditionally irrigated lands, have changed the use of natural resources, giving rise to a growing imbalance between water resources and irrigation demands and a loss of fertile soil and other environmental and cultural values of this traditionally agricultural area. Such factors constitute environmental problems that will need to be controlled if more sustainable conditions for agriculture are to be achieved. The objectives of the present work are to develop a dynamic system model containing the main social, economic, and environmental and to use this model to explore the long-term effects of several policies designed to promote the sustainability of this agrolandscape. Some preliminary conclusions suggest that regulation and agricultural policy are not enough to stop the loss of traditionally irrigated lands and that additional water management and environmental policies are necessary.     

Dryland Salinity and Ecosystem Distress Syndrome: Human Health Implications

Clearing of native vegetation for agriculture has left 1.047 million hectares of southwest Western Australia affected by dryland salinity, and this area may expand up to a further 1.7–3.4 million hectares if trends continue. Ecosystems in saline-affected regions display many of the classic characteristics of Ecosystem Distress Syndrome, one outcome of which has not yet been investigated in relation to dryland salinity: adverse human health implications. This article seeks to review existing information and identify potential adverse human health effects. Three key potential impacts on human health resulting from dryland salinity are identified: wind-borne dust and respiratory health; altered ecology of the mosquito-borne disease Ross River virus; and mental health consequences of salinity-induced environmental degradation. Given the predicted increase in extent and severity of dryland salinity over coming decades, adverse outcomes of salinity are likely to be further exacerbated, including those related to human health. There is a clear need to investigate the issues discussed in this review and also to identify other potential adverse health effects of dryland salinity. Investigations must be multidisciplinary to sufficiently examine the broad scope of these issues. The relationship between human health and salinity may also be relevant beyond Australia in other countries where secondary soil salinization is occurring.     

Construction process and development trend of ecological agriculture in China

China's ecological agriculture has played a pioneering role in sustainable development, which has attracted extensive attention and high praise from the international community. This paper systematically analyzed the development process of China's eco-agriculture, by combining with the practice of ecological agriculture construction in China for many years and the construction process of modern ecological agriculture base of the Ministry of Agriculture, and comprehensive literature research. The results showed that: 1) The development of China's eco-agriculture has gone through two periods: traditional ecological agriculture and modern ecological agriculture. Traditional ecological agriculture provides rich production experience. China's modern agricultural ecology has experienced four development stages: initial exploration (1981–1992), expansion and consolidation (1993–2004), steady advancement (2005–2011) and innovation and promotion (2012–present). Each stage has distinctive features and landmark achievements, which rammed the foundation for the green and sustainable development of agriculture and rural areas in China; 2) China's modern ecological agriculture has been incorporated into the act of government in 1993, and has basically formed a five-level demonstration and driving system of ecological agriculture including 2 pilot provinces for eco-agriculture, 10 demonstration cities for circular agriculture, 100 demonstration counties for eco-agriculture, 12 demonstration bases for eco-agriculture, and 1100 beautiful villages, which cover province, municipality, county, base and village. The advancing mechanism of modern ecological agriculture of “small circulation in the main body, circulation in the park and large circulation in the county”, has effectively promoted the development of ecological agriculture nationwide; 3) China's eco-agriculture has three distinct characteristics: comprehensiveness, sustainability and diversity. Its basic contents mainly include: agricultural ecology methodology and theoretical basis, optimization design of agricultural ecosystem, assembly and integrated application of eco-agricultural technology; 4) Under the trend of agricultural green development, China's eco-agriculture construction is innovating and improving system and mechanism, and ensuring the development towards high efficiency, industrialization, standardization, practicality and multi-function, thus gradually establishing a resource-saving, environment-friendly and ecological conservation-oriented modern ecological agricultural system with Chinese characteristics, constituting the ecological agriculture development pattern integrating rural production development, prosperous life and good ecology, and helping China's rural ecological revitalization.     

Variazioni del paesaggio agricolo italiano in relazione all'evoluzione delle tecniche agronomiche

Abstract

Variation of the Italian agricultural landscape in relation to the evolution of the agronomic techniques.- The agricultural activity and the practices that are connected with it more or less directly, have been transformed during the history of mankind according to the evolution of the various societies and policies. These variations are with no doubt the most “responsible” of the evolution of the agricultural landscape. The agronomic techniques that were used in the ancient agricultural societies were initially rough, the land being used temporarly by nomadic people and then abandoned when fertility or weather were not favourable to crop growth and replaced with new fertile areas. Therefore the impact of ancient agriculture on the landscape was very limited, also because of the low population density.

The permanent agriculture developed with the beginning of the great civilisations when the rural environment begun to assume a more stable aspect. During the Reinassance the diversification of agricultural activities had beneficial effects on the landscape, that used to be very variable, both as a result of the mixed cropping systems and the multiple agronomic techniqies used.

The most important upsetting of the agricultural landscape occurred in the last century, when agriculture become an economic activity, with the same dignity of the other productive sectors and related advantages and disadvantages. In this paper the impact of the main aspects of agricultural activity on the agricultural landscape are analysed, with particular attention to the choices that farmers had to make about crops, livestock and management of the rural landscape.     

An integrated greenhouse gas assessment of an alternative to slash-and-burn agriculture in eastern Amazonia

Fires set for slash‐and‐burn agriculture contribute to the current unsustainable accumulation of atmospheric greenhouse gases, and they also deplete the soil of essential nutrients, which compromises agricultural sustainability at local scales. Integrated assessments of greenhouse gas emissions have compared intensive cropping systems in industrialized countries, but such assessments have not been applied to common cropping systems of smallholder farmers in developing countries. We report an integrated assessment of greenhouse gas emissions in slash‐and‐burn agriculture and an alternative chop‐and‐mulch system in the Amazon Basin. The soil consumed atmospheric methane (CH₄) under slash‐and‐burn treatment and became a net emitter of CH₄ to the atmosphere under the mulch treatment. Mulching also caused about a 50% increase in soil emissions of nitric oxide and nitrous oxide and required greater use of fertilizer and fuel for farm machinery. Despite these significantly higher emissions of greenhouse gases during the cropping phase under the alternative chop‐and‐mulch system, calculated pyrogenic emissions in the slash‐and‐burn system were much larger, especially for CH₄. The global warming potential CO₂‐equivalent emissions calculated for the entire crop cycles were at least five times lower in chop‐and‐mulch compared with slash‐and‐burn. The crop yields were similar for the two systems. While economic and logistical considerations remain to be worked out for alternatives to slash‐and‐burn, these results demonstrate a potential ‘win‐win’ strategy for maintaining soil fertility and reducing net greenhouse gas emissions, thus simultaneously contributing to sustainability at both spatial scales.     

Ecosystem Perspective of Groundwater Arsenic Contamination in India and Relevance in Policy

Millions of people living in India are at risk by consuming arsenic contaminated groundwater. Several technological solutions have failed to address the problem due to segmental approaches, resulting in human suffering for a period of three decades. The article is based on an analysis of arsenic-related health problems from an ecosystem perspective through a primary survey conducted in five arsenic affected villages in the state of West Bengal and review of existing research and policy documents. Although modern agricultural practices and drinking water policies have resulted in arsenic contamination of groundwater, current mitigation policy is essentially confined to biomedical approaches, which includes potable water supply and medical care. The study also shows that existing disparity, difficulty in coping, inaccessibility to health service and potable water supply and lack of participation in decision making have resulted in more suffering among the poor. On the other hand, spreading of arsenic contamination in the ecosystem remains unabated. Foods grown in the affected area have emerged as additional sources of exposure to humans. There is lack of evidence of any perceivable benefits due to sustainable agriculture, as present nature of agriculture practice is essentially driven by crop yield only. Further research is needed to generate credible evidence of alternative agriculture paradigms that may eventually reduce body burden of arsenic through reduced dependency on groundwater.     

Risky Business: Temporal and Spatial Variation in Preindustrial Dryland Agriculture

Traditional dryland agriculture in the Pacific island was often labor-intensive and risky, yet settlement and farming in dry areas played an important role in the development of Polynesian societies. We investigate how temporal and spatial climatic fluctuations shape variation in agricultural production across dryland landscapes. We use a model that couples plant growth, climate, and soil organic matter dynamics, together with data from Kohala, Hawai'i, to understand how temperature, rainfall, nitrogen availability, and cropping activity interact to determine yield dynamics through time and space. Due to these interactions, the statistical characterization of rainfall alone is a poor characterization of agricultural yield. Using a simple linear model of human population dynamics, we show that the observed yield variation can affect long-term population growth substantially. Our approach to analyzing spatial and temporal fluctuations in food supply, and to interpreting the population consequences of these fluctuations, provides a quantitative evaluation of agricultural risk and human carrying capacity in dry regions.     

Social and cultural efficacies of medicines: Complications for antiretroviral therapy

Ethnoecological knowledge may be understood as spontaneous knowledge, culturally referenced of any society's members, learned and transmitted through social interactions and that are targeted at resolution of daily routine situations. The traditional knowledge in small scale economy societies as well as the non-academic knowledge in urban-industrial societies might be included in this concept. An ethnoecological approach study was performed here on people living at the communities of Alvinho, Almeida, Chã do Marinho, Floriano, and Chã de Oiti, all located in the municipality of Lagoa Seca, Paraíba state, Northeast Brazil. The general objective pursued here was to study the knowledge that peasant farmers have on management of plant species utilized for pest control. For this, the methodological instruments employed here to investigate the ethnoecological knowledge were: direct observation, structured and semi-structured interviews, and tours conducted by local peasant farmers. We analyzed the data obtained under an emic/etic view and also by comparing the local knowledge with those obtained from the literature. The results showed that people in those communities utilize management alternatives for controlling pests, which are mainly: (i) fallowing; (ii) crop rotation; (iii) destruction of crop remains and fruits attacked by pests; (iv) alternations of crops with repellent plants; and/or (v) mixed cropping; (vi) insect's larvae covered with soil; (vii) crops irrigated abundantly; and (viii) soil preparation. The recovery and comprehension we get about this knowledge as well as the farmers' savoir faire, are extremely important to the revival of ancient agricultural practices, which have been forgotten due to advances in modern agriculture. The data obtained here showed that a huge body of knowledge the farmers have on many forms or strategies of management are generally compatible with scientific knowledge.     

Farm Animal Production: Changing Agriculture in a Changing Culture

Western attitudes toward animals have undergone a gradual evolution during recent centuries, driven by the scientific recognition that humans and many other species share a common anatomical template, a common phylogenetic ancestry, and certain similarities in their social and emotional lives. This evolving view has been accompanied by a heightened popular respect for animals, which has caused increasing opposition to the relatively utilitarian treatment of animals in modern farming. Western culture also tends to venerate the pastoralist image of humans caring diligently for animals, and North Americans tend to venerate the agrarian life-style of farm families living in harmony with domestic animals and the land. These positive images, which have traditionally lent legitimacy to animal agriculture, have been diminished by changes in production methods during recent decades. The resulting debate between critics and defenders of modern animal production has led to widespread confusion and concern about how animal agriculture affects animal welfare, human health, the environment, and world food security. To resolve this situation will require research to create an accurate understanding of the diverse effects of modern animal agriculture, together with measures to harmonize agricultural practices with changing public values.     

Intensive agriculture and land use at Roman Gordion,central Turkey

Few archaeobotanical studies of Roman agricultural practices and their environmental impact in Anatolia (modern Turkey) have been published. New data from Roman levels at Gordion, a multi-period urban centre in central Anatolia, indicate that free-threshing wheat, most likely Triticum aestivum (bread wheat), was the focus of agricultural practice, in contrast to earlier periods when a more diverse agricultural system included greater amounts of barley and pulses. Evidence for increased levels of irrigation and wood fuel use relative to dung, along with regional overgrazing, provide further evidence for significant change in land-use practices during the Roman period. The emphasis on T. aestivum cultivation coupled with extensive grazing had significant environmental implications, leading to severe overgrazing and soil erosion on a regional scale. Historical sources and limited data from other Roman period sites suggest that similar patterns of agriculture may have been practiced across central Anatolia during the Roman period. We propose that this may have been due to externally imposed demands for taxation or military tribute in the form of wheat, and conclude that these demands led to the adoption of an unsustainable agricultural system at Gordion.     

Quantifying effects of different agricultural land uses on soil microbial biomass and activity in Brazilian biomes: inferences to improve soil quality

Maintenance of soil quality is a key component of agriculture sustainability and a main goal of most farmers, environmentalists and government policymakers. However, as there are no parameters or methods to evaluate soil quality directly, some attributes of relevant soil functions are taken as indicators; lately, an increase in the use of soil microbial parameters has occurred, and their viability as indicators of proper land use has been highlighted. In this study we performed a meta-analysis of the response ratios of several microbial and chemical parameters to soil disturbance by different land uses in the Brazilian biomes. The studies included native forests, pastures and perennial and annual cropping systems. The introduction of agricultural practices in all biomes covered previously with natural vegetation profoundly affected microbial biomass-C (MB-C)―with an overall decrease of 31%. Annual crops most severely reduced microbial biomass and soil organic C, with an average decrease of 53% in the MB-C. In addition, the MB-C/TSOC (total soil organic carbon) ratio was significantly decreased with the transformation of forests to perennial plantation (25%), pastures (26%), and annual cropping (20%). However, each biome reacted differently to soil disturbance, i.e., decreases in MB-C followed the order of Cerrado>Amazon>Caatinga>Atlantic Forest. In addition, the Cerrado appeared to have the most fragile soil ecosystem because of lower MB-C/TSOC and higher qCO₂. Unfortunately, the Cerrado and the Amazon, demonstrated by our study as the most fragile biomes, have been subjected to the highest agronomic pressure. The results reported here may help to infer the best land-use strategies to improve soil quality and achieve agriculture sustainability. The approach can also be very useful to monitor soil quality in other tropical and subtropical biomes.