松嫩平原农牧交错区优化生态-生产范式——以长岭县为例

松嫩平原农牧交错区位于松嫩平原的西部，中国北方农牧交错带的最东端;具有独特的地质环境特点，环境问题突出，是我国生态脆弱地区之一，及世界三大苏打盐碱土集中分布区之一。近年来，由于人为的不合理利用和开垦、以及粗放的生产模式，使该地区生态系统严重受损，土地沙漠化、水土流失、盐碱化、土地生产力下降等生态环境问题日益突出。因此，建立一个适合该地区生态环境条件、社会经济发展状况的优化生态-生产范式是必要而紧迫的。 本论文以松嫩平原农牧交错区为研究对象，以其典型地段为切入点，通过大量数据的收集、文献资料的查阅、野外考察与测定、室内分析处理等，得出了以下主要结论： 一、生态-地理环境背景分析 松嫩平原农牧交错区是多种生态-地理环境危害并存的区域，其中包括盐碱化、沙漠化、气候灾害、水资源短缺等等。当前，沙化土地和盐碱化土地的面积已占该地区土地总面积的34.27 %，并且呈逐年递增的趋势。松嫩平原农牧交错区气候灾害频发，主要是旱灾、水灾、风灾。此外，水资源短缺以及水质问题，同样影响着农业生产及社会经济发展。造成松嫩平原农牧交错区多种生态-地质环境危害并存的主要影响机制是：该地区自身的地质-地理环境特点、气候因素和人类活动的综合效应，并且人类活动日益成为主要驱动因子。 二、实例研究 松嫩平原农牧交错区优化生态-生产范式研究是以长岭县为例，通过对长岭县景观格局变化分析、土壤格局分布、农牧业生产特点、以及农业可持续性评价等，得出以下结论： 1、对研究区内土地利用格局分析表明：1980 ~ 2000年，在土地利用类型没有发生变化的基础上，表现为各土地利用类型面积上的增减;草地、林地大面积地向农田转移，农田面积明显增加;大规模地开垦农田，已经导致了景观的优势度增加，破碎度增加，多样性下降，这最终将使整个景观趋于更加不稳定。 2、长岭县土壤总体水平较差，障碍性土壤占长岭县总土地面积的55.38 %。从土地利用变化对不同地势条件下土壤理化性状影响分析，结果表明：（1）地势相对高的平台地，土壤肥力较高，且开垦对土壤理化性质的影响相对较小，更适合农业开发;（2）低地原生植被为草甸草原，其养分状况也比较好，但其地势较低，易发生水渍和盐碱化;（3）坡地是当地土壤养分最为贫瘠地区，也是风沙土较集中分布的区域，对其开垦会增大土壤的风蚀和水蚀，使土壤养分状况严重下降。 3、对研究区牧草资源分布格局、牧草资源承载力和利用现状等进行分析，结果表明：放牧系统提供的牧草资源已不能满足当地畜牧业对牧草资源的需求。草地提供的牧草资源仅能满足总牧草需求的16.6 %，放牧系统提供的牧草仅占总牧草需求的47.3 %;玉米秸秆转化为牧草资源的潜力巨大，经估算，占总牧草资源的78.3 %，其承载力为总牧草需求的2.4倍。当前，农牧交错区牧草资源的粗蛋白含量普遍偏低，不能完全满足动物生产的需要，制约了当地畜牧业发展。根据当地畜牧业现状、牧草资源潜力，我们提出：应在合理利用当地牧草资源的基础上，有计划地建立高产优质、富含粗蛋白的人工牧草基地，实现畜牧业可持续发展与生态保护的协调统一。 4、长岭县是以第一产业为主，即农业生产为主要经济来源。对农业生产结构的分析表明：农牧业生产占总农业产值的90 %以上，并以种植业为主，种植业一直占总农业产值60 %以上。受当地气候条件、土壤格局分布的限制，单一粮食生产、粗放的生产模式以及对天然草地资源的过分依赖，最终导致该地区农牧业发展缓慢，经济条件落后。 5、在上述分析的基础上，作者提出了长岭县优化生态-生产范式，即以高效农业生产、生活圈，水土保持和自然生态保育圈、牧草生产基地及生态功能保护圈的三圈等级系统。以此为依据，对土地利用格局进行调整，通过粮、草、经多元农业结构的建设，在合理利用与保护草地的基础上，使长岭县畜牧业走向产业化的发展模式。

热察绥地区过去300年土地利用覆被变化

The historical land use and land cover changes is one of the key issues in LUCC research. However, the achievement of China in this field doesn't match her position in the world yet. And the reliability of the quantitive records in Chinese historical literature, the basic data for historical land use research, has been doubted. This research focuses on Re-Cha-Sui, a typical area for the farming-pastoral region in the north of China, to make a detailed case study in this field. Based on a deep mining and calibration on the data from massive historical documents and land-use surveys, the author gives a detailed analysis on the administrative region evolution, historical population dynamics, reclamation policy, and the land statistic system. According to textual researches, parallel validation and physical geographical analysis, a unified land use series for recent 300 years, which founded on the results of modern land-use surveys, is constructed. And the thematic maps on the cultivation index for different counties in several temporal sections are plotted. Based on the endeavor above, the dynamic of forest and steppe is reconstructed as well. The temporal-spatial patterns of land use/land cover changes in the area is analyzed. And the influence of different driving forces are discussed. The main conclusions of the research are as followed: 1. The quantitive records in literatures on Re-Cha-Sui area are reflection of real amounts of croplands. It is practical to reconstruct a result comparable with the modern land-use surveys, based of a deep mining and considerate validation on historical documents. The unexceptional negative attitude towards the numerical records in historical documents is unnecessary. 2. In recent 300 years, 3 climax of reclamation appeared in Re-Cha-Sui area and altered the pure pastoral area into a farming-pastoral region. The interval were respectively the early time till mid time of the Qing dynasty, the end of the Qing dynasty till early time of the Republic of China(ROC), and the time after A.D. 1949. After the first expansion, the area of cropland in this region reached 2.0 million ha. Among them, Guisui area, which was most densely cultivated, had a cultivation index over 30%, which is similar with modern situation. The second expansion covered broader area, and the amount of cropland reached 3.5 million ha. The increase of farming area after 1949 is due to the recultivation of abandoned farmland. The current area of cropland in this region is 5.6 million ha. In the southern area where the land was reclaimed early, the amount on of the cropland has some fluctuation in 300 years. While in the new reclaimed area in the north, the area of cropland has kept the trend of increasing. 3. Due to the different natural conditions, most forests in Re-Cha-Sui area distribute in the mountain area of North Hebei province, and the upland of West Liaoning province, especially the former, which has a forest coverage near 70%. However, most of these forests were destroyed before the end of the Qing dynasty. In 1949, the natural forest near Chengde was nearly cleared up. They were partly renewed after 1949 due to plantation. 4. In the steppe zone such as northern Rehe, Suiyuan and Chahar, the area of steppe has a negative correlation with that of cropland. With the expansion of cropland, the percentage of steppe has shrunk from over 80% to 53%. In the mountain area of North Hebei province, steppe expanded with the shrinkage of forest, though cropland was expanding. The percentage once reached 60%, and then fell with the renew of forest. However, in the upland of West Liaoning province, the steppe shrink slowly from original 50% to current 26%, with the expansion of cropland. 5. The land use and land cover change in Re-Cha-Sui area in recent 300 years is driven by various factors, including human dimensions such as population, policy of the government, disorder of the society, cultural tradition, and natural factors such as climate change and natural disasters. Among them, pressure from surplus population is the basic driving force.

紫花苜蓿和短花针茅根系分布与土壤水分研究

以陕北农牧交错带人工草种紫花苜蓿(Medicago sativa L.)和天然草种短花针茅(Stipa breviflora Griseb.)为对象,采用根钻法调查两个草种的根系垂直分布以及刈割后苜蓿根系变化特征,并通过定位观测研究土壤水分动态变化。结果表明:紫花苜蓿和短花针茅根系密度随土壤深度增加而减少,而且均以直径小于等于1 mm的须根为主;0~50 cm土层紫花苜蓿和短花针茅根系量分别占0~100 cm剖面总量的67%和84%。紫花苜蓿和短花针茅根系分布与土壤水分消耗特征吻合。生长旺盛期苜蓿大量消耗0~140 cm土层土壤水分,5-9月平均有效土壤储水不足10 mm;生长季末深层(140~280 cm)土壤储水也逐渐降低,约为裸地储水量的50%。短花针茅0~280cm剖面土壤水分状况明显好于苜蓿地,比苜蓿地多储水100 mm左右;主要消耗浅层(0~50 cm)土壤水分,深层水分利用较少。

浑善达克沙地与河北沽源地区土地沙漠化研究

The Otindag sandy land and the Guyuan region of Hebei Province lie in the agro-pastoral zone, where sandy desertification is serious. So they are typical for us to study on. In this paper, detail investigation were made on the Remote Sensing, Hydrochemistry, Chronology, grain size analyzing of research region to monitor sandy desertification and environmental background. The main conclusions are presented as following: 1. According to the diverse natural condition, the research area is divided into three types as sandy land desertification, cultivated land desertification and desertification reflected by lake change. The monitoring result of the first type shows that the main performance way of the sandy desertification in Otindag sandy land is that (1) the expansion of both the shifting dune and the half fixed sandy dune, (2) the reduce of the fixed sandy dune. While the result of the second type shows (1) the desertification land in the Guyuan region has first increasing then reducing change for about 30 years. (2) The sand mainly concentrates west of the research area and small part of wind-drift sand distributes northeast the research area with the spot shape. (3) The meadow area increases obviously. As far as the third type, the Dalai Nur lake area occurs first expanding then reducing change and the wind-drift sand around the lake first reduces then increases. 2. The land cover of the different types change with the same law. It is worth notice that the lake area changes oppositely with that of the wind-drift sand. 3. For about 5,000 a B.P. -2800 a B.P., the well developed palaeosols emerged. After that, three layer palaeosols were founded in the profile of Otindag sandy land. The analyses of grain size show that the sand grains of the south were coarser than that of the north. The sand in the north and middle were well sorted, while the south poor sorted. 4. Both the natural and human impact on the process of sandy desertification. On this research result, different regions have different influences. So the measures to improve sandy desertification should be choosed respectively.

Of sheep and rain: large-scale population dynamics of the red kangaroo

1. We analysed time-series data from populations of red kangaroos (Macropus rufus, Desmarest) inhabiting four areas in the pastoral zone of South Australia. We formulated a set of a priori models to disentangle the relative effects of the covariates: rainfall, harvesting, intraspecific competition, and domestic herbivores, on kangaroo population-growth rate. 2. The statistical framework allowed for spatial variation in the growth-rate parameters, response to covariates, and environmental variability, as well as spatially correlated error terms due to shared environment. 3. The most parsimonious model included all covariates but no area-specific parameter values, suggesting that kangaroo densities respond in the same way to the covariates across the areas. 4. The temporal dynamics were spatially correlated, even after taking into account the potentially synchronizing effect of rainfall, harvesting and domestic herbivores. 5. Counter-intuitively, we found a positive rather than negative effect of domestic herbivore density on the population-growth rate of kangaroos. We hypothesize that this effect is caused by sheep and cattle acting as a surrogate for resource availability beyond rainfall. 6. Even though our system is well studied, we must conclude that approximating resources by surrogates such as rainfall is more difficult than previously thought. This is an important message for studies of consumer-resource systems and highlights the need to be explicit about population processes when analysing population patterns.

Soil carbon sequestration rates and associated economic costs for farming systems of south-eastern Australia

Soil organic carbon (C) sequestration rates based on the Intergovernmental Panel for Climate Change (IPCC) methodology were combined with local economic data to simulate the economic potential for C sequestration in response to conservation tillage in the six agro-ecological zones within the Southern Region of the Australian grains industry. The net C sequestration rate over 20 years for the Southern Region (which includes discounting for associated greenhouse gases) is estimated to be 3.6 or 6.3 Mg C/ha after converting to either minimum or no-tillage practices, respectively, with no-till practices estimated to return 75% more carbon on average than minimum tillage. The highest net gains in C per ha are realised when converting from conventional to no-tillage practices in the high-activity clay soils of the High Rainfall and Wimmera agro-ecological zones. On the basis of total area available for change, the Slopes agro-ecological zone offers the highest net returns, potentially sequestering an additional 7.1 Mt C under no-tillage scenario over 20 years. The economic analysis was summarised as C supply curves for each of the 6 zones expressing the total additional C accumulated over 20 years for a price per t C sequestered ranging from zero to AU$200. For a price of $50/Mg C, a total of 427 000 Mg C would be sequestered over 20 years across the Southern Region, <5% of the simulated C sequestration potential of 9.1 Mt for the region. The Wimmera and Mid-North offer the largest gains in C under minimum tillage over 20 years of all zones for all C prices. For the no-tillage scenario, for a price of $50/Mg C, 1.74 Mt C would be sequestered over 20 years across the Southern Region, <10% of the simulated C sequestration potential of 18.6 Mt for the region over 20 years. The Slopes agro-ecological zone offers the best return in C over 20 years under no-tillage for all C prices. The Mallee offers the least return for both minimum and no-tillage scenarios. At a price of $200/Mg C, the transition from conventional tillage to minimum or no-tillage practices will only realise 19% and 33%, respectively, of the total biogeochemical sequestration potential of crop and pasture systems of the Southern Region over a 20-year period.

Australian eco-pastoral poetry

Les Murray and Judith Wright are two Australian poets who are widely read as landscape poets. While this framing offers valuable insights into their work it often fails to bring the importance into a contemporary context or to recognise the long tradition Australia has had with , to use Leo Marx’ term, “the complex pastoral”. As Ruth Blair reminds us in her chapter “Hugging the Shore: The Green Mountains of South-East Queensland” in The Littoral Zone: Australian Contexts and their Writers it is accepted that North America has a tradition of the complex pastoral mode but it should be remembered that Australia also has a long history of this form. Both Judith Wright’s and Les Murray’s poetry encourages active campaigning for the environment .These Australian poets are eco-pastoral poets whose poetry encourages active reading rather than passive reflections. Their poetry speaks to the strong connection between the lived everyday landscape and the imagination of past, present and future. Their work is imbued with a strong sense of ecocritical awareness while at the same time drawing on pastoral conventions. These two Australian poets do not offer idealistic pastoral notions but rather reveal the complexities of lived human/nonhuman relationships. This paper will discuss these complexities and how poetry can be experienced as literature in action—ways for readers to connect with and negotiate with the land they inhabit. The research for this paper was, in part, drawn from the responses that local community library groups offered after reading the works of these poets. What became evident from this research was the way the poetry made the readers think not only of landscape as a place of refuge from the urban technological world but also as a contemporary place with connection to agency that motivates readers into active change.

Weed management in wide-row cropping systems: a review of current practices and risks for Australian farming systems.

Growing agricultural crops in wide row spacings has been widely adopted to conserve water, to control pests and diseases, and to minimise problems associated with sowing into stubble. The development of herbicide resistance combined with the advent of precision agriculture has resulted in a further reason for wide row spacings to be adopted: weed control. Increased row spacing enables two different methods of weed control to be implemented with non-selective chemical and physical control methods utilised in the wide inter-row zone, with or without selective chemicals used on the on-row only. However, continual application of herbicides and tillage on the inter-row zone brings risks of herbicide resistance, species shifts and/or changes in species dominance, crop damage, increased costs, yield losses, and more expensive weed management technology.

Strategic tillage in no-till farming systems in Australia’s northern grains-growing regions: II. Implications for agronomy, soil and environment

In semi-arid sub-tropical areas, a number of studies concerning no-till (NT) farming systems have demonstrated advantages in economic, environmental and soil quality aspects over conventional tillage (CT). However, adoption of continuous NT has contributed to the build-up of herbicide resistant weed populations, increased incidence of soil- and stubble-borne diseases, and stratification of nutrients and organic carbon near the soil surface. Some farmers often resort to an occasional strategic tillage (ST) to manage these problems of NT systems. However, farmers who practice strict NT systems are concerned that even one-time tillage may undo positive soil condition benefits of NT farming systems. We reviewed the pros and cons of the use of occasional ST in NT farming systems. Impacts of occasional ST on agronomy, soil and environment are site-specific and depend on many interacting soil, climatic and management conditions. Most studies conducted in North America and Europe suggest that introducing occasional ST in continuous NT farming systems could improve productivity and profitability in the short term; however in the long-term, the impact is negligible or may be negative. The short term impacts immediately following occasional ST on soil and environment include reduced protective cover, soil loss by erosion, increased runoff, loss of C and water, and reduced microbial activity with little or no detrimental impact in the long-term. A potential negative effect immediately following ST would be reduced plant available water which may result in unreliability of crop sowing in variable seasons. The occurrence of rainfall between the ST and sowing or immediately after the sowing is necessary to replenish soil water lost from the seed zone. Timing of ST is likely to be critical and must be balanced with optimising soil water prior to seeding. The impact of occasional ST varies with the tillage implement used; for example, inversion tillage using mouldboard tillage results in greater impacts as compared to chisel or disc. Opportunities for future research on occasional ST with the most commonly used implements such as tine and/or disc in Australia’s northern grains-growing region are presented in the context of agronomy, soil and the environment.

Economic analysis of fish farming in Ogun State

This study examined the economic potential of fish farming in Abeokuta zone of Ogun State in the 2003 production season. Descriptive statistics cost returns and multiple regression analysis were used in analyzing the data. The farmers predominantly practiced monoculture. Inefficiency in the use of pond size, lime and labour with over-utilization of fingerlings stocked was revealed by the study. The average variable cost of N124.67 constituted 45% of the total while average fixed cost was N149.802.67 per average farm size. Fish farming was found to be a profitable venture in the study area with a net income of N761, 400.58 for an average pond size of 301.47sq.m. Based on these findings, it is suggested that for profit maximization, the fish farm will have to increase the level of their use of fingerlings and fertilizers and decrease the use of lime labour and pond size

Breeding of Indian major carps and common carp in semi-arid zone of Haryana under controlled environment

Vast barren lands are lying vacant in the semi-arid zone of India, which can effectively be utilised for fish farming. Experiments conducted in semi-arid conditions at Damdama indicated that it is possible to breed Indian major carps and common carp under controlled conditions of modern carps hatchery CIFE D-80 without depending on rain.

Seawater irrigation systems for intensive marine shrimp farming in Thailand

The aim of the seawater irrigation system (SIS) is to clean up shrimp pond effluent and provide high quality seawater for shrimp farming. The system has 3 components: water intake; treatment reservoir and discharge system. There are criteria for site selection because shrimp farmers are required to form associations so they can work closely together. The construction site must be on the coastal area outside a mangrove forest and located away from a production agricultural area. All construction sites must have undergone an environmental impact assessment, and should be located on the area listed in Thailand's Coastal Zone Management Plan. Five SIS projects, which cover a culture area of 6,500 ha with 1,300 farmers (families), were completed and operated. The Department of Fisheries has planned for another 28 projects, that will cover almost 44,000 ha of culture area.

Ecological limits of high-density milkfish farming

In the Philippines at present, milkfish farming in ponds includes a wide range of intensities, systems and practices. To make aquaculture possible, ecosystems are used as sources of energy and resources and as sinks for wastes. The growth of aquaculture is limited by the life-support functions of the ecosystem, and sustainability depends on matching the farming techniques with the processes and functions of the ecosystems, for example, by recycling some degraded resources. The fish farm has many interactions with the external environment. Serious environmental problems may be avoided if high-intensity farms are properly planned in the first place, at the farm level and at the level of the coastal zone where it can be integrated with other uses by other sectors. It is believed that the key to immediate success in the mass production of milkfish for local consumption and for export of value-added forms may be in semi-intensive farming at target yields of 3 tons per ha per year, double the current national average. Intensive milkfish farming will be limited by environmental, resource and market constraints. Integrated intensive farming systems are the appropriate long-term response to the triple needs of the next century: more food, more income, and more jobs for more people, all from less land, less resources, and less non-renewable energy.

Exploring alternatives for milk quality improvement and more efficient dairy production in a smallholder farming context – case study: Mantaro Valley (Peru)

Consumer demand is revolutionizing the way products are being produced, distributed and marketed. In relation to the dairy sector in developing countries, aspects of milk quality are receiving more attention from both society and the government. However, milk quality management needs to be better addressed in dairy production systems to guarantee the access of stakeholders, mainly small-holders, into dairy markets. The present study is focused on an analysis of the interaction of the upstream part of the dairy supply chain (farmers and dairies) in the Mantaro Valley (Peruvian central Andes), in order to understand possible constraints both stakeholders face implementing milk quality controls and practices; and evaluate “ex-ante” how different strategies suggested to improve milk quality could affect farmers and processors’ profits. The analysis is based on three complementary field studies conducted between 2012 and 2013. Our work has shown that the presence of a dual supply chain combining both formal and informal markets has a direct impact on dairy production at the technical and organizational levels, affecting small formal dairy processors’ possibilities to implement contracts, including agreements on milk quality standards. The analysis of milk quality management from farms to dairy plants highlighted the poor hygiene in the study area, even when average values of milk composition were usually high. Some husbandry practices evaluated at farm level demonstrated cost effectiveness and a big impact on hygienic quality; however, regular application of these practices was limited, since small-scale farmers do not receive a bonus for producing hygienic milk. On the basis of these two results, we co-designed with formal small-scale dairy processors a simulation tool to show prospective scenarios, in which they could select their best product portfolio but also design milk payment systems to reward farmers’ with high milk quality performances. This type of approach allowed dairy processors to realize the importance of including milk quality management in their collection and manufacturing processes, especially in a context of high competition for milk supply. We concluded that the improvement of milk quality in a smallholder farming context requires a more coordinated effort among stakeholders. Successful implementation of strategies will depend on the willingness of small-scale dairy processors to reward farmers producing high milk quality; but also on the support from the State to provide incentives to the stakeholders in the formal sector.