水稻品种资源抗稻褐飞虱不同生物型和稻瘿蚊核心样品的综合评价

应用灰色关联度分析法对水稻品种资源抗稻褐飞虱不同生物型和稻瘿蚊中国Ⅳ型的核心样品进行综合评价。研究结果表明,在抗稻褐飞虱生物型Ⅱ、中抗稻褐飞虱生物型Ⅱ、抗稻褐飞虱盂加拉型、抗稻瘿蚊中国Ⅳ型的核心样品中,分别以IR29692—99—3—2—1、IR36、RP1579—1862—72—31—52、DUO KANG No．1与标准品种(粤香占)的关联度最大,在抗虫育种亲本选择时,可以作为首选抗源。     

广西稻瘿蚊生物型测定及抗源评价利用

采用国际稻瘿蚊抗性鉴定方法和6个鉴别品种Leuang 152（含Gm2）、OB677（含gm4）、IET2911（含Gm2）、W1263（含Gm1)、Ptb21和Muey Nawng 62M，对广西稻区代表点的稻瘿蚊田间种群生物型进行测定，结果表明广西有2个不同的生物型，即中国Ⅱ型和中国Ⅳ型。其中，柳江、融安、临桂、宜州、环江、天峨、都安、平果、隆林、容县、富川等11个代表点为中国Ⅱ型；南宁、合浦、浦北、大新、象州、忻城、苍梧、德保、百色等9个代表点为中国Ⅳ型。并筛选出一批抗中国Ⅱ型和中国Ⅳ型的水稻品种和材料，可供推广和选育抗虫水稻品种利用。广东农科院选育的抗蚊品种抗蚊青占在广西多点试种，表现为抗性强、丰产性好、适应性广，在稻瘿蚊严重发生地区推广种植，能显著地控制稻瘿蚊的为害，获得良好的经济效益和生态效益。     

Role of informal seed system in promoting landrace diversity and their on-farm conservation: a case study of rice in Indian Himalayas

Role of informal seed system in landrace diversification, in situ conservation on-farm and sustainability in production were investigated as a case study for rice diversity in Indian Himalayas. The diachronic pattern of landrace occurrence revealed substantial increase, both in landrace number and frequency, in time. The local level seed supply in Uttarakhand Himalaya revealed that about 96% seed supply originated from informal system and a mere 4% seed supply is met from formal seed supply networks. In higher elevation ranges, beyond 1200 masl, largely landrace cultivation is practiced and a greater landrace diversification in traditional production was observed. Substantial variations due to environmental adaptations in niche habitats help provide important donor germplasm for crop improvement to users. Further, the population genetic structure also indicated enough diversity being maintained on-farm. Developing pathways for strengthening local level seed system for landrace diversification linked to sustainability in food production and conserving agro-biodiversity has been emphasized.     

农业文化遗产中传统知识的概念与保护——以普洱古茶园与茶文化系统为例

传统知识不仅是地方社区内居民与自然环境长期适应中所积累的经验智慧,也是农业文化遗产的结构性存在,对遗产系统具有支持作用。因此,传统知识的传承保护是农业文化遗产保护工作的重要内容。本文通过归纳分析当前相关国际公约及研究中对于传统知识的定义及内涵,结合农业文化遗产特征将农业文化遗产中的传统知识定义为"农业文化遗产内,居民在长期生产生活过程中,围绕农业所积累的与生计维持、资源管理、生物多样性保护、精神信仰维持等多个方面密切相关的知识、创新及实践",可分为生计维持类传统知识、生物多样性保护类传统知识、传统技艺类传统知识、文化类传统知识及自然资源管理类传统知识5类。文章通过梳理农业文化遗产与传统知识的相关关系,以普洱古茶园与茶文化系统为例,结合遗产地实地情况,针对当前传统知识保护中所存在的实物载体遭到破坏、传承存在危机、受到旅游业冲击及保护措施相对低效等问题,提出加强保护意识、将传统知识保护纳入遗产系统保护规划、开展传统知识的调查编目、加强传承记录工作及充分利用现有制度对传统知识进行保护等措施,以期为农业文化遗产中传统知识的保护提供建议参考。     

Integration of biophysical and economic data using an expert system: results from a case study in northern Australia

Abstract. Biophysical and economic data from numerous sources are integrated using the ALES expert system. A systematic approach to data collection and evaluation procedure is presented. The collection of management data is emphasized if management and crop yield data are to be adequately correlated. Different land utilization types are evaluated for numerous land mapping units. The results show that direct comparison of land mapping units is possible both within and between different land utilization types. Use of the model enabled objective relationships to be developed between biophysical criteria, crop productivity and management, allowing economic measures of performance to be routinely determined for large databases. The study shows that land mapping units with the most favourable physical suitability class may not necessarily have the largest net return and that the best lands are determined not only by their ability to produce high yields but also their ability to achieve them at the least cost.     

Assessment of SoilGrids data for soil erosion estimation at watershed scale: A case study in northern Thailand

Soil erosion has been identified as one of the most destructive forms of land degradation, posing a threat to the sustainability of global economic, social and environmental systems. This underscores the need for sustainable land management that takes erosion control and prevention into consideration. This requires the use of state-of-the-art erosion prediction models. The models often require extensive input of detailed spatial and temporal data, some of which are not readily available in many developing countries, particularly detailed soil data. The soil dataset Global Gridded Soil Information (SoilGrids) could potentially fill the data gap. Nevertheless, its value and accuracy for soil erosion modelling in the humid tropics is still unknown, necessitating the need to assess its value vis-à-vis field-based data. The major objective of this study was to conduct a comparative assessment of the value of SoilGrids and field-based soil data for estimating soil loss. Soil samples were collected from five physiographic positions (summit, shoulder, back slope, foot slope, and toe slope) using the soil catena approach. Samples were collected using a 5-cm steel sample ring (undisturbed) and a spade (disturbed). Data of the landform, predominant vegetation types, canopy cover, average plant height, land use, soil depth, shear strength, and soil color were recorded for each site. The soil samples were subjected to laboratory analysis for saturated hydraulic conductivity, bulk density, particle size distribution, and organic matter content. Pedotransfer functions were applied on the SoilGrids and field-based data to generate soil hydrological properties. The resultant field-based data were compared with the SoilGrids data for corresponding points/areas to determine the potential similarities of the two datasets. Both datasets were then used as inputs for soil erosion assessment using the revised Morgan-Morgan-Finney model. The results from both datasets were again compared to determine the degree of similarity. The results showed that with respect to point-based comparison, both datasets were significantly different. At the hillslope delineation level, the field-based data still consistently had a greater degree of variability, but the hillslope averages were not significantly different for both datasets. Similar results were recorded with the soil loss parameters generated from both datasets; point-based comparison showed that both datasets were significantly different, whereas the reverse was true for parcel/area-based comparison. SoilGrids data are certainly useful, especially where soil data are lacking; the utility of this dataset is, however, dependent on the scale of operation or the extent of detail required. When detailed, site-specific data are required, SoilGrids may not be a good alternative to soil survey data in the humid tropics. On the other hand, if the average soil properties of a region, area, or land parcel are required for the implementation of a particular project, plan, or program, SoilGrids data can be a very valuable alternative to soil survey data.     

基于生态足迹的传统农业地区可持续发展评价—— 以贵州省从江县为例

由于自然条件的限制和历史等原因,贵州省从江县至今还保持着比较完好的稻田养鱼传统农业生产方式,并形成了独具特色的农业文化遗产.为全面认识这一农业文化遗产的价值,并为其合理保护提供理论依据和科学基础,本文分析了从江县2007年的生态足迹及其构成,总结了传统农业地区的资源消耗特点以及传统农业在区域生态平衡、资源消耗、可持续发展等方面所起的重要作用.研究表明,从江县居民对食物和住房的需求很高,分别占总需求的45.9%和33.3%,导致从江县耕地和林地生态足迹构成生态足迹的主体部分;相比之下,从江县的化石能源地生态足迹仅占总生态足迹的3.0%,而由林地提供的主要燃料柴薪才是能源生态足迹的主体部分,这与资源消耗较高的工业化地区明显不同.资源的低消耗使得从江县可以维持在生态平衡状态,人均生态盈余为0.058 1 hm2.可见,传统农业通过影响人们的农业生产方式和生活消费模式,不仅对区域的生态平衡维持和文化传承起着重要作用,且对区域社会经济可持续发展有重要意义.     

The extinction of genetic resources of Asian wild rice, Oryza rufipogon Griff.: A case study in Thailand

Natural populations of wild rice, Oryza rufipogon Griff., are now threatened with the disturbance of their natural habitats by various human activities. To obtain basic information on genetic erosion or loss of genetic diversity in wild rice, we investigated how environmental changes of habitat affected the genetic structure of its natural population at a study site in the central plain of Thailand. During 10 years from 1985 to 1994, the wild-rice population at this site was seriously destroyed and fragmented. Using two sets of seed sample collected in 1985 and 1994 from the same population, allozyme variability at 17 loci of 11 enzymes were examined. Isozyme genotypes of mother plants of seed samples were estimated by the segregation in each progeny, and we calculated genetic parameters for the population. Gene diversity severely decreased in the 1994 sample compared with the 1985 sample. It is supposed that declining and fragmentation of the wild rice population, which happened during the 10 years, caused loss of genetic variability and forced the habitually outbreeding plants to inbreed, accelerating a reduction in gene variability. Pgi1-1 allele which was common in Indica rice cultivars of this region was found in the wild rice plants growing at the side of rice fields. Probably, introgression has occurred between wild and cultivated rice plants, and consequently the intrinsic nature of wild rice was gradually blurred by cultivar genes. We must realize that the genetic erosion of wild rice is rapidly proceeding and that an action for their conservation in natural environment, so called in situ conservation, is urgently needed.     

Loss of pesticides from a litchi orchard to an adjacent stream in northern Thailand

In the hill country of northern Thailand use of agrochemicals is increasing steadily and contaminating streams and groundwater. We have measured pesticide leached from a litchi orchard to an adjacent stream and identified the flow components contributing to the pesticide transport after installing two discharge measurement stations with automatic water samplers in the stream. For 2 years, between June and September, we applied methomyl, and in 1 year additionally chlorothalonil, to the 2‐ha orchard and monitored water fluxes and pesticide concentrations in the stream water. Pesticide loads ranged from 1.6 to 3% of mass applied for chlorothalonil, a strongly sorbing fungicide, and 6.4–11.4% for the more weakly sorbing insecticide methomyl. Directly after application, pesticide transport was dominated by a fast flow component, reaching the flume before the discharge peak. Later, pesticides were transported mainly by preferential interflow, which peaked about 30 hours after a rain event. The groundwater pathway was not found to contribute to pesticide loss. Antecedent rain conditions proved to be important for the pesticide transport behaviour. While at the beginning of the rainy season large falls of rain did not lead to pesticide contamination, at the end of the season pesticide transport was induced by as little as 0.1 mm of rain. The occurrence of preferential interflow means that the hilly regions in northern Thailand are highly susceptible to contamination by pesticides used by farmers.     

试论农业和农村可持续发展与农业环境保护--以湖南省娄底地区为例

论述了可持续农业、农业发展（SARD）的内涵、意义和当地农业环境的现状与问题以及试点研究工作取得的初步成效，为探索人口、经济、社会和资源、环境相互协调的可持续发展道路提供了经验与依据。     

Improving the detection of agricultural drought: a case study of illinois corn production

Too little attention has been given to the manner in which drought detection and monitoring indices are applied in agricultural settings. In this research, results of an Illinois corn-weather sensitivity analysis were used to select values of the moisture anomaly index (MAI or z) and related Palmer drought severity index (PDSI or X) to match periods of maximum moisture (i.e., drought) sensitivity in the corn growing season. These partial growing season values were compared with their equivalent growing season average for 12 Illinois sites to evaluate which were most effective in explaining interannual variations in detrended corn yields. Results indicate that the Palmer indices calculated for only the peak corn moisture sensitivity periods, outperformed the mean growing season Palmer indices in accounting for 1960–1983 interannual variations in corn yields by a factor of more than two.     

The multiple land degradation effects caused by land-use intensification in tropical steeplands: A catchment study from northern Thailand

The strongly incised mountain landscape of northern Thailand has changed dramatically during the last few decades due to increased population pressure, agricultural commercialization, limitation to use old fallows and reforestation of upper catchments. The traditional shifting cultivation with fallow periods of 7 years and longer was gradually replaced by 1 to 4 year fallow periods. As a result, in high population areas the landscape became dominated by fields planted to rainfed upland crops, wetland rice terraces, fallow vegetation, and patches of secondary forest. This new land-use system seems to have triggered new land degradation processes that are easy to observe when travelling through this landscape.     

Quantified evaluation of agricultural soil capability at the local scale: a GIS-assisted case study from Ontario, Canada

Abstract. Rural agricultural areas in southern Ontario, Canada, with potential for aggregate extraction have become a focus of conflict over proposed land use change. Geophysical and soil physical field measurements were used to map soil variation for quantitative land evaluation at the farm level. Apparent electrical conductivity of terrain was shown to be strongly correlated with depth to the groundwater table on two separate test sites. A digital terrain model was used to create thematic maps of the predicted pre-growing season soil water regime by contouring irregularly spaced electromagnetic survey and soil inspection points. Overlay analysis with a geographical information system (GIS) was used to produce an agricultural soil capability map for crop production. Adoption of a larger map scale provided significant refinement in detail over the published Canada Land Inventory soil capability ratings for agriculture, but both showed that Class 2 soils are dominant. The approach can improve the reproducibility of land capability assessments.     

Arable weeds as indicators of agricultural intensity - A case study from Finland

The study aimed at developing an agro-biodiversity indicator based on trophic interactions between 25 common arable weeds and individual groups of farmland birds, pollinators (wild bees), phytophagous insects and insect pests. Each weed species was weighted based on the number of reported linkages with each animal group. Four biodiversity indices based on these weights were constructed and applied to exploring the ecological consequences of long-term changes in weed populations in Finland. Data were used from weed surveys of Finnish spring cereal fields conducted in the 1960s, 1980s and 1990s. The relative importance of weed species varied according to animal groups. Annual weed species able to produce numerous seeds were important for the farmland birds and some perennial weed species were important for the pollinators. The highest number of linkages was established between weed species and phytophagous insects. The number of harmful pest species associated with broad-leaved weeds was low for all species. The general pattern of changes in values of indices over recent decades was similar: there was a marked decline in the values between the 1960s and the 1980s, and a slight increase between the 1980s and the 1990s. These changes were regarded as being a consequence of changes in the intensity of agricultural practices. The slowest recovery of the values was for pollinators. The results suggest that the ecological consequences of changes in the intensity of agriculture can be explored with the aid of a biodiversity indicator based on species interactions. Owing to the differences in the importance of weed species for different animal groups, maintaining weed species richness is necessary to ensure ecosystem services are provided for the higher trophic levels in farmland.     

Conntribution of northern forests to the global C cycle: Canada as a case study

Boreal forests are exposed to periodic stand-replacing disturbances such as wildfire. Unchanging disturbance regimes in unmanaged forests result in an age-class structure in which the proportion of forest area is largest in the youngest age class and decreases exponentially in older age classes. The current (ca. 1970) age-class structure of Canadian forests contains a much smaller proportion of the forest area in each of the two youngest 20-yr age classes than in each of the next three age classes (i.e., the 40 to 99-yr age-classes). We hypothesize that more intensive disturbance regimes in the late 19^th and early 20^th centuries, compared to disturbances in the period 1920 to 1969, have resulted in this unusual age-class structure. The reduction in disturbance regimes has resulted in an increase of the average forest age and therefore an increase in total forest biomass carbon (C). This C sink is obtained without altering age-dependent growth or decomposition rates. If the average forest age of Canadian forests continues to increase, additional C sequestration of forests, (i.e., the C sink strength) will diminish. This result of a C sink in Canadian forest ecosystems is supported by more detailed C budget calculations for the year 1986.     

Amphibian pond loss as a function of landscape change – A case study over three decades in an agricultural area of northern France

Agricultural reform and infrastructural development are among the major drivers of biodiversity loss and landscape homogenization worldwide. Ponds and other small stagnant water bodies are crucial for maintaining regional biodiversity, yet they are vulnerable to human induced landscape change. We investigated for 199 ponds in the ‘département’ Pas-de-Calais in north-western France if pond persistence (n = 86, 43%) or disappearance (n = 113, 57%) was related to wider changes in the landscape, over the period 1975–2006. Landscape data were obtained from aerial photographs (1963), two ASTER satellite images (2001 and 2003) and observations on the ground (1975 and 2006) and land use around the ponds was described over concentric circles with five different radii in the 100–1000 m range. Overall, pond disappearance was associated with a decrease in grassland and an increase in arable fields around the ponds. We found that the small, man-made cattle ponds, with either natural substrate or concrete drinking troughs, were more often affected than the larger, semi-natural ponds. Since the cattle ponds are regularly used for amphibian reproduction, their massive abandonment therewith weakens the population network and puts the local occurrence of some of the rarer species at risk. Spatial extrapolation of models on pond persistence allowed the identification of areas most at risk of further pond loss. We suggest that local amphibian conservation efforts will be the most effective if the focus is on the marshes and dune areas and on pond preservation in the remaining grasslands.     

利用遥感和地理信息系统技术通过分析土壤性质预测洪水灾害: 以泰国Chiang Mai省Mae Rim分水岭为例

Physiography and soil in Mae Rim watershed,Chiang Mai Province,Thailand were investigated by using aerial photographs and satellite image in conjunction with field work,and soil infiltration rate and soil shear resistance were measured in field. Many factors affecting runoff were analyzed usig the Integrated Land and Water Informaiton System(ILWIS).As a result,a model determining flood hazar was set up.Three mps including runoff curve number map,runoff coefficent map,and flood inumdation map were created,In addition,the time of concentration was predicted.     

How to save a landrace from extinction: the example of a winter squash landrace (Cucurbita maxima Duchesne) in Northern Italy (Lungavilla-Pavia)

Genetic Resources and Crop Evolution - The present work shows the results of a seven-year project aimed at rescuing the winter squash (Cucurbita maxima Duchesne) landrace ‘Berrettina di...     

Degradation and restoration of sandy soils under different agricultural land uses in northeast Thailand: a review

Conversion of natural forest to agricultural land use has significantly lowered the soil organic matter (SOM) content in sandy soils of northeast Thailand. This paper reviews the findings of comparative studies on contents of SOM pools (labile, i.e. microbial biomass and particulate organic matter—POM and stable, i.e. humic substance) and related soil aggregate formation, in natural forest plots and cultivated fields (monocrops of cassava, sugarcane and rice) in sites representative of northeast Thailand from the viewpoints of terrain (i.e. undulating), soils (sandy) and land use and discusses the restoration of SOM and fertility (nitrogen) in these degraded soils. Monocultural agriculture brings about the degradation of all SOM pools and associated soil aggregation as compared to the forest system because of decreased organic inputs and more frequent soil disturbance. The build‐up of SOM was achieved through the continuous recycling of organic residues produced within the system. Low‐quality residues contributed the largest SOM build‐up in whole and fractionated SOM pools, including POM and humic substance. However, to restore N fertility, high quality residues, (i.e. with low C/N ratios, lignin and polyphenols) were also needed. Timing of N release to meet crop demand was achieved by employing a mixture of high and low quality residues. Selection of appropriate residues for N sources was affected by environmental factors, notably soil moisture regimes, which differed in upland field and lowland paddy subsystems. Copyright © 2007 John Wiley & Sons, Ltd.     

Soil losses due to cassava and sweet potato harvesting: A case study from low input traditional agriculture

Soil loss due to crop harvesting (SLCH) has been established as an important soil erosion process that has significantly contributed to soil degradation in highly mechanised agriculture. This has stimulated the need to investigate the importance of this process of erosion under low input agriculture where, until now, only water and tillage erosion are known as important phenomena causing soil degradation. This study was conducted in Eastern Uganda with the following objectives: (1) to assess the amount of soil lost due to the harvesting of cassava roots and sweet potato tubers under low input agriculture, (2) to look into the factors that influence variations in these soil losses, and (3) to estimate the amount of plant nutrients lost due to SLCH for cassava and sweet potato. Soil sticking to roots and tubers was washed and the soil suspension oven dried to estimate the amount of soil lost after harvesting. Mean annual soil loss for cassava was 3.4 tonnes ha⁻¹ and for sweet potato was 0.2 tonnes ha⁻¹. Ammonium acetate lactate extractable soil nutrient losses for cassava were N = 1.71 kg ha⁻¹ harvest⁻¹, P = 0.16 kg ha⁻¹ harvest⁻¹, K = 1.08 kg ha⁻¹ harvest⁻¹ and for sweet potato were N = 0.14, P = 0.01 kg ha⁻¹ harvest⁻¹, K = 0.15 kg ha⁻¹ harvest⁻¹. Difference in soil loss due to crop harvesting for cassava and sweet potato could be due to: (1) smaller yields of sweet potato leading to smaller soil losses on an area basis, (2) smoother skin and less kinked morphology of sweet potato that allowed less soil to adhere, and (3) the fact that sweet potato is planted in mounds which dry out faster compared to the soil under cassava. Soil moisture content at harvesting time and crop age were significant factors that explained the variations in the soil lost at cassava harvesting. Soil loss under cassava justifies the need to conduct further investigations on this process of soil erosion under low input agriculture.