关于新疆1∶100万农业地貌区划问题的讨论

根据新疆同一地貌区域形态成因，水热及农业发展方向和改造利用条件的相似性或不同地貌区间的差异性原则，建立起构造、新构造运动、外力作用，地貌形态等农业区划樗，以及农业地貌各级区域标志。     

屯留县旱农实验区农林牧优化结构研究

调整农林牧结构是干旱、半干旱地区农业走出低谷、摆脱困境的战略措施。本文通过对实验区资源评价、农业生产的历史考察和现状辨识。明确了农业发展的优势和主要问题,运用线性规划模型确立了多目标兼顾的农林牧优化结构。     

草地农业应为宁夏南部山区农业生态系统中的主体

<正> 1.草地农业系统的特征草地农业系统是农业生态系统之一。它是在大农业的生产中,以草地为主体,结合农田和林地,把土地、植物和家畜联系起来,进行土地—植物—动物“三位一体”的农牧业产品的物质生产体系。草地农业的主要特点是:第一,突出了草的作用,特别是豆科牧草的作用。在草地农     

Landscape patterns and agriculture: modelling the long-term effects of human practices on Pinus sylvestris spatial dynamics (Causse Mejean, France)

This paper focuses on understanding human impact on landscape. Both ecological and human practices are analysed as interacting processes. An agent-based model integrating biological and historical knowledge is used to analyse the pattern of Scots Pine encroachment in a French Mediterranean upland. In the STIPA model, pine trees are autonomous agents and a cellular automaton simulates land-use. We test the effects of shifting cultivation on tree establishment at the landscape scale. This allows us to understand how agropastoral practices patterned this area from the 17th to 19th century: simulations show the importance of shifting cultivation in limiting woodland progression. Fallow duration linked to environmental heterogeneity is a significant factor for explaining pine dynamics and landscape patterning at the scale of the study region. We put this result in perspective with current rangeland management policies that often consider grazing as the most relevant tool for open landscape maintenance. Our results also show the importance of taking into account time-scale effects when linking landscape patterns to agricultural systems.     

Linking Land-use, Water Body Type and Water Quality in Southern New Zealand

Land-use and vegetation cover have been linked to the nutrient levels (nitrogen, phosphorus) of surface waters in several countries. However, the links generally relate to streams and rivers, or to specific types of standing water, for example shallow lakes in a geologically defined region. We measured physical variables and nutrient chemistry of 45 water bodies representative of the wide range of lentic wetland environments (swamps, riverine wetlands, estuaries, reservoirs, shallow lakes, deep lakes) in Otago, New Zealand, and related these to catchment variables and land-use in order to assess the potential influence of catchment modification on water quality of these diverse wetlands. Catchment boundaries and land cover were derived from maps using ArcView GIS software. Our predictions that concentrations of nutrients and other components of water quality would correlate positively with the nature and intensity of catchment modification were confirmed in multivariate analyses. Physical and chemical measures were positively related to the extent of modification in the catchment (percentage of the catchment in pasture, planted forest, scrub and urban areas), and negatively related to lack of catchment modification (more of the catchment in bare ground, tussock grassland and indigenous forest). The strong negative correlations between nutrient concentrations, suspended sediment, water colour and the percentage of tussock cover in the catchment imply that increased conversion of the␣native tussock grassland to pastoral farming in␣Otago will increase nutrient concentrations and␣reduce water quality of the diverse lentic ecosystems.     

北京市蔬菜标准化基地存在的问题与对策研究

为推进农业标准体系落地,加快蔬菜的产业化进程,分析了北京市蔬菜产业及蔬菜标准化基地现状,汇总出推广基地标准化过程中存在的各种问题,并提出了提升农产品质量安全、推进蔬菜品牌建设等对策建议。     

Using the VS‐Fast methodology for soil degradation assessment: a case study from Senegal

Soil degradation threatens sustainable food production and accelerates global warming. Poorer countries, whose agricultural sectors are highly dependent on their natural resource bases, are hit particularly hard by declining soil productivity. Calls for soil‐quality monitoring are therefore, justified and this could inform decision‐makers on the preparation of appropriate interventions. However, the provision of monitoring methodologies is not an easy task. Soil degradation affects several soil characteristics that at larger scales cannot be evaluated with models or remote‐sensing techniques. Therefore, this study focuses on investigating the use of field‐based soil assessment methodologies to differentiate degrees of soil degradation. Specifically, we test the Visual Soil Field Assessment Tool (VS‐Fast) for detecting and monitoring soil degradation using a cross‐section of 71 sites in Senegal, the soil quality of which were classed by local experts. We found low correlation between VS‐Fast classes and expert assessments. By using an ordered logit model to quantify class boundaries, we show that experts categorized areas as ‘degraded’ for a wider range and higher VS‐Fast scores than the corresponding VS‐Fast class. Yet, from general linear models and analysis of variance procedures we found that areas classed by experts as ‘degraded’ had statistically significant lower VS‐Fast scores compared to those that were judged as ‘normal’ and ‘good’, while differences of the VS‐Fast scores between the latter two were negligible. It is remarkable that the visual assessment, the cheaper component of the VS‐Fast score, performs better in differentiating degradation status than its measured counterpart. The results support the need to investigate the applicability of other VSA methodologies that only use field observations and tactile methods.     

清末呼兰地区移民与农业开发

呼兰是清政府在东北最早开禁的地区。1860～1903年，清朝先后开放了蒙古尔山、通肯等地区，关内移民开始大量涌入呼兰地区．土地开发规模迅速扩大，粮食产量大幅度提高，农产品加工业崛起，农产商品率迅速提高，促进了农业的近代化。     

贵州省农业产业结构研究

运用产业结构相似系数、产业结构变化系数和描述产业结构稳定性的熵来对贵州省农业产业结构现状进行分析与评价,其研究成果对确定贵州省农业产业结构调整方向和发展贵州省农业农村经济有一定的参考价值。     

金代农业科学发展探讨

从耕作技术、水利兴修和农田灌溉3方面介绍了金代农业科学的成就，为人们了解金代农业生产方式提供参考。