加入WTO后中国东北地区农业发展趋势

加入WTO后 ,必将对中国农业和农村经济发展产生深远的影响。由于中国地域广阔 ,各地区差异很大 ,因此 ,对不同地区产生的影响是不一样的。在概要阐述东北地区农业特点的基础上 ,分析了中国加入WTO后对东北地区农业的影响及未来东北地区农业发展的趋势     

车载土壤样品信息快速采集装置

为服务于我国精准农业的发展,解决现有车载土壤采样设备自动化程度低、安全可靠系数不高等问题,研制了一种基于MSP430单片机的车载土壤样品信息采集装置,完成对土壤采样车运行状态监控以及土壤样品信息快速采集并即时发送土壤样品信息至土壤研究所,实验结果证明装置运行良好,满足预期设计要求。     

Nutrient input-output budget of shifting agriculture in Eastern Amazonia

A case study on the nutrient input-output budget of slash and burn agriculture was carried out in Northeast-Pará, Brazil, where such a land-use system has been practised for about 100 years. A common cropping period lasts for two years and the fields lie fallow for 4 to 8 years. We quantified rates of deposition, fertilization, and losses due to the burn, harvest and leaching. Six fields of different phases in the rotational cycle were under study during a 19 month period. During the fallow period, the input of Na, K, Mg, N, P and S via deposition exceeded the estimated losses with the seepage water. The Ca budget was almost balanced. The balance of fields in the transition from the fallow to the cropping phase was negative for Na, K, Ca, Mg, N, and S. The P balance was positive when NPK fertilizer was applied, and negative without fertilizer application. The nutrient balance for K, Mg, Ca, N, and P was also negative on the field in transition from the cropping to the fallow period. The nutrient budget for an entire land-use cycle of 9 years was estimated by the false time series approach. In the case of an NPK fertilization during the cropping period there were net losses of 75 kg K ha^–1, 125 kg Ca ha^–1, 16 kg Mg ha^–1, 285 kg N ha^–1 and 13 kg S ha^–1. Na (86 kg ha^–1) and P (11 kg ha^–1) were accumulated. The harvest was the most important flux for the K (61%) and P (62%) output. The element transfer into the atmosphere during the burn caused the main losses of N (60%), S (65%), Ca (58%) and Mg (41%). The most important path of Na loss was leaching (92%). The net K losses were severe as they represented 45% of the K store found extractable in the soil down to 1m depth and in the above ground biomass. The presented results may be useful in planning a sustainable and environmentally protective method of land-use within a shifting cultivation system. It is strongly recommended that slash burning be abandoned in order to keep the nutrients in the ecosystem.     

Effects of organic and conventional growth systems on the content of carotenoids in carrot roots, and on intake and plasma status of carotenoids in humans

BACKGROUND: The demand for organic food products has increased during the last decades due to their probable health effects, among others. A higher content of secondary metabolites such as carotenoids in organic food products has been claimed, though not documented, to contribute to increased health effects of organic foods. The aim was to study the impact of organic and conventional agricultural systems on the content of carotenoids in carrots and human diets. In addition, a human cross‐over study was performed, measuring the plasma status of carotenoids in humans consuming diets made from crops from these agricultural systems. RESULTS: The content of carotenoids in carrot roots and human diets was not significantly affected by the agricultural production system or year, despite differences in fertilisation strategy and levels. The plasma status of carotenoids increased significantly after consumption of the organic and conventional diets, but no systematic differences between the agricultural production systems were observed. CONCLUSION: The expected higher content of presumed health‐promoting carotenoids in organic food products was not documented in this study. Copyright © 2011 Society of Chemical Industry     

广东省农业用水定额编制概述

将广东省分为6个灌溉用水定额分区,并选定20个典型县,通过对各分区主要粮食作物、蔬菜、果树等灌溉用水定额进行调查,统计分析得出了各分区以水稻、薯类等为主的粮食作物,以叶菜、瓜果、椒类等为主的蔬菜和以香蕉、荔枝、龙眼等为主的果树等的农业灌溉用水定额。     

Can cities become self-reliant in food?

Modern cities almost exclusively rely on the import of resources to meet their daily basic needs. Food and other essential materials and goods are transported from long-distances, often across continents, which results in the emission of harmful greenhouse gasses. As more people now live in cities than rural areas and all future population growth is expected to occur in cities, the potential for local self-reliance in food for a typical post-industrial North American city was determined. Given current policies and bylaws and available area, crop yields, and human intake, three distinct scenarios were developed to determine the potential level of food self-reliance for the City of Cleveland, which has been plagued with home foreclosures and resulting vacant land, lack of access to healthy food, hunger, and obesity particularly in disadvantaged neighborhoods. Scenario I, which utilizes 80% of every vacant lot, can generate between 22% and 48% of Cleveland’s demand for fresh produce (vegetables and fruits) depending on the vegetable production practice used (conventional gardening, intensive gardening, or hydroponics), 25% of both poultry and shell eggs, and 100% of honey. Scenario II, which uses 80% of every vacant lot and 9% of every occupied residential lot, can generate between 31% and 68% of the needed fresh produce, 94% of both poultry and shell eggs, and 100% of honey. Finally, scenario III, which adds 62% of every industrial and commercial rooftop in addition to the land area used in scenario II, can meet between 46% and 100% of Cleveland’s fresh produce need, and 94% of poultry and shell eggs and 100% of honey. The three scenarios can attain overall levels of self-reliance between 4.2% and 17.7% by weight and 1.8% and 7.3% by expenditure in total food and beverage consumption, compared to the current level of 0.1% self-reliance in total food and beverage by expenditure. The analysis also reveals that the enhanced food self-reliance would result in $29 M to $115 M being retained in Cleveland annually depending upon the scenario employed. This study provides support to the hypothesis that significant levels of local self-reliance in food, the most basic need, is possible in post-industrial North American cities. It is concluded that while high levels of local self-reliance would require an active role of city governments and planners, public commitment, financial investment, and labor, the benefits to human health, the local and global environment, and the local economy and community may outweigh the cost.     

Habitat structure influences below ground biocontrol services: A comparison between urban gardens and vacant lots

Urban agriculture offers a framework for local self-reliance by provisioning food security, employment opportunities, and other community benefits. However, urban agriculture must rely on the supporting and regulating services of the soil food web. Hence, we quantified belowground biocontrol activity in urban gardens and vacant lots in two post-industrial cities using an in situ insect baiting technique. Due to the differences in habitat structure, we hypothesized that belowground biocontrol services will differ between gardens and vacant lots and the influence of habitat structure would differ with the type of biocontrol organism. Results revealed that biocontrol activity, as assessed by % mortality of baited insects, varied between 51% and 98% with higher activity often recorded in vacant lots than gardens. Major contributions to bait insect mortality were by ants, followed by microbial pathogens and entomopathogenic nematodes, respectively. Ants showed higher (p < 0.0001) % mortality in vacant lots (60% ± 33.4%) than in urban gardens (33.3% ± 22.2%) whereas microbial pathogens exhibited higher (p < 0.0001) mortality in gardens (27.8% ± 15%) than vacant lots (8.3% ± 16.7%). Ants caused higher (p < 0.0001) mortality when larger-mesh size cages were used compared with the smaller-mesh size cages, but mortality by microbial pathogens did not differ with cage type. The high biocontrol activity indicates the resilience of the soil food web in urban ecosystems and the differential effects of habitat structure on biocontrol activity can help guide landscape planning and vegetation management to enhance urban environments and boost local self-reliance.     

谈山西“人口半城镇化”问题及对策建议

对山西省城镇化工作中较为突出的"人口半城镇化"问题进行了研究,按照因地制宜、以人为本、科学发展的原则,从人口管理、土地管理、生态环境、行政管理等方面提出了有力的解决措施,以推动城镇化的发展。     

16.9－28 10PR R7农业轮胎的设计

介绍16.9-28 10PR R7农业轮胎的设计。结构设计:外直径1 427 mm,断面宽408 mm,行驶面宽度386 mm,行驶面弧度高32 mm,胎圈着合直径716 mm,胎圈着合宽度381 mm,断面水平轴位置(H_1/H_2)0.665,花纹深度39 mm,花纹饱和度25.2%,花纹周节数28。施工设计:胎面采用两方四块结构,胎体采用4层高强度1400dtex/2V_1锦纶6浸胶帘布,缓冲层采用2层930dtex/2锦纶6浸胶帘布,采用LCX-4B型成型机成型、立式硫化罐硫化。成品轮胎试验结果表明,轮胎的外缘尺寸和物理性能均满足设计及国家标准要求。