四川省攀西地区农业资源最优配置与综合开发的生态合理化方向

针对我国西南部地理环境特殊、农业资源开发潜力很大、生态环境成垂直立体多层次分布的攀西地区农业资源最优配置与综合开发等问题 ,在已有研究工作的基础上 ,应用技术经济学与农业生态经济学等有关理论与方法 ,遵照定量方法与定性分析相结合、静态分析与动态分析相结合以及研究工作采用PERT网络进行调控之原则 ,通过建立该区域的生态经济系统结构功能分析与优化模型体系和资源最优配置与农业结构优化模型体系 ,并由这些经济模型全面、系统、综合的分析与评价 ,从而为攀西地区农业资源的最优配置与农业综合开发提出立体生态经济可持续发展模式 ,为其实际开发项目的选择提供科学理论依据与具有说服力的对策方案。其研究成果将为扩大农业资源综合开发的成效 ,缩小东部与西部地区发展差距 ,改善该区域农业生态环境 ,保障长江三峡特大型水利水电枢纽工程安全与效益发挥 ,改变四川省老农业结构 ,合理调整该区域内“大工业、小农业”畸型经济结构 ,迅速改变民族地区的贫困落后面貌与促进民族和睦等均具重要的理论意义与战略意义。同时它也将是对可持续发展理论、对科学。

中国生态农业与农业现代化的关系——中国生态农业简介之五

中国农业现代化问题的研究由来已久,现在基本有了立论,即农业现代化应具备生物良种化、耕作机械化、管理信息化、技术科学化、生态合理化、环境优美化、资源利用持续化,集中表现为高产、高效、优质,即土地生产力和劳动生产力以及资源的持续利用作为农业现代化的核心内容和衡量标志。中国生态农业包含了这些内容,不失为我国农业现代化的最佳模式。因此,生态农业实质上是持久的现代农业,是实现农业持续发展的根本途径。1997年江泽民同志提出:

Inhibitory Effects of Aromatic Compounds on Soil Nitrification

Aromatic compounds (ACs) in soil can induce competitive inhibition for soil NH3 oxidation, and nitrification inhibitors can be used to this end. A laboratory incubation experiment was performed with 12 nitroaromatic compounds (NACs), 15 amidoaromatic compounds (AACs) and 20 hydroxyaromatic compounds (HACs) to assess the inhibitory effects of ACs on soil nitrification. Based on these results, the critical and optimal concentrations of ACs were determined for better inhibitory effects. Most of the test ACs were able to inhibit soil nitrification; the effectiveness differed with soil type. Among the ACs, the NACs with m-nitryl, amino or hydroxyl and the AACs with a nitro group or a chlorine atom on aromatic ring or with a p-hydroxyl were more effective. 3-nitroaniline, 4-aminophenol and 3-nitrophenol showed the greatest potential as nitrification inhibitors. The critical concentration of these compounds in brown soil and cinnamon soil was found to be 0.5 mg kg-1 soil. Due to the toxicity, carcinogenicity and mutagenicity of ACs, further toxicological and ecotoxicological research is necessary before ACs are used as nitrification inhibitors in agricultural and horticultural practices.

Analysis of ecological effects of comprehensive treatment in the Tarim River Basin using remote sensing data

Based on multi-type,multi-temporal remote sensing data,we have monitored recent changes in cultivated land use and vegetation,in sandy areas and salinized desertification in the Green Corridor zone of the main channel of the Tarim River Basin.The results of our investigation show that the ecological environment in the Green Corridor of the main channel of the Tarim River Basin has conspicuously improved from 2002 to 2004.These improvements show up largely in such aspects as an increase in the rate of vegetation cover,a reduction in desertification land areas and a weakening in the intensity of sandy and the salinized land.On the other hand,the cultivated area in the Tarim River Basin significantly increased from 2002 to 2004.The rate of growth in cultivated areas during this period was significantly higher than that from 1999 to 2002.The increase in the use of irrigation resulting from the substantial increase in cultivated areas has a long-term potential restraining effect on the restoration of ecological functions of the Tarim River.

Soil Attributes and Production of Eucalyptus in Monoculture and Silvopastoral Systems in the North of Minas Gerais, Brazil

The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and evaluated the following four systems： native vegetation system （Cerrado）, a degraded pasture, a Eucalyptus urograndis monoculture （E. urophylla x E. grandis） and a silvopastoral system （E. urograndis combined with Brachiaria brizantha cv. ＂Marandu＂）. The experimental design used was completely randomized. In each system, four soil samples were collected from the 0-20 cm depth layer, and the chemical and physical attributes of the soil were evaluated. The diameters of all Eucalyptus trees at 1.30 m above the ground as well as the total height were measured. Subsequently, the trees dimensions were measured and their individual volumes obtained by applying the Smalian formula. The correlation between the parameters for Eucalyptus production and soil attributes was established using the Pearson＇s correlation coefficient method. The planting of Eucalyptus in monoculture and silvopastoral systems contributed to the improvement of the soil＇s chemical and physical attributes, which indicates the potential of these systems for recovery of degraded pastures. The silvopastoral system yielded the highest average volume of wood per tree （0.2228 m^3）, with a productivity of 111.4 m^3/ha. The Eucalyptus monoculture yielded 0.1895 m^3 per tree and 315.71 m^3/ha due to the higher density of the crop. The growth and productivity of Eucalyptus showed highly correlation with the soil attributes, thus suggesting that well-managed crops are an indicator of the soil quality recovery.

An Overview of Karst Ecosystem in Southwest China: Current State and Future Management

Karst areas in Southwest China, with Guizhou as the focal center, are confronted with ecological deterioration and large areas of rocky desertification. Human activities are defined as the driving force behind the soil erosion. Further, local farmers in the area suffer from poverty due to a lack of drinking water, food and a weak living environment. Over one-third of national poverty-stricken counties occur in this part of China. To balance ecological protection and economic development in the region and help local farmers out of poverty we propose integrated controls and discuss on ground water exploration and sustainable use, soil conservation and remediation, and vegetation restoration （especially economic plant species） in this paper.