农业综合开发投资绩效评价初探

本文用层次分析法对我国农业综合开发投资进行了分析,并根据投资效果对各省份进行了排序,进而对我国农业综合开发绩效进行了评价,并提出了几点结论性的建议.     

Conjunctive use of groundwater and surface water to reduce soil salinization in the Yinchuan Plain,North-West China

Abstract

Poor water resource management is an important factor in soil salinization in arid areas. In this study, the status of soil salinization and its controlling factors are summarized for the Yinchuan Plain, North-West China. The conjunctive use of surface water diverted from the Yellow River and groundwater abstracted from a shallow aquifer is proposed to alleviate soil salinization in the plain. Scenarios are designed and simulated to determine the optimal proportions at which groundwater should be exploited for irrigation in the three cities of the plain. Policies and suggestions regarding sustainable water resources and soil salinization research in the plain are recommended.     

Quantifying the impact of agricultural technology usage on intra-household time allocation: Empirical evidence from rice farmers in Ghana

The use of improved agricultural technologies that lead to improved productivity, income and food security, could also destabilize intra-household time allocation. Using primary data from 917 rice farmers in Ashanti and Upper East Regions of Ghana, this paper employs a two-stage Bourguignon, Fournier, and Gurgand (BFG) selection bias correction model to quantify the impact of improved rice production technologies on intra-household time allocation. The empirical results indicate that farmers who take up improved rice technologies (fertilizer and improved rice seed) tend to increase labour input in farm work by 13.93 h per week. This has implications for the amount of time available for domestic work and leisure, especially for women in typical rice farming household. The design and development of technological innovations in the agricultural sector should take serious account of the domestic workload of women in farming communities to improve intensity and sustainability of use for both men and women.     

中国农业综合开发战略思考

农业综合开发是促进农业发展、推进农业现代化的重要手段.我国农业综合开发的基本任务是夯实农业发展基础,培植农业主导产业,依靠科技进步建设标准化农业和现代农业.本文对我国未来农业综合开发的方向、主要任务和措施做了比较详细的论述.     

Physicochemical and Bioactive Compounds of ‘Cantaloupe’ Melon: Effect of Ozone Processing on Pulp and Seeds

Melon seeds are an important source of bioactive compounds, which are considered to be health beneficial. Therefore, the objective of this work was to assess the impact of gaseous ozone treatments (30 and 60 min) on melon seeds paste (nonedible part) and compare with the effect on pulp (edible part). Ozone treatments were evaluated in terms of physicochemical (color, pH, and soluble solids content) and nutritional profiles (total phenolics, total carotenoids, and total antioxidant capacity) of processed material. Results indicate that ozone has a different impact on the two fruit matrices, being seeds less affected by this preservation treatment.     

Reduction of Captan,Boscalid and Pyraclostrobin Residues on Apples Using Water Only,Gaseous Ozone,and Ozone Aqueous Solution

Intensive use of plant protection products in modern agriculture and horticulture often results in increasing residue levels of active ingredients of plant protection products in fruits and vegetables. Even if the maximum residue levels are not exceeded, the synergic effects of various compounds may have a serious impact on consumers' health. In particular, more sensitive consumer groups, e.g., children, may be affected. Therefore, it is important to develop an effective method that could be utilized for reduction of pesticide residue levels in food products of plant origin. In this work, possible application of ozone to reduce pesticide residue levels in apples has been investigated. The fruits were treated with ozone in gaseous state, in ozonized water, and in water alone, which was used for rinsing the fruits. The experiments included tests on apples that were subjected to a protection program using captan, boscalid and pyraclostrobin. The ozonized water and treatment with a gaseous ozone were found to be not more efficient in reducing the pesticide content on the fruits than simple washing procedures, e.g., 81–95% reduction of captan residue or 40–67% reduction of boscalid residue and 20–42% reduction of pyraclostrobin residue. Still, ozonation of water used for rinsing prevented fruits from consecutive contamination by pesticide residues present in water after several rinsing cycles. It was proven that application of ozonation process as a part of post-harvest treatment of apples may be beneficial for the fruit quality.     

About the penetration of a horizontal axis cylindrical vortex into the nearby downwind region of a vertical porous fence

Wind tunnel experiments have been conducted on a cylindrical vortex embedded in a low turbulence stationary horizontal stream, running through a two-dimensional narrow vertical woven fence located on the wind tunnel floor.The vortex was continuously generated upwind of the fence by means of a vortex tube located well below the fence top level, with its axis aligned with the mean velocity of the external stream. The fence installed along the entire width of the tunnel had a porosity of 70%. Visualization experiments showed that approaching the fence the vortex moves away from the mean wind direction of the adjacent stream along a rising curved trajectory while the direction of the surrounding mean flow remained nearly horizontal. The results suggest that this deviation could be promoted by the vortex slanting velocity field relative to the fence, which “sees” a fence with much lower optical porosity than the fence perpendicular velocity of the nearby mean flow.The fence top shear layer flow, which dominates the downwind evolution of the mixing layer, appears to be highly sensitive to the presence of this type of vortex. The most energetic changes in the flow due to the presence of the vortex occurred in the mixing layer region. Windbreaks are usually designed in terms of mean velocity, turbulence intensity, geometric dimensions, and porosity. The results presented in this paper suggest that the sheltering ability of a porous fence depend also on the particular flow pattern of the oncoming turbulent structures embedded in the incident wind. The results show the importance for a particular wind sheltering application in knowing a priori at least some aspects of the flow pattern of the most representative turbulent structures of the local wind.     

The Bacterial Quality of an Upland Stream

Faecal coliform concentrations were determined at stream and water inflow sampling sites within an upland catchment in North Derbyshire containing rough, semiimproved and improved pastures. The results indicated that, during its passage through the catchment, the faecal indicators of the stream increased, and this may constitute a health risk to cavers using a popular recreational cave into which the stream drains. The decline in streamwater quality suggests that a semipermanent store of bacteria existed in catchment soils, and hydrological processes operated to transfer bacteria from the land to the stream channel. Contrary to expectations, intra-catchment differences in the bacterial quality of water at inflow and stream sampling sites could not be related to the intensity of agricultural land use in adjacent areas. This is explained with reference to changes in the nature of hydrological transport pathways associated with the improvement of pastures.     

Land Drainage: Agricultural Benefits and Environmental Impacts

The paper reviews the context and contribution of agricultural land drainage in the UK and discusses the design and performance of land drainage improvement and maintenance schemes. The environmental impacts of land drainage are considered, and how drainage activities can be, and are being, modified to meet environmental criteria.