The short term agronomic impact of raising canal water levels in grassland areas: A case study in the Belgian polders

This study tested the hypothesis that raising canal water levels with 30 cm beyond the growing season in intensively managed lowland grassland (2.4-3.7 m above sea level) in Belgium decreases the agronomic value of pastures The study ran 3 years before and 3 years after the water elevation. Using five pairs of plots inside and outside the wetted perimeter, it was not possible to demonstrate significant impacts of the elevated water level on dry matter yield, forage quality, botanical composition, and penetration resistance of the top soil layer of the grassland. In an ex situ lysimeter experiment, simulating the effect of a water level in canals up to 50 cm beneath the surface of the pastures indicated a significant decrease of the penetration resistance of the top soil layer.Results are discussed and confronted with the difficulties of field research addressing the elevation of water levels.     

“绿色贸易堡垒”与经济发展的“绿色通行证”

“绿色贸易堡垒”是国际贸易中非关税贸易堡垒重要的组成部分，它从保护环境的目的出发，在国际贸易中发挥着越来越重要的作用。文章通过对天津市现实状况的研究，提出克服绿色贸易堡垒，为天津市经济在入世后获得“绿色通行证”的对策建议。     

攀枝花市环保产业发展现状和对策

本文对攀枝花市的环保产业及其构成进行了分析，提出了该市环保产业的基本思路和具体目标，并针对该市环保产业存在的问题提出了发展环保产业的对策。