Preface. Section I: Towards Environmentally Acceptable Pest Management. Section II: Fertilizers in Agroecosystems. Section III: Environmental Aspects of Aquaculture. Section IV: Modelling of Agricultural Pollution. Section V: Wastewater Treatment and Irrigation. Section VI: Recycling of Municipal and Agricultural Wastes. Section VII: Pollution by Heavy Metals. Section VIII: Bioremediation. Section IX: Economic and Policy Aspects of Natural Resources.