ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

The use of sewage effluent subjected to proper treatment for agricultural irrigation has been increasingly considered as a supplemental source of freshwater in many countries where a shortage of potable water is current reality. However, concern exists over the pollution risk due to the toxic accumulation from sewage effluent, which is the main restraint on the application of sewage effluent irrigation. Extensive researches on system stability, environmental sustainability, and efficient control are highly necessary to ensure the efficient and safe use of sewage effluent for agricultural irrigation. The effects of sewage effluent application on drip emitters, irrigation system, environments and agricultural products were reviewed. The behaviors and interaction between nutrients, salts, microorganisms and typical pollutants were summarized. Several theoretical and technical issues that need to be further studied, including the micro mechanism and macro behaviors of the influences of sewage application on irrigation system performance, the dynamics process of environmental changes imposed by sewage irrigation, the effects of sewage application on nutrient uptake and utilization, and efficiently safe control mechanisms of sewage irrigation, were prospected. Expected researches on these issues can add new knowledge to the regulation theory of water, nutrients and salts for irrigation and it will be a contribution to enhancing the efficiency and safty of use of sewage effluent for agricultural irrigation.