施肥和灌溉对土壤和水质的影响

论述了选择土壤物理、化学和生物学性质参数的十项标准，五种重要的监测水质的方法，以及施肥和灌溉对土壤和水质的影响．雨养、漫灌、滴灌、细流灌和喷灌具有不同的水利用率，且对土壤物理、化学和生物学性质的影响各异．土壤生物化学性质是重要的监测土壤变化的参数．虽然施肥可能降低土壤pH值、总有机碳和盐基离子浓度，但土壤的其他指标如土壤结构、有机质、土壤微生物和养分状况都得以改良．过量施肥会使土质退化并带来严重的环境问题．消除了边际效应的土壤测渗计能够准确地监测施肥和灌溉对水质的影响．所综述研究表明如果施肥得当，土壤和水质可以改善或长期保持良性循环．

Effects of Irrigation and Fertilizer on Soil and Water Quality

Reviews five important methods to monitor water quality,ten guidelines for selecting soil physical,chemical and biological quality indicators and how these parameters are affected by typical irrigation systems and fertilizer types.It is found that:rain-fed,flood irrigation,drip irrigation,trickle irrigation and sprinkler irrigation have variable water use efficiencies and variable effects on soil.Soil biological and biochemical variables are considered to be essential to measure changes in soil quality.Soil quality parameters such as soil aggregate size,stability and solum thickness,bulk density,infiltration rate,soil organic matter,microbial biomass and increased nutrient availability are improved by fertilization,though soil pH,total organic carbon and basic cation contents may be decreased.Excessive fertilization can cause soil quality decline and serious environment problems.Improved lysimeters without edge flow can be used to measure accurately the effects of fertilizer and irrigation on drainage water quality.The conclusions are that water quality,soil quality and productive capacity can be maintained and improved in the long-term by careful use of fertilizers and irrigation.