Study on the indicators for assessment of agro-ecoenvironmental quality in saline region of Lower Haihe Plain

The establishment of adapted indicators and thresholds is an essential component of the evaluation of agro-ecoenvironmental quality.The indicators are measurable attributes of environment,and the thresholds may be defined as levels of indicators and can provide the baseline of assessment.There is a stage of relative balance between the process of desalinization and salt accumulation in Lower Haihe Plain,therefore the development of agro-product is always controlled by the change of soil and water quality.According to 11 selected criteria,a set of key indicators which is easy to use was chosen and interpreted from many candidate indicators.The trend indicators reflecting the salinization include groundwater table ,water quality,soil EC and so on,and the condition indicators contain soil texture,consistence and color.In addition,the simple and more common determination method for soil morphological features was recommended.