第八章土壤空气 soil air Integration at the local and regional scales Far m and watershed Greenhouse gases, Precision far ming Remote sensing Soil survey, etc Air Field and experi mental plots Far ming systems and crop management Soil, air and water quality weeds, etc Soil and Fine scale Rhizosphere Caboratory and small plots] N, P, K, heavy metals Soil organic matter and structure Rhizobium and microflora, etc Water第八章 土壤空气 soil air