ABSTRACT
Usually soil fertility is assessed in terms of certain inherent, fixed properties at the time of sampling, rather than over a period of time and reflecting the dynamic interaction of multiple factors. Also, soil fertility assessments are made as a rule in terms of specific chemical properties of the mineral portion of the soil, mostly the concentrations of essential plant nutrients in plant-available or unavailable forms,
6.1 Introduction .................................................................................................. 141 6.2 Biological Actors within Soil Systems ......................................................... 142 6.3 High Crop Productivity from “Poor Soils” in Madagascar .......................... 144 6.4 Increases of Beneficial Microorganisms in Rhizospheres in Response to
Management Practices .................................................................................. 148 6.5 Evidence on the Beneficial Effects of Root Endophytes .............................. 151 6.6 Effects of Soil Microbial Endophytes in Plant Canopies ............................. 152 6.7 Effects of Seed Endophytes for Root Emergence and Growth ..................... 154 6.8 Influence of Soil Microbes on Gene Expression in the Plant Canopy .......... 157 6.9 Implications for Advancement of Soil Science ............................................. 160 6.10 Conclusion .................................................................................................... 161 Abbreviations ......................................................................................................... 161 References .............................................................................................................. 162
plus various physical properties including soil texture, porosity, and water retention, among others.
