Establishing the Organic Matter Balance in Cultivated Soils

Soil organic matter is a major component of the biological system which converts solar energy into biomass. It is also a most sensitive indicator of soil evolution. Discussion of the fertility status of soils (Part II), of the interpretation of experimental results (Part III), and of the functioning of the soil-plant system (Chap. 22) has made this abundantly clear. It is therefore desirable to establish quantitative relationships between production (yield) and the evolution of the stock of organic matter in the soil.