Fifty per cent, more or less, of the soil organic matter from farm lands has been lost. The remainder is perhaps more resistant to loss and therefore is stable but that which has been lost was perhaps the most important half‐it resisted erosion, it made soils permeable, it increased water‐holding capacity and it produced healthy crops. The 50 per cent that has been lost is via two major mechanisms. One is loss per unit weight of soil by decomposition (mineralization) induced by cultivation, and the other is loss by erosion—loss by wash away and blow away of the surface soil which contains the most soil organic matter. Both mineralization and erosion are downhill processes. If they are not in equilibrium with reverse processes, the land cannot be sustainable. If agriculture is to be sustainable, we have to look at soil organic matter, first and foremost, as a means for maintaining stable‐tillable soil. Mining of soil for nutrients and letting soil organic matter levels decrease can never result in sustainable agriculture. The role of soil organic matter as a source of nitrogen and other nutrients is less important than that of providing excellent physical and biological properties of soil. Use of water‐soluble polymer soil conditioners can help.