Therefore, the potential to improve soil condition in the top 0–20 cm is still critical for plant productivity. It is where a large proportion of plant materials are added to the soil for decomposition and recycling of nutrients and where rainfall either enters the soil or runs off. It is where seeds are sown, germinate andĮmerge. Even so, the top 20 cm is a critical zone for the soil. This limits the capacity of SOM to influence soil productivity.
Increases in SOM have the capacity to have strong influence only the physical properties of the surface soils, perhaps only the top 10 cm, or the top 20 cm at most. The soil properties considered included aggregate stability, bulk density, water-holding capacity, soil erodibility, soil colour, soil strength, compaction characteristics, friability, nutrient cycling, cation exchange capacity, soil acidity and buffering capacity, capacity to form ligands and complexes, salinity, and the interaction of SOM with soil biology. The potential effect of varying the amount of SOM in soil on a range of individual soil properties was investigated using a literature search of published information largely from Australia, but also including relevant information from overseas. A review has been undertaken into how soil organic matter (SOM) affects a range of soil properties that are important for the productive capacity of soils.
0 kommentar(er)
