BY Ruwan Laknath Jayakody
Since there is limited literature available on soil health improvement in farming systems on tropical soils, any comprehensive study on soil health improvement under tropical conditions will be beneficial for bridging existing knowledge gaps.
This observation was made by Dr. M.G.T.S. Amarasekara (attached to the Rajarata University’s Agriculture Faculty’s Agricultural Engineering and Soil Science Department), in an editorial note on “Managing soil health towards sustainable agriculture” which was published in the Sri Lankan Journal of Agriculture and Ecosystems 3 (2) in December 2021.
Soil health has been defined by J.W. Doran and M.R. Zeiss in “Soil health and sustainability: Managing the biotic component of soil quality” as the capacity of a soil to function as a vital living system within the boundaries of ecosystems and the use of land, in order to sustain plant and animal production, maintain or enhance water and air quality, and promote plant and animal health. It is, Amarasekara explained, a key factor to be improved in order to move towards productive and environmentally sound farming systems, and hence, knowledge of soil functions such as decomposition, the cycling of nutrients and the dynamics of microbial populations, and their contributions to plant growth is vital so as to design soil health management practices.
Soil health and soil quality are two terms used to indicate the condition of a given soil; however, they may be differentiated in terms of the time scale with “soil health” referring to the condition of soil in a short period and “soil quality” referring to the same over a longer period, per D.F. Acton and L.J. Gregorich’s “Understanding soil health”.
Decomposition and nutrient cycling processes in the soil are generally governed, Amarasekara elaborates, by soil microbes.
- Lal’s “Restoring soil quality to mitigate soil degradation” noted therefore that unhealthy soil characteristics such as conditions of salinisation, acidification, compaction, crusting and water logging may adversely affect the soil biota biodiversity, thus reducing the quality of healthy soils.