The mechanism by which the degradation of soil structure in sodic soil occurs are the swelling of the clays and the dispersion of the colloids, and the classic approach to improve the soil structure in sodic soil is by adding a source of calcium (this is a chemical approach based upon exchange phenomena which is reversible in theory, even in practice ) but what about the physical aspects of the improvement of soil structure (porosity, saturated hydraulic conductivity), are these properties reversible or not ?
Dear Louadj, there are numerous references which revealed positive effect of Ca on soil structure and consequently upon soil physical characteristics u mentioned. Once you search in google using keywords 'calcium sulphate and soil structure'
regards
due to ion exchange soil structure is improved that means the dispersed particles again flocculate by presence of divalent cation and aggregate masses are formed resulting into improved porosity and decreased bulk density. Because of improved porosity water conduction through this soil also get enhanced.
for more illustration please read (Gulab and Kulig, 2008) paper
Once by addition of Ca sources, soil structure will improved. Now if soil structure will improved other parameter that you listed were closely related with the soil structure, hence definitely there is positive impact on that. I think there were so many research papers available. please see that.
There are several ways of ameliorating the effects of salinity and sodicity beyond use of gypsum, including addition of elemental sulphur, organic matter, and by phytoremediation. A few example papers can be found via these links:
http://www.sciencedirect.com/science/article/pii/S0038071705004074
http://www.tandfonline.com/doi/abs/10.1080/1065657X.2004.10702177
http://www.sciencedirect.com/science/article/pii/S006521130796006X
Soil degradation and the destruction of soil structure occurs through practices such as excessive tillage which breaks down humic and fulvic acids, the "glue" that binds soil colloids together. The accumulation of sodium in the profile through poor drainage or poor irrigation water quality use will also disperse clays and break down structure.Addition of composted organic matter, molasses, Ca based materials such as gypsum, practices such as minimum tillage,green manuring can all help in arresting and reversing the process of soil degradation.
We have used super-sulphated gypsum in quantities just sufficient to reverse the alkalinity.
Dr. Mirza Arshad Ali Beg
Dear colleague. The following paper could be useful to consider the contribution of water quality, soil texture and ESP on soil structure and hence hydraulic properties. GJ Levy, AI Mamedov, D Goldstein 2003. Sodicity and water quality effects on slaking of aggregates from semi-arid soils. Soil Science 168 (8), 552-562
Dear Dr younes ,
Thank you to share with your PhD thesis,
Best regards
our team did some model (chemical and computer) studies of humics in soils and conformational changes (see references on my site)
- Badges
- Science topic
- Similar topics
- Agriculture
- Soil Science