Introduction
pH, EC, and Organic carbon play an important role in the soil. By determining the EC of soil we can learn how much salt the soil is. By determining the EC of the soil we can determine how much acidic that soil is. In addition, organic carbon tells us how much fertile that soil is. These factors play an important role in the cultivation of crops or planting plants. pH is a major factor in determining which trees, bushes, or grasses will have good scope to grow smoothly in the land under natural conditions. pH influences the processes involved in the formation development of soils. Most mineral deposits are soluble in acid soils than in alkaline soils thus releasing ions toxic to plants. It affects the supply of nutrients to the plants. Alkaline pH reduces the solubility of all the micronutrients (particularly Fe, Zn, Cu & Mn) except Mo and Cl. Within a pH range of 6.5 to 7.5, most of the essential nutrients are available to plants.
The soil pH additionally affects plant growth by influencing the activity of helpful soil microbes. Most N-fixing microorganisms don’t seem to be terribly active in powerfully acidic soils. Bacteria releasing nitrogen and other nutrients for plant use are depressed by strong acidity. Fungi usually tolerate acidity better than do other microbes. Plant growth is also affected at high pH due to an excess of sodium ions in both soil exchange complex and solution, which actually deteriorate soil’s physical conditions for plant growth. Moreover, nutrient imbalance and sodium toxicity may also decrease plant growth [1]. Retention of led, zinc, copper, and other materials of the soil also depends on the pH. With higher pH their retention increases in the soil [2].
Electric conductivity, which is commonly referred by “EC”, is another important factor for soil, for example determining the salinity level of the soil. A researcher concentrated on determining soil salinity by determining the EC of aqueous extracts of collected soil samples. He also measured total dissolved solids in the saturated soil extract. He tried to determine a relation between soil concentrate and EC of soil to determine the salinity of the soil. He also discussed determining the soil salinity using chemical analysis but as it is not as fast as EC he applied the EC technique [3] [4]. Soil organic carbon is the base of soil fertility. It provides nutrients for plant growth, stimulates the structure, biological and physical health of the soil, and is a barrier against harmful substances. Soil organic carbon is a component of the natural carbon cycle, and also the world’s soils hold around double the quantity of carbon that’s found within the atmosphere and in vegetation. Organic material is basically manufactured by plants by plants utilizing carbon dioxide from the air and water. Plants (and animals, as a part of the food chain), die and come back to the soil wherever they’re rotten and recycled. Mineral deposits are released into the soil and carbon dioxide is released into the atmosphere [5].
Importance of pH
•pH is a scale that chemists use to measure acidity. Values below 7 are considered acidic, values above 7 are alkaline ( the opposite of acidic) and 7 is neutral.
•The aim in managing soil pH is not to achieve a particular pH value, but to adjust the acidity to the point where there are no toxic metals in solution and the availability of nutrients is at its maximum.
•Release of nutrients to plant- The optimum pH value helps to increase the activity of soil microbes. The complex forms (organic materials) must be broken down into simpler ones through decomposition by these microbes. Thus, the pH helps to increase the availability of plant nutrients in the soil and increase crop production.
Importance of EC
•Soil electrical conductivity affects yields, crop suitability, plant nutrient availability as well as soil microbial activities such as emission of greenhouse gases and respiration.
•Excess salt hinders plant growth by affecting the balance of soil-water.
•Salinity is influenced by humans through cropping, irrigation, and land management practices.
Importance of Organic Carbon
•Soil organic carbon is fundamental to soil fertility. Chemical, physical, and biological.
•Soil organic carbon improves soil structure
•Ecological soil function utilizes carbon as the initial food source.
•Soil organic carbon is the basis of sustainable agriculture.
Chemistry of soil is the interaction of various chemical constituents that takes place among the soil particles and in the soil solution—the water retained by the soil. The chemical interactions that occur in the soil are extremely complex, but understanding certain basic concepts regarding the chemical properties of the soil will help one to feel the chemistry of soils. We can conserve soil from different kinds of degradations such as soil degradation because of water (Riverbank Erosion) and wind erosion, fertility depletion, the decline in organic matter, reduction of macro and micro-fauna, etc by applying our knowledge regarding soil chemistry.
References
[1] S. (n.d.). Significance of Soil pH. Retrieved from https://agrihunt.com/articles/fertilizerindustry/significance-of-soil-ph/
[2] Harter, Robert D. “Effect of Soil pH on Adsorption of Lead, Copper, Zinc, and Nickel1.” Soil Science Society of America Journal, vol. 47, no. 1, 1983, p. 47., doi:10.2136/sssaj1983.03615995004700010009x.
[3] Corwin, D. L., & Yemoto, K. (2017). Salinity: Electrical Conductivity and Total Dissolved Solids. Methods of Soil Analysis,2(1), 0. doi:10.2136/msa2015.003920
[4] Rhoades, J. D., & Schilfgaarde, J. V. (1976). An Electrical Conductivity Probe for Determining Soil Salinity1. Soil Science Society of America Journal, 40(5), 647. doi:10.2136/sssaj1976.03615995004000050016x
[5] The importance of carbon in the soil. (n.d.). Retrieved from https://www.futurefarmers.com.au/young-carbon-farmers/carbon-farming/importance-of-carbonin-the-soil
Author:
Naznin Imrana
Dept.of soil and Environmental Sciences
University of Barishal
Email: [email protected]