Dear Yuan Liu,

The pH is the negative logarithm of Hydrogen Ion Concentration. At the variation of temperature affect the ionization or simply say vibration in the matter and decrease tendency of forming hydrogen bonds, thus leading to reduction in pH. Soil pH directly affects nutrient availability. The pH scale ranges from 0 to 14, with 7 as neutral. Numbers less than 7 indicate acidity while numbers greater than 7 indicate alkalinity.

Three soil pH ranges are particularly informative: a pH< 4 indicates the presence of free acids, generally from oxidation of sulfides; a pH

Dear Yuan Liu,

Soil pH level - a measure of its acidity or alkalinity. It is based on the measurement values of pH, which depends on the concentration of hydrogen ions (H +) in water or saline solution.

The state of balance (pH = 7) is called the neutral ground. The pH scale covers a continuous range from 0 (very strong acid) to 14 (very strong alkaline). However, the soil with such extremes almost never occur. For many reasons, if you do not maintain a balance, over time, many soils become more acidic or more alkaline.

For all those who work with the land, to know the acidity of the soil is very important for several reasons. For example, many plants and organisms in the soil or prefer more acid or more alkaline. Many plants will develop disease in alkaline or acidic soil. And then rebalancing can help retain soil nutrients.

Under conditions of heavy rains and insufficient evaporation for several years soil basic cations (Ca, Mg, K) is gradually depleted and replaced with the cations contained in the soil in colloidal form. In this case the acidity is increased. Clay soil often contains iron (Fe) and aluminum hydroxide (Al), which affect the retention in acidic soils cations and anions of fertilizers.

Soil acidity can also be increased by increasing the concentration of hydrogen due to the decomposition of organic substances, acidic fertilizers and replace the roots of base cations to H +.

Soil pH is reduced by evaporation and nitrogen denitrification. At high humidity of the soil pH value increases. In addition, pH value and further increase fertilizer following nitrate: calcium nitrate, magnesium nitrate, potassium nitrate and sodium.

Some alkaline soils contain calcium in the form of limestone, which plants can not extract. In this case it is possible to add sulfuric acid or sulfur for the recovery of the soil.

Regards, Shafagat