Search results
Results from the WOW.Com Content Network
Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a compound such as aluminium sulfate, which reacts in the soil to
The soil's pH also has a strong effect on the amount of volatilization. Specifically, highly alkaline soils (pH~8.2 or higher) have proven to increase urea hydrolysis. One study has shown complete hydrolysis of urea within two days of application on such soils. In acidic soils (pH 5.2) the urea took twice as long to hydrolyze. [7]
Spent acid (HCl, H 2 SO 4, etc.) can also be used to reduce the excess Na 2 CO 3 in the soil/water. Where urea is made available cheaply to farmers, it is also used to reduce the soil alkalinity / salinity primarily. [11] The ammonium (NH + 4) cation produced by urea hydrolysis which is a strongly sorbing cation exchanges with the weakly ...
3, which can be extremely damaging due to its acidic properties. [5] Zeolite catalysts have the potential to operate at substantially higher temperature than base metal catalysts; they can withstand prolonged operation at temperatures of 900 K (627 °C) and transient conditions of up to 1120 K (847 °C). Zeolites also have a lower potential for SO
Controlled-nitrogen-release technologies based on polymers derived from combining urea and formaldehyde were first produced in 1936 and commercialized in 1955. [3] The early product had 60 percent of the total nitrogen cold-water-insoluble, and the unreacted (quick-release) less than 15%.
The dilution also helps to reduce odor development following application. When diluted with water (at a 1:5 ratio for container-grown annual crops with fresh growing medium each season or a 1:8 ratio for more general use), it can be applied directly to soil as a fertilizer.
Synthetic polymers began replacing other chemical binders for soil stabilization in agriculture in the late 20th century. [1] Compared to traditional chemical binders, polymer soil additives can achieve the same amount of strengthening at much lower concentrations – for example, mixtures of 0.5-1% of various biopolymers have strength levels that match or exceed those of 10% cement mixtures ...
In general, organic matter contacting soil has too little nitrogen to support the biosynthetic needs of the decomposing soil microbial population. If the C:N ratio of the decomposing organic matter is above circa 30:1 then the decomposing microbes may absorb nitrogen in mineral form as, e. g., ammonium or nitrates. This mineral nitrogen is said ...