Search results
Results from the WOW.Com Content Network
Urea is the most used fertilizer in the world, due to its high content of nitrogen, low cost and high reactivity towards water. [32] When exposed to ocean waters, urea is metabolized by phytoplankton via urease enzymes to produce ammonia. [33] + +
Typical build ratios are .5 to 1 square foot of grow space for every 1 U.S. gal (3.8 L) of aquaculture water in the system. 1 U.S. gal (3.8 L) of water can support between .5 lb (0.23 kg) and 1 lb (0.45 kg) of fish stock depending on aeration and filtration.
It was found that the treatment of plants with Kelpak® and the bacteria, Pseudomonas fluorescens and Bacillus licheniformis, decreased plant stress responses and increased production. [72] The most recently mentioned study provides implications for crop benefits when the application of seaweed fertilizer to soils favors the growth of PGPR.
A maize crop yielding 6–9 tonnes of grain per hectare (2.5 acres) requires 31–50 kilograms (68–110 lb) of phosphate fertilizer to be applied; soybean crops require about half, 20–25 kg per hectare. [21] Yara International is the world's largest producer of nitrogen-based fertilizers. [22]
The plant had a production capacity of 570,000 tons per annum (TPA) and an initial construction cost of US$303 million. [13] The plant was supplied by Haldor Topsoe and was commissioned in 1982 after an additional investment of US$15 million. [13] As of 2024, FFC-I has a capacity to produce 403,000 TPA of ammonia and 695,000 TPA of urea. [14]
The structure of the molecule of urea is O=C(−NH 2) 2.The urea molecule is planar when in a solid crystal because of sp 2 hybridization of the N orbitals. [8] [9] It is non-planar with C 2 symmetry when in the gas phase [10] or in aqueous solution, [9] with C–N–H and H–N–H bond angles that are intermediate between the trigonal planar angle of 120° and the tetrahedral angle of 109.5°.
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] Surface residues, such as thatch and plant stubble exhibit increased urease activity.
One Confederate guano kiln in New Braunfels, Texas, had a daily output of 100 lb (45 kg) of saltpetre, produced from 2,500 lb (1,100 kg) of guano from two area caves. [30] From the 1930s, Bat Cave mine in Arizona was used for guano extraction, though it cost more to develop than it was worth. U.S. Guano Corporation bought the property in 1958 ...