Wetting agriculture

Biomass with a dry master content over 70 to 30 per cent uetghr, as opposed to " wet agricultural wastes which are used for fermentation-... 

Another application areas of microtomography are biology and agriculture. Fig.4a shows an X-ray transmission image through the tulip bulb in wet conditions. Damaged area can be found in the surface of this bulb. Fig.4b shows the reconstructed cross section with information about depth of damaged volume. 

Wettable powders are prepared by blending the toxicant in high concentration, usually from 15 ndash 95%, with a dust carrier such as attapulgite which wets and suspends properly in water. One to two percent of a surface-active agent usually is added to improve the wetting and suspensibiUty of the powder. Sprays of wettable powders are used widely in agriculture because of their relative safety to plants. 

Wet Process. Over 90% of the phosphoric acid produced, both in the United States and worldwide, is wet-process phosphoric acid used almost exclusively for agricultural appHcation as both fertilizers and animal feed supplements. Although constituting a small proportion of the total wet-acid production, a significant amount of phosphoric acid for food and technical appHcations is made by purification of wet-process acid. 

The estimated world production of wet-process phosphoric acid was 24,001,000 metric tons of P20 in 1993. Capacity was 34,710,000 metric tons. Over 90% of phosphoric acid production is wet-process (agricultural-grade) acid the remainder is industrial-grades (technical, food, pharmaceutical, etc) made by the thermal route or by the purification of wet-process acid. Table 11 fists U.S. production of wet-process and industrial-grade acids. 

Year Industrial-grade Wet-process agricultural-grade... 

Devising an economical method of producing agricultural-grade potassium phosphates from potassium chloride and wet-process phosphoric acid has been the subject of intense agricultural—chemical research (37—39). Limited quantities have been produced industrially. The impact on the overall quantities of phosphoms and potassium compounds consumed by the fertilizer industry is small. Because potassium phosphates are an excellent source of two essential fertilizer elements, this research is expected to continue. 

Sludge Disposal. Land disposal of wet sludges can be accomplished ia a number of ways Lagooniag or the application of liquid sludge to land by tmck or spray system, or by pipeline to a remote agricultural or lagoon site. 

Many similar hydrocarbon duids such as kerosene and other paraffinic and naphthenic mineral oils and vegetable oils such as linseed oil [8001-26-17, com oil, soybean oil [8001-22-7] peanut oil, tall oil [8000-26-4] and castor oil are used as defoamers. Liquid fatty alcohols, acids and esters from other sources and poly(alkylene oxide) derivatives of oils such as ethoxylated rosin oil [68140-17-0] are also used. Organic phosphates (6), such as tributyl phosphate, are valuable defoamers and have particular utiHty in latex paint appHcations. Another important class of hydrocarbon-based defoamer is the acetylenic glycols (7), such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol which are widely used in water-based coatings, agricultural chemicals, and other areas where excellent wetting is needed. 

We only briefly mentioned alkaline stabilization, but in reality this is a variation of sludge pasteurization. The basic process uses elevated pH and temperature to produce a stabilized, disinfected product. The two alkaline stabilization systems most common in the U.S. are a lime pasteurization system and a cement kiln dust pasteurization system. The lime pasteurization product has a wet-cake consistency, while the kiln dust pasteurization has a moist solid like consistency. Both products can be transported to agricultural areas for ultimate use. Literature studies show that the kiln dust product can capture a marketable value of 6.60/Mg ( 6.00/ton) to offset hauling costs, while the lime product does not appear to be able to capture financial credits for product revenues at this point in time. The reasons for this are not entirely clear. 

Controlling methane release from wetland, rice paddies and gaseous emissions from animals is more problematic. The release from rice paddies and wet lands is slow, intermittent and takes place over a wide geographic area, and thus very difficult to control. Gaseous emissions from agricultural animals contribute to atmospheric accumulation of methane due to fermentative digestion that produces methane in... 

In the same study, at the agricultural site in Mississippi, the total wet deposition of methyl parathion during the 6-month study was 1,740 pg/m (89% of the total wet depositional loading at that site), greater than the totals for each of the other 46 compounds monitored in the study (Majewski et al. 2000). Methyl parathion was not detected in the wet deposition at the Iowa site and was detected only once at each of the two Minnesota sites (Majewski et al. 2000). 

The agricultural chemicals in general are more dangerous to handle in solution than in wettable powder or dust form. Parathion and nicotine are the only exceptions to this as they seem to be about equally toxic in wet or dry form. 

Concentrations of lead (wet weight basis) in samples of eleven raw edible plants have been reported for growing areas in the United States that are uncontaminated by human activities other than normal agricultural practices (Wolnik et al. 1983a, 1983b). Results are as follows plant (mean pg/g wet weight) lettuce (0.013) peanut (0.010) potato (0.009) soybean (0.042) sweet com (0.0033) wheat (0.037) field com (0.022) onion (0.005) rice (0.007) spinach (0.045) tomato (0.002). 

Humidity. There are two conceivable effects of humidity. Particularly with respect to agricultural products the moisture content can influence the hardness and elasticity. For example, Segler (1951) observed that dry peas are more sensitive to breakage than wet ones. Moreover, Wyszynski and Bridgwater (1993) have reported that a lubricating layer of moisture on the particle surface can reduce the particle degradation. 

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