Paddy rice minerals

The endosperm is rich in soluble carbohydrates (NFE) and low in minerals, fat, and crude fiber. Oats, paddy rice, and barley have high fiber because they are husked grains. 

A Flavobacteriumsp. (ATCC 27551), isolated from rice paddy water, degraded parathion to 4-nitrophenol. The microbial hydrolysis half-life of this reaction was <1 h (Sethunathan and Yoshida, 1973 Forrest, 1981). When parathion (40 pg) was incubated in a mineral salts medium containing 5-day-old cultures of Flavobacterium sp. ATCC 27551, complete hydrolysis occurred in 72 h. The major degradation product was 4-nitrophenol (18.6 iig) (Sudhaker-Barik and Sethunathan, 1978a). 

There have been few reports of rice (Oryza sativa L.) responding to Mo application. Because most rice is grown in flooded paddies, the chemical interactions involving Mo are not the same as in dryland agriculture. When acid soils are flooded, there are increases in soil pH and changes in redox potential, thus changing the solubilities of Fe minerals (Ponnamperuma, 1972). Moore and Patrick (1991) reported increases in the amounts of MoO/ in soil solution with increasing pH in flooded soils, and those increases resulted in increased Mo uptake. The conditions in flooded soils may explain why there have been few reports of increased yields due to addition of Mo. 

Bacteria were isolated also from paddy water of diazinon-treated fields in Maligaya Rice Research and Training Center, Philippines, following the procedures used in the isolation of bacteria from the Institute rice fields. The most active isolate, Corynebacterium sp., decomposed diazinon in mineral solution only in the presence of ethyl alcohol or glucose (25). 

In the rice paddies of Japan, according to King, the soil was usually plowed to a depth of 3.5-4.5 inches but in China it was worked deep and often — much of it by hand labor. Apparently extreme efforts were made in China to maintain a soil- or dust-mulch, except, of course, where rice was grown. One can not help but wonder how such a laborious practice could have been followed over the centuries if it is without merit, as has been shown by scientists in recent years. Certainly it has some merit with respect to weed control, mineral availability, and soil aeration, if not for moisture conservation. 

The removal of the hull from paddy by dehusking exposes brown rice to the environment. Brown rice comprises four distinct outer layers, that is, nucellus, seed coat, pericarp, and aleurone. These layers are the part of bran of rice grain, along with the germ. The bran portion accounts for 5%-8% by weight of brown rice. The bran is the most nutritious part of the brown rice for it contains protein, fat, carbohydrate, and dietary fiber. In addition, the bran contains vitamins and minerals in quantities beneficial to humans. 

Biological. Sethimathan and Yoshida (1973a) isolated a Flavobacterium sp. (ATCC 27551) from rice paddy water that metabolized diazinon as the sole caibon source. Diazinonwas readily hydrolyzed to 2-isopropyl-4-methyl-6-ltydroxypyrimidine under aerobic conditions but less rapidly under anaerobic conditions. This bacterium as well as enrichment cultures isolated from a diazinon-treated rice field mineralized the hydrolysis product to carbon dioxide (Sethunathan and Pathak, 1971 Sethunathan and Yoshida, 1973). Rosenberg and Alexander (1979) demonstrated that two strains of Pseudomonas grew on diazinon and produced diethyl phosphorothioate as the major end product. The rate of microbial degradation increased in the presence of an enzyme (parathion hydrolase), produced by a mixed culture of Pseudomonas sp. (Honeycutt et al., 1984). 

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