Phosphorus, effect uptake

Vitamin D is necessary to allow the body to metabolize calcium and phosphorus effectively. Independent of the formation of vitamin D, it must be emphasized that excessive uptake of UV sunlight can lead to abnormal skin cell division and the possibility of skin cancer. 

As stated earlier, mycorrhizae enhance nutrient absorption. Greater soil exploitation by mycorrhizal roots as a means of increasing phosphate uptake is well established. The normal phosphate depletion zone around non-mycorrhizal roots is 1-2 mm, but an endomycorrhizal root symbiont increased this zone to 7 cm (140). This ability to increase the nutritional level (particularly with regard to phosphorus), and subsequently the overall better growth dynamics of the mycorrhizal plant has been suggested as the reason for the salt (43) and drought (44-46) tolerance and increased nodulation (47) observed in mycorrhizal associations. Another interesting aspect of this enhanced nutrient uptake is the possible effect of mycorrhizae on competitive ability between two plant species. Under some conditions, mycorrhizal... 

Jiao Y., Bailey L.D., Grant C.A. Effects of phosphorus and zinc fertilizer on cadmium uptake and distribution in flax and durum wheat. J Sci Food Agri 2004 84 777-785. 

Simpson, K. (1962). Effects of soil-moisture tension and fertilizers on the yield, growth and phosphorus uptake of potatoes. J. Sci. FoodAgric., 13,236-248. 

Pairunan, A.K., Robson, A.D. and Abbott, L.K. 1980. The effectiveness of vesicular-arbuscular mycorrhizas in increasing growth and phosphorus uptake of subterranean clover from phosphorus sources of different solubilities. New Phytologist 84 327-338. 

Detenbeck (37) and Detenbeck and Brezonik (38, 39) examined the effect of pH on phosphorus sorption for LRL sediments. Their results suggested that the flux of inorganic P from sediments could be diminished by as much as 90% if the pH of sediments decreased from 6.0 to 4.5. However, there was no observed treatment effect for TP and an apparent increase in SRP summer averages at pH 4.7 (Figure 4). Therefore, chemical sorption-desorption processes probably do not control phosphorus levels in LRL. The direction of response at lower pH implies that the balance between biotic uptake, deposition to sediments, and release from organic detritus by decomposition most likely controls SRP levels in the water column. 

A beneficial effect of humic substances on the nutrient uptake and contents of plants has been reported for the major inorganic elements, such as nitrogen, phosphorus, potassium (Mylonas and McCants, 1980), and sulfur (Guminski, 1968). In addition, the uptake and contents of nutrients such as calcium, magnesium (Mylonas and McCants, 1980), sodium (Vaughan and McDonald, 1976) and copper (Rauthan and Schnitzer, 1981) are also enhanced by humic substances. Most of these reports on the effects of HS on the nutrient contents of plants are purely descriptive, and little attempt has been made to elucidate the mechanisms of the action of the humic material. The authors proposed both an indirect and a direct effect of HS on plant nutrition. In the former case HS may, for example, chelate a cation, thus changing... 

To determine the effects of the deprivation of specific micronutrients on the water hyacinth (Eichhornia crassipes), Colley et al. (1979) studied the rate of uptake of iron and manganese in comparison with phosphorus. Results indicated that all three elements were actively absorbed by the root systems, but the rates of absorption differed markedly. The rate of absorption of manganese by roots was 13 and 21 times that for radio-iron and -phosphorus, and iron was taken up by the roots at nearly twice the rate of phosphorus. Manganese translocation appeared to be faster than phosphorus translocation by an order of magnitude and 65 times faster than iron translocation. 

Cellulose. Fiber components differ in their ability to bind to bile (41), the primary route of excretion of manganese (9). Cellulose, the most abundant natural fiber, has been studied for its potential effects on bile and lipid metabolism (42). It is naturally present in high fiber diets and is also commonly added to many commercially-produced food products. Previous studies have shown cellulose to decrease intestinal uptake of a variety of minerals, including zinc, phosphorus, calcium, magnesium, and iron (32,43,44). In many cases, however, the effect of cellulose has not been considered to be anti-nutritional (32). It has been generally believed that cellulose has a lower binding affinity for minerals than other constituents of dietary fiber (33,45). 

Reid, C. P. P. Bowen, G. D. (1979b). Effect of water stress on phosphorus uptake by mycorrhizas of Pinus radiata. New Phytologist, 83, 103-7. 

Harrison, W. G., and Harris, L. R. (1986). Isotope-dilution and its effects on measurements of nitrogen and phosphorus uptake by oceanic microplankton. Mar. Ecol. Prog. Ser. 27, 253—261. 

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