Phosphorus

About: Phosphorus is a research topic. Over the lifetime, 53120 publications have been published within this topic receiving 939731 citations. The topic is also known as: element 15 & P.

Zinc in Crop Production and Interaction with Phosphorus

Abstract: Proper plant nutrition is an important factor for improving yield and quality of agricultural productions. Zinc (Zn) is an essential micronutrient for normal healthy growth in plants, animals and humans that uptake as a divalent cation (Zn 2+ ) by plants. Zinc is playing principal metabolically role in plants. This micronutrient have an important role on most enzymes structure such as: dehydrogenises, aldolase and isomerases. Also zinc is effective in energy production and crebs cycle. In most of the Iranian soils pH is high and they are also calcareous, in this type of soils solvability of micronutrient is less and cause decline uptake these elements and finally requirement of plants to this elements is increasing. Crop yields and quality are reduced by zinc inadequate in soil. Zinc absorption capacity is reduced by high phosphorus utilization and zinc in plant and soil has an antagonism state with phosphorus (negative interaction), therefore zinc utilization is essential to obtain high yield and quality in crops.

Phosphorus removal in an enhanced biological phosphorus removal process: roles of extracellular polymeric substances.

Abstract: Phosphorus-accumulating organisms are considered to be the key microorganisms in the enhanced biological phosphorus removal (EBPR) process. A large amount of phosphorus is found in the extracellular polymeric substances (EPS) matrix of these microorganisms. However, the roles of EPS in phosphorus removal have not been fully understood. In this study, the phosphorus in the EBPR sludge was fractionated and further analyzed using quantitative (31)P nuclear magnetic resonance spectroscopy. The amounts and forms of phosphorus in EPS as well as their changes in an anaerobic-aerobic process were also investigated. EPS could act as a reservoir for phosphorus in the anaerobic-aerobic process. About 5-9% of phosphorus in sludge was reserved in the EPS at the end of the aerobic phase and might further contribute to the phosphorus removal. The chain length of the intracellular long-chain polyphosphate (polyP) decreased in the anaerobic phase and then recovered under aerobic conditions. However, the polyP in the EPS had a much shorter chain length than the intracellular polyP in the whole cycle. The migration and transformation of various forms of phosphorus among microbial cells, EPS, and bulk liquid were also explored. On the basis of these results, a model with a consideration of the roles of EPS was proposed, which is beneficial to elucidate the mechanism of phosphorus removal in the EBPR system.

Phosphorus in Runoff and Streams

Abstract: Publisher Summary This chapter discusses physical and chemical factors affecting the dynamics of phosphorus in runoff and streams. These factors determine not only the movement of phosphorus into runoff and streams but also its distribution between the aqueous and particulate phases. The factors affecting the dynamics and loads of phosphorus in runoff and streams illustrate the problems in interpreting the data thus far obtained. The major difficulty in data interpretation and comparison is the lack of uniformity in the forms of phosphorus measured. Surface runoff is a spasmodic rather that a continuous phenomenon, its composition at any location being highly heterogeneous and likely to change over short distances because the energy of the aqueous component, and therefore its ability to carry particulate material, varies with slope. The chapter explains the way the distribution of the phosphorus load between the solid and aqueous phases of surface runoff is measured. It also discusses the impact of phosphorus carried in streams on standing water.