Nitrogen ratio to phosphorus

Smith, V. H. (1983). Low nitrogen to phosphorus ratios favor dominance by blue-green algae in lake phytoplankton. Science 221, 669-671. 

Studies have shown that adding bioenhancement agents to oil spilled on land can enhance the removal rate of the saturate and some of the aromatic fraction of the oil, so that as much as 40% of the oil is degraded in time periods from one month to a year. It has been found that the agents are most effective when added at an oil-to-nitrogen-to-phosphorus ratio of 100 10 1. Fertilizers that maintain the soil at a more neutral level are best for degrading oil. Fertilizers that make the soil acidic usually slow biodegradation. Fertilizers that are more oil-soluble and less water-soluble are most effective as they are not as likely to be washed away. 

Molar Nitrogen to Phosphorus Ratios of Soils and Microbial Biomass in Select Hydrologic Units of the Everglades... 

Figure 16.20 Nitrogen-to-phosphorus (N P) ratios at Station ALOHA. (A) Depth profiles of N P forinorganic (NO3 P04 ) and total (TDN TDP) pools showing fundamentally different depth trends relative to the 16N 1P Redfield ratio, which is shown as a vertical dashed line in each plot. The elevated N P (>16) for the total dissolved pool, especially in the upper 100 m of the water column, indicates an excess of N relative to the P requirements for biomass production, if all DON and DOP are biologically available.The middle plot shows the depth dependence for the stoichiometric relationships if the DON and DOP pools are corrected for residual deep water concentrations (DON = 2.23 pM and DOP = 0.04 pM, respectively) to remove the contribution of the recalcitrant pools. After this correction, the near-surface N P appears to converge near the Redfield ratio with a broader envelope of values near the surface. This stoichiometry of the DOM pool may be an important factor in the selection for, or against, N2 fixing microorganisms. From Karl et al. (2001a).

Figure 26.5 The ratio of nitrogen to phosphorus (N P) excreted by mesozooplankton (squares) and microzooplankton (circles) plotted against the N P in the algal pool. Data from Le Borgne, 1982a. (Adapted from Sterner, 1990).

Figure 38.8 Effects of P04 scavenging on cellular partitioning of P and N P ratios in eight natural estuarine bloom samples of prokaryotic and eukaryotic algae. (A) Fractions of total cell-associated P in the intracellular (filled bars) and surface-adsorbed (open bars) pools (B) Nitrogen to phosphorus (N P) ratios calculated using total cellular P (filled bars) and intracellular P pools after removal of surface-adsorbed P with the oxalate reagent (open bars). Error bars represent the standard deviations of triplicate samples, and the dashed lines indicate the Redfield ratio. Fu et al. (2005a), Limnology and Oceanography.

The ratio of carbon to nitrogen to phosphorus (C N P) has important effects on the rate of biofilm development. It has been reported that membranes which suffered severe biofouling were found to contain a high percentage (typically >60%) of organics. Laboratory characterization of membrane biofilms found that a typical biofilm contains ... 

Another factor to consider is that the ratio of nitrogen to phosphorus in nutrient inputs from land will tend to reflect the extent of human activity in the landscape. As the landscape changes from one dominated by forests to one dominated by agriculture and then industry, total nutrient fluxes from land increase for both nitrogen and phosphorus, but the change is often greater for phosphorus and so the... 

Factors that affect the uptake of phosphorus from added plant residues by a crop include the carbon-to-phosphorus ratio (Umrit and Friesen, 1994), soil phosphorus availability (Thibaud et al., 1988), nitrogen availability (Umrit and Friesen, 1994) and the amount of added residues (Joseph et al., 1995). Armstrong et al. (1993) reported that the net release of phosphorus from P-... 

Fig. 15.6. CENTURY model-simulated results for soil phosphorus loss (organic and inorganic phosphorus) total nitrogen loss (nitrate, gaseous nitrogen and dissolved organic nitrogen) and nitrate loss (a) and change in live leaf carbon-to-nitrogen and carbon-to-phosphorus ratios (b) for the Hawaiian 4.1 million year soil chronosequence.

Equation 8.4 predicts that aerobic respiration should release dissolved inorganic nitrogen and phosphorus into seawater in the same ratio that is present in plankton, i.e., 16 1. As shown in Figure 8.3, a plot of nitrate versus phosphate for seawater taken from all depths through all the ocean basins has a slope close to 16 1. Why do both plankton and seawater have an N-to-P ratio of 16 1 Does the ratio in seawater determine the ratio in the plankton or vice versa Current thinking is that the N-to-P ratio of seawater reflects a quasi steady state that has been established and stabilized by the collective impacts of several biological processes controlled by marine plankton. 

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