No abstract

There is critical need for a practical indicator to assess the potential for phosphorus (P) movement from a given site to surface waters, either via surface runoff or subsurface drainage. The degree of phosphorus saturation (DPS), which relates a measure of P already adsorbed by a soil to its P adsorption capacity, could be a good indicator of that soil's P release capability. Our primary objective was to find a suitable analytical protocol for determining DPS and to examine the possibility of defining a threshold DPS value for Florida's sandy soils. Four farmer-owned dairy sprayfields were selected within the Suwannee River basin and soil profiles were randomly obtained from each site, as well as from adjacent unimpacted sites. The soil samples were divided either by horizon or depth, and DPS was determined for each soil sample using ammonium-oxalate (DPS(Ox)), Mehlich-1 (DPS(M1)), and Mehlich-3 (DPS(M3)) extracts. All methods of DPS calculations were linearly related to one another (r2 > 0.94). Relationships between water-soluble P and DPS indicate that the respective change points are: DPS(Ox) = 20%, DPS(M1) = 20%, and DPS(M3) = 16%. These relationships include samples from Ap, E, and Bt horizons, and various combinations thereof, suggesting that DPS values can be used as predictors of P loss from a soil irrespective of the depth of the soil within a profile. Taking into consideration the change points, confidence intervals, agronomic soil test values, and DPS values from other studies, we suggest replacing Mehlich-1 P values in the Florida P Index with the three DPS categories (DPS(M1) = <30, 30-60, and >60%) to assign different P loss ratings in the P Index.

The 3-factor model is likely to provide more specific information for studies in the field. In the construction of scales for use with diverse samples, researchers need to pay greater attention to racial/ethnic differences in interpretation of items.

Orange juice (OJ) was treated with a continuous high‐pressure carbon dioxide (HPCD) system, and the quality parameters pH, Brix, titratable acidity (TA), cloud, pectinesterase (PE) activity, color, and sensory attributes were determined. Treatment pressures were 38, 72, and 107 MPa, and CO2/juice (w/w) ratios were from 0.40 to 1.18. Residence time was kept at 10 min. Cloud increased between 446% and 846% after treatments. There were no significant changes in pH and Brix (α= 0.05). TA of the treated juice was found to be significantly different from that of control (α= 0.01). PE was not completely inactivated. There was a small, but significant increase in juice L‐value (α= 0.01) and a decrease in a‐value for color. There was no significant change in b‐values (α= 0.05). Statistical analysis for the sensory data showed no difference between fresh, frozen control juice and treated juice after 2 wk of refrigerated storage at 1.7 °C.

Eleven fishing tournaments for largemouth bass Micropterus salmoides floridanus, held on two Florida lakes during July 1984-June 1985, were studied to quantify fish mortality and to evaluate associations between mortality and environmental and tournament conditions. Postrelease mortality was determined by holding largemouth bass in floating mesh cages for 14 or 2 ! d. Prerelease, postrelease, and total mortality averaged 18.6% (range, 0.8-42.8%), 10.0% (2.2-26.7%), and 26.7% (5.2-47.8%), respectively. Prerelease and total mortality were significantly (P < 0.05) related to water temperature but not significantly related to air temperature, cumulative radiation, number of teams, mean catch per team, or mean weight per fish. Postrelease mortality was not significantly related to any measured variable. Most postrelease mortality occurred during the first 6 d after the tournament, and the greatest single-day postrelease mortality occurred within 24 h. We observed no gross pathology among the fish held in the cages. Comparison of our results with previous studies indicated the survival oflargemouth bass caught in tournaments has increased since the inception of live-release bass tournaments. Because of the relatively high survival of fish caught in tournaments, live-release bass tournaments may, on some waters, provide a means for reducing angler exploitation of largemouth bass. The variation in mortality suggests that further improvements in survival of largemouth bass caught in tournaments can be attained.Fishing tournaments for bass Micropterus spp.