Phosphorus Chemistry

Nutrient management is an important practice in improving crop and soil productivity. This study investigated the active phosphorus fraction of Organo-Mineral Fertiliser (OMF) amended soils in comparison to the unamended soils. The experiment was set up as a completely randomized block design in duplicates. Phosphorus fractionation extractions were carried out in soils amended with 5 and 10 t ha-1 OMF, inaddition to the unamended soils. For the unamended soils, the CaP (0.42+0.61 ug ml-1) and Saloid P (0.86+0.07 ug ml-1) fractions were low compared to FeP (12.7+10.9 ug ml-1) and AlP (2.27+1.39 ug ml-1) fractions. The P distribution in the unamended soils in increasing order was CaP<Saloid P<AlP<FeP. Application of OMF at 5 and 10 t ha-1 rearranged the P distribution in the order of Saloid P<AlP<CaP<FeP. The major influence of OMF was on soil pH (67 %) and this accounted for 80 % of the variation in the amended soils. Not minding the available P levels of the soil, the dominance of FeP and AlP fractions over saloid P and CaP fractions explain the chemistry of P-unresponsive soils and the need for a sustainable management system.

The Florida Everglades is being threatened by high-nutrient stormwater coming from agricultural runoff. The main nutrient problem is phosphorus, which causes the highly oligotrophic sawgrass (Cladium jamaicense) communities in the northern Everglades to become eutrophic Typha latifolia/T. domingensis
communities. Current government directives require that the total phosphorus concentration of storm water drainage into the Everglades be limited to approximately 10 ppb (mg-P/L). Over 23,000 ha treatment wetlands, referred to locally as stormwater treatment areas (STAs), have been created from
farmland to treat the stormwater. They are generally effective in removing 60–80% of the total phosphorus; however, the 10 ppb goal has rarely been achieved. A three-year experiment, involving mesocosms planted with Everglades-native wetland plants was conducted in the Florida Everglades from
March 2010 to March 2013. Eighteen flow-through mesocosms (6m
1m
1m with 40-cm water depth) received about 2.6 cm/day inflow. The eighteen mesocosms were randomly assigned with six different plant communities with three replicates of each treatment, consisting of sawgrass (C.
jamaicense); waterlily (Nymphaea odorata); cattail (Typha domingensis); submerged aquatic vegetation (SAV) including Najas guadalupensis, and Chara sp. and a Nymphaea–Eleocharis sp. mixed community; and soil without vegetation as a control. Total phosphorus (TP) in the inflow water was 25 ± 1mg-P/L (n = 55) over the 3 years. Through 2012 the average outflow of all of the treatments was 34±1mg-P/L, a 51%
decrease from the average outflow of 69±6mg-P/L for 2011. Outflows began to be routinely lower than the inflow in the 3rd year of the study. The average total phosphorus concentration decreased overall to 19±1 (n = 5) at the end of the study in 2013 suggesting that the suspected phosphorus reflux from the
mesocosm soils into the water column slowed after 2–2.5 years of mesocosm operation. Comparing outflows of the individual treatments for 2013, the Nymphaea, control/Chara, and Typha treatments were lower (p<0.05) than the inflow with average outflow concentration of 11±1, 15±3 and 16±1mg-P/L
respectively. When the 2013 data are isolated, 4 of the 6 vegetation treatments showed total phosphorus
removal, ranging from mixed community (17% removal), to Typha (28% removal), to the control (34%removal) and to Nymphaea (51% removal). We conclude that any treatment wetland constructed with
local Florida soils and designed to achieve low (10–15 ppb P) concentrations would probably take a
minimum of 2 years to become sinks of phosphorus. We also conclude that wetlands can be created to achieve these low thresholds if low TP loading and self-design strategies are incorporated into the project design.

"By Mohammad Hakimi (a), Keyvan Moeini (a), Zahra Mardani (a) and Reza Takjoo (b)
(a) Department of Chemistry, Payame Noor University, Tehran, I. R. Iran
(b) Department of Chemistry, School of Sciences, Ferdowsi University of Mashhad, Mashhad, I. R. Iran.

A new mixed-ligand copper(I) complex [Cu(L)(PPh3)2] (1) of methyl 2-(2-hydroxybenzylidene)hydrazinecarbodithioate (H2L) and triphenylphosphine was prepared and identified by elemental analysis, Fourier transform infrared, Raman, 1H, 13C, 31P NMR, and UV-Vis spectroscopy, molar conductivity, and single-crystal X-ray diffraction. The copper(I) ion in the crystal structure of (1) has a distorted tetrahedral geometry achieved by the coordination of the two phosphorus atoms of triphenylphosphine groups and a nitrogen and sulfur atom
of HL−. The intramolecular O–H···N and intermolecular C–H···S hydrogen bonds stabilize the crystal network of (1). In addition to these hydrogen bonds, there are π−π stacking between parallel aromatic rings belonging to the triphenylphosphine groups of adjusting complexes.
Three structural surveys, including coordination numbers of the copper atom, coordination modes of ligand, and all reported structures containing hydrazinecarbodithioate Schiff bases
are presented.

Supplemental data for this article can be accessed on the publisher’s website. CCDC 918484 for [Cu(L)(PPh3)2] (1) contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre through www.ccdc.cam.ac.uk/data request/cif.

Keywords: Hydrazinecarbodithioate; copper(I) complex; NS-donor ligand; X-ray crystal structure; racemic

DOI: 10.1080/10426507.2013.843001

New derivatives of 1,2-dihydro-2-alkenyl-3H-pyrazol-3-ones 6 and 7 have been synthesized at room temperature by a one-pot two-step reaction of PCl3, a ketone methylhydrazone, and a β-keto ester. With ketone methylhydrazones bearing at least a phenyl group in the α-positions to the CN bond and in the second step β-keto esters, such as propionyl- or butyrylacetates, we obtained 2-pyrrolylacetates 8 as unexpected products together with pyrazolones 7. The ratio of the two products depends on the nature of the groups in the α-positon to the CN bond. A chlorodiazaphospholine 1 is the key intermediate of this new reaction, and a plausible mechanism of formation of the azaheterocycles is reported.