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Phosphorus run-off from urban lawn care is a significant water quality concern in many US suburban communities. Many state and municipal governments in the USA adopt urban fertilizer laws or ordinances that prohibit the use of phosphorus-containing lawn fertilizers. This study assesses the long-term water-quality impacts of two phosphorus-reduction scenarios in a suburban watershed in Central New Jersey. While Scenario I reduces the phosphorus fertilizer application rates by 25%, Scenario II completely eliminates phosphorus fertilizer for urban lawns as required by such laws, rules or ordinances. The long-term water-quality impacts were estimated using the Soil and Water Assessment Tool and then compared to the total maximum daily load (TMDL) water-quality standards using the load duration curve approach. Scenario I will decrease total phosphorus (TP) load to streams by 15.34%. Scenario II achieves greater reduction in TP load to streams than Scenario I, but results in excessive nitrogen run-off and violation of the TMDL standard for total nitrogen.While many regulatory measures focus on reducing phosphorus run-off by prohibiting the use of phosphorus in urban lawn fertilizer, they should be carefully implemented to balance the nutrient needs to maintain healthy lawns and avoid such unintended consequences. [ABSTRACT FROM AUTHOR]

We propose the density-functional theory for one-dimensional harmonically trapped spin-1 bosons in the ground state with repulsive density-density interaction and antiferromagnetic spin-exchange interaction. The density distributions of spin-singlet-paired bosons and polarized bosons with different total polarization for various interaction parameters are obtained by solving the Kohn-Sham equations, which are derived based on the local density approximation and the Bethe ansatz exact results for a homogeneous system. Nonmonotonicity of the central densities is attributed to the competition between the density interaction and spin-exchange. The results reveal the phase separation of the paired and polarized bosons, the density profiles of which respectively approach the Tonks-Girardeau gases of Bose-Bose pairs and scalar bosons in the case of strong interaction. We give the radius-polarization phase diagram at strong interaction and find the critical polarization, which paves the way to directly observe the exotic singlet pairing in spinor gas experimentally. [ABSTRACT FROM AUTHOR]

We present a density-functional theory for the one-dimensional harmonically trapped Bose-Fermi mixture with repulsive contact interactions. The ground-state density distribution of each component is obtained by solving the Kohn-Sham equations numerically based on the local density approximation and the exact solution for the homogeneous system given by Bethe ansatz method. It is shown that for sufficiently strong interaction, a considerable amount of fermions are repelled out of the central region of the trap, exhibiting partial phase separation of Bose and Fermi components. Oscillations emerge in the Bose density curves, reflecting the strong correlation with fermions. For infinitely strong interaction, the ground-state energy of the mixture and the total density are consistent with the scenario that all atoms in the mixture are fully fermionized. [ABSTRACT FROM AUTHOR]