Indicator to predict the movement of phosphorus from soil to subsurface flow

The movement of phosphorus (P) in subsurface flow can contribute to losses from agricultural land. This study aims to identify a soil P threshold above which P loss is likely to accelerate as a function of soil and management type. Lysimeters (25 cm i.d. by 30 cm deep) were taken of four soils from agricultural watersheds in Pennsylvania and New York. The soils had a range of Mehlich-3 extractable P (7-517 mg of P kg(-1)) in surface soil (0-7.5 cm for grassland and 0-23 cm for cultivated/arable) and reactive P, filtered <0.45 microm (RP(<0.45 microm) in subsurface flow (0.007-1.53 mg of P L(-1)). The loss of P from lysimeters increased greatly when Mehlich-3 extractable P was in excess of a mean concentration of 280 mg kg(-1), the degree of saturation of P sorption sites exceeded 38%, and the corrected P sorption strength (corrected for desorption) derived from the monolayer Langmuir equation was less than 0.07 L of P mg(-1). Of these variables, P sorption strength was most consistently related to RP(<0.45 microm) in subsurface flow across a range of soil managements. Use of the corrected Langmuir sorption strength parameter to estimate subsurface flow RP(<0.45 microm) derived from four U.S. soils was tested on four soils of different physiochemical characteristics (one calcareous) from the U.K. The U.K. soils showed similar concentration trends to the U.S. soils, with elevated RP(<0.45 microm) below a sorption strength of 0.07 L of P mg(-1). We propose that the P sorption strength derived from the monolayer Langmuir equation may be used to estimate the potential for P loss in subsurface flow, when simpler environmental tests such as P saturation derived from acid ammonium oxalate extraction are unclear or unsuitable.     

Processes controlling soil phosphorus release to runoff and implications for agricultural management

Phosphorus (P) loss from agricultural land to surface waters is well known as an environmental issue because of the role of P in freshwater eutrophication. Much research has been conducted on the erosion and loss of P in sediments and surface runoff. Recently, P loss in sub-surface runoff via agricultural drainage has been identified as environmentally significant. High soil P levels are considered as a potential source of P loss. However, without favourable hydrological conditions P will not move. In this paper, we review the basis of soil P release into solution and transport in surface and sub-surface runoff. Our objectives are to outline the role of soil P and hydrology in P movement and management practices that can minimize P loss to surface waters. Remedial strategies to reduce the risk of P loss in the short-term are discussed, although it is acknowledged that long-term solutions must focus on achieving a balance between P inputs in fertilizers and feed and P outputs in production systems. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of implicit rewards on adults' motor skill responses.

The effects of implicit rewards on adult subjects were investigated by means of a simple motor skills task. Unlike previous data collected for children, implicit rewards had reinforcing effects for peers regardless of the sequential order in which they were presented to target subjects. The absence of either direct or implicit extinction with adults is hypothesized as due to developmental differences in their perceptions of the unfair implicit reward situation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicate matching in NLP: A review of research on the preferred representational system.

Reviews 15 studies investigating the use of the preferred representational system (PRS) in neurolinguistic programming (NLP) and summarizes the data collected. Aspects of design, methodology, population, and dependent measures are evaluated, with comments on the outcomes obtained. Results suggest that there is little supportive evidence for the use of the PRS in NLP in these 15 studies, with much data to the contrary. Questions of accountability are raised, and suggestions for future research are offered. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The environmentally-sound management of agricultural phosphorus

Freshwater eutrophication is often accelerated by increased phosphorus (P) inputs, a greater share of which now come from agricultural nonpoint sources than two decades ago. Maintenance of soil P at levels sufficient for crop needs is an essential part of sustainable agriculture. However, in areas of intensive crop and livestock production in Europe and the U.S.A., P has accumulated in soils to levels that are a long-term eutrophication rather than agronomic concern. Also, changes in land management in Europe and the U.S.A. have increased the potential for P loss in surface runoff and drainage. There is, thus, a need for information on how these factors influence the loss of P in agricultural runoff. The processes controlling the build-up of P in soil, its transport in surface and subsurface drainage in dissolved and particulate forms, and their biological availability in freshwater systems, are discussed in terms of environmentally sound P management. Such management will involve identifying P sources within watersheds; targeting cost-effective remedial measures to minimize P losses; and accounting for different water quality objectives within watersheds. The means by which this can be achieved are identified and include developing soil tests to determine the relative potential for P enrichment of agricultural runoff to occur; establishing threshold soil P levels which are of environmental concern; finding alternative uses for animal manures to decrease land area limitations for application; and adopting management systems integrating measures to reduce P sources as well as runoff and erosion potential.     

Research findings on neurolinguistic programming: Nonsupportive data or an untestable theory?

In an earlier review of the experimental literature on neurolinguistic programming (NLP), the present author (see record 1984-21020-001) concluded that the effectiveness of this therapy was yet to be demonstrated. In their comment on that review, E. L. Einspruch and B. D. Forman (see record 1986-08199-001) agreed with this conclusion but suggested that it was due to the presence of methodological errors in the research on NLP to date and that the efficacy of NLP was open to debate. In the present article, it is contended that those suggestions were based on misconceptions regarding the factors that limit the methodological worth of research. Several of the detailed criticisms from that review are refuted, and data from 7 recent studies that further demonstrate that research data do not support either the basic tenets of NLP or their application in counseling situations are presented. Implications for the use of NLP in counseling research or clinical practice are discussed. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)