. 2001. The importance of early season phosphorus nutrition. Can. J. Plant Sci. 81: 211-224. A review of studies conducted in a range of plant species indicated the importance of an adequate supply of P during early crop growth and outlined plant adaptations for accessing early season P. Potential implications of the requirement for early season P in the development of management practices to optimize P supply for crop production were also discussed. Phosphorus plays a critical role in energy reactions in the plant. Deficits can influence essentially all energy requiring processes in plant metabolism. Phosphorus stress early in the growing season can restrict crop growth, which can carry through to reduce final crop yield. Deficiencies during early growth generally have a greater negative influence on crop productivity than P restrictions imposed later in growth. Plants respond to P deficiencies by adaptations that increase the likelihood of producing some viable seed. The adaptations increase the ability of the plant to access and accumulate P and include modification of rhizosphere pH, diversion of resources to root production, increased root proliferation in high-P regions, and formation of associations with vesicular arbuscular mycorrhizae. Plants differ in strategies adopted and in efficiency of P absorption.Effective nutrient management for optimal crop production must ensure that P is supplied to the crop in adequate amounts early in the growing season. It is important that we develop methods to accurately predict the early season P supply from the soil, in order to avoid either over-fertilization or crop deficiencies. Practices to provide adequate P early in plant growth include placement of P fertilizer in or near the seed-row and maintenance of adequate concentrations of plant-available P in the soil through a long-term nutrient management strategy. Other possible management practices could include enhancement of seed concentrations of P, manipulation of tillage system and crop sequence, improved activity of mycorrhizae and other microbiological agents such as Penicillium bilaii to increase phytoavailability of soil P, or genetic selection of crops with an enhanced ability for early season uptake of P from both soil and fertilizer sources. As plants differ in relative abilities to access P from the soil and fertilizer applications, nutrient management must be tailored to the specific crop, in order to optimize P supply and crop productivity. By restricting fertilizer applications to situations where P supply is limiting to crop production and by use of effective P management practices, we can optimize the economic of fertilizer use while avoiding negative impacts on environmental quality. Une analyse des recherches effectuées sur diverses espèces végétales révèle l'importance d'un apport suffisant de phosphore au début de la période végétative et montre comment les plantes s'adaptent pour trouver le phosphore (P) dont elles ont besoin. Les auteurs ont aussi examiné les conséquences éventuelles de cette...

In this paper we employ dichotomous, multinomial and conditional logit models to analyze the employment-migration behavior of some 380,000 U.K. university graduates. By controlling for a range of variables related to human capital acquisition and local economic conditions, we are able to distinguish between different types of sequential migration behavior from domicile to higher education and on to employment. Our findings indicate that U.K. female graduates are generally more migratory than male graduates. We suggest that the explanation for this result lies in the fact that migration can be used as a partial compensation mechanism for gender bias in the labor market. Copyright Blackwell Publishing, Inc. 2007

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This paper explores the sources and impact of variations of a given school quality at either primary or secondary level as capitalised into the price of houses. The results provide new evidence on the complex and subtle ways in which housing markets capitalise the value of local public goods such as school quality and suggest that this is highly nonlinear. We expect variation in the capitalised price according to the elasticity of supply of 'school quality' in the local market, the certainty with which that quality can be expected to be maintained and the suitability of the dwelling to accommodate children.Concern over the quality of local schools, and over the variation in this quality, has drawn the attention of parents, policy makers and scholars. For many households, there is a single path to access quality education: identify an acceptable quality state-supported school and purchase a house in the area served by that school. Households lacking the means to move to such areas will face reduced educational opportunities, and that fact continues to generate concern.Interest in these issues has a long history. For economists, it goes back at least to Tiebout (1956) and Oates (1969). The questions they addressed were how do we determine the demand for and supply of local public goods, including education, and how do we pay for such goods. It was Oates who first drew attention to the ways in which the value of local public goods were capitalised in urban land markets. From this many implications flow including the role that land markets play in articulating social segregation (Brueckner et al., 1999) and the interaction this will have with the distribution of incomes (Cheshire et al., 2000) and the supply characteristics of local public goods and amenities. In this paper we explore the extent of capitalisation of educational quality into house prices, and examine how this might be affected by factors conditioning the supply of educational quality of a given expected standard as well as by local policies, such as land use planning.At least four methodological approaches can be distinguished in the literature concerned with estimating the value placed on school quality. The longest established is a straightforward hedonic approach of which two of the others are variants. The hedonic approach has some 80 years of evolutionary development behind it since agricultural economists first implemented it as a purely empirical technique to help identify the characteristics of vegetables commanding the highest price. Since Rosen's (1974) contribution it has become one of the * We would like to thank the Leverhulme Foundation and the Lincoln Institute of Land Policy for supporting the work underlying this paper. We would also like to thank numerous colleagues, the referees and the Editor of this Journal for valuable comments and insights. The usual disclaimer applies with respect to remaining errors.