Theorising age and generation in development: A relational approach

This introduction outlines the analytical approach informing the articles presented in this special issue. The project of ‘generationing’ development involves re-thinking development as distinctly generational in its dynamics. For this, we adopt a relational approach to the study of young people in development, which overcomes the limitations inherent to common categorising approaches. Concepts of age and generation are employed to conceptualise young people as social actors and life phases such as childhood and youth in relational terms. Acknowledging the centrality of young people in social reproduction puts them at the heart of development studies and leads the articles comprising this special issue to explore how young people’s agency shapes and is shaped by the changing terms of social reproduction brought about by development

Phosphorus content of ditch sediments as indicator of critical source areas (Research Note)

An inexpensive method for identifying high phosphorus (P) loads on ditches carrying water from critical source areas ("hot spots", i.e. manure-affected areas) was tested. Water flowing from the hot-spot areas is rich in dissolved nutrients (e.g. P) and nutrient-rich eroded material. In this study the water from hot spots contained an average of 2.2 mg/l dissolved reactive P but field ditch water 0.14 mg/l. We selected 62 ditches with varying P-load levels for sediment analysis. Five ponds and 16 lakes were also studied. The sediment samples were analysed by the AAAc-extraction (0.5 M ammonium acetate, 0.5 M acetic acid, pH 4.65) method used for routine soil testing in Finland. The analysis of sediment AAAc-P proved to be a useful method for identifying ditches carrying high P waters from hot spots. Half of the ditch sediments in the hot spot ditches showed high or excessive P concentrations. AAAc extraction of the sediment is less expensive than water analysis and the sampling can be extended to periods when no water flows in the ditches.;Tässä tutkimuksessa kehitettiin hinnaltaan kilpailukykyinen menetelmä pistemäisten fosforikuormitusalueiden paikantamiseen. Pistemäisiltä kuormitusalueilta tulevan veden liukoisten ravinteiden pitoisuudet ovat suuria ja veden kuljettama eroosioaines on runsasravinteista.Pistemäisten kuormituspisteiden veden liuenneen fosforin pitoisuus oli keskimäärin 2,2 mg/l ja peltoveden keskimäärin 0,14 mg/l tässä tutkimuksessa. Tutkimusaineistona olleista ojista valittiin 62 fosforikuormitukseltaan erilaista ojaa edelleen sedimenttitutkimukseen. Sedimenttinäytteet analysoitiin Suomessa käytössä olevalla viljavuusanalyysimenetelmällä. Ojasedimenttianalyysimenetelmä osoittautui hyväksi menetelmäksi, jolla voidaan paikantaa ojista tulevia korkeita fosforikuormituksia. Puolet kuormitusojien sedimentin fosforipitoisuuksista olivat viljavuusluokituksen mukaan "korkeita tai ""arveluttavan korkeita"". Fosforikuormituksen arviointi sedimenttianalyysimenetelmällä on edullisempaa kuin vesianalyysillä. Sedimenttimenetelmää voidaan käyttää myös silloin kun tutkittavat ojat ovat kuivia. Lisäksi menetelmän laboratoriokustannukset ovat edulliset.

Phosphorus content of ditch sediments as indicator of critical source areas (Research Note)

An inexpensive method for identifying high phosphorus (P) loads on ditches carrying water from critical source areas ("hot spots", i.e. manure-affected areas) was tested. Water flowing from the hot-spot areas is rich in dissolved nutrients (e.g. P) and nutrient-rich eroded material. In this study the water from hot spots contained an average of 2.2 mg/l dissolved reactive P but field ditch water 0.14 mg/l. We selected 62 ditches with varying P-load levels for sediment analysis. Five ponds and 16 lakes were also studied. The sediment samples were analysed by the AAAc-extraction (0.5 M ammonium acetate, 0.5 M acetic acid, pH 4.65) method used for routine soil testing in Finland. The analysis of sediment AAAc-P proved to be a useful method for identifying ditches carrying high P waters from hot spots. Half of the ditch sediments in the hot spot ditches showed high or excessive P concentrations. AAAc extraction of the sediment is less expensive than water analysis and the sampling can be extended to periods when no water flows in the ditches.