|
|
|
|
|
| Uusitalo, Risto. |
| Runoff phosphorus (P) associated with eroded soil contributes to eutrophication to some extent. The present work examines two methods for estimating the potential bioavailability of particulate P (PP) in runoff, and studies the concentrations and losses of different P forms in surface and subsurface runoff from arable soils. The potential bioavailability of PP was approximated by extraction with (i) anion exchange resin (AER-PP), giving a measure of desorbable PP under aerobic conditions, and with (ii) bicarbonate-dithionite (BD-PP), which dissolves redox-labile PP. Both methods were applied in runoff analysis without sediment preconcentration. |
| Tipo: Thesis |
Palavras-chave: Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/11135/1/met53.pdf |
| |
|
|
| Uusitalo, Risto; Turtola, Eila; Grönroos, Juha; Kivistö, Juhani; Mäntylahti, Väinö; Turtola, Ari; Lemola, Riitta; Salo, Tapio. |
| Soil test phosphorus (P) concentration has a major influence on the dissolved P concentration in runoff from agricultural soils. Thus, trends in soil test P partly determine the development of pollution potential of agricultural activities. We reviewed the changes of soil test P and P balances in Finnish agriculture, and assessed the current setting of P loss potential after two Agri-Environmental Programs. Phosphorus balance of the Finnish agriculture has decreased from +35 kg ha–1 of the 1980’s to about +8 kg P ha–1 today. As a consequence, the 50-yr upward trend in soil test P concentrations has probably levelled out in the late 1990’s, as suggested by sampling of about 1600 fields and by a modelling exercise. For the majority of our agricultural soils,... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2007 |
URL: http://orgprints.org/17083/1/uusitalo.pdf |
| |
|
|
| Uusitalo, Risto; Aura, Erkki. |
| Runoff from clayey soils often contains abundant particulate phoshorus (PP), part of which may solubilize in surface waters. Monitoring losses of potentially bioavailable forms of PP is expensive, calling for other ways to predict them. Such predictions could be based on soil loss and available soil P indices, e.g., agronomic P status. To study correlations between P pools in runoff versus soil P saturation (by Mehlich 3 extraction; DPSM3) and acetate soil test P (PAc), 15 clayey soils of south Finland were subjected to laboratory rainfall simulation. Runoff from these simulations was analyzed for concentrations of suspended soil (TSS), dissolved molybdate-reactive P (DRP), total P (TP), and, as normalized to soil loss, potentially bioavailable forms of... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2005 |
URL: http://orgprints.org/16844/1/uusitalo.pdf |
| |
|
|
| Turtola, Eila; Alakukku, Laura; Uusitalo, Risto; Kaseva, Antti. |
| Conservation tillage practices were tested against autumn mouldboard ploughing for differences in physical properties of soil, surface runoff, subsurface drainflow and soil erosion. The study (1991 -2001) was performed on a gently (2%) sloping clayey soil of southern Finland, with two replicates of the tillage treatments on 0.5 ha plots. The annual shares of surface runoff of the total flow (surface runoff + subsurface drainflow) were 8–42% for ploughing (depth 20–23 cm), 36–66% for shallow autumn stubble cultivation (depth 5–8 cm) and 36–82% for soil left untilled over winter. Surface runoff increased with decrease in the tillage intensity, and in line with the values of depressional water storage, macroporosity and saturated hydraulic conductivity.... |
| Tipo: Journal paper |
Palavras-chave: Environmental aspects; Soil. |
| Ano: 2007 |
URL: http://orgprints.org/16898/1/turtola.pdf |
| |
|
|
|
