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The effects of atmospheric deposition on N cycling in acidified soils were studied at three spruce and one beech forested sites in the Czech Republic. Nitrogen content and delta(15)N were monitored in bulk and throughfall precipitation, needles, leaves, soils and soil solutions. Changes in soil NO3- production, effect of admiring of atmospheric N in spruce forest and N consumption in deciduous forest are described using changes in N-15 fractionation of mineralized N in soil. Admiring of atmospheric NH4+ can be identified at low concentrations ofexchangeable NH4+. The delta(15)N ratio of atmospheric NO3- input ison average by 2 parts per thousand less negative than the delta(5)N ratio in soil water; admiring changes the delta(15)N of soil NO3- detected in lysimeters. [ABSTRACT FROM AUTHOR]

This study provides an assessment of the spatial variability of the long-term leaching of nutrients, total organic carbon (TOC) and iron (Fe-tot) from 22 forested catchments (0.69-56 km(2)), distributed across all but the northernmost areas of Finland. The natural, unmanagedKruunuoja catchment is located in a national park, while the other catchments represent Finnish forestry land. The average leaching of P-tot (4.2 kg km-2 yr-1) from the Kruunuoja catchment was small compared to the catchments representing forestry land (on average 10 kg km-2 yr-1). Moreover, P fertilization was the most important predictor for the spatial variation in P-tot leaching (r(2) = 0.45). Leaching of TOC, Fe-tot and N compounds was not closely related to forestry practices. Median C/N ratio inthe study streams was high (range 34-66). The average inorganic N proportion and leaching of NO3--N were lowest in the Kruunuoja catchment (7.3 % and 2.8 kg km-2 yr-1, respectively) and highest in the southernmost Teeressuonoja catchment (54 % and 100 kg km-2 yr-1, respectively) located in the highest N deposition area. The most important forestry practices since the1960's have affected about 2.4 % of the area of study sites per year(cf. 2 % in the entire country in 1991). Moreover, the mean annual runoff from the catchments (230-430 mm yr-1) agrees with the mean annual runoff from Finland (301 mm yr-1). Consequently, the results of the study catchments can be used to estimate average total annual leaching from Finnish forestry land: 2,700 t of P-tot, 48,000 t of N-tot, 110,000 t of Fe-tot and 1.5 million t of TOC. [ABSTRACT FROM AUTHOR]

Nitrogen deposition, leaching, and retention were monitored in a mature spruce (Picea abies Karsten) dominated mixed boreal forest in eastern Finland. Bulk precipitation, throughfall, stemflow, and percolation through the podzolic soil profile were monitored from 1993 to 1996. Mean annual bulk deposition of total N was 3.83 kg ha-1, of which 33 % was NH4+-N, 26 % was NO3--N, and 41 % was organic N. Throughfall+stemflow flux of total N was 2.93 kg ha-1 yr-1. Sixty-four % of NH4+-N and 38 % of NO3--N in bulk precipitation was retained by the tree canopy. Organic N was released (0.27kg ha-1 yr-1) from the tree canopy. Nitrate-N was retained and organic N was leached as the water passed through the ground vegetation and soil O-horizon. Ammonium-N and organic N wereretained mainly in the E-horizon. The output of total N from the E-horizon was only 5 % of the total N deposition in the forest stand during the study period and it was mainly as organic N. The output of inorganic N forms from under B-horizon was seasonal and occurred mainlyat spring snowmelt. [ABSTRACT FROM AUTHOR]

Sewage sludge can be used as fertiliser, offering the possibility of safely recycling this waste product as a resource in agricultural applications. As the environmental concerns related to waste recycling in agricultural applications are well-known, restrictions on the use of sewage sludge have been implemented by the EU and local authorities. This work aimed to evaluate the nitrogen leaching associated with the application of sludge and the effectiveness of the temporal restrictions on its application implemented to safeguard the environment in the Lombardy region of northern Italy (120 days in Nitrate Vulnerable Zones and 90 days elsewhere) using the CropSyst model which was first validated. The effects of fertilisation using four different sludge types on N leaching were simulated at five sites under cultivation with maize and rice crops; six different timing schemes for sludge application were tested, three of which involved dates that were in agreement (AT) with the regulation, while the other three were not in agreement (NAT). We detected a significant effect of the sludge type and application timing, whereas the effect of their interaction was never significant. The mean annual leaching was 22 to 154 kg N ha(-1). The higher the ammonium N content in the sludge was, the greater the potential for N leaching was found to be. For the maize crop, the distribution of sludge in the late fall period resulted in significantly greater N leaching (61 kg N ha(-1)) and led to lower yields (9 t DM ha(-1)) compared to late winter fertilisation (49 kg N ha(-1); 10 t DM ha(-1)), whereas no differences in N leaching or yield were detected between AT and NAT, which was also observed for the rice crop. Therefore, the applied temporal constraints did not always appear to be advantageous for protecting the environment from leaching., (Copyright © 2013 Elsevier B.V. All rights reserved.)