We investigate the possibility to replace the – so-called – Tier 1 IPCC approach to estimate soil N₂O emissions with stratified emissions factors that take into account both N-input and the spatial variability of the environmental conditions within the countries of the European Union, using the DNDC-Europe model. Spatial variability in model simulations is high and corresponds to the variability reported in literature for field data. Our results indicate that (a) much of the observed variability in N₂O fluxes reflects the response of soils to external conditions, (b) it is likely that national inventories tend to overestimate the uncertainties in their estimated direct N₂O emissions from arable soils; (c) on average over Europe, the fertilizer-induced emissions (FIE) coincide with the IPCC factors, but they display large spatial variations. Therefore, at scales of individual countries or smaller, a stratified approach considering fertilizer type, soil characteristics and climatic parameters is preferable.

Plastic greenhouse vegetable cultivation (PGVC) has played a vital role in increasing incomes of farmers and expanded dramatically in last several decades. However, carbon budget after conversion from conventional vegetable cultivation (CVC) to PGVC has been poorly quantified. A full carbon cycle analysis was used to estimate the net carbon flux from PGVC systems based on the combination of data from both field observations and literatures. Carbon fixation was evaluated at two pre-selected locations in China. Results suggest that: (1) the carbon sink of PGVC is 1.21 and 1.23 Mg C ha⁻¹ yr⁻¹ for temperate and subtropical area, respectively; (2) the conversion from CVC to PGVC could substantially enhance carbon sink potential by 8.6 times in the temperate area and by 1.3 times in the subtropical area; (3) the expansion of PGVC usage could enhance the potential carbon sink of arable land in China overall.

This paper focuses on the influence of uranium tailing piles on the contamination of their immediate surroundings. The monitoring was carried out on arable land near Pribram in Central Bohemia, Czech Republic. The monitored arable land is located 600 m northeast of the bottom of the piles. In addition, the high uranium (U) content in the topsoil ranged from 40 to 220 ppm. A former portion of it was found in an exchangeable fraction (49%). Both of these facts make this land unsuitable for agricultural use. The sequential extraction discovered a shift in the U content among sample spots situated in and outside the path of the predominant wind direction. In the first group, uranium binds mainly to Fe/Mn oxides, while in the other samples, U is accumulated in the more mobilizable fractions.

Background, aim, and scope Biowaste contains compounds of agricultural value such as organic carbon, nutrients, and trace elements and can partially replace mineral fertilizer (MIN) and improve the physical properties of the soil. However, the obvious benefits of land spreading need to be carefully evaluated against potential adverse effects on the environment and human health. Environmental contamination resulting from biowaste application is one of the key variables when assessing cost/benefits. This study provides data on the resulting concentration of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in the soil column as a result of the different types of fertilizers. Materials and methods In a long-term field experiment established in 1962, we investigated the influence of the application of biowaste-derived fertilizers such as sewage sludge (SSL), compost (COM), and farmyard manure (FYM) to a luvisol derived from loess on the contents of PCDD/Fs and DL-PCBs. Control plots amended only with MIN served as a basis to compare the biowaste-amended soils with soils affected only by atmospheric deposition, thus experimentally separating the two pathways of soil contamination. Samples of the soil column down to a depth of 90 cm were taken in 2001 and analyzed for PCDD/Fs and dioxin-like PCBs according to US-EPA methods 1613 and 1668, respectively. Results Thirty-nine years of experimental SSL and COM applications exceeding four times the maximal amount as laid down in German legislation resulted in a doubling of the international toxicity equivalent (I-TEQ) budget for PCDD/Fs and a threefold increase for DL-PCBs as compared to test plots amended with MIN only. As compared to MIN, the application of FYM had no effect on the PCDD/F and PCB content in soil. The average contribution of the DL-PCBs to the WHO-TEQ was 19% in the MIN and FYM plots and somewhat higher in the COM (23%) and in the SSL (27%) plots. Discussion Although the test plots received four times the maximum application of SSL as laid down in the German SSL ordinance and the investigated region represents the upper end of the topsoil concentrations typically found in Germany, the soils treated with SSL and COM were still a factor of 4 below the German guideline value of PCDD/Fs for arable land. No enhancement of translocation of PCDD/Fs and PCBs into the corresponding subsoils due to the presence of dissolved humic matter or other surfactants potentially present in the biowaste was observed. The similarity of congener patterns in all soils, irrespective of the type of fertilizer applied, points towards atmospheric deposition of PCDD/Fs and DL-PCBs as the main intake route in the soils. The higher levels in the SSL- and COM-amended soils can be explained by the fact that both biowastes are subject to atmospheric deposition occurring at their origin. In the case of COM, it is accumulation in the foliage, while in the case of SSL, atmospheric particulate from wet and dry deposition is collected in the wastewater treatment system via urban runoff. Conclusions It appears that the common practice of SSL applications in Germany does not pose a current threat to the agro-environment with regard to PCDD/Fs and DL-PCBs. However, time trend data on PCDD/Fs in SSL-amended soils will be needed to obtain a prognosis about the long-term effect of biowaste applications on soil quality.