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Can C-budget of natural capital be restored through conservation agriculture in a tropical and subtropical environment?
2022
De Moraes Sa, Joao Carlos | Lal, Rattan | Briedis, Clever | De Oliveira Ferreira, Ademir | Tivet, Florent | Inagaki, Thiago Massao | Potma Gonçalves, Daniel Ruiz | Canalli, Lutécia Beatriz | Bürkner dos Santos, Josiane | Romaniw, Jucimare
Conservation agriculture through no-till based on cropping systems with high biomass-C input, is a strategy to restoring the carbon (C) lost from natural capital by conversion to agricultural land. We hypothesize that cropping systems based on quantity, diversity and frequency of biomass-C input above soil C dynamic equilibrium level can recover the natural capital. The objectives of this study were to: i) assess the C-budget of land use change for two contrasting climatic environments, ii) estimate the C turnover time of the natural capital through no-till cropping systems, and iii) determine the C pathway since soil under native vegetation to no-till cropping systems. In a subtropical and tropical environment, three types of land use were used: a) undisturbed soil under native vegetation as the reference of pristine level; b) degraded soil through continuous tillage; and c) soil under continuous no-till cropping system with high biomass-C input. At the subtropical environment, the soil under continuous tillage caused loss of 25.4 Mg C ha−1 in the 0–40 cm layer over 29 years. Of this, 17 Mg C ha−1 was transferred into the 40–100 cm layers, resulting in the net negative C balance for 0–100 cm layer of 8.4 Mg C ha−1 with an environmental cost of USD 1968 ha−1. The 0.59 Mg C ha−1 yr−1 sequestration rate by no-till cropping system promote the C turnover time (soil and vegetation) of 77 years. For tropical environment, the soil C losses reached 27.0 Mg C ha−1 in the 0–100 cm layer over 8 years, with the environmental cost of USD 6155 ha−1, and the natural capital turnover time through C sequestration rate of 2.15 Mg C ha−1 yr−1 was 49 years. The results indicated that the particulate organic C and mineral associate organic C fractions are the indicators of losses and restoration of C and leading C pathway to recover natural capital through no-till cropping systems.
Show more [+] Less [-]Impacts of land uses on mercury retention in long-time cultivated soils, Brazilian Amazon
2013
Comte I. | Lucotte M. | Davidson R. | Reis de Carvalho C. | de Assis Oliveira F. | Rousseau G.X.
Many studies have shown the relationship between fire clearing and mercury contamination of aquatic ecosystems in the Brazilian Amazon. This study aimed at quantifying mercury content in long-time cultivated soils and at assessing the potential of a fire-free alternative clearing technique on mercury retention for long-time cultivated soils compared to traditional slash-and-burn. This case study included five land uses: one crop plot and one pasture plot cleared using slash-and-burn, one crop plot and one pasture plot cleared using chop-and-mulch, and one 40-year-old forest as a control. Low mercury concentrations were recorded in the surface horizon (24.83 to 49.48 ng g?1, 0–5 cm depth). The long-time cultivation (repeated burnings) of these soils triggered large mercury losses in the surface horizon, highlighted by high enrichment factors from surface to deeper horizons. The predominant effect of repeated burnings before the experimental implementation did not let us to distinguish a positive effect of the chop-and-mulch clearing method on soil mercury retention for crops and pastures. Moreover, some processes related to the presence of the mulch may favor mercury retention (Hg volatilization decrease, cationic sites increase), while others may contribute to mercury losses (cationic competition and dislocation, mobilization by the dissolved organic matter). (Résumé d'auteur)
Show more [+] Less [-]Integrated modeling of agricultural scenarios (IMAS) to support pesticide action plans: the case of the Coulonge drinking water catchment area (SW France)
2017
Vernier F. | Leccia-Phelpin O. | Lescot J.M. | Minette S. | Miralles A. | Barberis D. | Scordia C. | Kuentz-Simonet V. | Tonneau J.P.
Non-point source pollution is a cause of major concern within the European Union. This is reflected in increasing public and political focus on a more sustainable use of pesticides, as well as a reduction in diffuse pollution. Climate change will likely to lead to an even more intensive use of pesticides in the future, affecting agriculture in many ways. At the same time, the Water Framework Directive (WFD) and associated EU policies called for a “good” ecological and chemical status to be achieved for water bodies by the end of 2015, currently delayed to 2021–2027 due to a lack of efficiency in policies and timescale of resilience for hydrosystems, especially groundwater systems. Water managers need appropriate and user-friendly tools to design agro-environmental policies. These tools should help them to evaluate the potential impacts of mitigation measures on water resources, more clearly define protected areas, and more efficiently distribute financial incentives to farmers who agree to implement alternative practices. At present, a number of reports point out that water managers do not use appropriate information from monitoring or models to make decisions and set environmental action plans. In this paper, we propose an integrated and collaborative approach to analyzing changes in land use, farming systems, and practices and to assess their effects on agricultural pressure and pesticide transfers to waters. The integrated modeling of agricultural scenario (IMAS) framework draws on a range of data and expert knowledge available within areas where a pesticide action plan can be defined to restore the water quality, French “Grenelle law” catchment areas, French Water Development and Management Plan areas, etc. A so-called “reference scenario” represents the actual soil occupation and pesticide-spraying practices used in both conventional and organic farming. A number of alternative scenarios are then defined in cooperation with stakeholders, including socio-economi
Show more [+] Less [-]Towards integrated national modelling with particular reference to the environmental effects of nutrients
1998
Alkemade, J.R.M. | Grinsven, J.J.M. van | Wiertz, J. | Kros, J. (National Institute of Public Health and the Environment, Bilthoven (Netherlands))
The impact of land use on N2O emissions from watersheds draining into the Northeastern Atlantic Ocean and European Seas
1998
Kroeze, C. | Seitzinger, S.P. (WIMEK, Wageningen Agricultural University, Wageningen (Netherlands))
The sensitivity of surface waters of Great Britain to acidification predicted from catchment characteristics
1995
Hornung, M. | Bull, K.R. | Cresser, M. | Ullyett, J. | Hall, J.R. | Langan, S. | Loveland, P.J. | Wilson, M.J. (ITE, Merlewood Research Station, Grange-over-Sands, Cumbria, LA11 6JU (United Kingdom))
[Groundwater: Perspective and expectation, the Strategic Research Program on Environment]
1993
Fredericia, J.
Groundwater protection: the science and practice of land surface zoning
1995
Foster, S. | Skinner, A.C.
[Nickel problems in the groundwater in Roskilde county]
2002
Olsen, M., Hartelius, E. | Pratt, A. | Terkelsen, M. | Aktor, H.
[Zonation of groundwater and elements in task force plans in Frederiksborg County]
2002
Ruegge, K. | Bay, H. | Palsgaard, M. | Moeller, K.