ERE
Energy, Resources and the Environment

crops

Words on Wednesday: Remediation of degraded arable steppe soils in Moldova using vetch as green manure

July 8, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Wiesmeier, M., Lungu, M., Hübner, R., and Cerbari, V., 2015. Remediation of degraded arable steppe soils in Moldova using vetch as green manure, Solid Earth, 6, 609-620, doi:10.5194/se-6-609-2015, 2015.

Abstract:

In the Republic of Moldova, non-sustainable arable farming led to severe degradation and erosion of fertile steppe soils (Chernozems). As a result, the Chernozems lost about 40% of their initial amounts of soil organic carbon (SOC). The aim of this study was to remediate degraded arable soils and promote carbon sequestration by implementation of cover cropping and green manuring in Moldova. Thereby, the suitability of the legume hairy vetch (Vicia sativa) as cover crop under the dry continental climate of Moldova was examined. At two experimental sites, the effect of cover cropping on chemical and physical soil properties as well as on yields of subsequent main crops was determined. The results showed a significant increase of SOC after incorporation of hairy vetch mainly due to increases of aggregate-occluded and mineral-associated OC. This was related to a high above- and belowground biomass production of hairy vetch associated with a high input of carbon and nitrogen into arable soils. A calculation of SOC stocks based on equivalent soil masses revealed a sequestration of around 3 t C ha−1yr−1 as a result of hairy vetch cover cropping. The buildup of SOC was associated with an improvement of the soil structure as indicated by a distinct decrease of bulk density and a relative increase of macroaggregates at the expense of microaggregates and clods. As a result, yields of subsequent main crops increased by around 20%. Our results indicated that hairy vetch is a promising cover crop to remediate degraded steppe soils, control soil erosion and sequester substantial amounts of atmospheric C in arable soils of Moldova.

Bulk densities (BD) and soil organic carbon (SOC) contents of topsoil horizons of control and experimental sites in Orhei and Cahul after incorporation of HVW and harvest of the main crop. Error bars represent standard deviation (n D 10).

Bulk densities (BD) and soil organic carbon (SOC) contents
of topsoil horizons of control and experimental sites in Orhei
and Cahul after incorporation of HVW and harvest of the main crop. Error bars represent standard deviation (n = 10).

Words on Wednesday: A multi-model analysis of change in potential yield of major crops in China under climate change

March 4, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Yin, Y., Tang, Q., and Liu, X.: A multi-model analysis of change in potential yield of major crops in China under climate change, Earth Syst. Dynam., 6, 45-59, doi:10.5194/esd-6-45-2015, 2015

Abstract:

Climate change may affect crop growth and yield, which consequently casts a shadow of doubt over China’s food self-sufficiency efforts. In this study, we used the projections derived from four global gridded crop models (GGCropMs) to assess the effects of future climate change on the yields of the major crops (i.e., maize, rice, soybean and wheat) in China. The GGCropMs were forced with the bias-corrected climate data from five global climate models (GCMs) under Representative Concentration Pathway (RCP) 8.5, which were made available through the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). The results show that the potential yields of the crops would decrease in the 21st century without carbon dioxide (CO2) fertilization effect. With the CO2 effect, the potential yields of rice and soybean would increase, while the potential yields of maize and wheat would decrease. The uncertainty in yields resulting from the GGCropMs is larger than the uncertainty derived from GCMs in the greater part of China. Climate change may benefit rice and soybean yields in high-altitude and cold regions which are not in the current main agricultural area. However, the potential yields of maize, soybean and wheat may decrease in the major food production area. Development of new agronomic management strategies may be useful for coping with climate change in the areas with a high risk of yield reduction.

The MM of the relative change in the simulated yield of maize (a), rice (b), soybean (c) and wheat (d) with the CO2 effect at the end of the 21st century (2070–2099) compared with the simulated yield in the historical period (1981–2010).

The MM of the relative change in the simulated yield of maize (a), rice (b), soybean (c) and wheat (d) with the CO2 effect at the end of the 21st century (2070–2099) compared with the simulated yield in the historical period (1981–2010).