Fine-root dynamics, soil moisture and soil carbon content in a Eucalyptus globulus plantation under different irrigation and fertilization regimes

The minirhizotron technique was used to study the temporal dynamics of fine-roots over a 10 month period in a Eucalyptus plantation in central Portugal.Four treatments were applied:a control without irrigation or fertilisation( C), fertilisation twice per year (F), irrigated without fertilisation( I), and irrigated and fertilised once each week with fertiliser in the irrigation water (IL). In I and IL a drip-tube system was used,and fertiliser rates were adjusted based on the estimated plant nutrient demand. Soil moisture content was measured during the same period at 5 cm depth intervals down to 90 cm depth.Soil carbon content was measured at planting,30 months after planting and54 months after planting.Interrelations between fine-root dynamics, soil moisture , and soil carbon content are discussed

Multi-modelling predictions show high uncertainty of required carbon input changes to reach a 4‰ target

Soils store vast amounts of carbon (C) on land, and increasing soil organic carbon (SOC) stocks in already managed soils such as croplands may be one way to remove C from the atmosphere, thereby limiting subsequent warming. The main objective of this study was to estimate the amount of additional C input needed to annually increase SOC stocks by 4%(0) at 16 long-term agricultural experiments in Europe, including exogenous organic matter (EOM) additions. We used an ensemble of six SOC models and ran them under two configurations: (1) with default parametrization and (2) with parameters calibrated site-by-site to fit the evolution of SOC stocks in the control treatments (without EOM). We compared model simulations and analysed the factors generating variability across models. The calibrated ensemble was able to reproduce the SOC stock evolution in the unfertilised control treatments. We found that, on average, the experimental sites needed an additional 1.5 +/- 1.2 Mg C ha(-)(1) year(-1) to increase SOC stocks by 4%(0) per year over 30 years, compared to the C input in the control treatments (multi-model median +/- median standard deviation across sites). That is, a 119% increase compared to the control. While mean annual temperature, initial SOC stocks and initial C input had a significant effect on the variability of the predicted C input in the default configuration (i.e., the relative standard deviation of the predicted C input from the mean), only water-related variables (i.e., mean annual precipitation and potential evapotranspiration) explained the divergence between models when calibrated. Our work highlights the challenge of increasing SOC stocks in agriculture and accentuates the need to increasingly lean on multi-model ensembles when predicting SOC stock trends and related processes. To increase the reliability of SOC models under future climate change, we suggest model developers to better constrain the effect of water-related variables on SOC decomposition

Development of root biomass in an Eucalyptus globulus plantation under different water and nutrient regimes

The distribution along the soil profile of Eucalyptus globulus root biomass was followed in a plantation in central Portugal at 1, 2 and 6 years after planting, using an excavation technique. The experimental design consisted of a control (C)and 3 treatments: application of solid fertilizers twice a year (F), irrigation without the application of fertilizers (I) and irrigation combined with liquid fertilizers (IL). Bellow- and above-ground biomass decreased as follows: IL>I>F>C. So, water stress limited growth more severely than nutrient stress. The roots rapidly colonized the top soil volume (0-20 cm depth)during the first year after planting. Fine roots biomass 6 years after planting was 2.2, 1.8 and 1.6 times higher in IL treatment than it was respectively in control, and in F and I treatments. The distribution of fine roots along the soil profile 6 years after planting was more even in IL compared to the other treatments. However, fine roots in the top soil were more concentrated along the tree rows in the irrigated treatments than in the others. The proportion of below-ground biomass relative to the total tree biomass relative to the total tree biomass and the root/shoot ratio were higher in C than in the treatments at early growth stages. This pattern was not so clear 6 years after planting, due to the increased proportion of the tap root relative to total biomass, especially in the IL treatment

European consensus table on the use of botulinum toxin type A in adult spasticity.

Contains fulltext : 80790.pdf (publisher's version ) (Open Access)A group of clinicians from across Europe experienced in the use of botulinum toxin type A for the treatment of spasticity following acquired brain injury gathered to develop a consensus statement on best practice in managing adults with spasticity. This consensus table summarizes the current published data, which was collated following extensive literature searches, their assessment for level of evidence and discussion among the whole group. Published information is supplemented by expert opinion based on clinical experience from 16 European countries, involving 28 clinicians, who treat an average of approximately 200 patients annually, representing many thousand spasticity treatments with botulinum toxin per year

Greenhouse gas fluxes of agricultural soils in Finland

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