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Author Jing, Q.; Bélanger, G.; Baron, V.; Bonesmo, H.; Virkajärvi, P.
Title Simulating the Nutritive Value of Timothy Summer Regrowth Type Journal Article
Year 2013 Publication Agronomy Journal Abbreviated Journal Agronomy Journal
Volume 105 Issue 3 Pages 563
Keywords varying n nutrition; cation-anion difference; spring growth; swine manure; leaf-area; nitrogen; yield; model; digestibility; dynamics
Abstract The process-based grass model, CATIMO, simulates the spring growth and nutritive value of timothy (Phleum pratense L.), a forage species widely grown in Scandinavia and Canada, but the nutritive value of the summer regrowth has never been simulated. Our objective was to improve CATIMO for simulating the N concentration, neutral detergent fiber (NDF), in vitro digestibility of NDF (dNDF), and in vitro true digestibility of dry matter (IVTD) of summer regrowth. Daily changes in summer regrowth nutritive value were simulated by modifying key crop parameters that differed from spring growth. More specifically, the partitioning fraction to leaf blades was increased to increase the leaf-to-weight ratio, and daily changes in NDF and dNDF of leaf blades and stems were reduced. The modified CATIMO model was evaluated with data from four independent experiments in eastern and western Canada and Finland. The model performed better for eastern Canada than for the other locations, but the nutritive value attributes of the summer regrowth across locations (range of normalized RMSE = 8-25%, slope < 0.17, R-2 < 0.10) were not simulated as well as those of the spring growth (range of normalized RMSE = 4-16%, 0.85 < slope < 1.07, R-2 > 0.61). These modeling results highlight knowledge gaps in timothy summer regrowth and prospective research directions: improved knowledge of factors controlling the nutritive value of the timothy summer regrowth and experimental measurements of leaf-to-weight ratio and of the nutritive value of leaves and stems.
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-1962 ISBN Medium Article
Area Expedition Conference
Notes CropM, LiveM Approved no
Call Number MA @ admin @ Serial 4493
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Author Jing, Q.; Bélanger, G.; Baron, V.; Bonesmo, H.; Virkajärvi, P.; Young, D.
Title Regrowth simulation of the perennial grass timothy Type Journal Article
Year 2012 Publication Ecological Modelling Abbreviated Journal Ecol. Model.
Volume 232 Issue Pages 64-77
Keywords biomass; carbohydrate; leaf area index; n uptake; reserve-dependent growth; temperature; nutritive-value; carbohydrate reserves; phleum-pratense; catimo model; leaf-area; nitrogen-fertilization; spring harvest; meadow fescue; tall fescue; growth
Abstract Several process-based models for simulating the growth of perennial grasses have been developed but few include the simulation of regrowth. The model CATIMO simulates the primary growth of timothy (Phleum pratense L), an important perennial forage grass species in northern regions of Europe and North America. Our objective was to further develop the model CATIMO to simulate timothy regrowth using the concept of reserve-dependent growth. The performance of this modified CATIMO model in simulating leaf area index (LAI), biomass dry matter (DM) yield, and N uptake of regrowth was assessed with data from four independent field experiments in Norway, Finland, and western and eastern Canada using an approach that combines graphical comparison and statistical analysis. Biomass DM yield and N uptake of regrowth were predicted at the same accuracy as primary growth with linear regression coefficients of determination between measured and simulated values greater than 0.79, model simulation efficiencies greater than 0.78, and normalized root mean square errors (14-30% for biomass and 24-34% for N uptake) comparable with the coefficients of variation of measured data (1-21% for biomass and 1-25% for N uptake). The model satisfactorily simulated the regrowth LAI but only up to a value of about 4.0. The modified CATIMO model with its capacity to simulate regrowth provides a framework to simulate perennial grasses with multiple harvests, and to explore management options for sustainable grass production under different environmental conditions. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
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Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3800 ISBN Medium Article
Area Expedition Conference
Notes CropM, LiveM Approved no
Call Number MA @ admin @ Serial 4473
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Author Virkajärvi, P.; Lehtonen, H.; Järvenranta, K.
Title Regional impacts of climate change, observations and projections. Finnish Pilot study: North Savo region Type Conference Article
Year 2015 Publication Abbreviated Journal
Volume 6 Issue Pages SP6-5
Keywords
Abstract Regional adjustment of regulation is important (eg. water protection) Due to expected growing yield potential fertilisation restrictions need adjustmentNitrate directive restricts efficient and sustainable grass productionGreening practices have only slight – and partly negative  – impact on ruminant production (permanent grassland not suitable for northern conditions)Inefficient markets for agricultural land cause difficulties for farms that are increasing their productionCapitalisation of area payments to land prices + incentives for extensification (e.g. nature management and other set aside schemes under pillar 2) fit better part-time crop farms, not full-time livestock farmsthey express frustration on weak land supplyProduction based support for suckler cows and (dairy originated) beef production is vital for producersNo significant increase in production expected, budgetary limits of coupled supports No Label
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Publisher Place of Publication Brussels Editor
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Area Expedition Conference Climate-change impacts on farming systems in the next decades: Why worry when you have CAP? A workshop for decisionmakers., 2015-05-06, Brussels
Notes Approved no
Call Number MA @ admin @ Serial 2882
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Author Palosuo, T.; Rötter, P.; Lehtonen, H.; Virkajärvi, P.; Salo, T.
Title How to assess climate change impacts on farmers’ crop yields? Type Conference Article
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 327-334
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Area Expedition Conference Impacts World 2013, International Conference on Climate Change Effects, 2013-05-27 to 2013-05-30, Potsdam
Notes Approved no
Call Number MA @ admin @ Serial 2706
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Author Virkajärvi, P.; Korhonen, P.; Bellocchi, G.; Curnel, Y.; Wu, L.; Jégo, G.; Persson, T.; Höglind, M.; Van Oijen, M.; Gustavsson, A.-M.; Kipling, R.P.
Title Modelling responses of forages to climate change with a focus on nutritive value Type Journal Article
Year 2016 Publication Advances in Animal Biosciences Abbreviated Journal Advances in Animal Biosciences
Volume 7 Issue 03 Pages 227-228
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 2040-4700 ISBN Medium
Area Expedition Conference
Notes LiveM, ft_macsur Approved no
Call Number MA @ admin @ Serial 4876
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