T Morvan | Institut National de la Recherche Agronomique (original) (raw)

Papers by T Morvan

Plant and Soil, 2010

A 3-year field lysimeter experiment was performed to determine transformations of 15N-labeled cau... more A 3-year field lysimeter experiment was performed to determine transformations of 15N-labeled cauliflower (Brassica oleracea) residues incorporated into lysimeter topsoil in a potato (Solanum tuberosum)/cauliflower rotation. Only the potato crop received 150 kg mineral N ha−1y−1. Cauliflower yields were high (12–13 t fresh matter ha−1), and N returned to the soil represented 51% of the aboveground plant N uptake. The 15N recovery by the potato/cauliflower rotation began at 46%, then decreased sharply to 12 and 6% for the second and third year, respectively. The cumulative 15N leaching rate was only 3%; 63% remained in the soil 3 years after incorporation. Soil N mineralization rates described by a parallel first-order kinetic model predicted 27, 7 and 6% of residual N lost annually during the first, second and third year, respectively. Thus, a potato/cauliflower rotation with moderate N fertilization optimizes N recovery of crop residues and can control leaching loss efficiently.

The ex ante environmental evaluation of farming systems is increasingly demanded when proposing n... more The ex ante environmental evaluation of farming systems is increasingly demanded when proposing new developments of animal farming systems. Modelling is a promising approach to reduce the cost and the delay in studying the relationship between farming management and risky emissions. The simulation of decision is essential to better analyze ex ante changes in farm management, but is rarely considered in environmental models. MELODIE simulates the flows of carbon, nitrogen, phosphorus, copper, zinc and water within the whole pig and dairy farm over the long term. MELODIE upscales dynamic models developed at the field or animal scale by considering the management of the whole farm system coherently with the livestock farming system. The model is structured according to an ontology of agricultural production systems to represent the interactions between the biotechnical system and the decision system. The biotechnical module simulates the nutrient flows at a daily time step for each entity of the sub-models (soil/crop, animal and manure processes). MELODIE represents decisions at two time scales: every year, for drawing annual activity plans and every day for the context-dependent application of this plan. Thanks to the interactions between the biotechnical system and the decision system at different time scales, MELODIE is able to run consistently under different long-term climate series. The goal is to study the emerging properties of the system. Besides, because the nutrient flows within the farm are dynamically simulated, it is possible to study both the spatial and temporal heterogeneity of the environmental risks. This approach enables a better understanding of variability in the farming system according to climate. MELODIE is intended for use in research, not as a decision support system for farm management. It is a framework for virtual experimentation on animal farming systems, and could be extended to deal with other issues than nutrient flows.

Soil Biology & Biochemistry, 2011

In addition to total organic carbon and nitrogen, potential organic carbon mineralization under c... more In addition to total organic carbon and nitrogen, potential organic carbon mineralization under controlled laboratory conditions and indicators such as the indicator of remaining organic carbon in soil (I ROC ), based on Van Soest biochemical fractionation and short-term carbon mineralization in soil, are used to predict the evolution of exogenous organic matter (EOM) after its application to soils. The purpose of this study was to develop near infrared reflectance spectroscopy (NIRS) calibration models that could predict these characteristics in a large dataset including 300 EOMs representative of the broad range of such materials applied to cultivated soils (plant materials, animal manures, composts, sludges, etc.). The NIRS predictions of total organic matter and total organic carbon were satisfactory (R 2 P ¼ 0.80 and 0.85, ratio of performance to deviation, RPD P ¼ 2.2 and 2.6, respectively), and prediction of the Van Soest soluble, cellulose and holocellulose fractions were acceptable (R 2 P ¼ 0.82, 0.73 and 0.70, RPD P ¼ 2.3, 1.9 and 1.8, respectively) with coefficients of variation close to those of the reference methods. The NIRS prediction of carbon mineralization during incubation was satisfactory and indeed better regarding the short-term results of mineralization (R 2 P ¼ 0.78 and 0.78, and RPD P ¼ 2.1 and 2.0 for 3 and 7 days of incubation, respectively). The I ROC indicator was predicted with fairly good accuracy (R 2 P ¼ 0.79, RPD P ¼ 2.2). Variables related to the long-term C mineralization of EOM in soil were not predicted accurately, except for I ROC which was based on analytical and well-identified characteristics, probably because of the increasing interactions and complexity of the factors governing EOM mineralization in soil as a function of incubation time. This study demonstrated the possibility of developing NIRS predictive models for EOM characteristics in heterogeneous datasets of EOMs. However, specific NIRS predictive models still remain necessary for sludges, organo-mineral fertilizers and liquid manures.

Bioresource Technology, 2010

Our aim was to develop a typology predicting potential N availability of exogenous organic matter... more Our aim was to develop a typology predicting potential N availability of exogenous organic matters (EOMs) in soil based on their chemical characteristics. A database of 273 EOMs was constructed including analytical data of biochemical fractionation, organic C and N, and results of N mineralization during incubation of soil-EOM mixtures in controlled conditions. Multiple factor analysis and hierarchical classification were performed to gather EOMs with similar composition and N mineralization behavior. A typology was then defined using composition criteria to predict potential N mineralization. Six classes of EOM potential N mineralization in soil were defined, from high potential N mineralization to risk of inducing N immobilization in soil after application. These classes were defined on the basis of EOM organic N content and soluble, cellulose-, and lignin-like fractions. A decision tree based on these variables was constructed in order to easily attribute any EOM to 1 of the 6 classes.

European Journal of Soil Science, 2009

An indicator to evaluate the proportion of exogenous organic matter (EOM) remaining in soils over... more An indicator to evaluate the proportion of exogenous organic matter (EOM) remaining in soils over the long-term after application has been developed. A database was constructed with analytical data corresponding to 83 EOMs, including sludges, composts, animal wastes, mulches, plant materials and fertilizers. The data included results of proximal analysis (soluble, SOL, hemicellulose-, HEM, cellulose-, CEL, and lignin-like, LIC, fractions, in g kg−1 total organic matter) and of carbon (C) mineralization during long-term incubations under laboratory conditions (in g kg−1 exogenous organic C, EOC). The potential residual organic C after EOM application to soil was assessed from the extrapolation of the incubation results. Then, partial least square regression was used to relate EOM characteristics to the proportion of potentially residual organic C previously determined from the incubations. The biochemical fractions of EOM were not predictive enough to develop the indicator. The proportion of organic C mineralized during 3 days of incubation (C3d) was cumulated and appeared to be the most predictive variable of residual organic C. The proposed indicator of residual organic carbon in soils (expressed as g EOC kg−1) was IROC = 445 + 0.5 SOL – 0.2 CEL + 0.7 LIC – 2.3 C3d. The indicator was calculated for the main types of EOM applied to soils. When compared with the few field data of residual C measured in long-term field experiments, the values provided by the indicator seemed to be over-estimated (i.e. EOC degradation could be faster under field conditions than during laboratory incubations).

European Journal of Agronomy, 1997

A short field experiment (27 days) was carried out in summer 1995, to study the effect of an acti... more A short field experiment (27 days) was carried out in summer 1995, to study the effect of an actively growing grass sward on nitrogen transformations of a pig slurry. The ammonium fraction of the slurry was labelled with (15NH4)2SO4. The slurry was spread manually on microplots in mid-June, at the rate of 3 l/m2, on a cut ryegrass sward, and

L'intensification écologique vise à assurer un haut niveau de rendement physique tout en réduisan... more L'intensification écologique vise à assurer un haut niveau de rendement physique tout en réduisant les impacts environnementaux et la dépendance vis-à-vis de ressources externes non renouvelables. Pour aller dans ce sens, la gestion des effluents d'élevage demande de mieux connaître les processus écologiques concernés et leurs conséquences sur les cycles biogéochimiques à court, moyen et long terme. Des expérimentations et modélisations significatives sont présentées pour caractériser les valeurs fertilisantes à court et long terme, les effets en tant qu'amendement et les impacts environnementaux potentiels liés à l'usage de ces produits (eutrophisation, volatilisation ammoniacale, émissions de protoxyde d'azote). Les conséquences quant à l'évolution de leurs usages sont déclinées : conservation des éléments chimiques et optimisation de leur recyclage par les systèmes de culture, standardisation des effluents, gestion collective semblent être les maîtres mots d'une gestion des effluents d'élevage s'inscrivant dans le contexte de l'intensification écologique.

The relative contributions of water-soluble, waternon-soluble, Van Soest-soluble, and neutral det... more The relative contributions of water-soluble, waternon-soluble, Van Soest-soluble, and neutral detergent fiber (NDF) fractions of pig slurry (PS), cattle slurry (CS), cattle farmyard manure (FYM), and composted cattle farmyard manure (CFYM) to the overall C and N mineralization of the raw wastes were studied by incubating treated soil for 107 days at 15°C under non-limiting N conditions. The C or N mineralization of soluble fractions was calculated from the difference between C or N mineralization of the raw and non-soluble fractions. The organic N content of raw wastes ranged from 15 to 32 mg N g −1 dry matter and organic C to organic N ratio from 13 to 29. The water-soluble fraction (SOL W ) was close to 100 mg C g −1 raw waste C for CS, FYM, and CFYM but reached 200 mg C g −1 for PS. The Van Soest-soluble fraction (SOL VS ) was the main fraction for PS, CS, and CFYM (>500 mg C g −1 raw waste C) but only 303 mg C g −1 raw waste C for FYM. Both soluble and non-soluble fractions contributed to C decomposition of slurries, with half to more than half of the decomposed C derived from the degradation of soluble compounds. Most of the C decomposed from FYM was derived from the large NDF fraction, but the contribution from the water-soluble C to the decomposition was also significant. Carbon mineralization of CFYM was due to the degradation of the NDF fraction, whereas soluble C did not contribute. Amounts of N mineralized or immobilized by raw wastes and nonsoluble fractions at the end of incubation were significantly correlated (P<0.01) with their organic C to organic N ratio. The contribution of the Van Soest-soluble fraction to N mineralization varied greatly between the four wastes. Finally, large differences in the C degradability and N availability of the water and Van Soest-soluble fractions were demonstrated.

Plant and Soil, 2010

A 3-year field lysimeter experiment was performed to determine transformations of 15N-labeled cau... more A 3-year field lysimeter experiment was performed to determine transformations of 15N-labeled cauliflower (Brassica oleracea) residues incorporated into lysimeter topsoil in a potato (Solanum tuberosum)/cauliflower rotation. Only the potato crop received 150 kg mineral N ha−1y−1. Cauliflower yields were high (12–13 t fresh matter ha−1), and N returned to the soil represented 51% of the aboveground plant N uptake. The 15N recovery by the potato/cauliflower rotation began at 46%, then decreased sharply to 12 and 6% for the second and third year, respectively. The cumulative 15N leaching rate was only 3%; 63% remained in the soil 3 years after incorporation. Soil N mineralization rates described by a parallel first-order kinetic model predicted 27, 7 and 6% of residual N lost annually during the first, second and third year, respectively. Thus, a potato/cauliflower rotation with moderate N fertilization optimizes N recovery of crop residues and can control leaching loss efficiently.

The ex ante environmental evaluation of farming systems is increasingly demanded when proposing n... more The ex ante environmental evaluation of farming systems is increasingly demanded when proposing new developments of animal farming systems. Modelling is a promising approach to reduce the cost and the delay in studying the relationship between farming management and risky emissions. The simulation of decision is essential to better analyze ex ante changes in farm management, but is rarely considered in environmental models. MELODIE simulates the flows of carbon, nitrogen, phosphorus, copper, zinc and water within the whole pig and dairy farm over the long term. MELODIE upscales dynamic models developed at the field or animal scale by considering the management of the whole farm system coherently with the livestock farming system. The model is structured according to an ontology of agricultural production systems to represent the interactions between the biotechnical system and the decision system. The biotechnical module simulates the nutrient flows at a daily time step for each entity of the sub-models (soil/crop, animal and manure processes). MELODIE represents decisions at two time scales: every year, for drawing annual activity plans and every day for the context-dependent application of this plan. Thanks to the interactions between the biotechnical system and the decision system at different time scales, MELODIE is able to run consistently under different long-term climate series. The goal is to study the emerging properties of the system. Besides, because the nutrient flows within the farm are dynamically simulated, it is possible to study both the spatial and temporal heterogeneity of the environmental risks. This approach enables a better understanding of variability in the farming system according to climate. MELODIE is intended for use in research, not as a decision support system for farm management. It is a framework for virtual experimentation on animal farming systems, and could be extended to deal with other issues than nutrient flows.

Soil Biology & Biochemistry, 2011

In addition to total organic carbon and nitrogen, potential organic carbon mineralization under c... more In addition to total organic carbon and nitrogen, potential organic carbon mineralization under controlled laboratory conditions and indicators such as the indicator of remaining organic carbon in soil (I ROC ), based on Van Soest biochemical fractionation and short-term carbon mineralization in soil, are used to predict the evolution of exogenous organic matter (EOM) after its application to soils. The purpose of this study was to develop near infrared reflectance spectroscopy (NIRS) calibration models that could predict these characteristics in a large dataset including 300 EOMs representative of the broad range of such materials applied to cultivated soils (plant materials, animal manures, composts, sludges, etc.). The NIRS predictions of total organic matter and total organic carbon were satisfactory (R 2 P ¼ 0.80 and 0.85, ratio of performance to deviation, RPD P ¼ 2.2 and 2.6, respectively), and prediction of the Van Soest soluble, cellulose and holocellulose fractions were acceptable (R 2 P ¼ 0.82, 0.73 and 0.70, RPD P ¼ 2.3, 1.9 and 1.8, respectively) with coefficients of variation close to those of the reference methods. The NIRS prediction of carbon mineralization during incubation was satisfactory and indeed better regarding the short-term results of mineralization (R 2 P ¼ 0.78 and 0.78, and RPD P ¼ 2.1 and 2.0 for 3 and 7 days of incubation, respectively). The I ROC indicator was predicted with fairly good accuracy (R 2 P ¼ 0.79, RPD P ¼ 2.2). Variables related to the long-term C mineralization of EOM in soil were not predicted accurately, except for I ROC which was based on analytical and well-identified characteristics, probably because of the increasing interactions and complexity of the factors governing EOM mineralization in soil as a function of incubation time. This study demonstrated the possibility of developing NIRS predictive models for EOM characteristics in heterogeneous datasets of EOMs. However, specific NIRS predictive models still remain necessary for sludges, organo-mineral fertilizers and liquid manures.

Bioresource Technology, 2010

Our aim was to develop a typology predicting potential N availability of exogenous organic matter... more Our aim was to develop a typology predicting potential N availability of exogenous organic matters (EOMs) in soil based on their chemical characteristics. A database of 273 EOMs was constructed including analytical data of biochemical fractionation, organic C and N, and results of N mineralization during incubation of soil-EOM mixtures in controlled conditions. Multiple factor analysis and hierarchical classification were performed to gather EOMs with similar composition and N mineralization behavior. A typology was then defined using composition criteria to predict potential N mineralization. Six classes of EOM potential N mineralization in soil were defined, from high potential N mineralization to risk of inducing N immobilization in soil after application. These classes were defined on the basis of EOM organic N content and soluble, cellulose-, and lignin-like fractions. A decision tree based on these variables was constructed in order to easily attribute any EOM to 1 of the 6 classes.

European Journal of Soil Science, 2009

An indicator to evaluate the proportion of exogenous organic matter (EOM) remaining in soils over... more An indicator to evaluate the proportion of exogenous organic matter (EOM) remaining in soils over the long-term after application has been developed. A database was constructed with analytical data corresponding to 83 EOMs, including sludges, composts, animal wastes, mulches, plant materials and fertilizers. The data included results of proximal analysis (soluble, SOL, hemicellulose-, HEM, cellulose-, CEL, and lignin-like, LIC, fractions, in g kg−1 total organic matter) and of carbon (C) mineralization during long-term incubations under laboratory conditions (in g kg−1 exogenous organic C, EOC). The potential residual organic C after EOM application to soil was assessed from the extrapolation of the incubation results. Then, partial least square regression was used to relate EOM characteristics to the proportion of potentially residual organic C previously determined from the incubations. The biochemical fractions of EOM were not predictive enough to develop the indicator. The proportion of organic C mineralized during 3 days of incubation (C3d) was cumulated and appeared to be the most predictive variable of residual organic C. The proposed indicator of residual organic carbon in soils (expressed as g EOC kg−1) was IROC = 445 + 0.5 SOL – 0.2 CEL + 0.7 LIC – 2.3 C3d. The indicator was calculated for the main types of EOM applied to soils. When compared with the few field data of residual C measured in long-term field experiments, the values provided by the indicator seemed to be over-estimated (i.e. EOC degradation could be faster under field conditions than during laboratory incubations).

European Journal of Agronomy, 1997

A short field experiment (27 days) was carried out in summer 1995, to study the effect of an acti... more A short field experiment (27 days) was carried out in summer 1995, to study the effect of an actively growing grass sward on nitrogen transformations of a pig slurry. The ammonium fraction of the slurry was labelled with (15NH4)2SO4. The slurry was spread manually on microplots in mid-June, at the rate of 3 l/m2, on a cut ryegrass sward, and

L'intensification écologique vise à assurer un haut niveau de rendement physique tout en réduisan... more L'intensification écologique vise à assurer un haut niveau de rendement physique tout en réduisant les impacts environnementaux et la dépendance vis-à-vis de ressources externes non renouvelables. Pour aller dans ce sens, la gestion des effluents d'élevage demande de mieux connaître les processus écologiques concernés et leurs conséquences sur les cycles biogéochimiques à court, moyen et long terme. Des expérimentations et modélisations significatives sont présentées pour caractériser les valeurs fertilisantes à court et long terme, les effets en tant qu'amendement et les impacts environnementaux potentiels liés à l'usage de ces produits (eutrophisation, volatilisation ammoniacale, émissions de protoxyde d'azote). Les conséquences quant à l'évolution de leurs usages sont déclinées : conservation des éléments chimiques et optimisation de leur recyclage par les systèmes de culture, standardisation des effluents, gestion collective semblent être les maîtres mots d'une gestion des effluents d'élevage s'inscrivant dans le contexte de l'intensification écologique.

The relative contributions of water-soluble, waternon-soluble, Van Soest-soluble, and neutral det... more The relative contributions of water-soluble, waternon-soluble, Van Soest-soluble, and neutral detergent fiber (NDF) fractions of pig slurry (PS), cattle slurry (CS), cattle farmyard manure (FYM), and composted cattle farmyard manure (CFYM) to the overall C and N mineralization of the raw wastes were studied by incubating treated soil for 107 days at 15°C under non-limiting N conditions. The C or N mineralization of soluble fractions was calculated from the difference between C or N mineralization of the raw and non-soluble fractions. The organic N content of raw wastes ranged from 15 to 32 mg N g −1 dry matter and organic C to organic N ratio from 13 to 29. The water-soluble fraction (SOL W ) was close to 100 mg C g −1 raw waste C for CS, FYM, and CFYM but reached 200 mg C g −1 for PS. The Van Soest-soluble fraction (SOL VS ) was the main fraction for PS, CS, and CFYM (>500 mg C g −1 raw waste C) but only 303 mg C g −1 raw waste C for FYM. Both soluble and non-soluble fractions contributed to C decomposition of slurries, with half to more than half of the decomposed C derived from the degradation of soluble compounds. Most of the C decomposed from FYM was derived from the large NDF fraction, but the contribution from the water-soluble C to the decomposition was also significant. Carbon mineralization of CFYM was due to the degradation of the NDF fraction, whereas soluble C did not contribute. Amounts of N mineralized or immobilized by raw wastes and nonsoluble fractions at the end of incubation were significantly correlated (P<0.01) with their organic C to organic N ratio. The contribution of the Van Soest-soluble fraction to N mineralization varied greatly between the four wastes. Finally, large differences in the C degradability and N availability of the water and Van Soest-soluble fractions were demonstrated.