The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified （GM） crops production. In the European Uni...The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified （GM） crops production. In the European Union, there are no form of agriculture, whether conventional, organic or transgenic, should be excluded. Farmers are free to choose the production type they prefer, without being forced to change patterns already established in the area and without spending more resources. The European Commission defines the term coexistence as the farmers＇ ability to make a practical choice between conventional, organic and GM crop production, in compliance with the legal obligations for labelling and/or purity standards. In simple terms, coexistence is a way of allowing farmers to choose between the three agricultural systems. Farmers＇ choice of growing GM or non-GM crops depends not only on technical aspects related to the productivity gains and agronomic benefits to be gained from adopting this technology, but also on consumers＇ preferences. Particularly in Europe, consumers continue to be concerned about the potentially adverse implications of widespread GM crop production for the environment and food safety. Today only 16 Member States have adopted specific legislation on coexistence. Denmark was the first European Country that, in 2004, adopted a coexistence law and it is currently the coexistence reference model in all the European Union.展开更多
Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National ...Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.展开更多
文摘The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified （GM） crops production. In the European Union, there are no form of agriculture, whether conventional, organic or transgenic, should be excluded. Farmers are free to choose the production type they prefer, without being forced to change patterns already established in the area and without spending more resources. The European Commission defines the term coexistence as the farmers＇ ability to make a practical choice between conventional, organic and GM crop production, in compliance with the legal obligations for labelling and/or purity standards. In simple terms, coexistence is a way of allowing farmers to choose between the three agricultural systems. Farmers＇ choice of growing GM or non-GM crops depends not only on technical aspects related to the productivity gains and agronomic benefits to be gained from adopting this technology, but also on consumers＇ preferences. Particularly in Europe, consumers continue to be concerned about the potentially adverse implications of widespread GM crop production for the environment and food safety. Today only 16 Member States have adopted specific legislation on coexistence. Denmark was the first European Country that, in 2004, adopted a coexistence law and it is currently the coexistence reference model in all the European Union.
基金supported by the USDA National Institute of Food and Agriculture(NIFA),Evans Allen Grant,USA(No.224120)the National Science Foundation(NSF-CREST-CFEA),USA(No.1036600)the Agricultural Experimental Station,Alabama A&M University,Alabama,USA(Journal#:660)
文摘Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.
