agriculturalconservation agriculture biodiversityconservation biologicalproductivity carbon climatechangemitigation climaticchanges congresses conservationofnaturalresources corn crops cropsandclimate cropscience economicaspects effectofcarbonon environmentalaspects farmers farms fieldcrops foodconservation foodsupply geneticengineering germplasmresources greatbritain history landuse metabolism nitrogen plantdiversityconservation plantphysiology plants rice rural sustainableagriculture wheat