Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biologica...Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biological oxidation of ammonium(nitrification) in soil. Metal [M=V(Ⅲ), Cr(Ⅲ), Mn(Ⅱ), Fe(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Co(Ⅱ)] diethyldithiocarbamates (DEDTC) were synthesized by the reaction of sodium diethyldithiocarbamate with metal chloride in dichloromethane/water mixture. These metal diethyldithiocarbamates were screened for their ability to inhibit nitrification at different concentrations(10 μg/g soil, 50 μg/g soil and 100 μg/g soil). With increasing concentration of the complex, capacity to retard nitrification increased but the extent of increase varied for different metals. At 100 μg/g soil, different complexes showed nitrification inhibition from 22 36% to 46 45%. Among the diethyldithiocarbamates tested, Zn(DEDTC) 2 proved to be the most effective nitrification inhibitor at 100 μg/g soil. Manganese, iron and chromium diethyldithiocarbamates also proved to be effective nitrification inhibitors than the others at 100 μg/g soil. The order of percent nitrification inhibition in soil by metal diethyldithiocarbamates was: Zn(Ⅱ) > Mn(Ⅱ) > Fe(Ⅲ) > Cr(Ⅲ) >V(Ⅲ) > Co(Ⅱ) > Ni(Ⅱ) > Cu(Ⅱ).展开更多
Barley has been in use as food and fodder for thousands of years. and also used currently as the most important raw material in malting and brewing. The quality of malt barley is not much satisfied with the requiremen...Barley has been in use as food and fodder for thousands of years. and also used currently as the most important raw material in malting and brewing. The quality of malt barley is not much satisfied with the requirement by malting and brewing industry worldwide, although the great effort has been devoted to its improvement through breeding and agronomy. The quality of malt barley is involved in many physical and chemical traits, including hydrolytic enzymes. Of them, kernel protein content, beta-amylase activity, beta-glucan content and kernel plumpness have dramatic influence on malting or brewing quality. The expression of these quality parameters varies greatly in genotypes and is easily changed by diverse environments and agronomic practices. This paper reviewed the important role of various parameters influencing the quality of malt barley and the effect of different factors on them.展开更多
文摘Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biological oxidation of ammonium(nitrification) in soil. Metal [M=V(Ⅲ), Cr(Ⅲ), Mn(Ⅱ), Fe(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Co(Ⅱ)] diethyldithiocarbamates (DEDTC) were synthesized by the reaction of sodium diethyldithiocarbamate with metal chloride in dichloromethane/water mixture. These metal diethyldithiocarbamates were screened for their ability to inhibit nitrification at different concentrations(10 μg/g soil, 50 μg/g soil and 100 μg/g soil). With increasing concentration of the complex, capacity to retard nitrification increased but the extent of increase varied for different metals. At 100 μg/g soil, different complexes showed nitrification inhibition from 22 36% to 46 45%. Among the diethyldithiocarbamates tested, Zn(DEDTC) 2 proved to be the most effective nitrification inhibitor at 100 μg/g soil. Manganese, iron and chromium diethyldithiocarbamates also proved to be effective nitrification inhibitors than the others at 100 μg/g soil. The order of percent nitrification inhibition in soil by metal diethyldithiocarbamates was: Zn(Ⅱ) > Mn(Ⅱ) > Fe(Ⅲ) > Cr(Ⅲ) >V(Ⅲ) > Co(Ⅱ) > Ni(Ⅱ) > Cu(Ⅱ).
基金the National Natural Science Foundation of China(30070434,30270779)863 Program of China(2001AA2412)for their support to this research.
文摘Barley has been in use as food and fodder for thousands of years. and also used currently as the most important raw material in malting and brewing. The quality of malt barley is not much satisfied with the requirement by malting and brewing industry worldwide, although the great effort has been devoted to its improvement through breeding and agronomy. The quality of malt barley is involved in many physical and chemical traits, including hydrolytic enzymes. Of them, kernel protein content, beta-amylase activity, beta-glucan content and kernel plumpness have dramatic influence on malting or brewing quality. The expression of these quality parameters varies greatly in genotypes and is easily changed by diverse environments and agronomic practices. This paper reviewed the important role of various parameters influencing the quality of malt barley and the effect of different factors on them.
