Cashew nuts market in south western Nigeria is characterized by price fluctuations through space and time. This may be linked with the large number of market intermediaries who act between the primary producers and th...Cashew nuts market in south western Nigeria is characterized by price fluctuations through space and time. This may be linked with the large number of market intermediaries who act between the primary producers and the markets. The sample for the study comprised 250 cashew nuts marketers who were randomly selected from the five south westem states of Nigeria. About 76 % of the cashew nuts marketers had up to secondary school education and 86% of them had 15-year marketing experience and below. Pricing efficiency of the marketers was highest in Ogun state with average efficiency level of85.1% and least for Oyo state （68.9%）. In all, 720 tonnes were transacted in the region with 206 marketers handling maximum of 2 kg per month per individual. Gini-coefficient estimate of 82.3% implied that there was a concentrated market for the cashew nuts. To further increase the pricing efficiency of the commodity it is necessary to reduce the costs incurred on various physical aspects in marketing system. Corporate organizations, government agencies and co-operative societies should assist the cashew nuts marketers in the provision of credit facilities so as to ensure a higher level of pricing efficiency, stable market prices and reduced level of concentration of the marketers.展开更多
Little is known about the stable carbon isotopes of methane （CH4） emitted （δ13CH4elnitted） from permanently flooded rice fields and double rice-cropping fields. The CH4 emission and corresponding （δ13CH4emitted...Little is known about the stable carbon isotopes of methane （CH4） emitted （δ13CH4elnitted） from permanently flooded rice fields and double rice-cropping fields. The CH4 emission and corresponding （δ13CH4emitted under various field managements （mulching, water regime, tillage, and nitrogen （N） fertilization） were simultaneously measured in three typical Chinese rice fields, a permanently flooded rice field in Ziyang City, Sichuan Province, Southwest China, a double-rice cropping field in Yingtan City, Jiangxi Province, Southeast China, and a rice-wheat rotation field in Jurong City, Jiangsu Province, East China, from 2010 to 2012. Results showed different seasonal variations of δ13CH4emitted among the three fields during the rice-growing season. The values of （δ13CH4emitted were negatively correlated with corresponding CH4 emissions in seasonal variation and mean, indicating the importance of CH4 production, oxidation, and transport associated with isotopic fractionation effects to the δ13CH4emitted. Seasonal variations of δ13CH4emltted were slightly impacted by mulching cultivation, tillage, and N application, but highly controlled by drainage. Meanwhile, tillage, N application, and especially mulching cultivation had important effects on seasonal mean CH4 emissions and corresponding δ13CH4emitted with low emissions accompanied by high values of δ13CH4emitted. Seasonal mean values of （δ13CH4emitted from the three fields were similar, mostly ranging from -60‰ to -50‰ which are well in agreement with previously published data. These demonstrated that seasonal variations of （δ13CH4emitted mainly depended on the changes in CH4 emission from rice fields and further indicated the important effects of methanogenic pathways, CH4 oxidation, and CH4 transport associated with isotope fractionation effects influenced by field managements on δ13CH4emitted.展开更多
文摘Cashew nuts market in south western Nigeria is characterized by price fluctuations through space and time. This may be linked with the large number of market intermediaries who act between the primary producers and the markets. The sample for the study comprised 250 cashew nuts marketers who were randomly selected from the five south westem states of Nigeria. About 76 % of the cashew nuts marketers had up to secondary school education and 86% of them had 15-year marketing experience and below. Pricing efficiency of the marketers was highest in Ogun state with average efficiency level of85.1% and least for Oyo state （68.9%）. In all, 720 tonnes were transacted in the region with 206 marketers handling maximum of 2 kg per month per individual. Gini-coefficient estimate of 82.3% implied that there was a concentrated market for the cashew nuts. To further increase the pricing efficiency of the commodity it is necessary to reduce the costs incurred on various physical aspects in marketing system. Corporate organizations, government agencies and co-operative societies should assist the cashew nuts marketers in the provision of credit facilities so as to ensure a higher level of pricing efficiency, stable market prices and reduced level of concentration of the marketers.
基金financially supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB15020103)the National Key Technology Research and Development Program of China(No.2013BAD11B02)+2 种基金the National Natural Sciences Foundation of China(Nos.41571232 and 41271259)the State Key Laboratory of Soil and Sustainable Agriculture(No.Y412010003)the Knowledge Innovation Program of Institute of Soil Science,Chinese Academy of Sciences(No.ISSASIP1654)
文摘Little is known about the stable carbon isotopes of methane （CH4） emitted （δ13CH4elnitted） from permanently flooded rice fields and double rice-cropping fields. The CH4 emission and corresponding （δ13CH4emitted under various field managements （mulching, water regime, tillage, and nitrogen （N） fertilization） were simultaneously measured in three typical Chinese rice fields, a permanently flooded rice field in Ziyang City, Sichuan Province, Southwest China, a double-rice cropping field in Yingtan City, Jiangxi Province, Southeast China, and a rice-wheat rotation field in Jurong City, Jiangsu Province, East China, from 2010 to 2012. Results showed different seasonal variations of δ13CH4emitted among the three fields during the rice-growing season. The values of （δ13CH4emitted were negatively correlated with corresponding CH4 emissions in seasonal variation and mean, indicating the importance of CH4 production, oxidation, and transport associated with isotopic fractionation effects to the δ13CH4emitted. Seasonal variations of δ13CH4emltted were slightly impacted by mulching cultivation, tillage, and N application, but highly controlled by drainage. Meanwhile, tillage, N application, and especially mulching cultivation had important effects on seasonal mean CH4 emissions and corresponding δ13CH4emitted with low emissions accompanied by high values of δ13CH4emitted. Seasonal mean values of （δ13CH4emitted from the three fields were similar, mostly ranging from -60‰ to -50‰ which are well in agreement with previously published data. These demonstrated that seasonal variations of （δ13CH4emitted mainly depended on the changes in CH4 emission from rice fields and further indicated the important effects of methanogenic pathways, CH4 oxidation, and CH4 transport associated with isotope fractionation effects influenced by field managements on δ13CH4emitted.
