The newly released super high-yielding hybrid rice combinations, Yueza 122, Fengyou 428, Peiza 67, and the super high-yielding conventional cultivars, Guangchao 3 and Shengtai 1, were grown in both early and late seas...The newly released super high-yielding hybrid rice combinations, Yueza 122, Fengyou 428, Peiza 67, and the super high-yielding conventional cultivars, Guangchao 3 and Shengtai 1, were grown in both early and late seasons. The morphological characters of each population were investigated at the heading stage, and the data were analyzed by using ANOVY and other statistic methods. The plant ideal morphological characters at the heading stage were established as follows： 1 ） for the early-season cropping, 90-105 cm plant height; 11-12 tillers per plant; 35-40 em length and 2.1-2.2 cm width of flag leaf; 46-50 cm length and 1.8-2.1 cm width of the second leaf from the top （L2）; 59-64 cm length and 1.4-1.9 cm width of the third leaf from the top （L3）; 7°-14°, 18° and 200-33° for the ideal leaf angles of the flag leaf, L2 and L3, respectively; 2） for the late-season cropping, 90-100 cm plant height; 9-15 tillers per plant; 30-41 cm length and 1.8-2.0 cm width of flag leaf; 53-61 cm length and 1.3-1.8 cm width of L2; 52-58 cm length and 1.2-1.5 cm width of L3; 9°-19°, 15°-37° and 16°-49° for the ideal leaf angles of the flag leaf, L2 and L3, respectively. The main physiological characteristics of these varieties were also analyzed.展开更多
The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both ...The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both early and late crops were investigated. Using the analysis of variance and other statistic methods, the ideal morphological characteristics of South China double cropping super-rice at the active tillering stage were determined. They are 55-60 cm in the early crop and 60-76 cm in the late crop for the ideal plant height, about 15 tillers in the early crop and 14-19 tillers in the late crop for the ideal tiller number per plant, 40-44 cm in the early crop and 42-60 cm in the late crop for the ideal length of the first leaf under the top leaf, 1.2-1.4 cm in the early crop and 1.2-1.3cm in the late crop for the ideal width of the first leaf under the top leaf, 39- 44 cm in the early crop and 37-43 cm in the late crop for the ideal length of the second leaf under the top leaf, 1.1-1.4 cm in the early crop and about 1.1 cm in the late crop for the ideal width of the second leaf under the top leaf, 22-58o in the early crop and 4- 12o in the late crop for the ideal top leaf angle at the active tillering stage. Based on these results, a new concept of “dynamic plant type structure” for South China double cropping super rice breeding was suggested.展开更多
Since the early 1980 s, the multi-cropping index for rice has decreased significantly in main double-cropping rice area in China, which is the primary double-cropping rice(DCR) production area. This decline may bring ...Since the early 1980 s, the multi-cropping index for rice has decreased significantly in main double-cropping rice area in China, which is the primary double-cropping rice(DCR) production area. This decline may bring challenges to food security in China because rice is the staple food for more than 60% of the Chinese population. It has been generally recognized that rapidly rising labor costs due to economic growth and urbanization in China is the key driving force of the ‘double-to-single' rice cropping system adaption. However, not all provinces have shown a dramatic decline in DCR area, and labor costs alone cannot explain this difference. To elucidate the reasons for these inter-provincial distinctions and the dynamics of rice cropping system adaption, we evaluated the influencing factors using provincial panel data from 1980 to 2015. We also used household survey data for empirical analysis to explore the mechanisms driving differences in rice multi-cropping changes. Our results indicated that the eight provinces in the study can be divided into three spatial groups based on the extent of DCR area decline, the rapidly-declining marginal, core, and stable zones. Increasing labor cost due to rapid urbanization was the key driving force of rice cropping system adaption, but the land use dynamic vary hugely among different provinces. These differences between zones were due to the interaction between labor price and accumulated temperature conditions. Therefore, increasing labor costs had the greatest impact in Zhejiang, Anhui, and Hubei, where the accumulated temperature is relatively low and rice multi-cropping index declined dramaticly. However, labor costs had little impact in Guangdong and Guangxi. Differences in accumulated temperature conditions resulted in spatially different labor demands and pressure on households during the busy season. As a result, there have been different profits and rice multi-cropping changes between provinces and zones. Because of these spatial differences, regionally appropriate policies that provide appropriate subsidies for early rice in rapidly-declining marginal zone such as Zhejiang and Hubei should be implemented. In addition, agricultural mechanization and the number of agricultural workers have facilitated double-cropping; therefore, small machinery and agricultural infrastructure construction should be further supported.展开更多
Based on meteorological data including daily sunshine duration, temperature and precipitation from 97 meteorological stations in Hunan province during the period of 1981—2010, in combination with the field experiment...Based on meteorological data including daily sunshine duration, temperature and precipitation from 97 meteorological stations in Hunan province during the period of 1981—2010, in combination with the field experiment in different places at different sowing dates, the precise climatic risk zoning of double cropping super rice cultivation has been studied by using the spatial interpolation method and other Geographical Information System(GIS)technologies. Three key climatic factors were selected including chilling in May, high temperature heat damage during July to early August and low temperature damage in autumn in this study. Furthermore, based on the analysis of climatic conditions suitable for double cropping super rice cultivation and climatic disasters, 8-22 ℃ active accumulated temperature, sunshine duration from late March to October, climatic risk index of the low temperature in autumn, and climatic risk index of chilling in May were selected as key climatic factors to study the precise agro-meteorological regionalization of double cropping super rice in Hunan province. The results showed that: the high-yielding zones of double cropping super rice in Hunan were mainly located in Zhuzhou, Hengyang, Yongzhou and Chenzhou City, the moderate-yielding zones were primarily located in the east and north reaches of Dongting Lake,together with most of Changsha, Zhuzhou and Xiangtan City, and other regions in Hunan were not suitable for double cropping super rice. These findings can provide valuable information for the large-scale cultivation of double cropping super rice in Hunan province.展开更多
Recently,a great progress was made in breeding and cul-tivation of super rice in China.The South DemonstrationAcceptance Meeting of China Super Rice was held in Oct17,2000 in Xinchang County,Zhejiang Province.Yieldmon...Recently,a great progress was made in breeding and cul-tivation of super rice in China.The South DemonstrationAcceptance Meeting of China Super Rice was held in Oct17,2000 in Xinchang County,Zhejiang Province.Yieldmonitoring group organized by the Department of Science,Technology and Education,Ministry of Agriculture,Chi-na,was consisting of famous rice research scientists,a-gricultural technology extension experts,and governmentofficials.In the demonstration meeting,the group investi-gated the rice growth of the demonstration field of the im-展开更多
Changes in rice production in Southern China are crucial to national food security.This study employed Landsat images to map the distributions of paddy rice-cropping systems in Southern China in 1990 and 2015.The impa...Changes in rice production in Southern China are crucial to national food security.This study employed Landsat images to map the distributions of paddy rice-cropping systems in Southern China in 1990 and 2015.The impact of rice multiple cropping index changes on grain production capacity was then evaluated.Three important results were obtained for the 1990 to 2015 study period.First,the multiple cropping index for rice decreased from 148.3% to 129.3%,and 253.16×10^4 ha of land area was converted from double-cropping to single- cropping rice,termed “double to single”.The area with the most dramatic changes is in the Middle-Lower Yangtze Plain.The rice-cropping system distribution in Southern China showed a change from north to south with double-cropping rice shrinking and single-cropping rice expanding.Second,the “double to single” conversion led to a reduction of 6.1% and 2.6% in rice and grain production,respectively.Hunan and Jiangxi Provinces,located in the main rice producing areas,and Zhejiang,which has shown better economic development,exhibited large reductions in rice production due to the “double to single” conversion,all exceeding 13%.Third,the grain production capacity of converted “double to single” paddy fields is equivalent to that of 223.3 × 10^4 ha of newly reclaimed cultivated land,which is 54% of the total newly cultivated land reclaimed through the 2001–2015 land consolidation project.It is also 1.7 times the target goal for newly cultivated land in the national land consolidation plan for 2016–2020.Making full use of the converted “double to single” paddy fields can save 167.44 billion yuan in newly reclaimed cultivated land costs.Therefore,instead of pursuing low-quality new arable land,it is better to make full use of the existing high-quality arable land.Based on these results,the government should change the assessment method for cultivated land balance,and incorporate the sown area increased by improving the multiple cropping index into the cultivated land compensation indicator.展开更多
基金supported by China National 863 Program(2001AA211191)100 Innovation Projects of Guangdong Province(2KB64804N)Natural Science Foundation of Guangdong Province(990501).
文摘The newly released super high-yielding hybrid rice combinations, Yueza 122, Fengyou 428, Peiza 67, and the super high-yielding conventional cultivars, Guangchao 3 and Shengtai 1, were grown in both early and late seasons. The morphological characters of each population were investigated at the heading stage, and the data were analyzed by using ANOVY and other statistic methods. The plant ideal morphological characters at the heading stage were established as follows： 1 ） for the early-season cropping, 90-105 cm plant height; 11-12 tillers per plant; 35-40 em length and 2.1-2.2 cm width of flag leaf; 46-50 cm length and 1.8-2.1 cm width of the second leaf from the top （L2）; 59-64 cm length and 1.4-1.9 cm width of the third leaf from the top （L3）; 7°-14°, 18° and 200-33° for the ideal leaf angles of the flag leaf, L2 and L3, respectively; 2） for the late-season cropping, 90-100 cm plant height; 9-15 tillers per plant; 30-41 cm length and 1.8-2.0 cm width of flag leaf; 53-61 cm length and 1.3-1.8 cm width of L2; 52-58 cm length and 1.2-1.5 cm width of L3; 9°-19°, 15°-37° and 16°-49° for the ideal leaf angles of the flag leaf, L2 and L3, respectively. The main physiological characteristics of these varieties were also analyzed.
基金This work was supported by the National 863 Program of China(2001AA211191)the Natural Science Foundation of Guangdong Provice,China(990501)100 Scientific Innovation Projects of Guangdong Province,China.(2KB64804N).
文摘The morphological characters of the newly released super hybrid rice in South China, Yueza 122, Fengyou 428, Peiza 67, and super conventional varieties, Guangchao 3, Shengtai 1 at the active tillering stage in both early and late crops were investigated. Using the analysis of variance and other statistic methods, the ideal morphological characteristics of South China double cropping super-rice at the active tillering stage were determined. They are 55-60 cm in the early crop and 60-76 cm in the late crop for the ideal plant height, about 15 tillers in the early crop and 14-19 tillers in the late crop for the ideal tiller number per plant, 40-44 cm in the early crop and 42-60 cm in the late crop for the ideal length of the first leaf under the top leaf, 1.2-1.4 cm in the early crop and 1.2-1.3cm in the late crop for the ideal width of the first leaf under the top leaf, 39- 44 cm in the early crop and 37-43 cm in the late crop for the ideal length of the second leaf under the top leaf, 1.1-1.4 cm in the early crop and about 1.1 cm in the late crop for the ideal width of the second leaf under the top leaf, 22-58o in the early crop and 4- 12o in the late crop for the ideal top leaf angle at the active tillering stage. Based on these results, a new concept of “dynamic plant type structure” for South China double cropping super rice breeding was suggested.
基金National Program on Key Basic Research Project(No.2015CB452706)
文摘Since the early 1980 s, the multi-cropping index for rice has decreased significantly in main double-cropping rice area in China, which is the primary double-cropping rice(DCR) production area. This decline may bring challenges to food security in China because rice is the staple food for more than 60% of the Chinese population. It has been generally recognized that rapidly rising labor costs due to economic growth and urbanization in China is the key driving force of the ‘double-to-single' rice cropping system adaption. However, not all provinces have shown a dramatic decline in DCR area, and labor costs alone cannot explain this difference. To elucidate the reasons for these inter-provincial distinctions and the dynamics of rice cropping system adaption, we evaluated the influencing factors using provincial panel data from 1980 to 2015. We also used household survey data for empirical analysis to explore the mechanisms driving differences in rice multi-cropping changes. Our results indicated that the eight provinces in the study can be divided into three spatial groups based on the extent of DCR area decline, the rapidly-declining marginal, core, and stable zones. Increasing labor cost due to rapid urbanization was the key driving force of rice cropping system adaption, but the land use dynamic vary hugely among different provinces. These differences between zones were due to the interaction between labor price and accumulated temperature conditions. Therefore, increasing labor costs had the greatest impact in Zhejiang, Anhui, and Hubei, where the accumulated temperature is relatively low and rice multi-cropping index declined dramaticly. However, labor costs had little impact in Guangdong and Guangxi. Differences in accumulated temperature conditions resulted in spatially different labor demands and pressure on households during the busy season. As a result, there have been different profits and rice multi-cropping changes between provinces and zones. Because of these spatial differences, regionally appropriate policies that provide appropriate subsidies for early rice in rapidly-declining marginal zone such as Zhejiang and Hubei should be implemented. In addition, agricultural mechanization and the number of agricultural workers have facilitated double-cropping; therefore, small machinery and agricultural infrastructure construction should be further supported.
基金China Special Fund for Meteorological Research in the Public Interest(201206045)
文摘Based on meteorological data including daily sunshine duration, temperature and precipitation from 97 meteorological stations in Hunan province during the period of 1981—2010, in combination with the field experiment in different places at different sowing dates, the precise climatic risk zoning of double cropping super rice cultivation has been studied by using the spatial interpolation method and other Geographical Information System(GIS)technologies. Three key climatic factors were selected including chilling in May, high temperature heat damage during July to early August and low temperature damage in autumn in this study. Furthermore, based on the analysis of climatic conditions suitable for double cropping super rice cultivation and climatic disasters, 8-22 ℃ active accumulated temperature, sunshine duration from late March to October, climatic risk index of the low temperature in autumn, and climatic risk index of chilling in May were selected as key climatic factors to study the precise agro-meteorological regionalization of double cropping super rice in Hunan province. The results showed that: the high-yielding zones of double cropping super rice in Hunan were mainly located in Zhuzhou, Hengyang, Yongzhou and Chenzhou City, the moderate-yielding zones were primarily located in the east and north reaches of Dongting Lake,together with most of Changsha, Zhuzhou and Xiangtan City, and other regions in Hunan were not suitable for double cropping super rice. These findings can provide valuable information for the large-scale cultivation of double cropping super rice in Hunan province.
文摘Recently,a great progress was made in breeding and cul-tivation of super rice in China.The South DemonstrationAcceptance Meeting of China Super Rice was held in Oct17,2000 in Xinchang County,Zhejiang Province.Yieldmonitoring group organized by the Department of Science,Technology and Education,Ministry of Agriculture,Chi-na,was consisting of famous rice research scientists,a-gricultural technology extension experts,and governmentofficials.In the demonstration meeting,the group investi-gated the rice growth of the demonstration field of the im-
基金National Natural Science Foundation of China,No.41571095,No.41161140352
文摘Changes in rice production in Southern China are crucial to national food security.This study employed Landsat images to map the distributions of paddy rice-cropping systems in Southern China in 1990 and 2015.The impact of rice multiple cropping index changes on grain production capacity was then evaluated.Three important results were obtained for the 1990 to 2015 study period.First,the multiple cropping index for rice decreased from 148.3% to 129.3%,and 253.16×10^4 ha of land area was converted from double-cropping to single- cropping rice,termed “double to single”.The area with the most dramatic changes is in the Middle-Lower Yangtze Plain.The rice-cropping system distribution in Southern China showed a change from north to south with double-cropping rice shrinking and single-cropping rice expanding.Second,the “double to single” conversion led to a reduction of 6.1% and 2.6% in rice and grain production,respectively.Hunan and Jiangxi Provinces,located in the main rice producing areas,and Zhejiang,which has shown better economic development,exhibited large reductions in rice production due to the “double to single” conversion,all exceeding 13%.Third,the grain production capacity of converted “double to single” paddy fields is equivalent to that of 223.3 × 10^4 ha of newly reclaimed cultivated land,which is 54% of the total newly cultivated land reclaimed through the 2001–2015 land consolidation project.It is also 1.7 times the target goal for newly cultivated land in the national land consolidation plan for 2016–2020.Making full use of the converted “double to single” paddy fields can save 167.44 billion yuan in newly reclaimed cultivated land costs.Therefore,instead of pursuing low-quality new arable land,it is better to make full use of the existing high-quality arable land.Based on these results,the government should change the assessment method for cultivated land balance,and incorporate the sown area increased by improving the multiple cropping index into the cultivated land compensation indicator.
