Paddy rice agriculture is practiced in both rain-fed and irrigated ecosystems in the Philippines.However,small farms are prevalent in the region,and current satellite-based mapping techniques do not distinguish betwee...Paddy rice agriculture is practiced in both rain-fed and irrigated ecosystems in the Philippines.However,small farms are prevalent in the region,and current satellite-based mapping techniques do not distinguish between the two ecosystems at farm scales.This study developed an approach to rapidly map irrigated and rain-fed paddy rice in Iloilo,Philippines at 10 m resolutions using Google Earth Engine.This approach used an ensemble of classifiers based on time-series vegetation indices to produce dry and wet seasonal maps for the entire province.Results showed a predominance of rain-fed rice areas in both seasons,with irrigated rice making up only onefourth of the total rice area.The overall accuracy was achieved at 68%for the dry season and 75%for the wet season based on ground-acquired points and very high-resolution imagery.The two types of paddies were classified at accuracies up to 87%.Furthermore,the land cover maps showed a strong agreement with the municipal statistics.The resultant maps complement current official statistics and demonstrate the prowess of phenology-based mapping to create paddy inventories in a timely manner to inform food security and agricultural policies.展开更多
The hilly area of Southwest China is a typical rice production area which is limited by seasonal droughts and low temperature in the early rice growth period.A field experiment was conducted on three typical paddy fie...The hilly area of Southwest China is a typical rice production area which is limited by seasonal droughts and low temperature in the early rice growth period.A field experiment was conducted on three typical paddy fields(low-lying paddy field,medium-elevation paddy field,and upland paddy field)in this region.Nitrogen(N)treatment(180 kg N ha-1 year-1)was compared to a control treatment(0 kg N ha-1 year-1)to evaluate the effects of integrated rice management(IRM)on rice growth,grain yield,and N utilization.Integrated rice management integrated raised beds containing plastic mulch,furrow irrigation,and triangular transplanting.In comparison to traditional rice management(TRM),IRM promoted rice tiller development,with 7–13 more tillers per cluster at the maximum tillering stage and 1–6 more tillers per cluster at the end of tillering stage.Integrated rice management significantly increased the rice aboveground biomass by 34.4%–109.0%in different growth periods and the aboveground N uptake by 25.3%–159.0%.Number of productive tillers significantly increased by 33.0%,resulting in a 33.0%increase in grain yield and 8.0%improvement of N use efficiency(NUE).Grain yields were significantly increased in all three paddy fields assessed,with IRM being the most important factor for grain yield and productive tiller development.Effects of paddy field type and N level on N uptake by aboveground plants were reflected in the rice reproductive growth period,with the effects of IRM more striking due to the dry climate conditions.In conclusion,IRM simultaneously improved rice yield and NUE,presenting a valuable rice management technique in the paddy fields assessed.展开更多
基金Ministry of Foreign Affairs and Trade,New ZealandUniversity of Auckland.
文摘Paddy rice agriculture is practiced in both rain-fed and irrigated ecosystems in the Philippines.However,small farms are prevalent in the region,and current satellite-based mapping techniques do not distinguish between the two ecosystems at farm scales.This study developed an approach to rapidly map irrigated and rain-fed paddy rice in Iloilo,Philippines at 10 m resolutions using Google Earth Engine.This approach used an ensemble of classifiers based on time-series vegetation indices to produce dry and wet seasonal maps for the entire province.Results showed a predominance of rain-fed rice areas in both seasons,with irrigated rice making up only onefourth of the total rice area.The overall accuracy was achieved at 68%for the dry season and 75%for the wet season based on ground-acquired points and very high-resolution imagery.The two types of paddies were classified at accuracies up to 87%.Furthermore,the land cover maps showed a strong agreement with the municipal statistics.The resultant maps complement current official statistics and demonstrate the prowess of phenology-based mapping to create paddy inventories in a timely manner to inform food security and agricultural policies.
基金supported by the National Key Research and Development Program of China(Nos.2017YFD0301705 and 2018YFD0301203)the Innovation Ability Enhancement Nonprofit Research Deepening Project of Sichuan Province Financial Department,China(No.016GYSH-021)+1 种基金the Youth Foundation of Sichuan Academy of Agricultural Sciences,China(No.2015QNJJ-016)National Nonprofit Industry Research of China(No.201103003)
文摘The hilly area of Southwest China is a typical rice production area which is limited by seasonal droughts and low temperature in the early rice growth period.A field experiment was conducted on three typical paddy fields(low-lying paddy field,medium-elevation paddy field,and upland paddy field)in this region.Nitrogen(N)treatment(180 kg N ha-1 year-1)was compared to a control treatment(0 kg N ha-1 year-1)to evaluate the effects of integrated rice management(IRM)on rice growth,grain yield,and N utilization.Integrated rice management integrated raised beds containing plastic mulch,furrow irrigation,and triangular transplanting.In comparison to traditional rice management(TRM),IRM promoted rice tiller development,with 7–13 more tillers per cluster at the maximum tillering stage and 1–6 more tillers per cluster at the end of tillering stage.Integrated rice management significantly increased the rice aboveground biomass by 34.4%–109.0%in different growth periods and the aboveground N uptake by 25.3%–159.0%.Number of productive tillers significantly increased by 33.0%,resulting in a 33.0%increase in grain yield and 8.0%improvement of N use efficiency(NUE).Grain yields were significantly increased in all three paddy fields assessed,with IRM being the most important factor for grain yield and productive tiller development.Effects of paddy field type and N level on N uptake by aboveground plants were reflected in the rice reproductive growth period,with the effects of IRM more striking due to the dry climate conditions.In conclusion,IRM simultaneously improved rice yield and NUE,presenting a valuable rice management technique in the paddy fields assessed.
