Developing Subsistence Agriculture

Author(s):  
MISSING-VALUE MISSING-VALUE
2021 ◽  
Vol 13 (9) ◽  
pp. 4728
Author(s):  
Zinhle Mashaba-Munghemezulu ◽  
George Johannes Chirima ◽  
Cilence Munghemezulu

Rural communities rely on smallholder maize farms for subsistence agriculture, the main driver of local economic activity and food security. However, their planted area estimates are unknown in most developing countries. This study explores the use of Sentinel-1 and Sentinel-2 data to map smallholder maize farms. The random forest (RF), support vector (SVM) machine learning algorithms and model stacking (ST) were applied. Results show that the classification of combined Sentinel-1 and Sentinel-2 data improved the RF, SVM and ST algorithms by 24.2%, 8.7%, and 9.1%, respectively, compared to the classification of Sentinel-1 data individually. Similarities in the estimated areas (7001.35 ± 1.2 ha for RF, 7926.03 ± 0.7 ha for SVM and 7099.59 ± 0.8 ha for ST) show that machine learning can estimate smallholder maize areas with high accuracies. The study concludes that the single-date Sentinel-1 data were insufficient to map smallholder maize farms. However, single-date Sentinel-1 combined with Sentinel-2 data were sufficient in mapping smallholder farms. These results can be used to support the generation and validation of national crop statistics, thus contributing to food security.


2017 ◽  
Vol 82 (2) ◽  
pp. 397-413 ◽  
Author(s):  
B. Sunday Eiselt ◽  
J. Andrew Darling ◽  
Samuel Duwe ◽  
Mark Willis ◽  
Chester Walker ◽  
...  

Previous research on agriculture in the American Southwest focuses overwhelmingly on archaeological survey methods to discern surface agricultural features, which, in combination with climatological, geological, and geographical variables, are used to create models about agricultural productivity in the past. However, with few exceptions, the role of floodplain irrigation and floodwater farming in ancestral Pueblo agriculture is generally downplayed in scholarly discourse. Using a variety of methods, including Unmanned Aerial Vehicles (UAV), satellite imagery, pedestrian survey, and supervised classification of remotely sensed imagery, we examine this issue through a consideration of how ancestral Ohkay Owingeh (Tewa) people solved the challenges of arid land farming in the lower Rio Chama watershed of New Mexico during the Classic period (A.D. 1350–1598). Based on acreage estimates, our results indicate that runoff and rainwater fields in terrace environments would have been insufficient to supply the nutritional needs of an ancestral Tewa population exceeding 10,000 individuals. Based on these observations, we present a case for the substantial role of subsistence agriculture in the floodplain of the Rio Chama and its associated tributaries.


2000 ◽  
Vol 6 (4) ◽  
pp. 277 ◽  
Author(s):  
Kathy MacKinnon

Papua New Guinea (PNG) occupies the eastern half of the island of New Guinea and still boasts 33 million hectares of closed natural forest (77% of the country), home to numerous endemic species. Overall PNG is sparsely populated with some 700 distinct cultural/ language groups. Economic growth over the past two decades has been spurred by large-scale mining, petroleum and logging operations though the majority of the population continues to rely upon subsistence agriculture (swidden) and collection and utilization of forest products. Some 15 million hectares of forests are accessible for logging, of which 1.5 million hectares have already been logged, generally in an unsustainable manner. Of the over 6 million ha of approved timber blocks more than 1.5 million hectares have been located in areas of high biological value. Forest loss and degradation is now becoming a serious problem.


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