The scale and nature of pre-Columbian human impacts in Amazonia are currently hotly debated. Whereas pre-Columbian people dramatically changed the distribution and abundance of species and habitats ...in some parts of Amazonia, their impact in other parts is less clear. Pioneer research asked whether their effects reached even further, changing how ecosystems function, but few in-depth studies have examined mechanisms underpinning the resilience of these modifications. Combining archeology, archeobotany, paleoecology, soil science, ecology, and aerial imagery, we show that pre-Columbian farmers of the Guianas coast constructed large raised-field complexes, growing on them crops including maize, manioc, and squash. Farmers created physical and biogeochemical heterogeneity in flat, marshy environments by constructing raised fields. When these fields were later abandoned, the mosaic of well-drained islands in the flooded matrix set in motion self-organizing processes driven by ecosystem engineers (ants, termites, earthworms, and woody plants) that occur preferentially on abandoned raised fields. Today, feedbacks generated by these ecosystem engineers maintain the human-initiated concentration of resources in these structures. Engineer organisms transport materials to abandoned raised fields and modify the structure and composition of their soils, reducing erodibility. The profound alteration of ecosystem functioning in these landscapes coconstructed by humans and nature has important implications for understanding Amazonian history and biodiversity. Furthermore, these landscapes show how sustainability of food-production systems can be enhanced by engineering into them fallows that maintain ecosystem services and biodiversity. Like anthropogenic dark earths in forested Amazonia, these self-organizing ecosystems illustrate the ecological complexity of the legacy of pre-Columbian land use.
Climate change poses significant challenges to agriculture, with serious impacts on smallholder farmers’ food security and livelihoods. Climate-smart agriculture (CSA) is being promoted to facilitate ...climate change adaptation and mitigation. While there is evidence that CSA supports smallholders’ adaption to climate change, the rate of CSA adoption remains low, particularly in sub-Saharan Africa. Previous studies have explained the low adoption based on generic factors such as farm, farmer, institutional and location characteristics, yet little is known about the role of farmers’ cognitive traits. This study investigates the influence of farmer entrepreneurial orientation, a cognitive trait reflecting a farmer’s innovativeness, proactiveness and propensity to take risks. We use data from smallholder potato farmers in Kenya and estimate a set of multivariate probit models to analyse the adoption decisions. Results show that risk-taking positively influences the adoption of irrigation, changing cultivation calendar, use of certified seed, crop rotation and soil testing. Proactiveness is positively related to the use of irrigation, changing the cultivation calendar and use of certified seed, while it is negatively related to intercropping. Contrary to our hypothesis that innovative farmers are more likely to adopt CSA practices, we find a negative relation between innovativeness and the use of certified seed. After categorizing CSA practices based on the main resources required, we find that risk-taking is positively associated with the adoption of practices that require high intensity of skilled labour and financial resources. Innovativeness is negatively associated with practices that require high intensity of financial resources. Lastly, we find proactiveness to be positively associated with the adoption of finance-intensive practices but negatively associated with unskilled-labour-intensive practices. These findings imply, first, that development practitioners should consider the interrelations among CSA practices and farmer entrepreneurial orientation in designing development interventions. Second, policy-makers need to create an environment conducive to farmer entrepreneurship as an indirect way to support the adoption of appropriate CSA practices.
•Farmer entrepreneurship plays an important role in influencing the adoption decisions of smallholders.•We study the determinants of innovation adoption beyond the generic characteristics by exploring the role of farmer EO.•Focusing on the intensity of resources required to adopt CSA practices provide more insights on the adoption decisions.•There is need for targeted entrepreneurship training programs to influence smallholder farmers’ adoption decisions.•There is need to extend CSA intervention programs beyond the traditional staple crops in sub-Saharan Africa.
Since 1980, China has made impressive progress in increasing agricultural production, improving food security and reducing rural poverty. Increased use of chemical fertilizer has played a vital role ...in this, but presently fertilizer overuse is posing severe challenges for the environment and human health. In response to this, the Chinese government has announced policies to reduce chemical fertilizer use, while at the same time supporting rural incomes and maintaining food self-sufficiency in major grains.
The objective of the paper is to assess the effectiveness of these policies in reducing the nutrient surpluses, maintaining food self-sufficiency and supporting rural incomes throughout China.
We use a spatially and socially detailed general equilibrium model of the Chinese economy to simulate the potential impact of these policies on agricultural production, environmental pollution and rural incomes. The scenarios are developed in a step-wise fashion to show the contribution of specific measures included in the policies.
Our main results are that nitrate surpluses can be reduced by more than 50% and phosphate surpluses even by more than 75% without significant negative impacts on China's food self-sufficiency, provided that the government adopts appropriate policy combinations. At the same time, the income of the average crop farmer goes up slightly compared to the business-as-usual scenario. However, the spatial variability is large, requiring supplementary targeted income support measures, particularly in poverty-stricken provinces like Shaanxi, Chongqing, Guizhou and Yunnan where also the income gains of the new policies are below average.
The results show that appropriate policy combinations should address both the efficiency of chemical fertilizer use and the intensity of organic fertilizer use. Hence, substantial efforts are necessary in mobilizing stakeholder involvement in implementing the policies.
The impact of policy measures on nutrient surpluses. Display omitted
•Current overuse of fertilizer in China is unsustainable.•We simulate government policies with a spatial applied general equilibrium model.•Drastic reduction is possible by addressing chemical and organic fertilizer jointly.•Food self-sufficiency will not be put at risk by the policies.•Average farm incomes do not suffer, but the poorest regions need additional support.
Robotic weed control for vegetables is necessary to increase crop productivity, avoid intensive hand weeding as labour shortages in developed countries such as United States has led to a surge in ...food production costs. However, development of a reliable, intelligent robotic system for weed control in real-time for vegetables still remains a challenging task. The main issue arises while distinguishing crops from weeds in real-time. In this paper, a novel technique to crop signalling to distinguish crops from in-row weeds in complex natural scenarios, such as high weed densities commonly found on organic farms, in real-time using machine vision is presented. Crop signalling is a simple and low-cost technique in which a signalling compound is produced by or applied to the crop and where the signalling compound is machine readable and helps to create visual features that uniquely distinguish the crops from weeds. The crop and weed mapping algorithm presented here were specially designed and developed for a vision-based weeding robot equipped with a micro-jet herbicide-spraying system for weed control in a lettuce field. The proposed technique involves weed/crop mapping and decision making. Experimental results show that the crop detection accuracy was 99.75%, and 98.11% of sprayable weeds were detected. The proposed technique is highly accurate, reliable and more robust than other sensor-based techniques presented in the literature.
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•A real-time in-row weed-crop detection and classification algorithm was proposed.•A novel crop signaling technique was introduced to distinguish crops from weeds.•It utilized computer vision to determine the spatial location of lettuce and weed.•The algorithm was designed to equipped with a micro-jet herbicide-spraying system.•The algorithm outperformed existing methods in terms classification accuracy.
•Conservation agriculture-based sustainable intensification participatory research.•Reduced both labor use and production costs by 40%.•Increased gross margins by up to 25%.•Reduced drudgery for ...women and youth who do the majority of menial, laborious tasks.•Results applicable for a wide range of smallholder farming communities.
The Eastern Gangetic Plains of South Asia is a region of high rural poverty and low agronomic productivity, with crops grown using traditional management practices which are labor-intensive and uneconomical. Poor agronomic productivity is largely caused by unintentional, inefficient management practices which are exacerbated by labor shortages caused by increased migration away from rural areas as households require additional income from remittances. These labor shortages increase the cost of hiring labor, further contributing to low gross margins from cropping systems. The climates, soils and available water across the region indicate that, with improved management practices, this region has the potential to produce high yields for low production costs and labor requirements, ensuring high gross margins for smallholder farmers. We conducted on-farm participatory trials to compare the performance of traditional and improved conservation agriculture-based sustainable intensification management practices to understand which used less labor, had lower production costs and returned higher gross margins to smallholder farmers. Our study showed that compared to traditional management practices, conservation agriculture-based sustainable intensification practices reduced both labor use and total cropping system production costs by around 40% and increased gross margins by up to 25%. Trials were conducted on over 400 farms and thus our results are both statistically rigorous and representative of a range of common crop production management across the Eastern Gangetic Plains. These results show there is potential to increase livelihoods and reduce the impact of labor shortages for smallholder farmers living in diverse climatic, edaphic and social circumstances across the region. They have broader applications in labor-constrained smallholder cropping systems throughout South Asia and worldwide.
Blockchain technology, while still challenged with key limitations, is a transformative Information and Communications Technology (ICT) that has changed our notion of trust. Improved efficiencies for ...agricultural sustainable development has been demonstrated when ICT-enabled farms have access to knowledge banks and other digital resources. UN FAO-recommended ICT e-agricultural infrastructure components are a confluence of ICT and blockchain technology requirements. When ICT e-agricultural systems with blockchain infrastructure are immutable and distributed ledger systems for record management, baseline agricultural environmental data integrity is safeguarded for those who participate in transparent data management. This paper reviewed blockchain-based concepts associated with ICT-based technology. Moreover, a model ICT e-agriculture system with a blockchain infrastructure is proposed for use at the local and regional scale. To determine context specific technical and social requirements of blockchain technology for ICT e-agriculture systems, an evaluation tool is presented. The proposed system and tool can be evaluated and applied to further developments of e-agriculture systems.
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