Hasil untuk "Agriculture"

J. Pretty, Z. Bharucha

O. Ahumada, J. Villalobos

O. Deschenes, M. Greenstone, R. Mendelsohn et al.

A. Bhatnagar, M. Sillanpää, A. Witek-Krowiak

Kiminori Matsuyama

P. Thenkabail, Ronald B. Smith, E. Pauw

C. Udry

J. Keyantash, J. Dracup

F. Nicholson, Stephen R. Smith, B. J. Alloway et al.

M. Rosenzweig, K. Wolpin

J. Lin

K. Van Oost, T. Quine, Gerard Govers et al.

K. Jabran, G. Mahajan, V. Sardana et al.

Sharmeen Afroze, T. Sen

Ester Boserup

Margaret Mwangi, S. Kariuki

D. Pimentel, C. Edwards, R. Lal et al.

A catheter introducer adapted to facilitate insertion of a catheter into a patient without requiring a large aperture be made in the patient wherethrough a separate catheter may be inserted; the catheter introducer includes an elongate narrow wire adapted to pass through the catheter and be sufficiently long so as to protrude from an open distal end of the catheter, the wire being adapted to receive an electrical current charge therethrough so as to energize a protruding tip region of the wire and facilitate direct insertion of the catheter into the patient. The catheter introducer includes a removable lock head structured to be removably secured over a proximal hub portion of the catheter subsequent to insertion of the wire into the catheter, and is utilized as part of a method of inserting a catheter wherein a patient is first placed upon a grounded operating surface, the elongate wire of the catheter introducer is inserted into the catheter, current is introduced into the wire, the catheter is pushed easily through the patient's flesh as a result of contact by the energized protruding tip region of the wire with the patient's flesh, the catheter being inserted a desired distance into the patient after which the current is removed from the wire and the catheter introducer is removed from the catheter to allow normal use of the catheter.

Ling Ding, Shuaiya Zhang, Xiaoyu Wang et al.

Microplastics (MPs) are less than 5 mm, and have significant implications for the environment. As a new type of environmental pollutant, MPs have increasingly attracted the attention of scientists and have led to marked increases in both public and political awareness. However, their distribution and fates in the terrestrial environment are limited. We investigated the distribution and characteristics of MPs in the agricultural soils of Shaanxi Province, a typical agricultural province in China. We found evidence that 100% of agricultural soils contained MPs. The concentration of MPs in the soil ranged from 1430 to 3410 items/kg. Fibers and small-sized particles (0-0.49 mm) were the predominant type and size, respectively. Polystyrene (PS), polyethylene (PE), polypropylene (PP), high-density polyethylene (HDPE), polyvinyl chloride (PVC) and polyethylene terephthalate (PET) particles were identified in agricultural soil. Furthermore, the abundance of microplastics in agricultural soil is closely related to the planting type of soil and climatic factors. The results from this study confirmed the presence of a high abundance of MPs in agricultural soil, and proved that agricultural activities might have caused MP contamination in soil.

Raissa Fabregas, M. Kremer, Frank Schilbach

Mobile farming advice Mobile phones are almost universally available, and the costs of information transmission are low. They are used by smallholder farmers in low-income countries, largely successfully, to optimize markets for their produce. Fabregas et al. review the potential for boosting mobile phone use with smartphones to deliver not only market information but also more sophisticated agricultural extension advice. GPS-linked smartphones could provide locally relevant weather and pest information and video-based farming advice. But how to support the financial requirements of such extension services is less obvious, given the unwieldiness of government agencies and the vested interests of commercial suppliers. Science, this issue p. eaay3038 BACKGROUND Sustainably raising agricultural productivity for the 2 billion people living in smallholder farming households in the developing world is critical for reducing world poverty and meeting rising food demand in the face of climate change. Nevertheless, most smallholder farmers have no access to science-based agricultural advice. The widespread adoption of basic mobile phone technology presents opportunities to improve upon existing in-person agricultural extension efforts that are expensive and fraught with accountability problems. ADVANCES Meta-analyses suggest that the transmission of agricultural information through mobile technologies in sub-Saharan Africa and India increased yields by 4% and the odds of adoption of recommended agrochemical inputs by 22%. The delivery of market information can have additional system-wide impacts, reducing price dispersion and lowering transaction costs. Given the low and rapidly declining cost of information transmission, benefits likely exceed costs by an order of magnitude. Even basic phones and inexpensive text and voice messages can influence farmer behavior. Smartphones with GPS systems create the potential for larger gains through the transmission of more sophisticated media, such as videos, and for locally customized information on soil characteristics, weather, and pest outbreaks, delivered at the appropriate time during the agricultural season. Messages could be customized on the basis of farmer characteristics, such as education or financial circumstances. Experimentation, machine learning, and two-way communication with and between farmers could facilitate improvements of information and other services over time. Advances from behavioral science can improve information transmission and address behavioral barriers to the adoption of improved agricultural techniques. Mobile phone–based systems could increase the productivity and accountability of in-person extension agents and enhance supply chain functionality. Realizing the potential of digital agriculture will require an interdisciplinary effort to develop and rigorously test a variety of approaches, incorporating insights from behavioral science, agriculture, economics, and data science. OUTLOOK Multiple market failures associated with information markets limit the ability of mobile phone–based extension systems to reach socially efficient scale through purely commercial financing. Because the marginal costs of disseminating information are close to zero, the optimal scale of such systems is very large. However, fixed system development costs still must be covered. Multiple organizations have introduced digital agricultural extension systems with financial models based on selling subscriptions to individual farmers, but such systems have been able to reach only a small fraction of farmers in the developing world. Farmer payments may be insufficient to cover the fixed costs, because information is difficult to exclude from nonpurchasers and because it is challenging for farmers to verify the quality of the information. Existing evidence suggests substantial gaps between farmers’ willingness to pay for information and its social value. Advertising or agrochemical input sales could be used to finance information provision, but this approach could incentivize providers to distort information content in the absence of strong reputational costs of misinformation or appropriate regulation. Public financing could cover fixed costs and enable scale-up. Although agriculture ministries often deliver messages in ways that farmers find difficult to understand and use, recent examples suggest that if feedback mechanisms are in place, governments can improve their services over time. Models that incentivize farmers to share their experiences create scope for customization and efficiency gains as systems grow, because this data may be used to improve recommendations for other farmers. If successful, digital agricultural advisory systems could supply a model for digital development more broadly. Mobile phones can benefit farmers in low- and middle-income countries by improving access to agricultural advice and market price information. Mobile technologies, particularly smartphones, have the potential to bring sophisticated science-based agricultural advice to smallholder farmers to improve productivity, especially under rapidly changing economic and environmental conditions. However, market failures likely preclude efficient scaling of valuable digital advice applications. PHOTO: JAKE LYELL/ALAMY STOCK PHOTO The rapid spread of mobile phones creates potential for sustainably raising agricultural productivity for the 2 billion people living in smallholder farming households. Meta-analyses suggest that providing agricultural information via digital technologies increased yields by 4% and the odds of adopting recommended inputs by 22%. Benefits likely exceed the cost of information transmission by an order of magnitude. The spread of GPS-enabled smartphones could increase these benefits by enabling customized information, thus incentivizing farmers to contribute information to the system. Well-known distortions in markets for information limit the ability of such systems to reach the socially efficient scale through purely commercial means. There is a clear role for public support for digital agricultural extension, but messages designed by agricultural ministries are often difficult for farmers to understand and use. Realizing the potential of mobile communication systems requires feedback mechanisms to enable rigorous testing and continuous improvement.

Jia‐Zhen Duan, Chenchen Ren, Si-Qi Wang et al.

China’s agricultural sector is dominated by smallholder farms, which mostly exhibit relatively low nutrient use efficiency, low agricultural income and substantial non-point-source pollution. Here we assess the spatial feasibility and cost-effectiveness of agricultural land consolidation in China by integrating data from over 40,000 rural surveys, ecological modelling and geostatistical analysis. We found that 86% of Chinese croplands could be consolidated to establish a large-scale farming regime with an average field size greater than 16 ha. This would result in a 59% and 91% increase in knowledge exchange and machinery use, respectively, contributing to a 24% reduction in total nitrogen input, an 18% increase in nitrogen use efficiency and a 39% reduction in labour requirement, while doubling labour income. Despite requiring a one-time investment of approximate US$370 billion for land consolidation, total agricultural profits would double due to agricultural production costs being halved. The consolidation of small farms into large-scale agricultural enterprises may have important socioeconomic and environmental consequences. Based on 40,000 rural surveys, ecological modelling and geostatistical analysis, this study assesses the spatial feasibility and cost-effectiveness of land consolidation in China, and its impact on a set of sustainability indicators.