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João Vasco Silva

Bio: João Vasco Silva is an academic researcher from Wageningen University and Research Centre. The author has contributed to research in topics: Yield gap & Yield (finance). The author has an hindex of 11, co-authored 28 publications receiving 467 citations. Previous affiliations of João Vasco Silva include International Maize and Wheat Improvement Center & International Rice Research Institute.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors used a country-by-country, bottom-up approach to establish statistical estimates of actual grain yield, and compare these to modelled estimates of potential yields for either irrigated or rainfed conditions.

125 citations

Journal ArticleDOI
TL;DR: In this article, the authors explore the interrelations between farms and farming systems in the global food system and highlight trends in major regions of the world and explore possible trajectories for the future and ask: Who are the farmers of the future?
Abstract: Achieving SDG2 (zero hunger) in a situation of rapid global population growth requires a continued focus on food production. Farming not merely needs to sustainably produce nutritious diets, but should also provide livelihoods for farmers, while retaining natural ecosystems and services. Rather than focusing on production principles, this article explores the interrelations between farms and farming systems in the global food system. Evaluating farming systems around the world, we reveal a bewildering diversity. While family farms predominate, these range in size from less than 0.1 ha to more than 10,000 ha, and from hand hoe use to machine-based cultivation, enabling one person to plant more than 500 ha in a day. Yet, farming in different parts of the world is highly interdependent, not least because prices paid for farm produce are largely determined by global markets. Furthermore, the economic viability of farming is a problem, globally. We highlight trends in major regions of the world and explore possible trajectories for the future and ask: Who are the farmers of the future? Changing patterns of land ownership, rental and exchange mean that the concept of ‘what is a farm’ becomes increasingly fluid. Next to declining employment and rural depopulation, we also foresee more environmentally-friendly, less external input dependent, regionalised production systems. This may require the reversal of a global trend towards increasing specialisation to a recoupling of arable and livestock farming, not least for the resilience it provides. It might also require a slow-down or reversal of the widespread trend of scale enlargement in agriculture. Next to this trend of scale enlargement, small farms persist in Asia: consolidation of farms proceeds at a snail’s pace in South-east Asia and 70% of farms in India are ‘ultra-small’ – less than 0.05 ha. Also in Africa, where we find smallholder farms are much smaller than often assumed (< 1 ha), farming households are often food insecure. A raft of pro-poor policies and investments are needed to stimulate small-scale agriculture as part of a broader focus on rural development to address persistent poverty and hunger. Smallholder farms will remain an important source of food and income, and a social safety net in absence of alternative livelihood security. But with limited possibilities for smallholders to ‘step-up’, the agricultural engine of growth appears to be broken. Smallholder agriculture cannot deliver the rate of economic growth currently assumed by many policy initiatives in Africa.

118 citations

Journal ArticleDOI
TL;DR: In this article, the authors decompose the yield gap into efficiency, resource and technology yield gaps for irrigated lowland rice-based farming systems in Central Luzon, Philippines, and to explain those yield gaps using data related to crop management, biophysical constraints and available technologies.

99 citations

Journal ArticleDOI
TL;DR: In this article, a review of yield gap studies (50 agronomic-based peer-reviewed articles) was performed to identify the most commonly considered and explaining factors of the yield gap.

93 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the existing literature to assess the methods used to estimate rice yield gaps at a local scale and to summarize the yield gaps estimated in those studies, identify practical methods of analysis that provides realistic estimates of exploitable rice yield gap, and provide recommendations for future studies on rice yields that will allow accurate interpretation of available data at local level.

91 citations


Cited by
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Journal ArticleDOI
01 Jun 2018-Science
TL;DR: Cumulatively, the findings support an approach where producers monitor their own impacts, flexibly meet environmental targets by choosing from multiple practices, and communicate their impacts to consumers.
Abstract: Food’s environmental impacts are created by millions of diverse producers. To identify solutions that are effective under this heterogeneity, we consolidated data covering five environmental indicators; 38,700 farms; and 1600 processors, packaging types, and retailers. Impact can vary 50-fold among producers of the same product, creating substantial mitigation opportunities. However, mitigation is complicated by trade-offs, multiple ways for producers to achieve low impacts, and interactions throughout the supply chain. Producers have limits on how far they can reduce impacts. Most strikingly, impacts of the lowest-impact animal products typically exceed those of vegetable substitutes, providing new evidence for the importance of dietary change. Cumulatively, our findings support an approach where producers monitor their own impacts, flexibly meet environmental targets by choosing from multiple practices, and communicate their impacts to consumers.

2,353 citations

Posted Content
01 Jan 1995
TL;DR: In this article, the potential applicability of frontier methods in agricultural economics is discussed, along with the construction of technical, allocative, scale and overall efficiency measures relative to these estimated frontiers.
Abstract: In this paper recent developments in the estimation of frontier functions and the measurement of efficiency are surveyed, and the potential applicability of these methods in agricultural economics is discussed. Frontier production, cost and profit functions are discussed, along with the construction of technical, allocative, scale and overall efficiency measures relative to these estimated frontiers. The two primary methods of frontier estimation, econometric and linear programming, are compared. A survey of recent applications of frontier methods in agriculture is also provided. (This abstract was borrowed from another version of this item.)

821 citations

Journal ArticleDOI
TL;DR: The potential of PGPR to facilitate plant growth is of fundamental importance, especially in case of abiotic stress, where bacteria can support plant fitness, stress tolerance, and/or even assist in remediation of pollutants.

203 citations

01 May 2014
TL;DR: In this paper, a planetary N boundary should include both the benefits and adverse impacts of reactive N (Nr) and the spatial variability of Nr impacts, considering the need to avoid adverse impacts from elevated Nr emissions to water, air and soils, and to feed the world population in an adequate way.
Abstract: This paper first describes the concept of, governance interest in, and criticism on planetary boundaries, specifically with respect to the nitrogen (N) cycle. These criticisms are then systematically evaluated. We argue that planetary N boundaries should include both the benefits and adverse impacts of reactive N (Nr) and the spatial variability of Nr impacts. We revise the planetary N boundary by considering the need to: first, avoid adverse impacts of elevated Nr emissions to water, air and soils, and second, feed the world population in an adequate way. The derivation of a planetary N boundary, in terms of anthropogenic fixation of di-nitrogen (N 2 ) is illustrated by first, identification of multiple threat N indicators and setting limits for them; second, back calculating N losses from critical limits for N indicators, while accounting for the spatial variability of these indicators and their exceedance; and third, back calculating N fixation rates from critical N losses. The derivation of the needed planetary N fixation is assessed from the global population, the recommended dietary N consumption per capita and the N use efficiency in the complete chain from N fixation to N consumption. The example applications show that the previously suggested planetary N boundary of 35 Tg N yr −1 is too low in view of needed N fixation and also unnecessary low in view of most environmental impacts.

196 citations

Journal ArticleDOI
TL;DR: It is found that China is likely to remain self-sufficient in rice assuming current yield and consumption trajectories and no reduction in production area to 2030, and priority areas for improving yields to meet demands by 2030.
Abstract: China produces 28% of global rice supply and is currently self-sufficient despite a massive rural-to-urban demographic transition that drives intense competition for land and water resources. At issue is whether it will remain self-sufficient, which depends on the potential to raise yields on existing rice land. Here we report a detailed spatial analysis of rice production potential in China and evaluate scenarios to 2030. We find that China is likely to remain self-sufficient in rice assuming current yield and consumption trajectories and no reduction in production area. A focus on increasing yields of double-rice systems on general, and in three single-rice provinces where yield gaps are relatively large, would provide greatest return on investments in research and development to remain self-sufficient. Discrepancies between results from our detailed bottom-up yield-gap analysis and those derived following a top-down methodology show that the two approaches would result in very different research and development priorities.

164 citations