164 research outputs found

    Does Intensification of Grassland and Forage Use Lead to Efficient, Profitable and Sustainable Ecosystems?

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    The increasing demand for safe and nutritional dairy and beef products in our globalizing world, together with the needs to increase resource use efficiency and to protect biodiversity, provide strong incentives for intensification of grassland and forage use. This paper addresses the question in the title. Firstly, we present some notions about ‘intensification of agricultural production’. Secondly, we discuss the intensification of grassland-based dairy production in The Netherlands (NL), Chile and New Zealand (NZ). Finally, we arrive at some conclusions. External driving forces and ‘the law of the optimum’ provide strong incentives for intensification, i.e., for increasing the output per unit surface area and labour. The three country cases illustrate that intensification of grassland use is a global phenomenon, with winners and losers. Winners are farmers who are able to achieve a high return on investments. Losers are small farmers, who drop-out of business, unless they broaden the income-basis. The relationship between intensification and environmental impact is complex. Within certain ranges, intensification leads to increased emissions of nutrients and greenhouse gases to air and water per unit surface area, but to decreased emissions when expressed per unit of produce. The sustainability of a grassland-based ecosystem is ultimately defined by the societal appreciation of that system and by biophysical and socio-economic constraints. In conclusion, intensification may lead to more efficient and profitable, and thereby more sustainable grassland ecosystems, if the systems of departure are extensively managed, under-utilized, low-productive, over-exploited and/or unregulated systems, and the target systems meets societal demands

    Nitrogen Surplus Benchmarks for Controlling N Pollution in the Main Cropping Systems of China

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    This study was financially supported by National Key Research and Development Project of China (2017YFD0200105), China−UK PhD Placement Programme funded by CSC (201603780082), and contributes to “N-Circle” and “CINAg” projects funded by the Newton Fund via UK BBSRC/NERC (grants BB/N013484/1 and BB/N013468/1, respectively).Peer reviewedPostprintPostprin

    An analysis of China's grain production: Looking back and looking forward

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    Ensuring food security is the foundation of economic development and social stability. China is historically a country that is dominated by agriculture. In the past 60 years, China's total grain output increased by fivefold, from 113 million tons (MT) in 1949 to 571 MT in 2011, a statistic which provides inspiration to producers in other parts of the world. Grain production per capita doubled, from 209 to 425 kg during the same time period. At the national scale, China has succeeded in maintaining a basic self-sufficiency for grain for the past three decades. However, with the increasing population pressure and a growing appetite for animal products, China will need 776 MT grain by 2030 to feed its own people, a net increase of 35.9% from its best year on record. China's drive for future food security is challenged by problems such as low efficiency of resource use and resource limitation, diminishing return in yield response, competition for nonagricultural land uses, and environmental degradation. In this article, we analyze historical, temporal, and spatial variation in total grain production as well as the overall developing trends of current and future grain production, and discussed relevant options to overcome production constraints and further promote agricultural production.</p

    Nitrogen, Phosphorus, and Potassium Flows through the Manure Management Chain in China

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    The largest livestock production and greatest fertilizer use in the world occurs in China. However, quantification of the nutrient flows through the manure management chain and their interactions with management-related measures is lacking. Herein, we present a detailed analysis of the nutrient flows and losses in the “feed intake–excretion–housing–storage–treatment–application” manure chain, while considering differences among livestock production systems. We estimated the environmental loss from the manure chain in 2010 to be up to 78% of the excreted nitrogen and over 50% of the excreted phosphorus and potassium. The greatest losses occurred from housing and storage stages through NH<sub>3</sub> emissions (39% of total nitrogen losses) and direct discharge of manure into water bodies or landfill (30–73% of total nutrient losses). There are large differences among animal production systems, where the landless system has the lowest manure recycling. Scenario analyses for the year 2020 suggest that significant reductions of fertilizer use (27–100%) and nutrient losses (27–56%) can be achieved through a combination of prohibiting manure discharge, improving manure collection and storages infrastructures, and improving manure application to cropland. We recommend that current policies and subsidies targeted at the fertilizer industry should shift to reduce the costs of manure storage, transport, and application

    China’s pig relocation in balance

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    In 2015, the Chinese government banned livestock production in some regions (called non-livestock production regions, NLPRs) to control surface water pollution near vulnerable water bodies. In total, 90,000 NLPRs had been established by 2017, covering a land area of 0.82 million km2 and shutting down 0.26 million pig farms1. As a consequence, the number of slaughtered pigs decreased by 46 million head yr–1 between 2014 and 2017. The NLPRs policy is globally unprecedented in terms of the geographical area and number of farms affected, as well as its implementation speed. The NLPRs policy has reduced pork self-sufficiency in some provinces by up to 40% (ref. 2). However, it is unclear which farms and regions may take over the market share

    Nitrogen in Current European Policies

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    Europe, and especially the European Union (EU), has many governmental policy Âż measures aimed at decreasing unwanted reactivenitrogen (N r ) emissions from combustion, agriculture and urban wastes. Many of these policy measures have an Âżeff ects-basedapproachÂż, and focus on single N r compounds, single sectors and either on air or waters.Âż Th is chapter addresses the origin, objectives and targets of EU policy measures related to Nr emissions, considers which instrumentsare being used to implement the policies and briefl y discusses the eff ects of the policy measures.ApproachesÂż Th e chapter starts with a brief description of the basic elements of governmental policy measures.Âż A review of the main international conventions and EU policies related to emissions of Nr to air and water is then provided.Âż Finally the chapter provides a semi-quantitative assessment of the eff ectiveness and effi ciency of European policy measures.Key fi ndings/state of knowledgeÂż International conventions and other treaties have played a key role in raising awareness and establishing policy measures for Nr emissionsabatement in EU through so-called Directives and Regulations.Âż Th ere are many diff erent EU Directives, oft en addressing individual Nr compounds from individual sectors (e.g. NOx emissions fromcombustion; NH 3 emissions from agriculture, pollution of groundwater and surface water by nitrates from agriculture, discharge oftotal nitrogen from urban sewage to surface waters).Âż Many EU Directives have been revised following review and evaluation. Th ere are increasing eff orts to cluster single EU Directives intolarger Framework Directives.Âż Compliance with, and eff ectiveness of, the Directives diff ers between sectors; it decreases in the order (i) reducing NO x emissions fromcombustion sources, (ii) reducing nitrogen (and especially Phosphorus) discharges to waters from industries and households, and (iii)reducing NH 3 emissions and NO 3 leaching from agriculture.Âż Th ere is not much literature on the diff erences in the eff ectiveness and effi ciencies of Directives; a number of factors seem to be involvedin eff ectiveness and effi ciency, but these have not yet been analysed in a coherent manner.Major uncertainties/challengesÂż Th ere is a huge diversity in N r emission sources and pathways, while the number of policy instruments is limited. Th ere is need to fi ndthe optimal mix of policy instruments targeted to the emission sources as well as the stakeholders involved.Âż It has been indicated that some EU Directives addressing emissions of nitrogen compounds from specifi c sources have antagonisticeff ects. Th e magnitude of these eff ects is not yet well known.Âż Th ere is a delay in the environmental and ecological responses following the introduction of Directives; these are due to legislativedelays, lack of enforcement and control, constraints in practice and because of biogeochemical hysteresis eff ects; these eff ects are notyet well understood quantitatively.Âż In general, only modest reductions in Nr emissions from agriculture have been achieved to date; this refl ects the need for more eff ectiveand effi cient policy measures and/or greater enforcement of current policies.RecommendationsÂż To examine further the diff erences between sectors of the factors that contribute to the eff ectiveness and effi ciency of policy measuresfor the abatement of N r emissions.Âż T o explore further the eff ectiveness and effi ciency of more integrated N management and integrated policy measures for the abatementof adverse impacts of N r emissions.JRC.DDG.H.2-Climate change and air qualit

    Cleaning up nitrogen pollution may reduce future carbon sinks

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    Biosphere carbon sinks are crucial for reducing atmospheric carbon dioxide (CO2) concentration to mitigate global warming, but are substantially affected by the input of reactive nitrogen (Nr). Although the effects of anthropogenic CO2 emission and nitrogen deposition (indicated by Nr emission to atmosphere) on carbon sink have been studied, it is unclear how their ratio (C/N) changes with economic development and how such change alters biosphere carbon sinks. Here, by compiling datasets for 132 countries we find that the C/N ratio continued to increase despite anthropogenic CO2 and Nr emissions to atmosphere both showing an asymmetric para-curve with economic growth. The inflection points of CO2 and Nr emissions are found at around $15,000 gross domestic product per capita worldwide. Economic growth promotes the use of Nr and energy, while at the same time increases their use efficiencies, together resulting in occurrences of inflection points of CO2 and Nr emissions. Nr emissions increase slower but decrease faster than that of CO2 emissions before and after the inflection point, respectively. It implies that there will be relatively more anthropogenic CO2 emission but less N deposition with economic growth. This may limit biosphere carbon sink because of relative shortage of Nr. This finding should be integrated/included in global climate change modelling. Efforts, such as matching N deposition with carbon sequestration on regional scale, to manage CO2 and Nr emissions comprehensively to maintain a balance are critical

    Food and feed trade has greatly impacted global land and nitrogen use efficiencies over 1961–2017

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    International trade of agricultural products has complicated and far-reaching impacts on land and nitrogen use efficiencies. We analysed the productivity of cropland and livestock and associated use of feed and fertilizer efficiency for over 240 countries, and estimated these countries’ cumulative contributions to imports and exports of 190 agricultural products for the period 1961–2017. Crop trade has increased global land and partial fertilizer nitrogen productivities in terms of protein production, which equalled savings of 2,270 Mha cropland and 480 Tg synthetic fertilizer nitrogen over the analysed period. However, crop trade decreased global cropland productivity when productivity is expressed on an energy (per calorie) basis. Agricultural trade has generally moved towards optimality, that is, has increased global land and nitrogen use efficiencies during 1961–2017, but remains at a relatively low level. Overall, mixed impacts of trade on resource use indicate the need to rethink trade patterns and improve their optimality
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