Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Efficiënte keten: preventie reststromen: rapportage 2015/2016
Staps, Sjef ; Tromp, Seth ; Gogh, Bart van; Burgh, Marianne van der - \ 2017
Driebergen : Louis Bolk Instituut - 59
reststromen - biologische landbouw - agro-industriële ketens - biologische voedingsmiddelen - voedselketens - verliezen - bederfelijke producten - houdbaarheid (kwaliteit) - voedselverspilling - bewaartijd - residual streams - organic farming - agro-industrial chains - organic foods - food chains - losses - perishable products - keeping quality - food wastage - storage life
Het onderhavige rapport is bedoeld als openbare verslaglegging van de eerste twee onderzoeksjaren van het publiek-private samenwerking (PPS) project ‘Efficiënte keten, preventie reststromen’ (2015-2018). De ambitie van dit PPS-project is om derving (verspilling) in de biologische agrifood-keten te voorkomen, en daar waar reststromen ontstaan de kansen voor het vermarkten van deze reststromen te vergroten. Het rapport kan gebruikt worden als referentie voor het vinden van mogelijkheden om derving (verspilling) te voorkomen en daar waar reststromen desondanks ontstaan de kansen voor het vermarkten van deze reststromen te vergroten.
Monitor voedselverspilling : update 2009-2014
Soethoudt, Han ; Vollebregt, Martijntje ; Burgh, Marianne van der - \ 2016
Wageningen : Wageningen UR - Food & Biobased Research (Food & Biobased Research rapport 1703) - 31
voedselverspilling - monitoring - voedselproducten - consumentengedrag - verliezen - voedselafval - food wastage - food products - consumer behaviour - losses - food wastes
Monitor voedselverspilling : zelfmonitoring pilots
Soethoudt, Han ; Vollebregt, Martijntje ; Burgh, Marianne van der - \ 2016
Wageningen : Wageningen UR - Food & Biobased Research (Food & Biobased Research rapport 1702) - 28
voedselverspilling - reststromen - monitoring - voedselproducten - consumentengedrag - verliezen - voedselafval - food wastage - residual streams - food products - consumer behaviour - losses - food wastes
Remote sensing of land use and carbon losses following tropical deforestation
Sy, V. de - \ 2016
Wageningen University. Promotor(en): Martin Herold, co-promotor(en): Jan Clevers; L. Verchot. - Wageningen : Wageningen University - ISBN 9789462578036 - 142 p.
remote sensing - tropical forests - land use - carbon - losses - environmental degradation - forest monitoring - tropische bossen - landgebruik - koolstof - verliezen - milieuafbraak - bosmonitoring

The new Paris Agreement, approved by 195 countries under the auspice of the United Nations Framework Convention on Climate Change (UNFCCC), calls for limiting global warming to “well below" 2°Celsius. An important part of the climate agreement relates to reducing emissions from deforestation and forest degradation, and enhancing carbon stocks (REDD+) in non-Annex I (mostly developing) countries. Over the last decades the growing demand for food, fibre and fuel has accelerated the pace of forest loss. In consequence, tropical deforestation and forest degradation are responsible for a large portion of global carbon emissions to the atmosphere, and destroy an important global carbon sink that is critical in future climate change mitigation.

Within the REDD+ framework, participating countries are given incentives to develop national strategies and implementation plans that reduce emissions and enhance sinks from forests and to invest in low carbon development pathways. For REDD+ activities to be effective, accurate and robust methodologies to estimate emissions from deforestation and forest degradation are crucial. Remote sensing is an essential REDD+ observation tool, and in combination with ground measurements it provides an objective, practical and cost-effective solution for developing and maintaining REDD+ monitoring systems. The remote sensing monitoring objective for REDD+ is not only to map deforestation but also to support policy formulation and implementation. Identifying and addressing drivers and activities causing forest carbon change is crucial in this respect. Despite the importance of identifying and addressing drivers, quantitative information on these drivers, and the related carbon emissions, is scarce at the national level.

The main objective of this thesis is to explore the role of remote sensing for monitoring tropical forests for REDD+ in general, and for assessing land use and related carbon emissions linked to drivers of tropical deforestation in particular. To achieve this, this thesis investigates the following research questions:

What is the current role and potential of remote sensing technologies and methodologies for monitoring tropical forests for REDD+ and for assessing drivers of deforestation?

What is the current state of knowledge on drivers of deforestation and degradation in REDD+ countries?

What are land use patterns and related carbon emissions following deforestation, capitalising on available land use and biomass remote sensing data?

The research conducted in this PhD thesis contributes to the understanding of the role of remote sensing in forest monitoring for REDD+ and in the assessment of drivers of deforestation. In addition, this thesis contributes to the improvement of spatial and temporal quantification of land use and related carbon emissions linked to drivers of tropical deforestation. The results and insights described herein are valuable for ongoing REDD+ forest monitoring efforts and capacity development as REDD+ moves closer to becoming an operational mitigation mechanism.

Stochastic uncertainty and sensitivities of nitrogen flows on diary farms in The Netherlands
Oenema, J. ; Burgers, S. ; Keulen, H. van; Ittersum, M.K. van - \ 2015
Agricultural Systems 137 (2015). - ISSN 0308-521X - p. 126 - 138.
manure management-practices - nutrient management - use efficiency - systems - balances - budgets - losses - europe
Nutrient management decisions and environmental policy making must be based on sound data and proper analysis. Annual data collection and monitoring of farm and nutrient performance are wrought with uncertainties. Such uncertainties need to be addressed as it may lead to ambiguities and wrong conclusions. We developed an input-output N balance model to describe and quantify N flows in dairy farming systems. Input for this model was based on monitored data for one year (2005) from one experimental (detailed monitoring) and 14 pilot commercial dairy farms (less detailed monitoring). A Monte Carlo approach was used to quantify effects of uncertainty of input data on annual farm N surplus, soil surface N surplus and N intake during grazing, followed by a sensitivity analysis to apportion the different sources of uncertainty. Uncertainties in data input were described with probability density functions. Farm N surplus of the 14 pilot farms ranged between 81 and 294¿kg¿ha-1, soil surface N surplus between 35 and 256¿kg¿ha-1, and N intake during grazing between 27 and 108¿kg¿ha-1. The uncertainties of N flows – both relative and absolute – increased from farm N surplus (CV¿=¿8%; SD¿=¿15¿kg¿N¿ha-1) to soil surface N surplus (CV¿=¿12%; SD¿=¿16¿kg¿N¿ha-1) to N intake during grazing (CV¿=¿49%; SD¿=¿28¿kg¿N¿ha-1). Variation in uncertainty among farms in farm and soil surface N surplus and N intake during grazing was substantial and was related to the farm structure and farm characteristics such as production intensity, N fixation by clover and annual changes in stocks of roughage and manure. We found that a monitoring program based on more measurements instead of estimates and/or fixed rate values from literature will not always result in a better quantification of farm and soil surface N surplus on clover-based dairy farms. However, on farms with no N fixation, an intensive monitoring program reduced the uncertainty in farm and soil surface N surplus by 23% and the uncertainty of N intake during grazing was reduced by more than 30%. Knowledge about uncertainties of N flows is necessary to correctly interpret the N performance on dairy farms and its evolution through time. A first step is to get insights into the most uncertain N flows on a dairy farm. The next step, where possible, is to improve the estimation of the most uncertain N flows. Based on the insights from this study, these steps will underpin the validation of trends in N performance and justify decisions in environmental policy making and/or decisions for making on-farm improvements.
Verwaarding van voedselreststromen uit supermarkten : beheersing van voedselverspilling: belemmeringen en oplossingen (BO-20-015-005)
Schripsema, A.S. ; Burgh, M. van der; Sluis, A.A. van der; Bos-Brouwers, H.E.J. - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research 1549) - ISBN 9789462574045 - 92
voedselverspilling - verspilling - voedsel - voedselproducten - supermarkten - reststromen - verliezen - biobased economy - food wastage - wastage - food - food products - supermarkets - residual streams - losses
In opdracht van het Ministerie van Economische Zaken heeft Wageningen UR Food & Biobased Research de belemmeringen en kansen van het verwaarden van voedselreststromen uit supermarkten in kaart gebracht. Uit de literatuur blijkt dat er nog veel onbekend is over de omvang van voedselrestromen, de preventie ervan en de verwaarding van deze reststromen in supermarkten. Daarom is een case study uitgevoerd om op basis van interviews met supermarktondernemers en reststroomverwerkers een actueel beeld te verkrijgen van (i) de huidige omvang van voedselverlies in supermarkten, (ii)de mogelijkheden tot het hoogwaardig verwerken van deze reststromen, (iii) de belemmeringen die hoogwaardig verwerking in de weg staan, en (iv) mogelijke manieren om deze belemmeringen weg te nemen.
Monitor voedselverspilling : update Monitor voedselverspilling 2009-2013 & mogelijkheden tot (zelf) monitoring van voedselverspilling door de keten heen
Bos-Brouwers, H.E.J. ; Soethoudt, J.M. ; Vollebregt, H.M. ; Burgh, M. van der - \ 2015
Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research 1541) - ISBN 9789462574007 - 56
voedselverspilling - verspilling - voedsel - monitoring - voedselproducten - consumentengedrag - verliezen - voedselafval - food wastage - wastage - food - food products - consumer behaviour - losses - food wastes
Voor het ministerie van Economische Zaken is binnen het project Monitoring Voedselverspilling een update opgesteld van de stand van zaken met betrekking tot de voedselverspilling in Nederland tot en met de cijfers over 2013. Tevens is de mogelijkheid tot zelfmonitoring van voedselverspilling door bedrijven in kaart gebracht.
Driegangenmenu uit de kliko
Thung, P. ; Ramaker, R. ; Bos-Brouwers, H.E.J. - \ 2015
Resource: nieuwssite voor studenten en medewerkers van Wageningen UR 9 (2015)14. - ISSN 1389-7756 - p. 14 - 15.
voedselverspilling - verliezen - voedselafval - etensresten - etensbordafval - food wastage - losses - food wastes - leftovers - plate waste
Jaarlijks gooit de gemiddelde Nederlander een kleine vijftig kilo aan voedsel in de kliko. Onderzoekers laten de inwoners van Wageningen nu tegen elkaar strijden om zo min mogelijk te verspillen. Deze foodbattle start op maandag 16 maart.
Waar is de kromme sperzieboon gebleven? (interview met Hilke Bos-Brouwers)
Sikkema, A. ; Bos-Brouwers, H.E.J. - \ 2015
Resource: nieuwssite voor studenten en medewerkers van Wageningen UR 9 (2015)14. - ISSN 1389-7756 - p. 12 - 13.
voedselverspilling - verliezen - voedselketens - groenten - voedselafval - food wastage - losses - food chains - vegetables - food wastes
Begin deze week vond in Abu Dhabi een groot internationaal landbouwcongres plaats. Een grote delegatie van Wageningen UR presenteerde daar haar methode om de voedselverspilling in de wereld terug te dringen. Bovendien moet ketenonderzoek de hot spots van verspilling blootleggen. Bijvoorbeeld: waar blijft de kromme sperzieboon?
Voedselverspilling : welvaartsprobleem of schaarste?
Gogh, Bart van - \ 2015
food wastage - food wastes - losses - consumers - food chains
Hoe duurzaam is een regionale voedselketen?
Sukkel, W. ; Vijn, M.P. - \ 2015
Ekoland januari (2015). - ISSN 0926-9142 - p. 58 - 59.
regionale voedselketens - voedselketens - voedselproductie - duurzaamheid (sustainability) - biologische voedingsmiddelen - voedselverspilling - verliezen - regional food chains - food chains - food production - sustainability - organic foods - food wastage - losses
In de laatste vijf tot acht decennia is ons voedselsysteem enorm veranderd. Van kleinschalige productie, korte regionale ketens en een nauwe band tussen productie en consumptie, naar een mondiaal, complex en dynamisch voedselsysteem gericht op massaproductie en –consumptie. Er zijn in toenemende mate zorgen over de duurzaamheid van ons moderne voedselsysteem. Een mogelijke oplossing is een meer regionaal ingerichte voedselketen. Maar is dit werkelijk duurzamer?
Prof. Jacqueline Bloemhof over streven naar duurzame logistiek
Bloemhof, J.M. - \ 2015
Wageningen : Wageningen UR
voedselketens - logistiek - duurzaamheid (sustainability) - verliezen - afval - voedselverspilling - food chains - logistics - sustainability - losses - wastes - food wastage
Een CO2-neutrale toeleveringsketen zonder afvalverliezen is nog een luchtkasteel. De verwezenlijking hiervan is een proces van de lange adem waarin goede ideeën en ervaringen stap voor stap naar duurzaamheid moeten leiden.
The Impacts of Reducing Food Loss in Ghana : A scenario study using the global economic simulation model MAGNET
Rutten, M.M. ; Verma, M. - \ 2014
Wageningen : Wageningen UR (Report / LEI Wageningen UR 2014-035) - 42
verliezen - voedselverspilling - voedselproductie - voedselprijzen - ghana - economische impact - voedselzekerheid - losses - food wastage - food production - food prices - economic impact - food security
When Ghana reduces food loss by 50% by the year 2025, at all stages of supply chains for the paddy, fruits vegetables and nuts, maize, fish and oilseeds, the impacts for producers vary across sectors; consumers gain from food price reduction, but if they are wage labourers, they might lose income. A more efficient food production system in Ghana will also result in an additional 0.8% increase in its Gross Domestic Product in 2025; a welfare increase equivalent of USD 19 per capita and a slightly higher (29 Kcal per capita) calorie intake. The study was done for the Ministry of Economic Affairs as part of its BO research programme on food waste. The aim of the research was to investigate the medium- to long-term macroeconomic impacts of tackling food losses, with Ghana serving as an informative case.
Intensification of grassland and forage use: driving forces and constraints
Oenema, O. ; Klein, C. de; Alfaro, M. - \ 2014
Crop and Pasture Science 65 (2014)6. - ISSN 1836-0947 - p. 524 - 537.
resource use efficiency - volcanic soil - production ecology - production systems - urea application - southern chile - nitrogen-cycle - food security - losses - management
The increasing demand for safe and nutritional dairy and beef products in a globalising 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: 'Does intensification of grassland and forage use lead to efficient, profitable and sustainable ecosystems?' We present some notions about intensification of agricultural production, and then discuss the intensification of grassland-based dairy production in The Netherlands, Chile and New Zealand. Finally, we arrive at some conclusions. External driving forces and the need to economise (the law of the optimum) provide strong incentives for intensification, that is, 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 the business unless they broaden their income base. 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 use of water per unit surface area, but to decreased emissions when expressed per unit of product. The sustainability of a grassland-based ecosystem is ultimately defined by the societal appreciation of that system and by biophysical and socioeconomic constraints. In conclusion, intensification may lead to more efficient and profitable and, thereby, more sustainable grassland ecosystems. This holds especially for those systems that are currently not sustainable because they are either underutilised and of low productivity or over-exploited and unregulated, and as long as the adapted systems meet societal and ecological constraints.
Comparative study of nitrate leaching models on a regional scale
Roelsma, J. ; Hendriks, R.F.A. - \ 2014
Science of the Total Environment 499 (2014). - ISSN 0048-9697 - p. 481 - 496.
agricultural land-use - soil-crop model - groundwater nitrate - sandy soils - drinking-water - system stone - netherlands - nitrogen - losses - simulation
In Europe and North America the application of high levels of manure and fertilisers on agricultural land has led to high levels of nitrate concentrations in groundwater, in particular on sandy soils. For the evaluation of the development of the quality of groundwater a sound quantitative basis is needed. In this paper a comparison has been made between observations of nitrate concentrations in the upper groundwater and predictions of nitrate leaching models. Observations of nitrate concentrations in the upper groundwater at three different locations in regions with mainly sandy soils in the eastern and northern part of the Netherlands were used to test the performance of the simulation models to predict nitrate leaching to the upper groundwater. Four different types of simulation models of different levels of complexity and input data requirement were tested. These models are ANIMO (dynamic complex process oriented model), MM-WSV (meta-model), WOG (simple process oriented model) and NURP (semi-empiric model). The performance of the different simulation models was evaluated using statistical criteria. The dynamic complex process oriented ANIMO model showed the best model performance. The MM-WSV meta-model was the second best model, whilst the simple process oriented WOG model produced the worst model performance. The best model performance showed the dynamic complex process oriented ANIMO model in predicting the nitrate concentrations in the upper groundwater of the Klooster catchment. The good performance of the ANIMO model for this catchment can be explained by the additional information about the use of manure and fertilisers at farm level in this study area. The ANIMO model may be a good tool to predict nitrate concentrations in the upper groundwater on a regional scale. However, the use of a detailed process oriented simulation model requires a comprehensive set of input data. If such a comprehensive data-set is not available the MM-WSV model (meta-model) proves to be a good alternative. The WOG and NURP models are suitable for long term (>8 years) predictions of average nitrate concentrations in the upper groundwater on a regional scale. (C) 2014 Elsevier B.V. All rights reserved.
Nitrate leaching and apparent recovery of urine-N in grassland on sandy soils in the Netherlands
Corré, W.J. ; Beek, C.L. van; Groenigen, J.W. van - \ 2014
NJAS Wageningen Journal of Life Sciences 70-71 (2014). - ISSN 1573-5214 - p. 25 - 32.
nitrogen - groundwater - lysimeter - dynamics - ammonia - losses - system - input
Urine patches are an important nitrogen input source in managed pasture systems. The objective of this study was to quantify the effect of artificial urine application at different dates on nitrate leaching in a well drained sandy soil. In three subsequent years, we measured nitrate leaching and apparent urine-nitrogen recovery (ANR) in a field experiment and in two lysimeter experiments over a period of 1 year post urine application. Artificial urine patches with 400 kg ha-1of urine-N were applied at different times of the grazing seasons. For the field experiment, we compared nitrate leaching measurements with NURP model calculations. In the field experiment, greatest ANR was measured for spring and summer applications (averaging 31% of applied urine-N), and significantly declined to 0% for October applications. Nitrate leaching increased under urine patches, with a significant effect of application date. This effect was not, however, consistent over the three years. Total recovery of N in grass and of mineral N in leachate and soil was generally less than the amount of urine-N applied, with a balance deficit of 60-80% (field) or 10-70% (lysimeters). For the field experiment, the total increase in nitrate leaching corresponded reasonably well with NURP model calculations. However, the effect of application date on nitrate leaching was much smaller in the field experiment. Our results suggest that restrictions to grazing in autumn probably will be effective in decreasing the annual amount of nitrate leached, although this decrease remains hard toquantify.
Food losses and waste in the context of sustainable food systems
Timmermans, A.J.M. ; Ambuko, J. ; Belik, W. ; Huang, Jikun - \ 2014
Rome : CFS Committee on World Food Security HLPE (HPLE report / High Level Panel of Experts on Food Security and Nutrition 8) - 116
voedselverspilling - verliezen - voedselzekerheid - duurzaamheid (sustainability) - food wastage - losses - food security - sustainability
The issue of global food losses and waste has recently received much attention and has been given high visibility. According to FAO, almost one-third of food produced for human consumption – approximately 1.3 billion tonnes per year – is either lost or wasted globally: their reduction is now presented as essential to improve food security and to reduce the environmental footprint of food systems. In this context, the Committee on World Food Security (CFS), in its Thirty-ninth Session (October 2012) requested the High Level Panel of Experts on Food Security and Nutrition (HLPE) to undertake a study on “Food losses and waste in the context of sustainable food systems” to be presented to the CFS Plenary in 2014. The very extent of food losses and waste invites to consider them not as an accident but as an integral part of food systems. Food losses and waste are consequences of the way food systems function, technically, culturally and economically. This report analyses food losses and waste in a triple perspective: a systemic perspective, a sustainability perspective, including the environmental, social and economic dimensions of sustainability, and a food security and nutrition perspective, looking at how food losses and waste relate to the various dimensions of food security and nutrition
Reducing food wastage, improving food security? An inventory study on stakeholders’ perspectives and the current state
Tielens, J. ; Candel, J.J.L. - \ 2014
Den Haag : Food & Business Knowledge Platform - 37
voedselzekerheid - voedselverspilling - verliezen - voedselvoorziening - ontwikkelingslanden - food security - food wastage - losses - food supply - developing countries
This study is concerned with the relation between food wastage reduction and the improvement of food security. The central question of this inventory study is to what extent interventions to reduce food wastage are effective contributions for food security, in particular for local access in developing regions, but also the food system stability in general? To investigate this, an overview of international actors working in the field of wastage has been made, with a European/Dutch focus. Their activities and motivations and their assumptions on the relation between reducing food wastage and increasing food security have been mapped. Following this, a synthesis of insights on this relation from scientific and grey literature was made. Finally, conclusions were drawn up.
Monitor voedselverspilling : update 2009-2012
Soethoudt, J.M. ; Bos-Brouwers, H.E.J. - \ 2014
Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research 1486) - ISBN 9789462570542 - 53
voedselverspilling - voedselketens - verliezen - ketenmanagement - etensresten - overschotten - voedselafval - monitoring - food wastage - food chains - losses - supply chain management - leftovers - surpluses - food wastes
In opdracht van het ministerie van Economische Zaken (MinEZ) is in 2011-2012 door Wageningen UR Food & Biobased Research een monitor ontworpen, met het doel een betrouwbaar beeld te geven van de hoeveelheid voedselverspilling in Nederland. Belangrijke elementen in deze opdracht waren dat het beeld cijfermatig moet zijn, onderbouwd zoveel mogelijk op basis van openbare bronnen. Het ministerie wil met de uitkomsten van de monitor het beleid, om tussen 2009 en 2015 een reductie van 20% voedselverspilling in de keten te realiseren, verifiëren. Dit document is de eerste update na de in 2013 verschenen tussenrapportage over 2009-2011 (Soethoudt & Timmermans, 2013). De voorliggende rapportage brengt de hoeveelheid voedselverspilling in Nederland tussen 2009-2012 in kaart.
Resource use efficiency and farm productivity gaps of smallholder dairy farming in North-west Michoacán, Mexico
Cortez Arriola, J. ; Groot, J.C.J. ; Amendola Massiotti, R.D. ; Scholberg, J.M.S. ; Mariscal Aguayo, D.V. ; Tittonell, P.A. ; Rossing, W.A.H. - \ 2014
Agricultural Systems 126 (2014). - ISSN 0308-521X - p. 15 - 24.
recent trends - nitrogen - performance - volatilization - tropics - systems - losses - yield
Smallholder dairy farms that intensify production risk resource degradation and increased dependence on external feeds and fertilizers due to lack of knowledge and appropriate technology, which undermines farm productivity and profitability. Here we analyze underlying causes at farm level of such process through an integrated analysis at the farm scale by assessing current resource use efficiency for grazing-based dairy farming systems representative of NW Michoacán, Mexico. Whole-farm yield gaps were quantified by comparing current farms to virtual reference farms that have the same farm surface area but improved farm management. Productivity of reference farms was calculated by assuming best crop production practices (as observed within the set of case study farms) and improved herd management. Three family-based (FB) and three semi-specialized (SS) dairy systems spanning three levels of intensification in terms of density of livestock units (LU): extensive (E, 1.2 LU ha-1) were monitored during one year (rainy and dry seasons) to assess productivity and resource use efficiencies. Milk production was generally low and variable (2.2–4.3 Mg milk cow-1 lactation-1, and 0.6–5.8 Mg ha-1) due to high incidence of mastitis, a large fraction of non-productive animals in the herd and inefficient reproduction management. During the dry season, grazing areas provided insufficient metabolizable energy, and milk production was sustained through increased use of concentrates (from 310 g kg-1 DMI in rainy season to 454 g kg-1 DMI-1 in dry season of the herd) and conserved forage. All farms had positive nitrogen, phosphorus and potassium balances, averaging 75 ± 16, 15 ± 6, and 19 ± 6 kg ha-1, respectively. Nutrients in animal excreta were mostly not recycled on the farms but lost to the environment, and nutrient surpluses increased with livestock density. The reference farms exhibited an attainable milk yield of 2.7 Mg ha-1 on the basis of full feed self-supply, and 4.2 Mg ha-1 when the crude protein limitation in the ration was lifted. Compared to the reference farm actual milk yields were on average 78.4% lower on FB farms and 57.9% lower on SS farms. The underlying causes of the farm yield gap differed between farms and were due to sub-optimal areas of forage maize, low forage and forage maize productivity and deficient herd management. We conclude that the farm yield gap analysis was effective in identifying the major shortcomings in management of the dairy farming systems and enabled formulation of change avenues for farm reconfiguration focusing on combined improvements in crop, feed and herd management and recycling of nutrients through manure management.
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