Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management.

Improved management of nitrogen (N) in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK) were studied, and a common method was developed for undertaking farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11 440 ha of farmland included in the study. In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha−1 yr−1, respectively. All landscapes showed hotspots, especially from livestock farms, including a special UK case with large-scale landless poultry farming. Overall, the average N surplus from the land-based UK farms dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N ha−1 yr−1, but was similar to the N surplus of PL and DK (122 ± 20 and 146 ± 55 kg N ha−1 yr−1, respectively) when landless poultry farming was included. We found farm N balances to be a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate concentrations in soils and groundwater, measured during the period of N management data collection in the landscapes from 2007–2009. This indicates that farm N surpluses may be used as an independent dataset for validation of measured and modelled N emissions in agricultural landscapes. No significant correlation was found with N measured in surface waters, probably because of spatial and temporal variations in groundwater buffering and biogeochemical reactions affecting N flows from farm to surface waters. A case study of the development in N surplus from the landscape in DK from 1998–2008 showed a 22% reduction related to measures targeted at N emissions from livestock farms. Based on the large differences in N surplus between average N management farms and the most modern and N-efficient farms, it was concluded that additional N-surplus reductions of 25–50%, as compared to the present level, were realistic in all landscapes. The implemented N-surplus method was thus effective for comparing and synthesizing results on farm N emissions and the potentials of mitigation options. It is recommended for use in combination with other methods for the assessment of landscape N emissions and farm N efficiency, including more detailed N source and N sink hotspot mapping, measurements and modelling.

Probabilistic analysis of water availability for agriculture and associated crop net margins.

Rising water demands are difficult to meet in many regions of the world. In consequence, under meteorological adverse conditions, big economic losses in agriculture can take place. This paper aims to analyze the variability of water shortage in an irrigation district and the effect on farmer?s income. A probabilistic analysis of water availability for agriculture in the irrigation district is performed, through a supply-system simulation approach, considering stochastically generated series of stream-flows. Net margins associated to crop production are as well estimated depending on final water allocations. Net margins are calculated considering either single-crop farming, either a polyculture system. In a polyculture system, crop distribution and water redistribution are calculated through an optimization approach using the General Algebraic Modeling System (GAMS) for several scenarios of irrigation water availability. Expected net margins are obtained by crop and for the optimal crop and water distribution. The maximum expected margins are obtained for the optimal crop combination, followed by the alfalfa monoculture, maize, rice, wheat and finally barley. Water is distributed as follows, from biggest to smallest allocation: rice, alfalfa, maize, wheat and barley.

Unbalanced value chain in perishable agricultural products.

Value chain in agriculture is a current issue affecting from farmers to consumers. It questions important issues as profitability, and even though continuity of certain sectors. Although there has been an evolution along time in the structure and concentration of intermediate and final levels of the value chain between distribution and retail sector, a similar evolution seems not to arrive at the initial level of the chain, the production sector. This produces large imbalances in power and leverage between levels of the value chain that could imply several problems for rural actors. Relatively little attention has been paid to possible market distortions caused by the high level of concentration distribution side of the agrifood system.

Discrete element analysis for the assessment of the accuracy of load cell-based dynamic weighing systems in grape harvesters under different ground conditions

Dynamic weighing systems based on load cells are commonly used to estimate crop yields in the field. There is lack of data, however, regarding the accuracy of such weighing systems mounted on harvesting machinery, especially on that used to collect high value crops such as fruits and vegetables. Certainly, dynamic weighing systems mounted on the bins of grape harvesters are affected by the displacement of the load inside the bin when moving over terrain of changing topography. In this work, the load that would be registered in a grape harvester bin by a dynamic weighing system based on the use of a load cell was inferred by using the discrete element method (DEM). DEM is a numerical technique capable of accurately describing the behaviour of granular materials under dynamic situations and it has been proven to provide successful predictions in many different scenarios. In this work, different DEM models of a grape harvester bin were developed contemplating different influencing factors. Results obtained from these models were used to infer the output given by the load cell of a real bin. The mass detected by the load cell when the bin was inclined depended strongly on the distribution of the load within the bin, but was underestimated in all scenarios. The distribution of the load was found to be dependent on the inclination of the bin caused by the topography of the terrain, but also by the history of inclination (inclination rate, presence of static periods, etc.) since the effect of the inertia of the particles (i.e., representing the grapes) was not negligible. Some recommendations are given to try to improve the accuracy of crop load measurement in the field.

Irrigated agriculture: Water resources management for a sustainable environment

In the last decade, research on irrigation has mainly been aimed at reducing crop water consumption. In arid and semi-arid environments, in relation to the limited water resources, the use of low quality water in agriculture has also been investigated in order to detect their effects on soil physical properties and on crop production. More recently, even the reduction of energy consumption in agriculture, as well as the effects of external factors, climate change and agricultural policies, have been major research interests. All these objectives have been considered in the papers included in this special issue. However, in the last years, approaches aimed at reducing crop water requirements have significantly changed. Remote sensing with satellites or unmanned vehicles, and vegetation spectral measurements, among others, represent in fact the newest frontier of existing technologies. Knowledge of soil hydraulic properties, often forgotten because of the difficulty of their estimation, can also be considered as a new way to reduce water consumption.

Effects of a bifenthrin-treated net on the natural enemies Aphidius colemani (Haliday) and Adalia bipunctata L. in a cucumber crop in Central Spain. Semi-field experiments

Pest management practices that rely on pesticides are growing increasingly less effective and environmentally inappropriate in many cases and the search of alternatives is under focus nowadays. Exclusion of pests from the crop by means of pesticide-treated screens can be an eco-friendly method to protect crops, especially if pests are vectors of important diseases. The mesh size of nets is crucial to determine if insects can eventually cross the barrier or exclude them because there is a great variation in insect size depending on the species. Long-lasting insecticide-treated (LLITN) nets, factory pre-treated, have been used since years to fight against mosquitoes vector of malaria and are able to retain their biological efficacy under field for 3 years. In agriculture, treated nets with different insecticides have shown efficacy in controlling some insects and mites, so they seem to be a good tool in helping to solve some pest problems. However, treated nets must be carefully evaluated because can diminish air flow, increase temperature and humidity and decrease light transmission, which may affect plant growth, pests and natural enemies. As biological control is considered a key factor in IPM nowadays, the potential negative effects of treated nets on natural enemies need to be studied carefully. In this work, the effects of a bifentrhin-treated net (3 g/Kg) (supplied by the company Intelligent Insect Control, IIC) on natural enemies of aphids were tested on a cucumber crop in Central Spain in autumn 2011. The crop was sown in 8x6.5 m tunnels divided in 2 sealed compartments with control or treated nets, which were simple yellow netting with 25 mesh (10 x 10 threads/cm2; 1 x 1 mm hole size). Pieces of 2 m high of the treated-net were placed along the lateral sides of one of the two tunnel compartments in each of the 3 available tunnels (replicates); the rest was covered by a commercial untreated net of a similar mesh. The pest, Aphis gossypii Glover (Aphidae), the parasitoid Aphidius colemani (Haliday) (Braconidae) and the predator Adalia bipunctata L. (Coccinellidae) were artificially introduced in the crop. Weekly sampling was done determining the presence or absence of the pest and the natural enemies (NE) in the 42 plants/compartment as well as the number of insects in 11 marked plants. Environmental conditions (temperature, relative humidity, UV and PAR radiation) were recorded. Results show that when aphids were artificially released inside the tunnels, neither its number/plant nor their distribution was affected by the treated net. A lack of negative effect of the insecticide-treated net on natural enemies was also observed. Adalia bipunctata did not establish in the crop and only a short term control of aphids was observed one week after release. On the other hand, A. colemani did establish in the crop and a more long-term effect on the numbers of aphids/plant was detected irrespective of the type of net. KEY WORDS: bifenthrin-treated net, Adalia bipunctata, Aphidius colemani, Aphis gossypii, semi-field

The use of geographic information systems for the optimal location of biomass power plants in the Madrid Community (Spain)

This article has been extracted from the results of a thesis entitled “Potential bioelectricity production of the Madrid Community Agricultural Regions based on rye and triticale biomass.” The aim was, first, to quantify the potential of rye (Secale Cereale L.) and triticale ( Triticosecale Aestivum L.) biomass in each of the Madrid Community agricultural regions, and second, to locate the most suitable areas for the installation of power plants using biomass. At least 17,339.9 t d.m. of rye and triticale would be required to satisfy the biomass needs of a 2.2 MW power plant, (considering an efficiency of 21.5%, 8,000 expected operating hours/year and a biomass LCP of 4,060 kcal/kg for both crops), and 2,577 ha would be used (which represent 2.79% of the Madrid Community fallow dry land surface). Biomass yields that could be achieved in Madrid Community using 50% of the fallow dry land surface (46,150 ha representing 5.75% of the Community area), based on rye and triticale crops, are estimated at 84,855, 74,906, 70,109, 50,791, 13,481, and 943 t annually for the Campiña, Vegas, Sur Occidental, Área Metropolitana, Lozoya-Somosierra, and Guadarrama regions. The latter represents a bioelectricity potential of 10.77, 9.5, 8.9, 6.44, 1.71, and 0.12 MW, respectively.

ESCREVENDO CARTAS PARA UM PROGRAMA DE TV: CARTAS NA CONTEMPORANEIDADE

As cartas são uma das formas de comunicação a distância mais antigas de que se tem notícia. Além disso, há séculos são feitos tratados e estudos de como as cartas são e de como devem ser escritas. Este estudo enfoca as cartas enviadas ao programa televisivo Globo Rural, da TV Globo no ano de 2005, data de seu 25º aniversário. Em um primeiro momento, através de um banco de dados, composto por 418 cartas, delineou-se a identidade e as demandas dos telespectadores que escreveram ao programa. Percebeu-se, entre outras questões, que além das pessoas residentes em áreas rurais e que mantêm relação com o campo, muitos telespectadores de áreas urbanas e profissionais de áreas de conhecimento não-rurais também entram em contato com o programa através de cartas. Em um segundo momento, através de escolhas intencionais, com uma abordagem qualitativa, sem intenção de generalização, discutiu-se algumas características atuais da maneira de se escrever cartas. Ao comparar com antigos tratados datados da Era Antiga pode-se concluir que as cartas analisadas ainda mantêm muitos traços discursivos definidos desde então.(AU)

ESCREVENDO CARTAS PARA UM PROGRAMA DE TV: CARTAS NA CONTEMPORANEIDADE

As cartas são uma das formas de comunicação a distância mais antigas de que se tem notícia. Além disso, há séculos são feitos tratados e estudos de como as cartas são e de como devem ser escritas. Este estudo enfoca as cartas enviadas ao programa televisivo Globo Rural, da TV Globo no ano de 2005, data de seu 25º aniversário. Em um primeiro momento, através de um banco de dados, composto por 418 cartas, delineou-se a identidade e as demandas dos telespectadores que escreveram ao programa. Percebeu-se, entre outras questões, que além das pessoas residentes em áreas rurais e que mantêm relação com o campo, muitos telespectadores de áreas urbanas e profissionais de áreas de conhecimento não-rurais também entram em contato com o programa através de cartas. Em um segundo momento, através de escolhas intencionais, com uma abordagem qualitativa, sem intenção de generalização, discutiu-se algumas características atuais da maneira de se escrever cartas. Ao comparar com antigos tratados datados da Era Antiga pode-se concluir que as cartas analisadas ainda mantêm muitos traços discursivos definidos desde então.(AU)

Induced intensification: Agricultural change in Bangladesh with implications for Malthus and Boserup

Bangladesh is dominated by a small-holder agrarian economy under extreme stress. Production shortfalls, increasing economic polarization, and chronic malnutrition are persistent, but major famine has been diverted in part by significant growth in agriculture. This recent history is open to both Malthusian and Boserupian interpretations—a history we explore here through a test of the induced intensification thesis of agricultural change. This thesis, framed by variations in the behavior of small-holders, has grown from a simple demand-production relationship to a consideration of the mediating influences on that relationship. The induced intensification thesis is reviewed and tested for 265 households in 6 villages in Bangladesh from 1950–1986. A time-series analysis of an induced intensification model provides relatively high levels of explained variance in cropping intensity (frequency and land productivity) and also indicates the relative impacts of household class, environment, and cropping strategies. On average, the small-holders in question kept pace with the demands on production, although important class and village variations were evident and the proportion of landless households increased. These results, coupled with evidence that agricultural growth involved intensification thresholds, provide clues about Malthusian and Boserupian interpretations of Bangladesh, and suggest that small-holder agriculture there is likely to continue on a “muted” path of growth.

Plant biology in the future

In the beginning of modern plant biology, plant biologists followed a simple model for their science. This model included important branches of plant biology known then. Of course, plants had to be identified and classified first. Thus, there was much work on taxonomy, genetics, and physiology. Ecology and evolution were approached implicitly, rather than explicitly, through paleobotany, taxonomy, morphology, and historical geography. However, the burgeoning explosion of knowledge and great advances in molecular biology, e.g., to the extent that genes for specific traits can be added (or deleted) at will, have created a revolution in the study of plants. Genomics in agriculture has made it possible to address many important issues in crop production by the identification and manipulation of genes in crop plants. The current model of plant study differs from the previous one in that it places greater emphasis on developmental controls and on evolution by differential fitness. In a rapidly changing environment, the current model also explicitly considers the phenotypic variation among individuals on which selection operates. These are calls for the unity of science. In fact, the proponents of “Complexity Theory” think there are common algorithms describing all levels of organization, from atoms all the way to the structure of the universe, and that when these are discovered, the issue of scaling will be greatly simplified! Plant biology must seriously contribute to, among other things, meeting the nutritional needs of the human population. This challenge constitutes a key part of the backdrop against which future evolution will occur. Genetic engineering technologies are and will continue to be an important component of agriculture; however, we must consider the evolutionary implications of these new technologies. Meeting these demands requires drastic changes in the undergraduate curriculum. Students of biology should be trained in molecular, cellular, organismal, and ecosystem biology, including all living organisms.

An Independent Art Movement: The Independent Artist, Community Television, and the Age of Information

The history of community television shows that it has been a home to activist and non-profit organizations that have created programs focused on freedom of speech. This project proposes that community television is also a place where artists can have freedom of artistic expression. The reflective paper reviews the creation of my film designed to inform and attract artists to community television. In it I critically reflect on the artistic, technical, artistic/technical, and production changes made throughout my journey from being a visual artist to becoming a video-artist. The reflective paper, along with the film, act as a wake-up call to artists who are unaware of community television and the advantages it has to offer them.

Save the Planet - Buy Organic: The Role of Consumers in the Sustainable Agricultural Movement

The severity of the environmental situation in agriculture is described. Progress made so far is then listed and critiqued. Misconceptions that sustainable agriculture cannot produce as much food as industrial agriculture, as well as the false impression that sustainably-produced foods must cost more are discussed. In conclusion, the only force strong enough to convince farmers to switch to sustainable practices is the consumer. Advertisements and educational campaigns will inform consumers about industrial agriculture. The shift in demand for sustainable goods will eventually cause prices to fall, allowing more consumers to purchase these formally expensive goods. This process will make a sustainable agricultural revolution possible and profitable.

Drivers of agricultural capital productivity in selected EU member states. Factor Markets Working Paper No. 30, September 2012

The aim of this Working Paper is to provide an empirical analysis of the marginal return on working capital and fixed capital in agriculture, based on data gathered by the Farm Accountancy Data Network from seven EU member states. Particular emphasis is placed on the detection of credit market imperfections. The key idea is to provide farm group-specific estimates of the shadow price of capital, and to use these to analyse the drivers of on-farm capital use in European agriculture. Based on Cobb Douglas estimates of farm-type specific production functions, we find that working capital is typically used in more than economically optimal quantities and often displays negative marginal returns across countries and farm types. This is less often the case with regard to fixed capital, but it is only in a small set of sectors where access to fixed capital appears severely constrained. These sectors include field crop and mixed farms in Denmark, dairy farms in East Germany, as well as mixed farms in Italy and the UK. The relationship between farm financial indicators and the estimated shadow prices of capital varies considerably across countries and sectors. Among the farms with a high shadow price for fixed capital in Denmark, high debt levels and little owned land tended to induce more intensive capital use, which may reflect the liberal Danish banking system. In East Germany, Italy and the UK, high debt levels made farmers more tightly capital constrained. Hence, in the latter group of countries, more traditional mechanisms of capital allocation based on debt capacity seemed to be at work. As a general conclusion, EU agriculture appears to be characterised by overcapitalisation rather than by credit constraints.

The Role of Pluriactivity in Farm Exit and Labour Supply Decisions. Factor Markets Working Document No. 67, August 2013

EDITED VERSION TO BE PUBLISHED SOON Pluriactivity has been a topic of research in agriculture for the best part of a century. It is a term which has both broad and narrow definitions and hence is subject to multiple interpretations. This paper considers two forms of pluriactivity: within the farm gate pluriactivity, also commonly referred to as farm diversification, and beyond the farm-gate pluriactivity, also known as multiple job holding. Previous studies of pluriactivity have shown that it can inhibit the natural process of structural change in the farm sector, by allowing small and unprofitable farms to survive with the support of income from outside the sector. In this paper, two empirical models of pluriactivity are estimated using farm level data for Ireland. The first examines the impact of on-farm diversification on off-farm labour supply, while the second investigates the relationship between off-farm labour supply and farm exit which is specified in the context of retirement and non-succession. The result of the first model suggests that farms that engage in within the farm gate pluriactivity are less likely to engage in beyond the farm gate pluriactivity, in other words more diversified farmers are less likely to work off farm. The second model confirms previous findings in the literature that part-time farmers have a reduced probability of having a farm successor. While the model results are specific to the Irish case, they do provide some value insights into the impacts of pluriactivity on structural change in farming.