In the present study, the effect of weather on maize yields in northern China was examined using data from 10 districts in Inner Mongolia and two in Shaanxi province. A regression model with a flexible functional form was specified on the basis of agronomic considerations. Explanatory variables included in the model were seasonal growing degree days, precipitation, technological change (e.g. adoption of new crop varieties, improved equipment, better management, etc.) and dummy variables to account for regional fixed effects. Results indicated that a fractional polynomial model in growing degree days could explain variability in maize yields better than a linear or quadratic model. Growing degree days, precipitation in July, August and September, and technological changes were important determinants of maize yields. The results could be used to predict potential maize yields under future climate change scenarios, to construct financial weather products and for policy makers to incentivize technological changes and construction of infrastructure (e.g. irrigation works) that facilitate adaptation to climate change in the agricultural sector.

From 1999 to 2006, 36 field experiments were conducted in five sugar beet growing areas in Greece (Larissa, Plati, Serres, Xanthi and Orestiada) to monitor yield. Locations differed significantly regarding thermal variables during the growing season with Xanthi having the most favourable thermal conditions (Tmax, average daily maximum temperature; Tmean, average daily mean temperature; GDD, growing degree days) for sugar beet growth. From early June to the end of the harvesting campaign, successive harvests were conducted. Over the years, fresh root weight and sugar yield at the last harvest of the season (FRWLH, SYLH) did not differ significantly among locations. Also, there were no significant differences among locations regarding GDD for maximum FRW and SY (GDDMFRW, GDDMSY), with the means over location estimated at 2639·9 and 2792·5 °C, respectively. Days after seeding (DAS) necessary for maximum yield (DASMFRW, DASMSY, respectively) differed among locations, with the longest period (DASMFRW 206·4 days, DASMSY: 204·5 days) occurring in the northernmost location (Orestiada). Means for DASMFRW and DASMSY at the five locations were estimated at 190·4 and 188·9·days, respectively. Excluding Xanthi and combining the remaining locations, FRWLH and SYLH were negatively correlated with the average temperatures (Tmean, Tmax and Tmin, daily minimum temperature) over the growing season. The opposite was evident for Xanthi where sugar beet was grown under sub-optimal temperatures. The optimum mean Tmax of the five locations was estimated at 25·5 and 25·1 °C for FRWLH and SYLH, respectively. Elongation of the growing season, by means of early sowing, would increase yield by decreasing average temperatures (Tmean, Tmax) over the growing season in locations with the highest recorded temperatures (Larissa, Plati, Serres and Orestiada). In Xanthi, the projected temperature increase, as a result of climate change, is expected to have a positive effect on yields.

Soil organic carbon (C) plays a critical role in supporting the productive capacity of soils and their ability to provide a wide range of ecologically important functions including the storage of atmospherically derived carbon dioxide (CO2). The present paper collates available information on Scottish soil C stocks and C losses and reviews the potential pressures on terrestrial C, which may threaten future C stocks. Past, present and possible future land use, land management practices and land use changes (LUCs) including forestry, agriculture, nitrogen (N) additions, elevated CO2 and climate change for Scotland are discussed and evaluated in relation to the anthropogenic pressures on soil C.

The review deduces that current available data show little suggestion of significant changes in C stocks of Scottish soils, although this may be due to a lack of long-term trend data. However, it can be concluded that there are many pressures, such as climate change, intensity of land use practices, scale of LUC, soil erosion and pollution, which may pose significant threats to the future of Scottish soil C if these factors are not taken into consideration in future land management decisions. In particular, this is due to the land area covered by vulnerable peats and highly organic soils in Scotland compared with other areas in the UK. It is therefore imperative that soil C stocks for different land use, management practices and LUCs are monitored in more detail to provide further insight into the potential changes in sequestered C and subsequent greenhouse gas emissions, as advised by the United Nations Framework Convention on Climate Change (UNFCCC).

Rainfall and temperature are unpredictable in Mediterranean environments, which results in inconsistent environmental conditions for crop growth and a critical source of uncertainty for farmers and growers. The objectives of the present study were to: (i) quantify and compare the plasticity of durum breeding lines, a modern cultivar and landraces on the basis of yield and agronomic traits and (ii) study associations between plasticity of yield and plasticity of agronomic and phenological traits. Plasticity was quantified using linear models for 11 durum breeding lines, one modern cultivar and two landraces grown in 21 diversified environments. The results showed that the effects due to environment, genotype and genotype×environment (G×E) interaction were significant, which indicates the existence of differences among genotypes for plasticity. Yield ranged from 1939 to 2419 kg/ha across environments and the range of plasticity was 0·66–1·13. The breeding lines and the modern cultivar had higher grain yields compared with the landraces at the same level of plasticity. The landraces with below-average plasticity in yield were characterized as tall in stature and late in heading and maturity, whereas the breeding lines and modern cultivar with above-average plasticity in yield were early in heading and maturity, semi-dwarf and high-yielding, which indicates the success in breeding the materials for unpredictable environmental conditions. In conclusion, yield plasticity was associated with yield improvement and high yield plasticity tends to associate with earliness, shorter plants and low grain weight.

A growing trend for nutraceutical and gluten-free cereal-based products highlights the need for development of new products. Buckwheat is one of the potential candidates for such products and the present paper reviews the functional and nutraceutical compounds present in common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum). The vital functional substances in buckwheat are flavonoids, phytosterols, fagopyrins, fagopyritols, phenolic compounds, resistant starch, dietary fibre, lignans, vitamins, minerals and antioxidants, which make it a highly active biological pseudocereal. Cholesterol-lowering effects that lessen the problems of constipation and obesity are important health benefits that can be achieved through the functional substances of buckwheat.

The crop growth model HERMES was used to model crop rotation cycles at 12 experimental sites in the Czech Republic. A wide range of crops (spring and winter barley, winter wheat, maize, potatoes, sugar beet, winter rape, oats, alfalfa and grass), cultivated between 1981 and 2009 under various soil and climatic conditions, were included. The model was able to estimate the yields of field crop rotations at a reasonable level, with an index of agreement (IA) ranging from 0·82 to 0·96 for the calibration database (the median coefficient of determination (R2) was 0·71), while IA for verification varied from 0·62 to 0·93 (median R2 was 0·78). Grass yields were also estimated at a reasonable level of accuracy. The estimates were less accurate for the above-ground biomass at harvest (the medians for IA were 0·76 and 0·72 for calibration and verification, respectively, and analogous medians of R2 were 0·50 and 0·49). The soil mineral nitrogen (N) content under the field crops was simulated with good precision, with the IA ranging from 0·49 to 0·74 for calibration and from 0·43 to 0·68 for verification. Generally, the soil mineral N was underestimated, and more accurate results were achieved at locations with intensive fertilization. Simulated yields, soil N, water and organic carbon (C) contents were compared with long-term field measurements at Němčice, located within the fertile Moravian lowland. At this station, all of the observed parameters were reproduced with a reasonable level of accuracy. In the case of the organic C content, HERMES reproduced a decrease ranging from c. 85 to 77 tonnes (t)/ha (for the 0–0·3 m soil layer) between the years 1980 and 2007. In spite of its relatively simple approach and restricted input data, HERMES was proven to be robust across various conditions, which is a precondition for its future use for both theoretical and practical purposes.

The identification of factors determining the adaptation and nitrogen (N) utilization of spelt wheat is important for the successful introduction of the crop to a new environment. The present study was carried out to investigate the relative importance of grain-filling rate and duration of grain growth and to analyse the nitrogen utilization efficiency (NUtE) and biomass production efficiency of spelt under Mediterranean conditions. The performance of spelt was evaluated in relation to a well-adapted bread wheat cultivar. Three spelt cultivars (Ressac, Poème and Cosmos) and one bread wheat cultivar (Centauro) were grown for two growing seasons on a silty clay soil under two N levels (0 and 100 kg N/ha). Grain-filling parameters were estimated using the cubic polynomial model. This model provided good fit to the grain-filling data of spelt cultivars, with high coefficients of determination (R2) that ranged from 0·868 to 0·999. Cultivar differences were found for all grain-filling parameters studied, and these differences accounted for most of the variation observed within each particular grain-filling component in both years. Grain filling of spelt plants took place under adverse environmental conditions, mainly high temperatures, which led to a shortening of the grain-filling period. This fact was not fully compensated by the increase in the grain-filling rate, and eventually resulted in a reduction of the final spelt grain weight. Selection for early-flowering cultivars could be a successful strategy to moderate the influence of the environment on grain filling and improve the adaptation of spelt under Mediterranean conditions. The mean grain-filling rate was positively correlated with dry matter translocation, suggesting the crucial role of reserve assimilates in the vegetative tissues for the grain growth of spelt. The efficiency of N utilization to produce biomass was greater during the grain-filling period than the vegetative period. Averaged across N application rates, NUtE in spelt ranged from 20·1 to 29·5 g grain/g plant N. Cultivar differences in NUtE were observed in both years. Grain yield per unit grain N (grain DM/grain total N at maturity) contributed more to the total variation in NUtE among spelt cultivars compared with N harvest index (NHI). Spelt showed lower NUtE values, probably due to its higher grain N concentration and lower NHI compared with wheat. Low straw N concentration at maturity may be an indicator of improved NUtE in spelt, as evidenced by the negative relationship detected between the two variables. These results provide a better understanding of factors related with the adaptation and N utilization of spelt under Mediterranean conditions.

The present paper reviews some of the high-level challenges facing the global food system over the next 40 years, drawing in particular on the UK Government's Foresight Report on the ‘Future of Food and Farming’, to set the scene for discussions about the sustainable use of nitrogen in agriculture. It reviews the likely demand and supply pressures on the food system, and the pressing requirements to improve sustainability and address the needs of the world's poorest. It argues that the food system is entering a period of radical change, led particularly by growth in demand, which requires action on food production, diet, waste and efficiency, and governance. A key challenge on the supply side is sustainable intensification – producing more from the same amount of land with fewer and less profound negative effects on the environment. Increasing the efficiency of nitrogen fertilizer application will be critical for increasing yields while reducing the many major environmental consequences of leaching and run-off.

To evaluate the effects of a modern cultivation system of plastic film mulching with drip irrigation (MD) on soil greenhouse gas fluxes, methane (CH4) and nitrous oxide (N2O) fluxes were quantified and contrasted in an MD system and a traditional system of mulch-free flood-irrigated (MFF) cotton (Gossypium hirsutum L.) in fields of northwest China. The results showed that soil N2O flux and the absorption rate of CH4 were lower in the MD than the MFF sites. A possible reason for the higher CH4 emissions at MD sites was that the relatively low gaseous oxygen (O2) availability and high ammonium (NH4+) content in the MD soil increased CH4 generation by methanogens and decreased CH4 oxidation by methanotrophs. The lower N2O in the MD sites may be due to an increase of soil denitrification by Thiobacillus denitrificans that reduced some nitrous compounds further into nitrogen gas (N2). Taking into account the global warming potentials of CH4 and N2O in a 100-year time horizon, during the entire growth period, the contribution of CH4 to the greenhouse effect was significantly lower than N2O in these two treatments. Considering these two greenhouse gas fluxes together, a transition from non-mulching cultivation to mulching cultivation could reduce atmospheric emissions by c. 20 g CO2 e m2/season. Based on these findings and previous studies, it can be concluded that mulched-drip irrigation cultivation is a good way to decrease the emission of greenhouse gases and reduce the global warming impact of arid farmlands.

The polyphagous onion thrips Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a serious pest in many protected and field crops and has recently been found to occur in high numbers in Pisum sativum L. crops. In the present study, the abundance of T. tabaci was compared on two pea cultivars in the field. Data on sweep net catches at different sampling times during the day suggest that peak activity of the thrips is at noon. Significantly more thrips larvae and adults were caught on the early pea cultivar Cud Kelwedonu compared with the very early cultivar Pionier, particularly during and after flowering of the peas. Analysis of primary plant compounds indicated that the higher leaf nitrogen and sucrose contents in the leaves of cvar Cud Kelwedonu promote thrips population growth in pea. The preference of T. tabaci for leaves of cvar Cud Kelwedonu was confirmed in experiments in the laboratory. Thrips tended to settle, caused significantly more feeding damage and laid significantly more eggs on the leaves of Cud Kelwedonu. Knowledge on abundance, activity patterns and host use of T. tabaci in pea may contribute to optimizing cultivar selection, monitoring and timing of possible control measures in the future.

Arbuscular mycorrhizal (AM) fungi increase nitrogen (N) uptake by their host plants, but their role in plant N capture from soil organic material is still unclear. In particular, it is not clear if AM fungi compete with the host plant for the N coming from the decomposing organic matter (OM), especially when the AM extraradical mycelium (ERM) and plant roots share the same soil volume. The goal of the present research was to study the effects of AM fungi on wheat N capture after the addition of 15N-labelled OM to soil. Durum wheat (Triticum durum) was grown under controlled conditions in a sand:soil mix and the following treatments were applied: (1) AM inoculation with Glomus mosseae and uninoculated control; and (2) soil amended with 15N-enriched maize leaves and unamended soil. The addition of OM reduced plant growth and N uptake. The AM fungi increased both plant growth and N uptake compared with uninoculated control plants and the effect was enhanced when wheat was grown in soil amended with OM compared with the unamended control. Although AM fungi increased soil N mineralization rates and total plant N uptake, they strongly reduced wheat N recovery from OM, suggesting that AM fungi have marked effects on competition between plants and bacteria for the different N sources in soil.

Alfalfa is a model plant defined as less sensitive than others to iron (Fe) deficiency. In the present work, some mechanisms induced in low Fe availability conditions were studied, including the effect of inoculation of alfalfa seeds with Pseudomonas putida. The effect of different Fe contents in the nutrient solution on the growth parameters was evaluated at 3 and 10 days, observing that low Fe conditions promoted biomass accumulation. Activation in the mechanisms of Fe acquisition, through acidification of the media and an increase in the ferric chelate reductase (FCR) activity, was observed in the absence of Fe at 10 days. The presence of P. putida KT2442 in the rhizosphere eliminated FCR activation through the excretion of siderophores. The effect of the siderophores on the modulation of FCR activity was demonstrated using a ppsD mutant strain, unable to segregate them, observing an activation of the activity similar to that observed in the absence of the bacteria. This, together with the demonstrated mechanisms to increase Fe availability, contributed to the conclusion that alfalfa can be used for recovery programmes of soils with low Fe availability.

The allelic composition at five glutenin loci was assessed by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (1D SDS–PAGE) on a set of 155 landraces (from 21 Mediterranean countries) and 18 representative modern varieties. Gluten strength was determined by SDS-sedimentation on samples grown under rainfed conditions during 3 years in north-eastern Spain. One hundred and fourteen alleles/banding patterns were identified (25 at Glu-1 and 89 at Glu-2/Glu-3 loci); 0·85 of them were in landraces at very low frequency and 0·72 were unreported. Genetic diversity index was 0·71 for landraces and 0·38 for modern varieties. All modern varieties exhibited medium to strong gluten type with none of their 13 banding patterns having a significant effect on gluten-strength type. Ten banding patterns significantly affected gluten strength in landraces. Alleles Glu-B1e (band 20), Glu-A3a (band 6), Glu-A3d (bands 6 + 11), Glu-B3a (bands 2 + 4+15 + 19) and Glu-B2a (band 12) significantly increased the SDS-value, and their effects were associated with their frequency. Two alleles, Glu-A3b (band 5) and Glu-B2b (null), significantly reduced gluten strength, but only the effect of the latter locus could be associated with its frequency. Only three rare banding patterns affected gluten strength significantly: Glu-B1a (band 7), found in six landraces, had a negative effect, whereas banding patterns 2 + 4+14 + 15 + 18 and 2 + 4+15 + 18 + 19 at Glu-B3 had a positive effect. Landraces with outstanding gluten strength were more frequent in eastern than in western Mediterranean countries. The geographical pattern displayed from the frequencies of Glu-A1c is discussed.

Aluminium (Al) toxicity is the major factor-limiting crop productivity in acid soils. In the present study, physiological and transcriptional responses of broad bean leaves to Al stress were investigated. Malondialdehyde (MDA) content, H2O2 content and protein carbonyls (PC) level in leaves were increased after 100 μm AlCl3 stress treatment, whereas the total protein content was decreased, compared with the plants without Al treatment. Stomatal closure in leaves of broad bean was increased after Al stress, suggesting that the photosynthesis rate might be affected by Al stress. The relative citrate secretion in leaves was decreased after Al treatment for 24 h according to the 13C-NMR analysis, indicating that citrate in leaves might be transported to the root to chelate Al3+. To investigate the molecular mechanisms of Al toxicity in leaves of broad bean, a suppression subtractive hybridization (SSH) library was constructed to identify up-regulated genes: cDNA from leaves subjected to 12, 24, 48 and 72 h of 50 and 100 μm AlCl3 stress were used as testers and cDNA from leaves subjected to 0 μm AlCl3 treatment for the same lengths of time as above were used as a driver. The SSH analysis identified 156 non-redundant putative Al stress-responsive expressed sequence tags (ESTs) out of 960 clones. The ESTs were categorized into ten functional groups, which were involved in metabolism (0·21), protein synthesis and protein fate (0·10), photosynthesis and chloroplast structure (0·09), transporter (0·08), cell wall related (0·06), signal transduction (0·05), defence, stress and cell death (0·05), energy (0·03), transcription factor (0·03) and unknown proteins (0·30). The effect of Al treatment on expression of 15 selected genes was investigated by reverse transcription polymerase chain reaction (RT–PCR), confirming induction by Al stress. The results indicated that genes involved in organic acid metabolism, transport, photosynthesis and chloroplast structure, defence, stress and cell death might play important roles under Al stress.

Predicted future climate changes in northern Europe include increased air temperature and altered precipitation patterns. There is a lack of knowledge about potential climate change effects on the biomass yield and security of agricultural crops. The present study determined the potential impact of future climate change on the yield and harvest security of timothy (Phleum pratense L.). Harvest security was assessed using data on accumulated precipitation and the length of dry spell period within the 7 days after cutting. Timothy production as a function of weather, soil and management practices was simulated using the LINGRA model for the periods 1961–90, 2046–65 and 2080–99, and the locations Apelsvoll, Ås, Sola, Tromsø and Værnes in Norway and harvest systems with 600 and 800 °C days between cuts. One hundred years of daily weather data were generated with the LARS-WG tool, using future daily weather data sets based on 12 Global Climate Models. Total seasonal biomass yield varied between 690 g dry matter (DM)/m2 for the 800 °C days harvesting regime in the period 1961–90 at Tromsø and 1548 g DM/m2 for the same harvesting regime in the period 2046–65 at Sola. In general, the biomass was higher in the two future periods than in 1961–90 across locations and harvesting regimes, mainly owing to more cuts per season. Accumulated precipitation after cutting varied between 12·2 mm after the first cut for the 600 °C days harvesting regime in the period 1961–90 at Værnes and 42·5 mm after the fourth cut in the 800 °C days harvesting regime in the period 2080–99 at Sola. The longest duration of dry spell 7 days after pre-planned harvest varied between 1·8 days after the fourth cut at Sola in the 600 °C days harvesting regime for the period 2080–99, and 3·9 days after the first cut at Ås in the 800 °C days harvesting regime for the period 2046–65. Potential consequences of these results are discussed.

Current production systems for crops, meat, dairy and bioenergy in the European Union (EU) rely strongly on the external input of nitrogen (N). These systems show a high productivity per unit of land. However, the drawback is a complex web of N pollution problems contributing in a major way to degradation of ecosystems. European Union Directives and national policies have improved nutrient management and reduced fertilizer N use in most European countries, which has curbed the N pollution trends particularly in regions with high stocking rates of animals. However, improvement is slowing down and environmental targets for N are not within reach. Building on the 2011 European Nitrogen Assessment, the current paper reviews key features of the complex relationships between N use and food production in Europe in order to develop novel options for a more N-efficient, less N-polluting and secure European food system. One option is to relocate feed and livestock production from Northwestern to Central and Eastern Europe. This would allow a reduction of N rates and N pollution in cereal production in Northwest Europe by 30% (50 kg N/ha), while increasing total cereal production in Europe. Another option is a change towards legume-based cropping systems to produce animal feed, in order to decrease dependence on N fertilizer and feed imports. The greatest challenge for Europe is to decrease the demand for feed commodities, and thus for land and N, by a shift to more balanced (and healthier) diets with less animal protein. These drastic changes can be stimulated by targeted public–private research funding, while the actual implementation can be enhanced by smart payment schemes using, for example money from the Common Agricultural Policy, certification and agreements between stakeholders and players in the food and energy chain. Involving networks of consumers, producers and non-governmental organizations is critical. An effective strategy starts with convincing consumers with a Western diet to eat less meat and dairy by communicating the associated health benefits and smaller ecological footprints. Internalizing the cost of N pollution leading to increased prices for N-intensive food products may also enhance involvement of consumers and provide financial resources to compensate farmers for loss of income and extra costs for stricter N measures.

Fertilizer nitrogen (N) accounts for the majority of the greenhouse gas (GHG) emissions associated with intensive wheat production, and the form of fertilizer N affects these emissions. Differences in manufacturing emissions (as represented in the current carbon accounting methodologies) tend to favour urea, even when using the best available manufacturing technologies (BAT), whereas differences in fertilizer N efficiency and emissions of ammonia tend to favour ammonium nitrate (AN). To resolve these differences, data from 47 experiments in two large UK studies conducted from 1982 to 1987 and from 2003 to 2005 were reanalysed, showing that on average urea efficiency was 0·9 of AN (although mean ammonia emissions in 10 subsidiary experiments indicated an efficiency difference of 0·2); treating urea with a urease inhibitor (TU; AGROTAIN®, active ingredient N-(n-butyl) thiophosphoric triamide (n-BTPT)) brought its efficiency almost in line with AN; however, a significantly greater mean optimum N amount for TU (+0·1 of AN) was not fully explained. A standard response function relating wheat yield to applied AN was modified for degrees of relative inefficiency, thus enabling yields and GHG intensities (kg CO2e/tonne (t) grain) to be calculated using a PAS2050 compatible model for GHG emissions for any N amount of any N form. With AN manufactured by average European technology (AET), the estimated GHG intensity of wheat producing 8 t/ha was 451 kg/t; whereas with urea or TU made by AET it was 0.87–0.99 or 0.84–0.86 of this respectively. Using BAT for fertilizer manufacture, the grain's GHG intensity with AN and TU was 368 kg/t, but was 1·03–1·17 of this with untreated urea. The range of effects on GHG intensities arose mainly from remaining uncertainties in the inefficiencies of the N forms. Generally, economic margins and GHG intensities were not much affected by adjustments in N use for relative inefficiencies or different prices of urea-based fertilizers compared with AN. Overall, TU appeared to provide the best combination of economic performance and GHG intensity, unless the price for N as TU exceeded that for N as AN.