Search

The current study focuses on yield and nutritional quality changes of wheat grain over the last 166 years. It is based on wheat grain quality analyses carried out on samples collected between 1850 and 2016. Samples were obtained from the Broadbalk Continuous Wheat Experiment (UK) and from herbaria from 16 different countries around the world. Our study showed that, together with an increase in carbohydrate content, an impoverishment of mineral composition and protein content occurred. The imbalance in carbohydrate/protein content was specially marked after the 1960’s, coinciding with strong increases in ambient [CO2] and temperature and the introduction of progressively shorter straw varieties. The implications of altered crop physiology are discussed., This work was supported by the Spanish Innovation and Universities Ministry (AGL2016-79868-R; PCIN-2017-007), BBSRC Institute Strategic Programme grants, Designing Future Wheat (BB/P016855/1) and Soil to Nutrition (S2N, BBS/E/C/00I0310), the Long-term Experiments National Capability grant (BBS/E/C/000J0300), the Lawes Agricultural Trust and the Basque Country Government consolidated group programme (IT‐932‐16).

Selection and management of synthetic nitrogen (N) fertilizers, including nitrification inhibitors, are considered an effective strategy to mitigate N oxide emissions, but depends strongly on soil characteristics and climatic conditions. We evaluated the effect of the use of a nitrification inhibitor (2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA)) or splitting calcium ammonium nitrate (CAN) on the N oxides and CH4 emissions, yield, N use efficiency (NUE) and bread-making quality in a winter wheat (Triticum aestivum L.) crop. During a typical rainfall cropping season, neither splitting CAN nor using DMPSA reduced significantly the area-scaled or yield-scaled emissions in comparison to a single application of CAN without inhibitors. This could be explained by the low emissions in CAN amended plots. Conversely, in the subsequent extremely dry cropping season, higher N oxide peaks occurred after soil rewetting and the effectiveness of DMPSA was significant in these conditions (e.g. 83% mitigation for NO). No improvement in the NUE, yield or bread-making quality was achieved with a split application or DMPSA added to the fertilizer. Under the conditions of the study, splitting CAN should not be recommended from a yield-scaled emissions viewpoint, while the use of DMPSA may be encouraged due to large variability in the amount and distribution of rainfall.

The increase of the global demand for dairy products is reflected in a rise of animal feed and forage productivity. In the coastal Atlantic climate conditions of northern Spain the maize-ryegrass rotation is a common management used to satisfy this forage demand. With the aim of mitigating greenhouse gases (GHG) emissions associated with fertilization in this type of intensive management, the use of nitrification inhibitors (NI) such as 3,4-dimethylpyrazol phosphate (DMPP) or the isomeric mixture of 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid and 2-(4,5-dimethyl-1H-pyrazol-1-yl) succinic acid (DMPSA) could be a useful strategy. Until now, the new NI DMPSA has only been evaluated under Mediterranean conditions. The objective of this study was to compare the efficiency of DMPSA with respect to DMPP reducing GHG emissions when applied in a maize-ryegrass rotation under Atlantic climate conditions. Nitrogen fertilizer was applied as ammonium sulphate, with and without both NIs, split into two applications of 80 and 100 kg N ha−1 in the case of maize and in three applications of 80, 60 and 60 kg N ha−1 in the case of ryegrass. An unfertilized control treatment was also included. Nitrous oxide (N2O) and methane (CH4) fluxes were measured using the closed chamber technique. The new NI DMPSA showed a similar behaviour to DMPP, mitigating N2O emissions down to the levels of the unfertilized soil. The effect of DMPSA reducing N2O losses lasted for the same time as for DMPP (l

Agricultural sustainability is compromised by nitrogen (N) losses caused by soil microbial activity. Nitrous oxide (N2O) is a potent greenhouse gas (GHG) produced as consequence of nitrification and denitrification processes in soils. Nitrification inhibitors (NI) as 3,4-dimethylpyrazole-succinic acid (DMPSA) are useful tools to reduce these N losses from fertilization. The objective of this work was to test the efficiency of DMPSA in two different tillage management systems, conventional tillage (CT) and no-tillage (NT), in a winter wheat crop under Humid Mediterranean conditions. N fertilizer was applied as ammonium sulphate (AS) with or without DMPSA in a single or split application, including an unfertilized treatment. GHG fluxes N2O, CO2 and CH4) were measured by the closed chamber method. amoA and nosZl genes were quantified by qPCR as indicators of nitrifying and denitrifying populations. Nitrification was inhibited by DMPSA in both CT and NT, while the higher water filled pore space (WFPS) in NT promoted a better efficiency of DMPSA in this system. This higher efficiency might be due to a greater N2O reduction to N-2 as result of the nosZl gene induction. Consequently, DMPSA was able to reduce N2O emissions down to the unfertilized levels in NT. Provided that NT reduced CO2 emissions and maintained crop yield compared to CT, the application DMPSA under NT management is a promising strategy to increase agro-systems sustainability under Humid Mediterranean conditions. (C) 2019 The Author(s). Published by Elsevier B.V. This project was funded by de Spanish Government (AGL2015-64582-C3-2-R MINECO/FEDER and RTI2018-094623-B-C21 MCIU/AEI/FEDER, UE), by the Basque Government (IT-932-16) and by EuroChem Agro Iberia S.L.-UPV/EHU 2017.0016. Mario Corrochano-Monsalve held a grant from the Ministry of Economy and Business of the Spanish Government and Ximena Huerfano received a specialization fellowship for PhD researches from the UPV/EHU.

The increase in the atmospheric CO concentration is predicted to influence wheat production and grain quality and nutritional properties. In the present study, durum wheat (Triticum durum Desf. cv. Sula) was grown under two different CO (400 versus 700 μmol mol) concentrations to examine effects on the crop yield and grain quality at different phenological stages (from grain filling to maturity). Exposure to elevated CO significantly increased aboveground biomass and grain yield components. Growth at elevated CO diminished the elemental N content as well as protein and free amino acids, with a typical decrease in glutamine, which is the most represented amino acid in grain proteins. Such a general decrease in nitrogenous compounds was associated with altered kinetics of protein accumulation, N remobilization, and N partitioning. Our results highlight important modifications of grain metabolism that have implications for its nutritional quality., This work was supported by the Spanish Ministry of Science and Innovation (AGL2016-79868-R).

Nowadays agricultural practices are based in the use of N fertilizers which can lead to environmental N losses. These losses can occur as nitrous oxide (N 2 O) emissions as result of the microbial processes of nitrification and denitrification. N 2 O together with carbon dioxide (CO 2 ) and methane (CH 4 ) are the strongest greenhouse gases (GHG) associated with agricultural soils. Nitrification inhibitors (NI) have been developed with the aim of decreasing fertilizer-induced N losses and increasing N efficiency. One of the most popular NI is the 3,4-dimethylpyrazol phosphate (DMPP) which have proven to be an advisable strategy to mitigate GHG emissions while maintaining crops yield. A new NI, 3,4-dimethylpyrazole succinic (DMPSA), has been developed. The objective of this study was to compare the impact of the new nitrification inhibitor DMPSA on greenhouse gases emissions, wheat yield and grain protein with respect to DMPP. For this purpose a field-experiment was carried out for two years. Fertilizer dose, with and without NIs, was 180 kg N ha −1 applied as ammonium sulphate (AS) split in two applications of 60 kg N ha −1 and 120 kg N ha −1 , respectively. A single application of 180 kg N ha −1 of AS with NIs was also made. An unfertilized treatment was also included. The new nitrification inhibitor DMPSA reduces N 2 O emissions up to levels of the unfertilized control treatment maintaining the yield and its components. The DMPSA shows the same behavior as DMPP in relation to N 2 O fluxes, as well as wheat yield and quality. In spite of applying a double dose of N at stem elongation than at tillering, N 2 O losses from that period are lower than at tillering as a consequence of the influence of soil water content and temperature reducing the N 2 O/N 2 ratio by denitrification. NI efficiency in reducing N 2 O losses is determined by the magnitude of the losses from the AS treatment.

This work explores whether the natural abundance of N isotopes technique could be used to understand the movement of N within the plant during vegetative and grain filling phases in wheat crop (Triticum aestivum L.) under different fertilizer management strategies. We focus on the effect of splitting the same N dose through a third late amendment at flag leaf stage (GS37) under humid Mediterranean conditions, where high spring precipitations can guarantee the incorporation of the lately applied N to the soil-plant system in an efficient way. The results are discussed in the context of agronomic parameters as N content, grain yield and quality, and show that further splitting the same N dose improves the wheat quality and induces a better nitrogen use efficiency. The nitrogen isotopic natural abundance technique shows that N remobilization is a discriminating process that leads to an impoverishment in 15N of senescent leaves and grain itself. This technique also reflects the more efficient use of N resources (fertilizer and native soil-N) when plants receive a late N amendment.

Wheat is among the most widely grown cereals in the world. In order to enhance its production, its management is based on the addition of nitrogen (N) fertilizers. Nevertheless, its application could increase nitrous oxide (N2O) emissions, which effects are very pernicious to the environment, being a strong greenhouse gas (GHG). Regarding GHG, soil processes can also produce or consume carbon dioxide (CO2) and methane (CH4). Nitrification inhibitors (NI) have been developed with the aim of decreasing fertilizer-induced N losses and increase N efficiency. The fact that the application of a NI enhances N use efficiency is a good reason to think that more N should be also available for increasing the grain N concentration of wheat plants. If the application of NI means an increase in N use efficiency, it is plausible to consider that more N would be available, hence, increasing the grain N concentration of wheat. We present a two-year field-experiment to evaluate the influence of the NI 3,4-dimethylpyrazol phosphate (DMPP) on grain yield, grain quality and GHG emissions. Fertilizer dose, with and without DMPP, was 180 kg N ha−1 applied as ammonium sulfate nitrate (ASN) splitted in two applications of 60 kg N ha−1 and 120 kg N ha−1, respectively. A treatment with a non-splitted application of ASN with DMPP and an unfertilized treatment were also included. The splitted application of ASN with DMPP was able to reduce N2O emissions, without affecting yield and its components. The alternative management of a non-splitted application of DMPP was more efficient mitigating N2O emissions, whilst keeping yield and slightly reducing grain protein content. In consequence of the low N2O fluxes from our soils, the EF applied in our region should be lower than the default value of 1% proposed by IPCC.

A pot experiment with wheat plants was carried out to study how late application of nitrogen (N) fertilizer affects the use of pre-anthesis N reserves during the grain-filling period. Increasing doses of N fertilizer were applied (0, 40, and 52 mg N plant–1), either in two amendments (growth stages GS20 and GS30, according to Zadoks scale) or in three amendments (GS20, GS30, and GS37). The experiment was arranged in a complete randomized three-block design with 129 plants per treatment. The plants were watered daily, harvested every 2 d between anthesis and maturity, and were separated into roots, leaf sheaths, leaf blades, and ears for further N determination. Grain N concentration improved due to a late N application in GS37 by 14% (higher N dose) and by 7% (further splitting the same N-fertilizer dose, respectively). The higher the N-fertilizer dose applied, the greater was the amount of pre-anthesis reserves in vegetative organs, these reserves became later available for remobilization. Although splitting the same N dose in three amendments did not increase the N reserves, these reserves were more efficiently remobilized allowing an improvement in grain N concentration. The fertilizer management did not change the temporary pattern of N accumulation in the ear, but did induce a change in the amount of N remobilized and in the contribution of each organ (root, leaf sheath, leaf blade) to this remobilization. Late N amendment allowed a greater N availability of leaf blades and ear N reserves (from 20% up to 26% and from 19% up to 22%, respectively) for remobilization towards the grain, decreasing the root contribution from 28% down to 15%, while the contribution of leaf sheaths was maintained around 35% irrespective of the N applied.

An experiment was carried out to determine how the late application of nitrogen (N) fertilizer affects the use of pre-anthesis carbon reserves during the grain-filling period of pot-grown wheat with no water shortage. Increasing doses (equivalent to 0, 140, and 180 kg N ha–1) of N fertilizer were applied, either in two amendments (stages GS20 and GS30) or in three amendments (stages GS20, GS30, and GS37, according to Zadoks scale). The management of fertilizer by combining an increased N rate with late N application was able to stimulate canopy development, to raise photosynthetic capacity and carbohydrate accumulation during the vegetative stages, and to increase grain yield. Based on the dynamics of carbohydrate accumulation in the ear, three phases were differentiated during the grain-filling period, whose temporary pattern remained stable regardless of the fertilizer management. The net remobilization of carbohydrates started 12 d after anthesis from the leaves and 28 d after anthesis from roots and stems. The increase of the N dose with late N application allowed on one hand a lower use of the pre-anthesis carbon reserves in favor of greater de novo photosynthesis during the grain-filling period, and on the other hand greater relative contribution of the leaf and ear C reserves to remobilization towards the grain. Further splitting the dose increased only the relative contribution of ear C reserves. The stem contribution seemed to be independent of N applied whereas the root contribution tended to diminish with late N application.

Wheat grain nitrogen content depends on the cultivar, the environmental conditions, and the fertilization management. In this study, the response of Soissons variety to N fertilizer management was studied by applying increasing N rates and splitting them into two or three amendments. Not only increasing the N fertilization rate but also splitting the N rate had a beneficial effect on grain quality, and even a lower N rate further splitted throughout the time was able to equal the grain quality. The content of metabolic proteins in the grain remained constant independently of the grain N content, whereas an increase in the reserve protein content was observed as grain N content increased. An exponential increase in the quality parameters of dough extensibility, tenacity and strength was produced which was related to small increases of the glutenin fraction over a certain threshold value, suggesting that a higher glutenin polymerization degree was responsible for the increase in quality. Both increasing the fertilizer N rate and splitting lead to an increase in the high molecular weight glutenin subunits, which would allow a greater formation of disulphide bonds leading to a greater polymerization degree that should be responsible for the increase in quality.

Predicted reduced precipitation, enhanced evaporative demand and increasing CO in the atmosphere will strongly influence wheat production. The association of wheat with arbuscular mycorrhizal fungi (AMF) improves growth under stressful conditions. Our objective was to test the influence of mycorrhizal inoculation on yield, and accumulation of macro- and micro-nutrients and gliadins in grains of durum wheat (Triticum durum Desf.) plants grown under different CO concentrations and water regimes. The main factors of the experimental design were mycorrhizal inoculation (inoculated or non-inoculated plants); atmospheric CO concentration (ambient, ACO, or elevated, ECO); and water regime (optimal or restricted water regime). At ACO, the simultaneous application of AMF and water deficit decreased the number of seeds per spike without affecting the biomass of grains, and grains accumulated higher contents of copper, iron, manganese, zinc and gliadins. The opposite effect was observed with ECO where, regardless of mycorrhizal and water treatment factors, a general depletion of contents of micro- and macro-nutrients and gliadins was detected. Whereas mycorrhizal inoculation together with drought applied to plants cultivated at ACO improved wheat grain quality parameters, under ECO, mycorrhization did not ameliorate grain quality parameters detected in plants that produced the largest grain dry matter values.