Field-scale evaluation of biosolids-derived organomineral fertilizers applied to winter wheat in England

Field-scale experiments in four crop seasons established the agronomic performance of biosolids-derived organomineral fertilizers (OMF) for winter wheat (Triticum aestivum L.) production in England. Two OMF formulations (OMF10 10:4:4 and OMF15 15:4:4) were compared with urea and biosolids granules (≈5:6:0.2) to determine crop responses and fertilizer effects on soil chemical properties. Fertilizers were applied at N rates between 0 and 250 kg ha–1 at regular increments of 50 kg ha–1 N. Average grain yields with OMF10 and OMF15 were higher than with biosolids granules, but lower than with urea (P < 0.05). The optimum N application rates, and corresponding grain yields, were 245 and 7900 kg ha–1 for biosolids, 257 and 9100 kg ha–1 for OMF10, 249 and 9500 kg ha–1 for OMF15, and 225 and 10350 kg ha–1 for urea, respectively. Differences in grain yield between fertilizer treatments were explained by differences in yield components, particularly number of grains and thousand-grain-weight. Grain-N recoveries were 31% for biosolids, ≈40% for OMF, and 52% for urea. Organomineral fertilizers-induced changes in soil extractable P and soil P Index were not significant. Thus, application of OMF replenished P offtake by the crop and therefore supported the choice of the proposed OMF formulations. By contrast, extractable P increased in biosolids and decreased in urea-treated soils, respectively. Heavy metals in soil were unaffected by fertilizer treatment and lower than permissible limit values. The use of OMF for winter wheat production appears to be a sustainable approach to recycling biosolids to land

Impacts of elevated atmospheric CO₂ on nutrient content of important food crops.

One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients

Impacts of elevated atmospheric CO2 on nutrient content of important food crops

One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients

Glyphosate Resistance of C3 and C4 Weeds under Rising Atmospheric CO2.

The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C3 and C4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C3 and C4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant's functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C3 weeds which have a simpler photosynthetic pathway, than for C4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be of essential in managing weed control by herbicide use, and to thus ensure an increase in global food production in the event of increased atmospheric [CO2] levels

Effects of elevated CO2 on plant growth and nutrient partitioning of rice (Oryza sativa L.) at rapid tillering and physiological maturity

This work investigates the relationship between plant growth, grain yield, nutrient acquisition and partitioning in rice (Oryza sativa L.) under elevated CO2. Plants were grown hydroponically in growth chambers with a 12-h photoperiod at either 370 or 700 mmol CO2 mol-1 concentration. Plant dry mass (DM), grain yield and macroand micronutrient concentrations of vegetative organs and grains were determined. Elevated CO2 increased biomass at tillering, and this was largely due to an increase in root mass by 160%. Elevated CO2 had no effect on total nutrient uptake (N, P, K, Mg and Ca). However, nutrient partitioning among organs was significantly altered. N partitioning to leaf blades was significantly decreased, whereas the N partitioning into the leaf sheaths and roots was increased. Nutrient use efficiency of N, P, K, and Mg in all organs was significantly increased at elevated CO2. At harvest maturity, grain yield was increased by 27% at elevated CO2 while grain (protein) concentration was decreased by a similar magnitude (28%), suggesting that critical nutrient requirements for rice might need to be reassessed with global climate change

Expression regulation of myo-inositol 3-phosphate synthase 1 (INO1) in determination of phytic acid accumulation in rice grain.

Phytic acid (PA) is the primary phosphorus (P) storage compound in the seeds of cereals and legumes. Low PA crops, which are considered an effective way to improve grain nutrient availability and combat environmental issues relating to seed P have been developed using mutational and reverse genetics approaches. Here, we identify molecular mechanism regulating PA content among natural rice variants. First, we performed genome-wide association (GWA) mapping of world rice core collection (WRC) accessions to understand the genetic determinants underlying PA trait in rice. Further, a comparative study was undertaken to identify the differences in PA accumulation, protein profiles, and gene expression in low (WRC 5) and high PA (WRC 6) accessions. GWA results identified myo-inositol 3-phosphate synthase 1 (INO1) as being closely localized to a significant single nucleotide polymorphism. We found high rates of PA accumulation 10 days after flowering, and our results indicate that INO1 expression was significantly higher in WRC 6 than in WRC 5. Seed proteome assays found that the expression of INO1 was significantly higher in WRC 6. These results suggest that not only the gene itself but regulation of INO1 gene expression at early developmental stages is important in determining PA content in rice

Influence of rising atmospheric C02 concentrations and temperature on growth, yield and grain quality of cereal crops

A possible scenario for the end of the 21st century is that the atmospheric C02 concentration will be in the range of 510-760 uL L-I and that the mean global temperature will be 1.5-4.5C higher. Further, there maybe greater incidences of extreme climatic events, which together with the C02 and temperature changes will influence development, growth and grain yield of cereals such as rice and wheat. For these C3 plants, the driving force for the growth response to elevated CO2 is higher leaf C02 assimilation rates (A). However, theresponse of A to C02 depends on temperature with maximum absolute increases occuring at temperatures which do not cause flower abortion, while negligible increases are observed at low temperatures. At high temperatures, where A is reduced because of partial inactivation of photosynthetic enzymes, the increase in A due to C02 enrichment is still observed. Other factors, such as changes in shoot water relations or hormone concentrations, may influence growth at elevated CO2 concentrations. Wheat and rice development is accelerated by high temperature and consequently grain yield is reduced because there is less time for radiation to be intercepted during the vegetative phase. Although high C02 also accelerates development in rice and, to a lesser extent in wheat, the extra carbohydrate produced by increases in A results in at least a 40% increase in grain yield at temperatures which do not cause flower abortion. This is due mainly to increased tiller numbers rather than increases in the number or weight of individual grains. However, the yield enhancement due to high C02 will not necessarily compensate for decreases in yield caused by accelerated development at high temperatures. As predicted by the response of A to high C02, the relative increase in yield, due to rising C02 concentrations, is smaller at lower temperatures. Elevated atmospheric CO, may improve the tolerance of plants to heat-induced drought stress by facilitating the maintenance of cell volume and photosynthetic function in the leaves. Increased carbohydrate storage in the stems may also be an advantage during grain filling if the flag leaves senesce prematurely. However, it is unlikely that the effect of very high temperatures on flower abortion will be ameliorated by high CO2. For bread making, the quality of flour produced from grain developed at high temperatures is poorer. High CO2 may also have an effect through a reduction in the protein content of wheat grain. For rice, the amylose content of the grain, a major determinant of cooking quality is increased under elevated CO2