Download or read book Influences of Nitrogen Supply and Elevated CO2 on Nitrogen Consumption Nitrogen Loss Tissue Nitrogen Concentration and Yield of Hydroponic Wheat written by Karl B. Ritchie and published by . This book was released on 1994 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy News written by and published by . This book was released on 1995 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sept.-Oct. issue includes list of theses and dissertations for U.S. and Canadian graduate degrees granted in crop science, soil science, and agronomic science during the previous academic year.
Download or read book Elevated CO2 reduces the nitrogen concentration of plant tissues written by M F. Cotrufo and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy Abstracts written by and published by . This book was released on 1991 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes abstracts of the annual meetings of the American Society of Agronomy; Soil Science Society of America; Crop Science Society of America ( - of its Agronomic Education Division).
Download or read book Biostimulants in Agriculture II Towards a Sustainable Future written by Maurizio Ruzzi and published by Frontiers Media SA. This book was released on 2024-06-11 with total page 1221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern agriculture needs to review and broaden its practices and business models, by integrating opportunities coming from different adjacent sectors and value chains, including the bio-based industry, in a fully circular economy strategy. Searching for new tools and technologies to increase crop productivity under optimal and sub-optimal conditions and to improve resources use efficiency is crucial to ensure food security while preserving soil quality, microbial biodiversity, and providing business opportunities for farmers. Biostimulants based on microorganisms or organic substances obtained from renewable materials represent a sustainable, efficient technology or complement to synthetic counterparts, to improve nutrient use efficiency and secure crop yield stability. Under the new European Union Regulation 2019/1009, plant biostimulants were defined based on four agricultural functional claims as follows: Plant biostimulants are products that stimulate plant nutrition processes independently of the product's nutrient content with the sole aim of improving one or more of the following characteristics of the plant and/or the plant rhizosphere: 1) nutrient use efficiency, 2) tolerance resistance to (a)biotic stress, 3) quality characteristics or 4) availability of confined nutrients in the soil or rhizosphere’. Many diverse natural substances and chemical derivatives of natural or synthetic compounds, as well as beneficial microorganisms, are cataloged as plant biostimulants including i) humic substances, ii) plant or animal-based protein hydrolysates, iii) macro and micro-algal extracts, iv) silicon, v) arbuscular mycorrhizal fungi (AMF) and vi) plant growth-promoting rhizobacteria (PGPR) belonging to the Azotobacter, Azospirillum and Rhizobium genera.
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1976 with total page 1732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nutrient Use Efficiency in Plants written by Malcolm J. Hawkesford and published by Springer. This book was released on 2014-11-14 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nutrient Use Efficiency in Plants: Concepts and Approaches is the ninth volume in the Plant Ecophysiology series. It presents a broad overview of topics related to improvement of nutrient use efficiency of crops. Nutrient use efficiency (NUE) is a measure of how well plants use the available mineral nutrients. It can be defined as yield (biomass) per unit input (fertilizer, nutrient content). NUE is a complex trait: it depends on the ability to take up the nutrients from the soil, but also on transport, storage, mobilization, usage within the plant, and even on the environment. NUE is of particular interest as a major target for crop improvement. Improvement of NUE is an essential pre-requisite for expansion of crop production into marginal lands with low nutrient availability but also a way to reduce use of inorganic fertilizer.
Download or read book Effects of Elevated Carbon Dioxide Plus Chronic Warming on Plant Nitrogen Relations and Leaf Hyponasty written by Dileepa Madushanka Jayawardena and published by . This book was released on 2020 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric carbon-dioxide (CO2) enrichment is largely the cause of current global warming. Hence, in the future, organisms will experience the interactive effects of elevated CO2 (eCO2) and chronic warming rather than their individual effects. Though individual effects of eCO2 or chronic warming on plant responses have been studied in some detail, interactive effects of eCO2 and chronic warming on plant responses such as nitrogen (N) relations (uptake, translocation, assimilation) and leaf hyponasty (upward bending of leaves) have been rarely studied. Therefore, the goals of my dissertation work included (1) investigation of eCO2 plus chronic warming on plant N relations, using tomato (Solanum lycopersicum L. cv. Big Boy) and wheat (Triticum aestivum L. cv. Glenn) followed by a meta-analytic review, and (2) investigation of eCO2 plus chronic warming on leaf hyponasty and subsequent effects of hyponasty on plant growth, using tomato and other economically-important species. These goals were achieved by growing plants in a full-factorial experimental design, using two levels of CO2 (ambient vs. elevated) and two temperature regimes (near-optimal vs. supra-optimal) in controlled-environment growth chambers. In all experimental trials conducted, eCO2 plus warming inhibited tomato vegetative growth, whereas warming alone inhibited growth to a smaller extent, and eCO2 alone increased growth. One potential reason for inhibition of plant growth at eCO2 plus warming could be the observed increase in leaf hyponasty. Warming or eCO2 alone caused modest leaf hyponasty, whereas eCO2 plus warming caused severe leaf hyponasty, which correlated with decreased leaf area and biomass. This could be explained by decreased light interception, and thus in situ photosynthesis, as leaves became more vertically-oriented. Severe hyponasty driven by eCO2 plus warming was observed only in the compound-leaved species tested, but not in the simple-leaved species tested. Tomato plants grown at eCO2 plus warming also had the lowest nitrate (NO3-) and ammonium (NH4+) -uptake rates, as well as the lowest root-to-shoot net-N translocation. Moreover, eCO2 plus warming decreased whole-plant N assimilation in tomato, which was mainly driven by the inhibition of whole-plant NO3- assimilation. However, tomato plants grown at eCO2 plus warming had higher in vitro activities of key N-assimilation enzymes (an index of assimilation capacity) and higher % carbon (C) and N levels in roots, indicating that inhibition of N assimilation was not due to the damage to these enzymes nor due to resource limitation for root functions. Thus, in tomato, eCO2 plus warming may decrease N uptake and assimilation in large part because of reduced whole-plant growth, and thus N demand, caused by leaf hyponasty. In wheat, plant growth, %N, protein concentration, and root N-uptake rates were each significantly affected only by CO2, while N- and NO3--assimilation were significantly affected only by warming. However, plants grown at eCO2 plus warming had the lowest concentrations of N and protein, and, hence, lower nutritional quality, with decreased protein concentration at eCO2 plus warming likely due to the inhibition of N assimilation. A comprehensive meta-analysis of the effects of eCO2 plus warming on plant N relations further supported the above-mentioned experimental observations. According to the meta-analysis, eCO2 alone or in combination with warming reduced shoot %N (more so at ≥300 vs.
Download or read book The impact of rising carbon dioxide levels on crop nutrients and human health written by Smith, Matthew R. and published by Intl Food Policy Res Inst. This book was released on 2018-07-06 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon dioxide (CO2) levels are rising globally at a rapid pace, on track to surpass 550 parts per million (ppm) by midcentury. Studies have found that, when grown under elevated CO2 concentrations of 546–586 ppm, many food crops—including wheat, rice, barley, and soybeans—have lowered concentrations of nutrients, including many that are important for overall health, such as iron, zinc, and protein. Elevated CO2 also affects both the quantity and quality of forage, thereby affecting animal performance and production and, consequently, the availability of nutrients from animal-source foods, such as meat, milk, and eggs. This loss of dietary nutrients in foods could translate to increased nutritional deficiency for hundreds of millions of people already on the brink of deficiency—mainly developing countries in Asia, the Middle East, and North Africa based on dietary preferences for the commodities most affected. This policy note examines the link between rising CO2 levels and declining nutritional content for a number of major crops, as well as forage. The discussion includes a comparison of the varying effects by crop, and strategies to address this challenge in the context of climate change.
Download or read book Nitrogen in Agriculture written by Khan Amanullah and published by BoD – Books on Demand. This book was released on 2018-02-01 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen is the most yield-restraining nutrient in crop production globally. Efficient nitrogen management is one of the most important factor for improving nitrogen use efficiency, field crops productivity and profitability. Efficient use of nitrogen for crop production is therefore very important for increasing grain yield, maximizing economic return and minimizing nitrous oxide (N2O) emission from the fields and nitrate (NO3) leaching to ground water. Integrated nitrogen management is a good strategy to improve plant growth, increase yield and yield components, grain quality and reduce environmental problems. Integrated nitrogen management (combined use of chemical + organic + bio-fertilizers) in field crop production is more resilient to climate change.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1990 with total page 1842 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Advances on Nitrogen Use Efficiency in Crop Plants and Climatic Challenges written by Hamada AbdElgawad and published by Frontiers Media SA. This book was released on 2023-08-25 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen (N) is a mineral nutrient that is essential for the normal growth and development of plants that is required in the highest quantity. It is an element of nucleic acids, proteins, and photosynthetic metabolites, therefore crucial for crop growth and metabolic processes. Recently, it was estimated that N fertilizers could meet the 48% demand of the world’s population. However, overuse and misuse of N fertilizers raised environmental concerns associated with N losses by nitrous oxide (N2O) emissions, ammonia (NH3) volatilization, and nitrate (NO3−) leaching. For instance, NH3 is a pollutant in the atmosphere, N2O is a greenhouse gas that has a warming potential 298 times higher than CO2 and contributes to ozone depletion, and NO3− causes eutrophication of water bodies. Agricultural practices account for about 90% of NH3 and 70% of N2O anthropogenic emissions worldwide. The efficient use of N chemical fertilizers can be attained through cultural and agronomic practices. Nitrogen use efficiency (NUE) is an important trait that has been studied for decades in different crops. The grain production or economic return from the per unit supply of N fertilizer simply explained the NUE. Several definitions were suggested by different researchers. NUE can be defined as the product of N uptake efficiency (NUpE) and N utilization efficiency (NUtE). An increase in NUE increases the yield, biomass, quality, and quantity of crops. N is generally applied as chemical fertilizer to the soil, whereas a small amount is added to some crops like grain legumes through the fixation process. On the other hand, crop plants take N through the root system in the form of nitrate or ammonium which is thereby used in different metabolic processes. A number of studies have been conducted to increase the NUE in different crops and it has been indicated that NUE can be improved by agronomic, physiological, biochemical, breeding as well as molecular approaches. Nitrogen is the main limiting nutrient after carbon, hydrogen, and oxygen for the photosynthetic process, phyto-hormonal and proteomic changes, and the growth-development of plants to complete their lifecycle. Excessive and inefficient use of N fertilizer results in enhanced crop production costs and atmospheric pollution. Atmospheric nitrogen (71%) in the molecular form is not available for the plants. For the world's sustainable food production and atmospheric benefits, there is an urgent need to upgrade nitrogen use efficiency in the agricultural farming system. Nitrogen losses are too high, due to excess amount, low plant population, poor application methods, etc., which can go up to 70% of total available nitrogen. These losses can be minimized up to 15–30% by adopting improved agronomic approaches such as optimal dosage of nitrogen, application of N by using canopy sensors, maintaining plant population, drip fertigation, and legume-based intercropping. Therefore, the major concern of modern days is to save economic resources without sacrificing farm yield as well as the safety of the global environment, i.e. greenhouse gas emissions, ammonium volatilization, and nitrate leaching.
Download or read book Bibliography of Agriculture with Subject Index written by and published by . This book was released on 1987-10 with total page 1238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Elevated Carbon Dioxide and Chronic Warming on Nitrogen N Uptake and Assimilatory Proteins of Tomato Roots Provided Different Forms of Inorganic N nitrate and Ammonium written by Dileepa M. Jayawardena and published by . This book was released on 2015 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric CO2 enrichment is expected to benefit plant growth, despite causing global warming and nitrogen (N) dilution in plants. Most plants procure most of their N as two inorganic forms, nitrate (NO3- ) or ammonium (NH4+), using membrane-localized transport proteins in roots which are key targets of improving N-use efficiency in plants. Though it is expected that there will be interactive effects of elevated CO2, chronic warming, and N form on root N relations, this has not been studied. In this study, tomato (Solanum lycopersicum L. cv. Big Boy) plants were grown at two levels of CO2 (ambient=400 ppm vs. elevated=700 ppm) and under two temperature regimes (30oC vs. 37oC), while providing either NO3- (1.5 mM) or NH4+ (1.5 mM) as the sole N source. To assess plant N relations under these conditions, plant biomass (shoot, root, total), %N (shoot, root, total), root N-uptake rate, the concentration of total root proteins, and the concentration of N uptake and assimilatory proteins in roots per unit total root protein and per gram of dry root mass were measured. Elevated CO2 and chronic warming acted synergistically to severely inhibit the growth of plants, regardless of N form, while individually, these factors slightly increased growth. Although %N in roots among all treatments was similar, the combination of elevated CO2 and warming decreased (1) the rate of N uptake by roots, (2) the concentration of total protein in roots, indicating an inhibition of N assimilation (especially in NH4+-treated plants), and (3) shoot %N, indicating a possible negative effect on N translocation from roots to shoots (especially in NO3--treated plants). However, for the most part, the concentrations in roots of the main N-uptake and N-assimilation proteins were little affected by elevated CO2 and warming, and when affected, were not correlated with root total protein or N-uptake rate; hence, N uptake and assimilation in roots were controlled by the activities of these proteins rather than their concentrations. Taken together, these results indicate that elevated CO2 and chronic warming will act synergistically to decrease plant N uptake and assimilation, thereby decreasing growth and protein concentration; thus, future global warming may potentially decrease both crop production and its food quality.
Download or read book Interactive Effects of Elevated Carbon Dioxide Concentration with Nutrient Availability and Leaf Development on Plant Carbon Metabolism written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Climate Change on Nutrient Uptake and Nutrient uptake Proteins in Roots written by Deepesh Raj Bista and published by . This book was released on 2017 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric levels of carbon dioxide (CO2), which are increasing due to human activities, might reach 500-900 ppm by 2100, and this will typically increase plant growth and reproduction. However, with increases in CO2, the Earth's surface temperature also will increase, which will cause many regions of the Earth to experience increases in evapo-transpiration and increases in the frequency, intensity, and duration of drought. In addition to decreasing plant growth and reproduction, drought also decreases the concentration (%) of nitrogen (N) and phosphorous (P) in plant tissues. The growth of plants in elevated CO2, compared to current levels, also decreases plant %N and %P, but such decreases might be offset by increased fertilization. I investigated if declines in plant nutrient concentration during drought or with elevated CO2 were associated with decreases in the rate at which roots take up nutrients from the soil, and if this is related to the concentration of the major nutrient-uptake proteins found in roots- something that has never been investigated. In my first study, I found that drought reduced %N and %P in roots and shoots, and this decrease was associated with decreases in root N- and P-uptake rate and a decrease in the concentration of the major P-, but not N-, uptake protein in roots. In my second study, both drought and elevated CO2 decreased plant %N and %P in most cases, and their effects were additive for shoot tissue. Root N- and P-uptake rates were strongly decreased by drought, but were not significantly affected by CO2. Moreover, elevated CO2 exacerbated the decrease in plant nutrient concentration during drought, despite increasing the expression or activity of nutrient-uptake proteins. In my third study, I found that elevated CO2 increased biomass, but reduced %N, indicating that there was a dilution of N with elevated CO2. Root N-uptake rate was unaffected by CO2 at low N, but was decreased at high N. At low and medium N levels, high CO2 caused a decrease in the main N-uptake protein (NRT1), both per unit total root protein and per gram root, whereas NRT1 levels increased at high N with elevated CO2. Thus, decreases in plant N concentration, and hence food quality, with elevated CO2 were not caused by decreases in the concentration of N-uptake proteins in roots, and increases in NRT1 at high N could not prevent a decrease in %N at high CO2. So, if we "connect the dots", the above results indicate that increases drought stress with climate change will decrease plant nutrient concentration, and hence food quality, at least in part, by decreases in the rate of nutrient uptake by roots, which is only sometimes associated with decreases in the concentration of nutrient-uptake proteins in roots. High CO2 with drought would only exacerbate the decline in plant %N and %P with drought. Moreover, improving plant nutrient concentration during drought in a high-CO2 world cannot be accomplished simply by increasing fertilizer rates or breeding crops to express higher levels of nutrient-uptake proteins.
