Nitrogen Fertilization Enhances Soil Organic Carbon Accumulation by Improving Photosynthetic C Assimilation and Root Exudation Efficiency in a Salt Marsh PDF Download
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Author: juanyong li
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Although salt marshes cover only a small area of the Earth, their contribution to long term carbon (C) burial is comparable to C sinks in many more dominant terrestrial ecosystem types. Continuous nitrogen (N) loading alters plant growth and subsequently has the potential to impact soil organic carbon (SOC) accumulation in salt marshes. However, there is presently little information concerning the input and allocation of photosynthesized C in plant-soil-microbial systems. This knowledge gap hampers the quantification of C fluxes and the clarification of the mechanisms controlling the C budget under N loading in salt marsh ecosystems. To address this, we conducted an N fertilization field observation combined with a five hour 13C-pulse labeling experiment in a salt marsh dominated by Suaeda. salsa (S. salsa) in the Yellow River Delta, China. N fertilization increased net 13C assimilation of S. Salsa by 177.37%, which was primarily allocated to aboveground biomass and SOC. However, N fertilization had little effect on 13C allocation to belowground biomass. Correlation analysis showed that 13C incorporation in soil was significantly and linearly correlated with 13C incorporation in shoots rather than in roots both in a 0N (0 g N m-2 yr-1) and +N (20 g N m-2 yr-1) group. The results suggest that SOC increase under N fertilization was mainly due to an increased C assimilation rate and more efficient downward transfer of photosynthesized C instead of root lysate and detritus. In addition, N fertilization strongly improved the 13C amounts in the chloroform-labile SOC component by 315%. However, the absolute increment of newly fix 13C mainly existed in the form of residual SOC, which had more tendency for burial in the soil. Thus, N fertilization enhanced SOC accumulation although C loss increased via belowground respiration. These results have important implications for predicting the carbon budget under further human-induced N loading.
Author: juanyong li
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Although salt marshes cover only a small area of the Earth, their contribution to long term carbon (C) burial is comparable to C sinks in many more dominant terrestrial ecosystem types. Continuous nitrogen (N) loading alters plant growth and subsequently has the potential to impact soil organic carbon (SOC) accumulation in salt marshes. However, there is presently little information concerning the input and allocation of photosynthesized C in plant-soil-microbial systems. This knowledge gap hampers the quantification of C fluxes and the clarification of the mechanisms controlling the C budget under N loading in salt marsh ecosystems. To address this, we conducted an N fertilization field observation combined with a five hour 13C-pulse labeling experiment in a salt marsh dominated by Suaeda. salsa (S. salsa) in the Yellow River Delta, China. N fertilization increased net 13C assimilation of S. Salsa by 177.37%, which was primarily allocated to aboveground biomass and SOC. However, N fertilization had little effect on 13C allocation to belowground biomass. Correlation analysis showed that 13C incorporation in soil was significantly and linearly correlated with 13C incorporation in shoots rather than in roots both in a 0N (0 g N m-2 yr-1) and +N (20 g N m-2 yr-1) group. The results suggest that SOC increase under N fertilization was mainly due to an increased C assimilation rate and more efficient downward transfer of photosynthesized C instead of root lysate and detritus. In addition, N fertilization strongly improved the 13C amounts in the chloroform-labile SOC component by 315%. However, the absolute increment of newly fix 13C mainly existed in the form of residual SOC, which had more tendency for burial in the soil. Thus, N fertilization enhanced SOC accumulation although C loss increased via belowground respiration. These results have important implications for predicting the carbon budget under further human-induced N loading.
Author: Sham S. Goyal
Publisher: CRC Press
ISBN: 9781560221418
Category : Science
Languages : en
Pages : 512
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Book Description
The latest advancements and innovations in regulating the nitrogen levels in your crops Enhancing the Efficiency of Nitrogen Utilization in Plants examines current research to present an overview of inorganic nitrogen uptake and metabolism in plant life and crop production. This comprehensive resource is divided into sections for quick and easy reference, focusing on physiology and adaptive mechanisms, molecular genetics, and applied aspects. The world’s leading experts in agronomy, crop science, and plant physiology analyze the most effective methods and management practices to ensure maximum plant growth and production. Enhancing the Efficiency of Nitrogen Utilization in Plants develops links between basic and applied research and practical crop production. This unique book addresses a wide range of topics that relate to nitrogen use efficiency, and to plant and crop responses to applications of nitrogen via fertilizers, including nitrogen acquisition and reduction; crop rotation; molecular approaches, genetics, and markers; balanced fertilization and controlled-release fertilizers; nitrogen decline, supply, and demand; crop breeding; radiation use; nutrient deficiency and toxicity; nitrate induction and signaling; nitrogen transport; and nitrogen use at the leaf and canopy level . Enhancing the Efficiency of Nitrogen Utilization in Plants examines: plant responses to changes in the supply of the two inorganic nitrogen sources of nitrate and ammonium root system control mechanisms of nitrogen uptake nitrate uptake and reduction in higher and lower plants how nitrogen affects biomass production in a canopy nitrogen’s effects on radiation interception and radiation use efficiency senescence and photosynthesis the regulation of nitrogen and carbon metabolisms by sugars and nitrogen metabolites integrated nitrogen fertilization the use of legumes for soil improvement root system control mechanisms fertility and crop nutrient demand chemical and biological processes that influence nitrogen transformation or loss the use of simulation models to measure water and nutrient transport in soils and much more Enhancing the Efficiency of Nitrogen Utilization in Plants is an invaluable classroom aid for academics working in plant physiology and agronomy, and an essential professional resource for researchers working in plant and crop production.
Author: Li Wang
Publisher: Frontiers Media SA
ISBN: 2832549322
Category : Science
Languages : en
Pages : 141
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Book Description
The improvement in global crop production over the past several decades has been associated with increased use of nitrogen (N) fertilizer. However, on average, less than 50% of the nitrogen added to croplands globally is harvested as crop product. Inefficient use of N fertilizer by crops will result in substantial agricultural nitrogen losses, posing threats to human and ecosystem health. Crop production must increase dramatically to meet the growing demand for food and biofuels projected for 2050. To boost crop yield with lowered environmental cost, the use of high-potential crop cultivars and efficient nitrogen fertilizer management are required. Recent advances in N management practices, such as enhanced-efficiency fertilizer use, improved manure management and machine deep placement of fertilizer have opened up new strategies to achieve improved crop production with N use reduction. A better understanding of the key crop traits and regulatory processes in response to N fertilizer managements will facilitate the increase in crop yield, N use efficiency while minimizing impacts on the environment.
Author: Sindhu Jagadamma
Publisher:
ISBN:
Category : Cropping systems
Languages : en
Pages : 282
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Book Description
Abstract: The adoption of recommended management practices (RMPs) such as nitrogen (N) fertilization and cropping systems play important role in increasing crop residue production, with attendant increase in soil organic carbon (SOC) sequestration, agronomic productivity, and soil quality. This study was conducted with the objectives to evaluate the effect of long term N fertilization and cropping systems on: (i) SOC and soil organic nitrogen (SON) concentrations and pools, (ii) SOC sequestration rate (iii) soil quality determinants such as aggregation, total porosity and soil pH, and (iv) agronomic productivity and its relation with SOC pool. Replicated soil samples were obtained from a long-term experiment (23-yrs) at the Northwestern Illinois Agricultural Research and Demonstration Center, Monmouth, IL during Spring, 2004 up to a depth of 90 cm. The soil type is Muscatune silt loam (Fine-silty, mixed, superactive, mesic Aquic Argiudolls). The experimental design was split-split plot within a randomized complete block with three cropping systems [continuous corn (Zea mays) (CCC), and two rotation plots with corn and soybean (Glycine max) grown in alternate years (CSB and SBC respectively)] as the main plot, presence or absence of cover crop [oats (Avena sativa)] as sub plot and five N rates [0 (N0), 70 (N1), 140 (N2), 210 (N3) and 280 (N4) kg N ha−1] in the split-split plot arrangement. Results showed significant increase in both SOC and SON concentrations and pools by the addition of N fertilizers, with SOC pool ranging from 68.4 Mg ha−1 (N0) to 75.8 Mg ha−1 (N4), and SON pool ranging from 6.5 Mg ha−1 (N0) to 6.9 Mg ha−1 (N3) for 0-30 cm depth. The SOC sequestration rate over 23 years of N application ranged from 158 kg ha−1 yr−1 (N2) to 324 kg ha−1 yr−1 (N4) for 0-30 cm depth. Both soil bulk density (Pb) and C:N ratio significantly decreased with increase in the rates of N fertilizer for 0-30 cm depth. Continuous corn system, across all N treatments, sequestered 6 Mg ha−1 more SOC for 0-30 cm depth compared to corn-soybean rotation. Both water stable aggregates (WSA) and mean weight diameter (MWD) increased with increase in the rates of N, with mean WSA values ranging from 47 to 54% and MWD from 0.44 to 0.71 mm. The soils under CCC had more WSA (52.1%), which is 3% higher than that under corn-soybean rotation. The MWD values of cropping system treatments ranged from 0.5 to 0.65 mm, with the highest value corresponding to CCC. Both WSA (R2=0.23) and MWD (R2=0.32) were positively correlated with SOC concentration. The CCC system and increased rates of N fertilization increased corn residue (stover) yield, and thus the amount of biomass returned to the soil. However, N fertilization had no significant influence on soybean residue production. Regression analysis indicated a significant positive relationship between stover yield and SOC pool, but not between soybean residue yield and SOC pool. This study indicated that long-term continuous corn cultivation and judicious N fertilization are desirable management strategies for increasing SOC sequestration, enhancing soil physical quality , and improving sustainability of production systems.
Author: Luo Yiqi
Publisher: Elsevier
ISBN: 0080500714
Category : Science
Languages : en
Pages : 434
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Book Description
This book focuses on the interactive effects of environmental stresses with plant and ecosystem functions, especially with respect to changes in the abundance of carbon dioxide. The interaction of stresses with elevated carbon dioxide are presented from the cellular through whole plant ecosystem level. The book carefully considers not only the responses of the above-ground portion of the plant, but also emphasizes the critical role of below-ground (rhizosphere) components (e.g., roots, microbes, soil) in determining the nature and magnitude of these interactions. * Will rising CO2 alter the importance of environmental stress in natural and agricultural ecosystems?* Will environmental stress on plants reduce their capacity to remove CO2 from the atmosphere?* Are some stresses more important than others as we concern ourselves with global change?* Can we develop predictive models useful for scientists and policy-makers?* Where should future research efforts be focused?
Author: Hamada AbdElgawad
Publisher: Frontiers Media SA
ISBN: 2832532470
Category : Science
Languages : en
Pages : 423
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Book Description
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.
Author: J F Morot-Gaudry
Publisher: CRC Press
ISBN: 1482279843
Category : Science
Languages : en
Pages : 489
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Book Description
This publication contains the most important information acquired over the last twenty years in the area of nitrogen metabolism and envisages new strategies to improve plant species of agronomic value by devising new techniques for growing them.
Author: Georges Hofman
Publisher:
ISBN: 9782950629999
Category : Plants
Languages : en
Pages : 48
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Book Description
Author: J. E. Sheehy
Publisher: Int. Rice Res. Inst.
ISBN: 9712201465
Category : Photosynthesis
Languages : en
Pages : 304
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Book Description
Author: Malcolm J. Hawkesford
Publisher: Springer
ISBN: 331910635X
Category : Science
Languages : en
Pages : 287
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Book Description
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.
