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Nitrogen Movement Retention And Uptake In The Corn Zea Mays L Root Zone As Influenced By Cultivation And Water Management
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Book Synopsis Nitrogen Movement, Retention and Uptake in the Corn (Zea Mays L.) Root Zone as Influenced by Cultivation and Water Management by : Alex Reuben Saka
Download or read book Nitrogen Movement, Retention and Uptake in the Corn (Zea Mays L.) Root Zone as Influenced by Cultivation and Water Management written by Alex Reuben Saka and published by . This book was released on 1984 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ecology of Arable Land — Perspectives and Challenges by : M. Clarholm
Download or read book Ecology of Arable Land — Perspectives and Challenges written by M. Clarholm and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agriculture in the industrial world has gone A common interest of the contributors is increas through dramatic changes over the past decades. ing the understanding of the turnover of carbon Mechanization in combination with high inputs of and inorganic nutrients in terestrial ecosystems. fertilizers and pesticides has turned deficits of agri The authors approach this topic from different cultural products into surplus. Over the same directions depending on their interests and ex period we have experienced increased environment pertise. Difficulties are identified in the quantifica al problems in both the atmosphere and our water tion of below-ground production where death and resources, which have been associated with the re-growth, if incorporated into the calculations, changes in management practices. can change production figures considerably as Concern about the potential pollution by compared to values derived from "peak" estimates. nitrogen fertilizers as well as the low utilization The role of root-derived carbon is investigated in efficiency of applied nitrogen by plants has created relation to nutrient competition between roots and a need for a better understanding of nitrogen microorganisms, the cost of N2 fixation and the cycling in the plant-soil-water system. To achieve decomposition of organic nitrogen. Mycorrhizae this, it is neccessary to study process interactions use root-derived carbon and their roles in phos and process regulation in an ecosystem context. phorus conservation and in supplying nutrients to During the last decade many ecosystem studies the host are exemplified.
Book Synopsis Root Zone Water Quality Model by : Lajpat Ahuja
Download or read book Root Zone Water Quality Model written by Lajpat Ahuja and published by Water Resources Publication. This book was released on 2000 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication comes with computer software and presents a comprehensive simulation model designed to predict the hydrologic response, including potential for surface and groundwater contamination, of alternative crop-management systems. It simulates crop development and the movement of water, nutrients and pesticides over and through the root zone for a representative unit area of an agricultural field over multiple years. The model allows simulation of a wide spectrum of management practices and scenarios with special features such as the rapid transport of surface-applied chemicals through macropores to deeper depths and the preferential transport of chemicals within the soil matrix via mobile-immobile zones. The transfer of surface-applied chemicals (pesticides in particular) to runoff water is also an important component.
Book Synopsis Water and Nitrogen Use Efficiency of Corn (Zea Mays L.) Under Water Table Management by : Ajay Singh
Download or read book Water and Nitrogen Use Efficiency of Corn (Zea Mays L.) Under Water Table Management written by Ajay Singh and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Drainage and water table management are essential for crop production in humid regions. Water table management not only increases crop yield, but also reduces nitrate leaching to water bodies. This study investigated the water and nitrogen use efficiency of corn under two water management conditions and three nitrogen fertilizer levels. The sap flow heat balance method was used to measure the daily water uptake of corn, over an extended period of the growing season. The impacts of climate change on grain corn and biomass yield in eastern Canada under tile drained conditions was also evaluated over a 30 year future period (2040 to 2069). The study was conducted at a field scale in 2008 and 2009 at St. Emmanuel, Quebec. The two water management conditions were: conventional drainage (FD), and controlled drainage with subirrigation (CD-SI). The three nitrogen (N) fertilizer treatments (low, medium, and high N) were applied in a strip across three blocks. The seasonal water balance indicated that the plants in the CD-SI plots had more water than required in the wet periods, despite the system automation, while the FD plots exhibited deficit water conditions. Water could be saved in the wet periods by better regulating water supplied by subirrigation. However, in dry years, the CD-SI system increased yield. The grain corn water use efficiency (WUE) for FD plots was 2.49 and 2.46 kg m-3, in 2008 and 2009, respectively. In these years, the grain WUE for CD-SI plots was 2.43 and 2.26 kg m-3. Water management treatments demonstrated significant difference (p 0.05) in grain yields in 2009, at low and high nitrogen levels. However, at the medium nitrogen level, water management demonstrated no significant effect (p 0.05) on grain yields. The two water treatments had no effect on the above-ground dry biomass yields in both years. Mean nitrogen use efficiency (NUE) of grain corn and biomass varied from 27 to 99 kg kg-1. Highest NUE (99 kg kg-1) was observed under low N (~120 kg N ha-1) and lowest NUE (41 kg kg-1) occurred in the high N (~260 kg N ha-1). This might be due to higher nitrogen losses due to leaching, residual nitrogen in the soil, and more denitrification in high N plots. The rate of plant water uptake measured by the sap flow method, varied from 3.55 to 5.11 mm d-1 from silking to full dent stage of corn growth. These rates were consistent with ETc calculated by the FAO-56 Penman-Monteith method (3.70 to 5.93 mm d-1) for both years. Although, silking is considered as a critical stage for corn growth, water demand was highest at the milk stage (45.63 to 59.80 mm). Transpiration during this stage constituted 10 to12% of the total water requirement of the corn for the season. The silking to full dent stage accounted for approximately 40% of the total water requirement of the crop. The STICS (JavaStics v1.0) crop model was used to examine the impacts of climate change, under the B1 emissions scenario, on corn yield from 2040-2069. The model was calibrated using 2008 field measured data, and then validated using the 2009 data set. Corn grain yield was underestimated by 1.5 to 2.6 Mg ha-1 for the two years of measurement. Total dry biomass was also underestimated by 0.9 to 2.6 Mg ha-1. Simulations for the B1 emissions scenario using synthetic weather data was run under the same crop conditions as in 2008. Tukey's studentized range (HSD) test of corn grain yield indicated that yields at high and low N, and high and medium N were different at the 95% confidence level. Grain and biomass production from 2040-2069 under B1 emissions scenario responded differently (p 0.05) for the three N treatments. However, the Mann-Kendall test showed neither increasing nor decreasing trend (MK-stat - 1.96) at a 95% confidence level. " --
Book Synopsis Carbon and Nutrient Dynamics in Natural and Agricultural Tropical Ecosystems by : L. Bergström
Download or read book Carbon and Nutrient Dynamics in Natural and Agricultural Tropical Ecosystems written by L. Bergström and published by . This book was released on 1998 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil fertility is one of the most important factors regulating yield and productivity in both the agricultural and natural ecosystems of the tropics, and maintaining soil fertility has become a key challenge to sustainable development in this region. This book presents the ecological processes and management practices which affect soil fertility and then looks at ways to integrate this knowledge to develop economically feasible solutions. Based on a symposium held at the University of Zimbabwe in May 1996, the volume is partly the result of ten years of research by the Soil Biology and Fertility Project in Zimbabwe and includes contributions from researchers in Africa, Asia, Europe and North America. The book is divided into five sections covering nutrient dynamics in soil, decomposition of crop residues, tree-soil-crop interactions in agroforestry and in ecosystem dynamics, and prospects for the future. Essential reading for agronomists, soil scientists and ecologists studying the tropics, this volume is also an important reference for decision-makers in land use and development in tropical countries.
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1986 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis American Doctoral Dissertations by :
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fertilizer Nitrogen Use Efficiency and Nutrient Uptake by Maize (Zea Mays L.) in Vertisols in Kenya by : Dalmas Owino Sigunga
Download or read book Fertilizer Nitrogen Use Efficiency and Nutrient Uptake by Maize (Zea Mays L.) in Vertisols in Kenya written by Dalmas Owino Sigunga and published by . This book was released on 1997* with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general objectives of this study were to increase the understanding of nitrogen (N) losses in maize cropping on Vertisols, and to develop management options to reduce such losses and to improve fertilizer N use efficiency. The specific objectives were. to quantify the effects of fertilizer N sources and management practices on (i) fertilizer N losses through denitrification, NH3 volatilization and bypass flow, (ii) fertilizer N use efficiency by maize, considering agronomic, recovery, and physiological N efficiencies, and (iii) the uptake of nutrients other than N. Both laboratory- and field-based investigations were conducted. Laboratory experiments were carried out to identify and rank the factors influencing denitrification, NH3 volatilization, and bypass flow. Field experiments were conducted to test various management options. It was found that the critical soil moisture content for denitrification to commence was 60% of the water holding capacity (WHC), but substantial denitrification occurred at 80% WHC. Denitrification rate depended primarily on soil moisture content and available C. The amount of N lost through denitrification was determined by both the rate and duration of denitrification. From the laboratory investigations it was confirmed that NH3 volatilization depended primarily on soil pH and fertilizer properties. It was also found that Kenya Vertisols have pH ranging between 5.5 and 9.1, indicating different potentials for NH3 volatilization. Incorporating fertilizer materials within the 0-5 cm soil layer significantly reduced NH3-N losses. Nitrate-N was the main N-form in which N was recovered in the bypass flow, and the amount of N recovered increased with increasing rate of N03-N application. NH4-N treatment had no effect on N loss through bypass flow. The results showed that bypass flow can be an important avenue of N03-N loss from Vertisols especially if applied early in the season when the characteristic cracks of Vertisols have not closed. Drains, 40 and 60 cm deep, led to deeper rooting depth and higher yields of maize than the 0 and 20 cm deep drains. Besides, the uptake of N, P, and K was higher on drained than undrained plots. The late maturing hybrid H614 was superior to early maturing H511 in terms of N uptake and nitrogen use efficiency. It is recommended that 40 cm deep drains with inter-drain spacing of 15 - 20 metres be provided as prerequisite step in the management of Vertisols for maize production.
Book Synopsis Comprehensive Dissertation Index by :
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Influence of Rooting Depth on Nitrogen Uptake in Zea Mays L. Under Optimum and N-deficient Conditions by : Chelsea A. Sutherland
Download or read book The Influence of Rooting Depth on Nitrogen Uptake in Zea Mays L. Under Optimum and N-deficient Conditions written by Chelsea A. Sutherland and published by . This book was released on 2010 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A well developed root system is a necessity for the acquisition of nutrients. Nitrogen (N) is predominantly found in water soluble chemical compounds that are highly mobile and expected to leach to deeper soil layers in the course of the cropping season. The purpose of this study was to evaluate the importance of root architectural traits of maize genotypes (Zea mays L.) under optimum and N-deficient conditions. It was hypothesized that deep rooted plants would be better able to acquire N and thus have enhanced performance. Maize inbred lines with contrasting root architecture: three genotypes with a shallow rooting system and 4 with a deep rooting system were sown in a randomized complete split-plot design. Root systems were measured destructively at six weeks after planting, at flowering, and at physiological maturity. Nitrogen acquisition by the plant was monitored over time by measuring leaf nitrogen content and SPAD as a proxy-measure for leaf chlorophyll. Furthermore grain yield was measured. The results indicated that steeper root angles produce deeper roots, and root angles, depth and branching are negatively correlated. Performance of both shallow and steep genotypes was similar under both conditions, as shallow genotypes responded to N deficient conditions by producing steeper root angles over time. These structural alterations facilitated N acquisition and minimized the differences between rooting types.
Download or read book 2005 Regional Directory written by and published by . This book was released on 2005 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Influence of N Fertilization and Plant Population on Nutrient Uptake, Several Yield Components and Some Agronomic Characteristics of Five Corn (Zea Mays L.) Hybrids by : Donald William Kemper
Download or read book The Influence of N Fertilization and Plant Population on Nutrient Uptake, Several Yield Components and Some Agronomic Characteristics of Five Corn (Zea Mays L.) Hybrids written by Donald William Kemper and published by . This book was released on 1971 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field experiments were conducted in 1969 and 1970 to determine the effects of corn hybrid, rate of applied nitrogen and plant population on nutrient uptake, yield, several yield components and several agronomic characteristics of corn (Zea mays L.). The corn was planted at equidistant intervals with plant spacings ranging from 25,4 to 50.8 on, the range of plant populations was 39,520 to 158,080 plants/ha. Nitrogen was broadcast in 67 kg increments (0 to 538 kg of nitrogen/ha) at planting as ammonium nitrate. The corn hybrids used wereN6 x B14, N31 x N28, N28 x C103, Nebr. 808 and Ner. 501D. Irrigation water was supplied as necessary. Ramrod and atrazine were applied for weed control at the rate of 3.36 and 1.12 kh/ha respectively. The parameters measured include the following: uptake of nitrogen, phosphorus, potassium and sulfur (percentage uptake, uptake/plant and uptake/unit area) and dry matter accumulation at the 6-, 11-leaf and at the silking stage were measured. Crain yield, the number of cars and plants per plot and the number of ears per 100 plants, shelling percentage, dry matter of the graing, car lenght, ear width, 100 kernel weight, grain protein, dates of 50% tassel and 50% silked, and dates of the first and last pollen shed were the measured parameters. Plant height, stalk diameter, leaf area and LAI were measured only in 1969. Lodging, breakage and stripping damage were measured only in 1970 becuase of severe wind damage to the crop. As a result of decreased plant size, the uptake of nutrition...
Book Synopsis Integrating Root and Leaf Phenotypes to Enhance Nitrogen Use Efficiency in Maize (Zea Mays L.). by : Jennifer Yang
Download or read book Integrating Root and Leaf Phenotypes to Enhance Nitrogen Use Efficiency in Maize (Zea Mays L.). written by Jennifer Yang and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing crop varieties with greater resource use efficiency and tolerance to abiotic and biotic stress is a key strategy for mitigating effects of climate change and resource depletion, while ensuring food security for a rapidly growing human population. Nitrogen is the mineral element required in greatest abundance by plants, and its availability is a primary determinant of plant growth and crop yield. Yet, nitrogen fertilizer is one of the most costly agricultural inputs, and inaccessible in sufficient quantities to low-input farmers. Conversely, excess application of fertilizer to maximize yields in intensive commercial operations has resulted in environmental damage and economic losses; an estimated 50% of applied nitrogen is not captured by crops, and contaminates ground water, creates hypoxic zones, or volatilizes as harmful greenhouse gases.Maize (Zea mays L.) is a dominant crop, with approximately 1 billion tons produced globally for food, fuel, and industrial uses per year. Breeding maize varieties with enhanced nitrogen use efficiency (NUE, defined as grain yield per unit soil nitrogen) both in capturing nitrogen in soil (uptake efficiency, NUpE) and converting acquired nitrogen into grain yield (utilization efficiency, NUtE) would have substantial environmental and economic benefits. Selection under increased planting densities has indirectly contributed to modest gains in NUE in modern maize varieties, along with agronomic advances. However, trait-based approaches could lead to targeted improvement in NUE for both high-input farms and nitrogen-deficient soils.In maize, a shoot-borne, nodal root system is responsible for the majority of nitrogen uptake, and consists of successive nodes (whorls) of axial roots with multiple orders of lateral branching. These root nodes develop acropetally as leaves emerge, and increase in diameter and number to support exponential shoot growth. My research had three primary objectives: (1) to evaluate the extent of genotypic variation in anatomical phenotypes across root nodes and develop optimal phenotyping strategies under different nitrogen conditions, (2) to identify nodal root traits or trait combinations associated with improved NUpE, and (3) to determine whether variation in root and leaf anatomy are strongly linked, and explore combinations of root and shoot phenotypes which could optimize NUE in maize.
Download or read book Regional Directory written by and published by . This book was released on 2005 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Soil Factors Affecting Corn (Zea Mays L.) Root Growth, Fertilizer Nitrogen Uptake and Nitrogen Leaching Losses in Three Quebec Soils by : Benjamin Caspar Warnaars
Download or read book Soil Factors Affecting Corn (Zea Mays L.) Root Growth, Fertilizer Nitrogen Uptake and Nitrogen Leaching Losses in Three Quebec Soils written by Benjamin Caspar Warnaars and published by . This book was released on 1972 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Soil Factors Affecting Corn (Zea Mays L.) Root Growth, Fertilizer Nitrogen Uptake and Nitrogen Leaching Losses in Three Quebec Soils by : Warnaars, Benjamin Caspar
Download or read book Soil Factors Affecting Corn (Zea Mays L.) Root Growth, Fertilizer Nitrogen Uptake and Nitrogen Leaching Losses in Three Quebec Soils written by Warnaars, Benjamin Caspar and published by 1972 [1973]. This book was released on 1972 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin written by and published by . This book was released on 1971 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
