Download or read book Nitrogen Use Efficiency in Corn as Affected by Time and Method of Application written by Muhtesem Torun and published by . This book was released on 1992 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrogen Use Efficiency and Yield of Corn Zea Mays L as Affected by Weed Management and Time of Nitrogen Fertilizer Apllication written by Vivas Caraniwan, I and published by . This book was released on 1990 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was conducted to determine the effect of weed control methods and time of nitrogen fertilizer application on yield and nitrogen fertilizer use efficiency of corn and to identify weed control practice(s) and time(s) of nitrogen fertilizer application that promote nitrogen use efficiency and high yield of corn at minimum cost. Weed control methods had no significant effects on all parameters studied except for leaf area index (LAI) and weed fresh weight at 50 DAP. Leaf area indices from W6 (handweeding four times) and W5 (preemergence application of atrazine + pendimethalin + hilling-up) were significantly higher than W1 (off-barring + hilling-up) and W2 (hoeing + hilling-up). W6 gave the mst effective control of weeds based on fresh weed weight at 50 DAP. W2 and W5 provided poor control of weeds. W1 and W4 (preemergence application of pendimethalin + spot hoeing + hilling-up) provided less satisfactory control of weeds than W6 but better control than W3 (preemergence application of atrazine + spot hoeing + hilling-up). The differences in crop LAI and weed control efficacies were not reflected in grain yield and nitrogen use efficiency of the crop indicating that all the six weed control methods provided adequate control of weeds in the trial site. The time of N fertilizer application signifantly affected early crop growth and vigor, days to tasseling and silking, plant and ear height, leaf area index, total dry matter yied, ear kernel filling length, number of kernel rows per ear, number of kernels (...).

Download or read book Nitrogen in the Environment Sources Problems and Management written by R.F. Follett and published by Gulf Professional Publishing. This book was released on 2001-12-03 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen in the Environment: Sources, Problems, and Management is the first volume to provide a holistic perspective and comprehensive treatment of nitrogen from field, to ecosystem, to treatment of urban and rural drinking water supplies, while also including a historical overview, human health impacts and policy considerations. It provides a worldwide perspective on nitrogen and agriculture. Nitrogen is one of the most critical elements required in agricultural systems for the production of crops for feed, food and fiber. The ever-increasing world population requires increasing use of nitrogen in agriculture to supply human needs for dietary protein. Worldwide demand for nitrogen will increase as a direct response to increasing population. Strategies and perspectives are considered to improve nitrogen-use efficiency. Issues of nitrogen in crop and human nutrition, and transport and transformations along the continuum from farm field to ground water, watersheds, streams, rivers, and coastal marine environments are discussed. Described are aerial transport of nitrogen from livestock and agricultural systems and the potential for deposition and impacts. The current status of nitrogen in the environment in selected terrestrial and coastal environments and crop and forest ecosystems and development of emerging technologies to minimize nitrogen impacts on the environment are addressed. The nitrogen cycle provides a framework for assessing broad scale or even global strategies to improve nitrogen use efficiency. Growing human populations are the driving force that requires increased nitrogen inputs. These increasing inputs into the food-production system directly result in increased livestock and human-excretory nitrogen contribution into the environment. The scope of this book is diverse, covering a range of topics and issues from furthering our understanding of nitrogen in the environment to policy considerations at both farm and national scales.

Download or read book Plant Biotechnology written by Agnès Ricroch and published by Springer Nature. This book was released on 2021-08-30 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written in easy to follow language, the book presents cutting-edge agriculturally relevant plant biotechnologies and applications in a manner that is accessible to all. This book updates and introduces the scope and method of plant biotechnologies and molecular breeding within the context of environmental analysis and assessment, a diminishing supply of productive arable land, scarce water resources and climate change. New plant breeding techniques including CRISPR-cas system are now tools to meet these challenges both in developed countries and in developing countries. Ethical issues, intellectual property rights, regulation policies in various countries related to agricultural biotechnology are examined. The rapid developments in plant biotechnology are explained to a large audience with relevant examples. New varieties of crops can be adapted to new climatic conditions in order to reduce pest-associated losses and the adverse abiotic effects

Download or read book Effects of In season Fertilizer Strategies on the Yield and Nitrogen Use Efficiency of Irrigated Corn written by Alexander Soroka and published by . This book was released on 2016 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inefficient use of nitrogen (N) fertilizer in agronomic crop production can lead to water quality concerns and reduced yields for growers. Nitrogen left in the soil after crop harvest is subject to leaching losses to groundwater or gaseous losses to the atmosphere. Split additions of N via sidedressing or fertigation can better time N applications with corn N uptake and improve N use efficiency (NUE). Irrigation can also stabilize yields and raise NUE at decade time scales. The objectives of this study were to 1) quantify the effect of N rate and timing under central pivot irrigation on grain yield and N use efficiency in Delaware using a plot study and 2) investigate the impact of irrigation on yield and NUE in Delaware using historical yield data. A plot study was completed by establishing irrigated corn on well-drained soil which received zero N (control) or 6.72 Mg ha-1 poultry litter, 34 kg ha-1 starter N at planting, and 0, 82, 140, or 198 kg ha-1 of in-season N (applied at sidedress at V5 or via fertigation at V5, V8, V11, and V13). Grain yield was determined for each treatment at harvest using a weigh wagon. Pre-plant soil, post-harvest grain, residue, and in-season soil samples were collected and analyzed to allow calculation of NUE by several methods. Nitrogen application rate affected yields and NUE more than N timing and application when in-season N was applied. Yields of irrigated corn were statistically similar at N rates exceeding 82 kg ha-1; average yields over the study period were 17 Mg ha-1. Partial factor productivity of nitrogen was above 60 kg kg-1 for corn at all N rates except the highest rate. Total aboveground biomass for irrigated corn treatments receiving supplemental N generally contained more N in plant tissue (values ranged from 214 to 254 kg ha-1) than Chesapeake Bay Model Scenario Builder (SB) maximum uptake estimates of 218 kg ha-1. Mass balance estimates of NUE indicated that 13 to 49% of available N applied to plots could not be unaccounted for in plant tissue or soils. The mass balance approach illustrated a trend for increasing unaccounted for N with increasing N rate but, this was only significant in 2014. Leachate concentrations of NO3-N at 60 cm depth were highest in plots receiving supplemental N, with mean concentrations of 7 and 22 mg L-1 NO3-N in 2014 and 2015, respectively. Currently, irrigated land receives an interim credit of 4% reduction in total N in the Chesapeake Bay Model. This reduction is modeled like a filter, where irrigated corn would release 4% less N than comparable rainfed fields. Historical data from University of Delaware corn hybrid variety trials were analyzed to evaluate effects of irrigation on corn yields and NUE over time. Historical yield data and calculated NUE (from variety trials and UD field plot studies) were compared to values in the literature and those used by the Chesapeake Bay Program. In the last two decades, hybrid variety trials met and exceeded the 12.5 Mg ha-1 yield maximum value used in the Chesapeake Bay Model SB. Rainfed plots were 80 and 85% as efficient as irrigated plots in converting applied N to grain yield over the 35 year history of UD corn variety trials. A scenario indicated that irrigated corn could consume 1,030 Mg more N annually than rainfed plots if they were fertilized based on UD N rates for a realistic irrigated yield goal. Based on results of a two-year plot study at UD Warrington Irrigation Farm and analysis of 35 years of yield data from UD variety trials, we make the following preliminary recommendations: 1) lower UD N rate recommendations for high yielding irrigated corn by 15 % to account for increased NUE of irrigated corn and 2) Evaluate if irrigation's NUE would be more appropriately modeled as a separate crop category or, as a BMP. Future research should focus providing data to further refine these recommendations by quantifying NUE at a regional scale. On-farm strip trials could be conducted by UD researchers with a common protocol at multiple locations to evaluate how NUE and yields are affected by irrigation and N management. In addition, we also recommend collection and analysis of leachate and groundwater samples as part of these strip trials to determine risk of N losses at different locations under various soil and management conditions.

Download or read book Soil Science Agricultural and Environmental Prospectives written by Khalid Rehman Hakeem and published by Springer. This book was released on 2016-08-01 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil is the most important natural non-renewable resource developed over a longer period of time due to weathering of rocks and subsequently enrichment of organic matter. Soil provides habitat for numerous microorganisms and serves as a natural medium for plant growth, thereby providing the plants with anchorage, nutrients and water to sustain the growth. Soil also serves as a universal sink for all types of pollutants, purifies ground water and is a major reserve of carbon in the universe. The role of soils to provide ecosystem services, maintenance of environmental/human health and ensuring the food security makes it as the most important and basic natural resource. Soil Science helps us to elaborate and understand how the soils provide all these services. Soil Science also provides us the basic knowledge dealing with the origin of the soil parent material, weathering of parent material and the formation of soils, morphological, physico-chemical and biological features of soils, classification of soils and role of soils in the provision and maintenance of ecosystem services, food security and environmental quality. This book encompasses the various processes, functions and behaviour of soils very comprehensively to acquaint the students of soil, plant and environmental sciences about their role to perform different agricultural and environmental functions.

Download or read book Rice is Life Scientific Perspectives for the 21st Century written by and published by Int. Rice Res. Inst.. This book was released on 2005 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flux and Sources of Nutrients in the Mississippi Atchafalaya River Basin written by and published by . This book was released on 1999 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corn Production and Fate of Fertilizer Nitrogen as Affected by Time and Rate of Nitrogen Application written by William Edward Jokela and published by . This book was released on 1985 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Method of Economic Analysis Applied to Nitrogen Fertilizer Rate Experiments on Irrigated Corn written by James Leo Paschal and published by . This book was released on 1956 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Use of Nitrogen Timing and Nitrification Inhibitors as Tools in Corn and Wheat Production in Kansas written by Timothy J. Foster and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: World population, together with the cost of crop production inputs, is increasing rapidly. The current seven billion people on earth are expected to reach nine billion by 2050 with resulting demands on world food production. In addition, the quality of our environment is being impacted by human activities, including agricultural production and crop fertilization. Nitrogen (N) management is the process of applying N fertilizers in a way to maximize use of N by crops, while minimizing loss to the environment. It is becoming imperative, as a means of increasing crop yields and food supplies, while reducing input usage, and minimizing the impact of N fertilization on the quality of our environment, that improved N application practices be identified and utilized. The objectives for this study were to compare the timing of anhydrous ammonia (AA) fertilizer N applications, fall and spring, with and without two different nitrification inhibitors (NI) as possible tools to enhance yield and Nitrogen Use Efficiency (NUE) in corn (Zea mays) and winter wheat (Triticum aestivum L.) in Kansas. Two different nitrification inhibitors were tested as alternatives, N-Serve (nitrapyrin) produced and marketed by Dow AgroSciences, and an experimental product under development by Koch Agronomic Services LLC. Three differing rates of the experimental product were used to assist in determining the optimal rate for this product. The study was conducted over two growing seasons, 2012 and 2013, which differed significantly in rainfall, rainfall distribution, and resulting NUE. Experiments were established at three sites for both crops in both years, on sites/soils selected for differing potentials for N loss, and mechanisms of N loss. One site was established at the Kansas State University Agronomy North Farm (N Farm), where yield potential was high, and N loss potential was low. A second site was established under irrigation at the Kansas River Valley Experiment Field near Topeka, KS (KRV), on a coarse silt loam soil with high potential for N loss through leaching. The third site was established at the East Central Kansas Experiment Field near Ottawa KS (ECK), on a clay pan soil with a high potential for denitrification loss. Weather conditions together with soil characteristics played a major role in the performance of N timing applications and impacted the response to the use of the inhibitors. In low N loss environments such as the N Farm, fall applications of AA to increase spring time-availability for producers showed minimal negative effects on yield or NUE. When combined with a nitrification inhibitor in the fall, performance was similar to spring application for both corn and wheat. At the KRV site leaching loss or potential loss from fall application was high for corn and wheat in both years, however little impact on NUE with NI use was observed. At the high ECK denitrification site, there was only one N loss potential event leading to inhibitor performance at Ottawa in corn in 2013.

Download or read book Predicting N Fertilizer Needs for Corn in Humid Regions written by and published by . This book was released on 1992 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Rate and Time of Nitrogen Fertilization on Corn and the Use of Chlorophyll and Nitrogen Analysis as a Guide method to Soil Nitrogen Status written by Rodolfo Plinio Peregrina and published by . This book was released on 1952 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrogen in Agricultural Systems written by James Stuart Schepers and published by ASA-CSSA-SSSA. This book was released on 2008 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: Review of the principles and management implications related to nitrogen in the soil-plant-water system.

Download or read book Dark Green Color Index as a Method of Real time In season Corn Nitrogen Measurement and Fertilization written by Upton Gardner Siddons and published by . This book was released on 2013 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season. Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated with leaf nitrogen concentration. Our objectives were: (1) to develop quantitative relationships among yield, corn leaf nitrogen concentration, and DGCI measurements taken in the mid-vegetative stages of growth development; and (2) to determine the amount of nitrogen to apply to recover yield based upon DGCI measurements on 6-leaf corn (V6). Various corn hybrids were planted across two years in Arkansas. A wide range of N applications were made at emergence and at V6 stage. SPAD, DGCI, and leaf nitrogen measurements were taken prior to V6 application and again at tasseling. Leaf nitrogen concentrations, DGCI, and SPAD were found to be closely associated. Crops with varying early-season N deficiencies demonstrated a non-linear, quadratic response to V6 N applications. Combining the responses of yield to V6 N application amounts with concurrent mid-season DGCI measurements allowed for the development of calibration equations. These calibrations equations allow corrective, mid-season N applications to be made based on an observed DGCI value, which allows for the recovery of 90 or 95% of the crop's yield potential.

Download or read book OECD Compendium of Agri environmental Indicators written by OECD and published by OECD Publishing. This book was released on 2013-06-25 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive data and analysis on the environmental performance of agriculture in OECD countries since 1990, covering soil, water, air and biodiversity and looking at recent policy developments in all 34 countries.

Download or read book Managing Nitrogen for Groundwater Quality and Farm Profitability written by Ronald F. Follett and published by . This book was released on 1991 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: