Download or read book Final Report written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Increasing Nitrogen Use Efficiency in Corn Production Systems Quantifying Effects of Quality of Soil Structure and Water Regimes written by and published by . This book was released on 2001 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of the research reported in this paper was to develop measures of the quality of soil structure for the mineralization of organic nitrogen and for the uptake of mineral nitrogen by corn. Plant & microbiological response to varying water contents in soils of different structure were used to define measures of the quality of soil structure. Plant response was characterized in controlled environments using gas exchange measurements. Microbiological response was characterized using measurements of net nitrogen mineralization after incubating the soil under controlled environment with & without an amendment of red clover residue. Measurements with plants were made at different stages of plant development from early vegetative to grain-filling and under different water regimes. The study results demonstrated the utility of characterizing the structural quality of soils using least-limiting water ranges derived from a combination of plant-derived gas exchange measurements and measurements of net nitrogen mineralization. The long term goal of the research is to use measure of the quality of soil structure & water regimes, in conjunction with measures of potentially available nitrogen, to develop more accurate recommendations for fertilizer nitrogen applications and thereby increase nitrogen use efficiency.

Download or read book Soil Fertility in Calcareous Tropical Soils from Yucatan Mexico and Villa Clara Cuba Affected by Land Use and Soil Moisture Effects written by Edith Aguila Alcantara and published by Cuvillier Verlag. This book was released on 2007 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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. " --

Download or read book Soil Greenhouse Gas Emissions and Nitrogen Use Efficiency in Corn Zea Mays L as Affected by Nitrogen Management written by Amal Roy and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Irrigation Water and Nitrogen on Physiological Traits Yield and Quality of Silage Corn written by Abdelaziz Nilahyane and published by . This book was released on 2016 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field studies on corn for silage were conducted at the University of Wyoming Research and Extension Center located in Powell, Wyoming during 2014 and 2015 growing seasons. The objectives of the study were to: determine the effect of irrigation water and nitrogen (N) on growth, yield, and water use efficiency (WUE) of corn for silage grown under sub-surface drip irrigation (SDI) and on-surface drip irrigation (ODI) systems; determine the effect of irrigation strategies and N on dry matter (DM) yield and nutritive value of corn for silage grown under both SDI and ODI systems; investigate the effect of limited water on growth, physiological attributes, and WUE of corn for silage; and evaluate irrigation water and N management strategies of corn for silage at multiple locations using a simulation approach. The field studies were laid out as a randomized complete block design in a split-plot arrangement with four replications under the SDI and three replications under the ODI. Irrigation was the main treatment and included three strategies based on the crop evapotranspiration (ETc): full irrigation (100ETc), 80ETc, and 60ETc. Nitrogen was the sub-treatment and included 0, 90, 180, 270, and 360 kg N ha−1 as urea-ammonium-nitrate aqueous solution. Results showed that irrigation water and N fertilization strategies affected canopy height, leaf area index (LAI), DM yield, WUE, and irrigation WUE of corn for silage under SDI and ODI systems. The effect of irrigation water was significant during the late vegetative and early reproductive growth stages, suggesting that these are the critical stages to avoid water stress. The combination of 80ETc and 180 kg N ha−1 worked well and could be used for silage corn production in semi-arid conditions. Under SDI, the irrigation water strategies did not affect the nutritive value of corn for silage. On the other hand, significant effect of N rates on crude protein (CP), acid detergent fiber (ADF), and total digestible nutrients (TDN) was observed. Similarly, the irrigation water strategies under the ODI showed little to no effect on the nutritive value of corn for silage. Our results showed no effect of N on nutritive value of corn for silage when delivered via ODI. Data suggests that 200 kg N ha−1 and 253 mm of seasonal water use and 180 kg N ha−1 and 280 mm of seasonal water use might be optimal combinations for yield and nutritive value of corn for silage grown under SDI and ODI systems, respectively. The crop physiological responses to water showed that water stress during the period from V14 to R2 growth stages affected photosynthesis, stomatal conductance, and transpiration rates, indicating that these stages are critical to water needs of corn for silage. The simulated results indicated that irrigation water and N fertilizer rate affected LAI, aboveground biomass, N uptake, and WUE of silage corn grown at different locations in Wyoming. The simulated results indicated 100ETc × 180 kg N ha−1 as most suitable for high yield production of silage corn across locations in Wyoming. The model outputs for scenario of no water and N limitations (potential yield) suggested that an increase to as much as 61% on corn biomass could be achieved if irrigation water and N practices are well managed. Overall, results from field research and those from simulations suggest that irrigation water strategy, N fertilizer rate, and timing are key factors affecting growth, yield, and physiology of corn for silage grown in the semi-arid conditions in Wyoming.

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 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 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 A Hitchhiker s Guide to Statistics in Plant Biology written by Stephen R. Bowley and published by Guelph, Ont. : Any Old Subject Books. This book was released on 1999-01-01 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adoption of Nitrogen Efficient Eco innovations by United States Corn Farmers written by Catharine Elizabeth Weber and published by . This book was released on 2014 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenically introduced nitrogen has compromised environmental quality, but is an essential element for crop production, particularly corn production. Increasing nitrogen use efficiency by adopting eco-innovations such as nitrogen soil testing, plant tissue testing and nitrogen transformation inhibitors can ameliorate this problem. Data from the 2010 USDA Agricultural Resource Management Survey of corn producers was used to examine the factors affecting adoption of these practices. Twenty-one percent of the 1840 corn farmers had adopted nitrogen soil testing, three percent had adopted plant tissue testing and ten percent had adopted nitrogen inhibitors. A multivariate probit regression found significant results for each category of explanatory variable that was examined. Older farmers were less likely to adopt nitrogen soil testing and nitrogen inhibitors. Farmers who did not obtain external nitrogen recommendations were less likely to adopt all three practices than farmers who received recommendations from a crop consultant. Those who received recommendations from fertilizer dealers were less likely to adopt nitrogen soil testing. Those who indicated that high prices influenced their decision to plant corn on that field were more likely to adopt plant tissue testing but less likely to adopt the other two practices. All regions were more likely to adopt nitrogen soil testing than the Midwest. Those who adopted conservation tillage were more likely to adopt nitrogen inhibitors and those who received conservation payments were more likely to adopt nitrogen soil testing and plant tissue testing. Adoption was also associated with the adoption of several other technologies.

Download or read book Water Resources Research Catalog written by and published by . This book was released on 1970 with total page 1860 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improving Fertilizer Nitrogen Use Efficiency Using Alternative Legume Interseeding in Continuous Corn Production Systems written by Dale Alan Keahey and published by . This book was released on 1997 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contrasting Soil Management Practice Nitrogen Source and Harvest Method Effects on Corn Production in Ohio and Tennessee written by Casey Theresa Sullivan and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current global agricultural production is completed with little regards to sustainable soil use. It is clear that the research and use of sustainable management practices must be expanded in order to preserve this natural resource. The objectives of this research were to focus on improving soil fertility and resource use efficiency by 1) evaluating farm management practices to find those that conserve soil and improve yields, 2) looking at alternative methods of fertilizing through the reuse of waste materials in agriculture. The last objective was to 3) test a more efficient method data collection and research production, resulting in more rapid outreach and use of sustainable methods. A study initiated in May 2015 in Ohio compared no-till (NT) and tillage (T) management practices by examining the release of preserved nitrogen (N) from a soil that has been under long-term no-till corn and soybean production. Crop N sufficiency and yields from the T and NT treatments were compared at varying urea application rates. The results showed that the T whole plot consistently provided higher N uptake, crop productivity, and yields when compared to the NT whole plot, but results may have been influenced by unusually high rainfall following fertilizer application. A study initiated in May 2015 in Tennessee tested the use of an industrial byproduct, spent microbial biomass (SMB) as a potential N source for corn. The biomass was compared at varying rates to the current farmer urea application rate. Nitrogen availability and crop uptake was compared within the treatments and no significant differences between the urea treatment and SMB treatment yields were found, indicating that SMB could offer a sufficient source of N in local corn production. To improve efficiency in corn research and data collection, a reduced effort hand-harvest method was compared to the currently accepted method in the Ohio and Tennessee studies. Yields extrapolated using the ten plant harvest method and the current hand harvest method were not found to be significantly different in either study (p>0.05). These results indicate the potential use of this method in future maize studies to improve project efficiency and increase research production.

Download or read book Effects of Nitrogen Population and Hybrid on the Yield and Quality of Irrigated Corn for Silage on Providence Soil written by and published by . This book was released on 1974 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: