33,617 research outputs found

    The economic impact of future biological nitrogen fixation technologies

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    The economic impact of some future biological nitrogen fixation technologies are estimated using AGSIM, a dynamic, partial equilibrium, econometric model of the U.S. agricultural sector. Five separate scenarios were modeled: (1) legumes fix more nitrogen, (2) legumes fix more nitrogen with an increase in legumes yields of 10 percent, (3) nitrogen fertilization requirements on all crops are reduced 50 percent with no yield changes, (4) total elimination of nitrogen fertilization and (5) total elimination of nitrogen fertilization and non-legume yields decrease 10 percent. Results indicate that biological nitrogen fixation technologies have a high value to society. Increasing the efficiency of legumes to fix nitrogen may have an annual benefit of 1,067millionwhiledecreasingnitrogenfertilizationby1,706thousandtons.Totaleliminationofnitrogenfertilizationofthecropshasanannualbenefitof1,067 million while decreasing nitrogen fertilization by 1,706 thousand tons. Total elimination of nitrogen fertilization of the crops has an annual benefit of 4,484 million.Crop Production/Industries,

    The Effects of Nitrogen Fertilization and Deficit Irrigation Practices on Tomato Growth and Chlorophyll Concentration

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    Irrigation and fertilization are absolutely necessary in order to increase productivity in agricultural production. Water is the most important source of life on the earth. All living things need absolute water so that they can continue plants life. The fact that the nutrients present in the soil can complete the natural cycle is completely dependent on the water cycle. Irrigation is the amount and time required for the root zone of the plant in soil, which is needed by the plant and cannot enough by precipitation in agriculture. This study was carried out in the farmer\u27s greenhouse conditions between 2004-2005 years. Three different doses of nitrogen (N1:75 ppm N, N2:150 ppm N, N3:225 ppm N) were applied to the tomato plant grown in the greenhouse. S1:100% full irrigation, S2:50% irrigation according to pot capacity. The study was based on a trial randomized block design with 3 replications. At the end of 2 years, the results gave us; the best plant growth was measured with N3S1 an average height by128 cm. The worst plant height was obtained from N1S2 an average height by 88 cm. Plant body diameter has been found between 0,82cm and 0,54cm. Irrigation practices were more effective to total chlorophyll content than the fertilization practices. As a result, the deficit irrigation has also developed as well as full irrigation. Deficit irrigation and nitrogen fertilizer increased crop yield in arid regions.It is suggested that irrigation water can be reduced and adequate fertilization can be increased crop production in arid regions

    Herbage Accumulation and Mass in Massai Grass Plots Mixed with Forage Peanut and Fertilized with Nitrogen

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    The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha-1 of N). Canopy heights of the plots were evaluated weekly and when they reached values of about 50 cm two samples were collected and the total herbage accumulation and mass were calculated. The treatments without nitrogen fertilization and legume had the lowest herbage accumulation and mass (5,080 and 2,060 kg ha-1 of DM, respectively), when compared to the plots that had nitrogen fertilization and legume. The treatments with or without legume but with nitrogen fertilization had the same herbage accumulation and mass (9,775 and 2,630 kg ha-1 of DM, respectively). Thus, the presence of the legume resulted in greater herbage accumulation and mass in relation to those plots without legume and nitrogen fertilization. However, when nitrogen fertilization was performed no additive effect with the presence of the legume was observed, indicating that the nitrogen fertilization somehow inhibited the benefit of the legume on forage production. So, based on the short-term results obtained, the use of nitrogen fertilization or the use of forage peanuts should be done separately

    Effects of nitrogen fertilization on beech and Norway spruce and on the preformed defences of their fine roots against fungal pathogens

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    The main objective of this thesis was to determine the effect of nitrogen fertilization on beech and Norway spruce and on the pre-formed defences of their fine roots to fungal pathogens. I investigated the influence of nitrogen fertilization on root parameters of beech and Norway spruce in field experiments. The plots were situated at three sites in Switzerland on acidic and calcareous soils. For nine years, the trees had been treated with dry ammonium nitrate resulting in 0, 10, 20, 40, 80 and 160 kg N ha-1 year-1, respectively. Fine roots of beech and Norway spruce showed a significant decrease of fungistatic phenolics with increasing nitrogen fertilization. The in vitro growth of Heterobasidion annosum and Cylindrocarpon destructans was inhibited by the presence of most of the fungistatic phenolic compounds in the concentrations found in the roots. In this thesis I also addressed questions about the effect of increased nitrogen fertilization on fine roots of beech growing on different soil conditions. Relative length of fine roots and the root tip density of beech were reduced by nitrogen fertilization on acidic soil but not on calcareous soil. The nutrient concentrations in beech leaves decreased due to increased nitrogen fertilization. I suggest that increased nitrogen deposition may increase the susceptibility of trees to pathogens and may affect the water and nutrient uptake of trees

    Nisbah Daun Batang, Nisbah Tajuk Akar Dan Kadar Serat Kasar Alfalfa (Medicago Sativa) Pada Pemupukan Nitrogen Dan Tinggi Defoliasi Berbeda

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    The study aimed to determine the effect of nitrogen fertilization and defoliation of different height to the leaf stem ratio, shot root ratio and crude fiber content in alfalfa plants (Medicago sativa). This research used factorial randomized block design (FRBD) 4x2 with 3 replicate. The main factor is the dose of nitrogen fertilization (0, 30, 60, 90 kg N/ha), the second factor is the heigth of the defoliation (5 and 10 cm). Parameters measured were leaf stem ratio, shot root ratio and crude fiber content of alfalfa. The results showed that there was no effect of nitrogen fertilization and defoliation high contrast ratio of leaf to stem, shot root ratio and crude fiber content of alfalfa. Data were analyzed with the results of research based on the F test of variance procedure and Duncan's multiple range test. The results showed that there was no effect of nitrogen fertilization and different defoliation height to leaf stem ratio, shoot root ratio and crude fiber of alfalfa. There are indication that leaf stem ratio and shoot root ratio obtained the best results in the treatment of nitrogen fertilization of 30 kg N/ha and defoliation height of 5 cm

    Precision Nitrogen Fertilization Technology with Micro Grids

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    Sensor-based precision fertilizer technologies are being developed and researched by production scientists. One such technology uses normalized difference vegetation index (NDVI) reflectance measurements of growing winter wheat plants and a nitrogen fertilizer optimization algorithm (NFOA) to determine nitrogen requirement necessary for plants to reach their yield plateau. A number of precision fertilizer application systems that use this technology are considered in this paper. A linear response stochastic plateau wheat yield function conditional on NDVI reflectance measurements is estimated and used within an expected profit-maximization framework to estimate upper bounds on the returns from the precision nitrogen application systems. The on-the-go precision system that assumes perfect information was approximately $7 per acre more profitable than the convention of applying 80 pounds of nitrogen prior to planting in the fall. The whole-field precision system was break-even with conventional methods.Research and Development/Tech Change/Emerging Technologies,

    The effects of nitrogen fertilization on the yield and quality of two burley tobacco varieties

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    An experiment was conducted in 1978 at the University of Tennessee Tobacco Experiment Station, Greeneville, Tennessee, to study the effects of nitrogen fertilization on the yield and quality of two hurley tobacco (Nicotiana tabacum L.) varieties, namely Va 509 and Ky 17. The experimental design was a split plot with the rates of nitrogen fertilization being the main plots and the varieties the sub-plots. No significant differences were found for yield, crop index and grade index between the two varieties or among the different nitrogen fertilization rates. The tobacco varieties were not significantly influenced by the nitrogen rates although changing the levels of nitrogen fertilization significantly increased the concentrations of total nitrogen and nico tine and significantly decreased the amount of chloride in the cured leaf. Nitrogen rates had a tendency to decrease leaf potassium and increase leaf calcium but these differences were not significant

    Nitrogen fertilization of soybeans

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    Cover title.Digitized 2007 AES.Includes bibliographical references (page 23)

    Nitrogen fertilization of apples

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    Nitrogen Fertilization in Blackberry

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    Nutrition studies for blackberry crop are scarce worldwide. This chapter presents several aspects of nitrogen (N) in blackberry (Rubus spp.) nutrition. Soil characteristics that can influence nitrogen fertilization are the large discrepancies in the rates recommended in the literature, forms and times of application, sources of nitrogen, differences between cultivars and the main symptoms of N deficiency. The impact of moderate and severe nitrogen deficiency on vegetative growth and yield of ‘Tupy’ blackberry is also presented. In addition, a nitrogen fertilization recommendation system is proposed, based on the organic matter content of the soil, the age of the plants, and the expected productivity of the cultivars
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