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Search Results: 1 - 10 of 6729 matches for " nitrogen fertilizer "
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The effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer  [PDF]
Gholam Reza Mohammadi, Mohammad Eghbal Ghobadi
Agricultural Sciences (AS) , 2010, DOI: 10.4236/as.2010.13018
Abstract: A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pesticides. This period is an ideal time to establish a cover crop. In order to investigate the effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer, field studies were carried out during the 2007-2008 growing season at the Agricultural Research Farm, Razi University, Kermanshah, Iran. The experiment was conducted in a split plot arrangement based on a randomized complete block design with three replications. The main plots consisted of four cover crops including alfalfa (Medicago sativa L.), berseem clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.) and winter rye (Secale cereale L.) and a control (no cover crop). The sub plots consisted of two fertilizer N rates (0 and 250 kg ha-1). Cover crops were grown for nearly 5 months and then were incorporated into the soil as green manures. The results indicated that corn plant traits including seed yield, the number of seeds per ear and leaf chlorophyll content were significantly influenced by cover crops. Whereas, the cover crops had no signif-icant effects on the number of ears per plant, 100-seed weight and harvest index of corn. Among the cover crop species, common vetch produced higher dry weight and showed the highest positive effects on the corn plant traits. Dry weight produced by this cover crop was 56.41, 120.16 and 124.19% higher than those of winter rye, berseem clover and alfalfa, respectively. Common vetch enhanced seed yield, the number of seeds per ear and leaf chlorophyll content of corn by 46.30, 21.95 and 8.52%, respectively, compared to control. All of the corn traits under study, except the number of ears per plant and harvest index were significantly improved by nitrogen fertilizer. In general, this study revealed that the autumn-seeded cover crops, especially common vetch can be used to improve corn yield. However, the cover crops should be supplemented with nitrogen fertilizer to obtain optimal results.
Crescimento e produtividade da bananeira cv. Grande Naine sob diferentes combina??es de nitrato de cálcio e ureia
Alves, Márcio da Silva;Coelho, Eugênio Ferreira;Paz, Vital Pedro da Silva;Andrade Neto, Torquato Martins de;
Revista Ceres , 2010, DOI: 10.1590/S0034-737X2010000100020
Abstract: the use of nitrogen sources through fertigation requires improved techniques so that farmers may obtain maximum economic benefit combined with lower soil impact. the objective of this work was to evaluate different combinations of two nitrogen sources applied by fertigation on the growth and yield of banana cv. grand naine during the first, second and third production cycles. the experiment was arranged in a randomized block design with five replications, where six complementary percentages of urea and nitrate were applied by irrigation water in a drip irrigation system. plant height, pseudostem diameter, total leaf área, productivity, fruit length and diameter of the second bunch were evaluated. results showed that the combination of different nitrogen sources applied by fertigation did not affect the growth and yield of cv. grand naine.
Impacts of Land Use, Fertilizer and Manure Application on the Stream Nutrient Loadings in the Salmon River Watershed, South-Central British Columbia, Canada  [PDF]
Zhanxue Zhu, Klaas Broersma, Asit Mazumder
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.328096
Abstract: Manure and fertilizer applications can increase soil productivity and land economic values, but the controversial result can be a decline of water quality due to the increased nutrient exports from soils to the streams. The impacts of landuse, manure and fertilizer application on nutrient exports from soils to the streams were analyzed using the SWAT (Soil Water Assessment Tool) model for the Salmon River watershed in south-central British Columbia, Canada. The results showed that the animal farms had the highest rates of nutrient exports from soils to the streams and the natural forested lands had the lowest. It was estimated that the whole Salmon River watershed would export approximately 11.52 t·yr-1 of organic nitrogen (ON), 8.05 t·yr-1 of nitrate nitrogen (NO3-N), 2.30 t·yr-1 of organic phosphorus (OP) and 1.36 t·yr-1 of soluble reactive phosphorus (SRP) if the whole watershed was covered by natural vegetation without human disturbance. Current landuse changes, by converting natural vegetation lands to agriculture and animal farms and associated manure and fertilizer applications, have in-creased approximately 53.30 t·yr-1 of ON, 9.68 t·yr-1 of NO3-N, 22.69 t·y-1 of OP and 6.23 t·y-1 of SRP exports to the streams in the whole watershed. The SWAT model predicted that a daily 100 kg·ha-1 of fresh manure deposit from grazing cows during grazing season from later spring to later fall could increase 2.57 kg·ha-1·yr-1 of ON, 0.39 kg·ha-1·yr-1 of NO3-N, 2.35 kg·ha-1·yr-1 of OP and 0.48 kg·ha-1·yr-1 of SRP export to the streams. Fertilization could increase 1.57 kg ha-1 yr-1 of ON and 4.02 kg·ha-1·yr-1 of NO3-N export to the streams if 100 kg·ha-1·yr-1 of nitrogen (NH4NO3) fertilizer was applied in spring. Also fertilization could increase 1.18 kg·ha-1·yr-1 of OP and 0.20 kg·ha-1·yr-1 of SRP export to the streams if 100 kg·ha-1 phosphorus (P2O5) fertilizer was applied in spring.
Influence of Nitrogen Fertilizer and Foliar Application of Salicylic Acid on Wheat  [PDF]
Omar Maghawry Ibrahim, Bakry Ahmed Bakry, Alice Tawfeek Thalooth, Mohamed Farouk El-Karamany
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.513140
Abstract:
Two cemented plots experiments were carried out during the winter seasons of 2012/2013 and 2013/2014, Soil Salinity Laboratory, Alexandria, Egypt, to study the effect of three levels of salicylic acid (SA) (0, 50, 100 ppm) and three rates of nitrogen fertilizer (75, 100, 125 kg N/feddan) on yield and yield components of wheat (Sakha 93). The experimental design was split plot with four replicates. The results indicated that increasing nitrogen fertilizer rates resulted in significant increase in plant height (cm), number of grain/spike, number of spikes/m2, 1000 grain weight (gm), grain yield (gm/plot), straw yield (gm/plot), and biological yield (gm/plot). Increasing salicylic acid rates resulted in significant increase in all the previous characters, in addition to grain weight/spike (gm). The interactions had no significant effect on the studied characters. The path analysis revealed that 1000 grain weight was the most important character with direct effect of 0.54 followed by number of spikes/m2 with direct effect of 0.33 followed by number of grain/spike with direct effect of 0.16.
Productivity and Dry Matter Accumulation of Sugarcane Crop under Irrigation and Nitrogen Application at Rio Verde GO, Brazil  [PDF]
Alefe Viana Souza Bastos, Renato Campos de Oliveira, Nelmício Furtado da Silva, Marconi Batista Teixeira, Frederico Antonio Loureiro Soares, Edson Cabral da Silva
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.614240
Abstract: Dry matter production and productivity of stem currently are being widely studied in sugarcane, reinforcing the study in question, which aims to assess the accumulation of dry matter of the aerial segment and the productivity of stems of sugarcane crops within the first cycle, at different levels of water replacement (WR) with and without nitrogen fertilization, through a subsurface drip irrigation system. The assay was conducted in the experimental area of the Federal Institut Goiano, Campus Rio Verde, GO, Brazil, in a dystroferric Rhodic Hapludox soil, cerrado phase (savannah), and comprised experimental splits of three furrows with an 8-meter long double row. Experimental design consisted of randomized blocks in a 5 × 2 factorial array, with four replications. Evaluated factors comprised five levels of WR (100%, 75%, 50%, 25% and 0% of field capacity), with and without the application of nitrogen (0 and 100 kg·ha-1 urea). Harvest occurred in May 2013 and stem productivity (SP), productivity of pointers (PP), productivity of straw (PS), harvest index (HI), dry matter of stem (DMS), dry matter of pointers (DMP), the relationship between dry matter of pointer and dry matter of stem (DMP/DMS) and total dry matter of the aerial segment (TDM) were determined. The variables SP, PP, DMS and DMP had a linear growth in proportion to WR increase, whereas HI and DMP/DMS adjusted to a quadratic model. Nitrogen fertilization affected positively the variables SP, HI, DMS and DMP/DMS and occurred interaction to TDM; also increasing the productivity stem and the harvest index.
Volatiliza??o de N-NH3 de fontes nitrogenadas em cana-de-a?úcar colhida sem despalha a fogo
Costa, M. C. G.;Vitti, G. C.;Cantarella, H.;
Revista Brasileira de Ciência do Solo , 2003, DOI: 10.1590/S0100-06832003000400007
Abstract: where sugarcane is harvested without burning, a thick layer of straw remains on the soil. this crop residue modifies the agroecosystem and requires a reformulation of the crop management. urea is the most common nitrogen source for sugarcane but, when applied on top of the crop residue, nh3-nloss rates are high. this work was carried out under field conditions in the sugarcane production region of piracicaba, state of s?o paulo, brazil, on an arenic kanhaplodult, using the third rattoon of the variety sp 80-1842, harvested mechanically without previous burning. the objective of this study was to evaluate the agronomic efficiency of nitrogen sources applied over sugarcane trash by the determination of nh3-n losses by volatilization, crop yield and quality. the nitrogen rate was 100 kg ha-1. the experimental design was in completely randomized blocks with five replications and five treatments: t0- control, t1- urea, t2- uran, t3- urea + ammonium sulfate, t4-liquid residue enriched with n. static semi-open nh3 collectors were used to evaluate losses by ammonia volatilization. the results showed that nh3-n losses were higher in t1 and t3 (36 and 35 %, respectively), and lower in t2 and t4 (15 and 9 %, respectively). sugarcane yields were affected by the nitrogen fertilization as well as by volatilization losses.
GROWTH OF Inga vera WILLD. SUBSP. Affinis UNDER RIZOBIA INOCULATION
Maia,Julio; Scotti,Maria Rita;
Revista de la ciencia del suelo y nutrición vegetal , 2010, DOI: 10.4067/S0718-27912010000200005
Abstract: nitrogen, in general, is the largest limiting plant growth nutrient in the tropics and is required as a synthetic fertilizer to improve plants productivity. therefore, studies aiming in understanding and using nitrogen fixation by leguminous trees have been done as a low-cost alternative for chemical fertilizer. native legume trees such as inga vera have been recommended in the rehabilitation of degraded areas due their ability to establish symbiosis with nitrogen fixation organisms replacing nitrogen fertilization. these species are able to increase soil organic matter, nitrogen and phosphorus availability. thus, the present study aims to assess the inoculation effects of native rhizobia strains on nodulation, dry matter production, nitrogen and phosphorus leaf incorporation in i. vera seedlings. with this purpose, four strains were obtained from inga nodules and tested in a greenhouse. the inoculation of i, vera seedlings with native rhizobium strains promoted an increase in shoot dry mass as well as in leaf nitrogen content. according to symbiotic efficiency equation, this approach ranged from 50 to 80% indicating that the nitrogen fertilization for this species can be partially replaced by rhizobia inoculation.
Nitrification Inhibition in Soil and Ecosystem Functioning An Overview
F. Azam,S. Farooq
Pakistan Journal of Biological Sciences , 2003,
Abstract: Form (NH4 or NO3) and availability of N has significant implications to the functioning and sustainability of agroecosystems. Most of the fertilizer nitrogen (N) applied to agricultural soils is in the form of NH4 or NH4-forming fertilizers. This form of N is rapidly oxidized to NO3 by nitrifying microorganisms leading to significant losses of N through NO3-leaching and denitrification. Both denitrification and NO3-leaching have environmental implications and economic concerns. Strategies have therefore been sought to regulate the process of nitrification leading to its complete or partial inhibition. Indeed, climax ecosystems are developed in such a way that the process of nitrification is already fairly inhibited. This paper presents an overview on: I) the process of nitrification, ii) microorganisms involved, iii) the implications of nitrification and nitrification inhibition to ecosystem functioning and finally iv) the methods to inhibit nitrification.
Effect of Different Nitrogen Applications on Fatty Acid Composition of Rapeseed Cultivars Grown in the Region of Southeast Anatolia
Davut Karaaslan,Mensure ozguven
Pakistan Journal of Biological Sciences , 2001,
Abstract: This study was carried out to determine the effect of different nitrogen fertilizers (0, 8, 16 and 24 kg N/da) on oil quality of winter (cv. Askona, Karola and Silvia) and spring rapeseed (cv. Lirawell, Semu 86/225 Na and Westar). The experiment was conducted in the research area of the Field Crops Department, Faculty of Agriculture, Dicle University in the 1995-1996 and 1996-1997 winter growing season in Diyarbakir. Fatty acid composition was not affected by N doses, but it varied among cultivars. The composition of the fatty acid of the rapeseed cultivars was 4.07-4.21% palmitic acid, 0.288-0.320% palmitoleic acid, 2.12-2.28% stearic acid, 65.60-66.58% oleic acid, 16.44-18.62% linoleic acid, 6.40-7.01% linolenic acid and 1.27-2.01% eicosenic acid.
GROWTH OF Inga vera WILLD. SUBSP. Affinis UNDER RIZOBIA INOCULATION
Julio Maia,Maria Rita Scotti
Revista de la Ciencia del Suelo y Nutrición Vegetal , 2010,
Abstract: Nitrogen, in general, is the largest limiting plant growth nutrient in the tropics and is required as a synthetic fertilizer to improve plants productivity. Therefore, studies aiming in understanding and using nitrogen fixation by leguminous trees have been done as a low-cost alternative for chemical fertilizer. Native legume trees such as Inga vera have been recommended in the rehabilitation of degraded areas due their ability to establish symbiosis with nitrogen fixation organisms replacing nitrogen fertilization. These species are able to increase soil organic matter, nitrogen and phosphorus availability. Thus, the present study aims to assess the inoculation effects of native rhizobia strains on nodulation, dry matter production, nitrogen and phosphorus leaf incorporation in I. vera seedlings. With this purpose, four strains were obtained from inga nodules and tested in a greenhouse. The inoculation of I, vera seedlings with native rhizobium strains promoted an increase in shoot dry mass as well as in leaf nitrogen content. According to symbiotic efficiency equation, this approach ranged from 50 to 80% indicating that the nitrogen fertilization for this species can be partially replaced by rhizobia inoculation.
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