scholarly journals Response of some yellow maize crosses to N- fertilizer rates and plant densities at Toshka Region

2016 ◽  
Vol 38 (3) ◽  
pp. 337-354
Author(s):  
Abdelmoniem Awadalla ◽  
Ahmed Salah Morsy
2021 ◽  
Vol 182 ◽  
pp. 105997
Author(s):  
Davide Cammarano ◽  
Bruno Basso ◽  
Jonathan Holland ◽  
Alberto Gianinetti ◽  
Marina Baronchelli ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 395
Author(s):  
Alex J. Lindsey ◽  
Adam W. Thoms ◽  
Marshall D. McDaniel ◽  
Nick E. Christians

Soil health and sustainable management practices have garnered much interest within the turfgrass industry. Among the many practices that enhance soil health and sustainability are applying soil additives to enhance soil biological activity and reducing nitrogen (N) inputs—complimentary practices. A two-year study was conducted to investigate if reduced N fertilizer rates applied with humic substances could provide comparable turfgrass quality as full N rates, and whether humic fertilizers would increase biological aspects of soil health (i.e., microbial biomass and activity). Treatments included synthetic fertilizer with black gypsum (SFBG), poly-coated humic-coated urea (PCHCU; two rates), urea + humic dispersing granules (HDG; two rates), urea, stabilized nitrogen, HDG, and a nontreated control. Reduced rates of N with humic substances maintained turfgrass quality and cover, and reduced clipping biomass compared to full N rates. There were no differences in soil physical and chemical properties besides soil sulfur (S) concentration. SFBG resulted in the highest soil S concentration. Fertilizer treatments had minimal effect on microbial biomass and other plant-available nutrients. However, PCHCU (full rate) increased potentially mineralizable carbon (PMC) and N (PMN) by 68% and 59%, respectively, compared to the nontreated control. Meanwhile SFBG and stabilized nitrogen also increased PMC and PMN by 77% and 50%, and 65% and 59%, respectively. Overall, applications of reduced N fertilizer rates with the addition of humic substances could be incorporated into a more sustainable and environmentally friendly turfgrass fertilizer program.


2014 ◽  
Vol 94 (2) ◽  
pp. 425-432 ◽  
Author(s):  
R. E. Karamanos ◽  
K. Hanson ◽  
F. C. Stevenson

Karamanos, R., Hanson, K. and Stevenson, F. C. 2014. Nitrogen form, time and rate of application, and nitrification inhibitor effects on crop production. Can. J. Plant Sci. 94: 425–432. Nitrogen management options for anhydrous ammonia (NH3) and urea were compared in a barley–wheat–canola–wheat cropping sequence (2007–2010) at Watrous and Lake Lenore, SK. The treatment design included a factorial arrangement of N fertilizer form (NH3versus urea), nitrification inhibitor application, time of N application (mid-September, mid- to late October, and spring) and four N fertilizer rates (0, 40, 80 and 120 kg ha−1). Anhydrous ammonia applications at 40 kg N ha−1in 2008 (fall) and in 2010 (all times of application) resulted in wheat yield reductions relative to the same applications for urea. For wheat years, yield was reduced for both fall versus spring N fertilizer applications, when no nitrification inhibitor was applied and the inclusion of nitrification inhibitor maintained wheat yield at similar levels across all times of N fertilizer applications, regardless of form. Protein concentration was approximately 2 g kg−1greater with urea compared with NH3at both sites in 2008 and only at Watrous in 2010. Also, early versus late fall N fertilizer applications consistently increased N concentration of grain only for the 40 and/or 80 kg N ha−1rates. Effects of nitrification inhibitor on N concentration were not frequent and appeared to be minimal. Urea had greater agronomic efficiency (AE) than NH3at the lower N fertilizer rates. The nitrification inhibitor had a positive effect on wheat AE only for early fall N fertilizer applications. It can be concluded that for maximum yields NH3or urea will be suitable if applied at rates of 80 kg N ha−1and greater. If N fertilizer is applied at 40 kg N ha−1, especially in fall without inhibitor, urea is better. In terms of protein concentration for wheat, urea seemed to better than NH3and fall was better than spring application.


2001 ◽  
Vol 1 ◽  
pp. 22-29 ◽  
Author(s):  
S. Kuo ◽  
B. Huang ◽  
R. Bembenek

Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during the high N leaching period for vetch cover crop treatment and for the control without the cover crops. The correlation, however, failed for other cover crops largely because of variable effectiveness of the cover crops in reducing NO3leaching during the 5 years of this study. Further research is needed to determine if relay cover crops planted into standing summer crops is a more appropriate approach than fall seeding in this region to gain sufficient growth of the cover crop by fall. Testing with other main crops that have earlier harvest dates than corn is also needed to further validate the effectiveness of the bicultures to increase soil N availability while protecting the water quality.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zerihun Sinta ◽  
Gezahegn Garo

Ethiopia is endowed with diverse agroecologies suitable for the production of tropical, subtropical, and temperate vegetables. Agronomic practices such as plant density and fertilizer management are known to affect the crop environment, which influences the growth and ultimately the yield. So far limited research has been done on plant density determination and rate of nitrogen fertilizer in Ethiopia in general and the study area in particular. Thus, this experiment was carried out to evaluate the influence of plant density and nitrogen fertilizer rates on the yield and yield components of beetroot (Beta vulgaris L.). Four plant densities (133 333, 100 000, 80 000, and 66 666 plants per hectare) and four nitrogen (N) fertilizer rates (0, 46, 92, and 138 kg N ha−1) were arranged in a factorial combination in a randomized complete block design with three replications. The results revealed that the main and interaction effects of plant density and nitrogen fertilizer rates on total root yield, root length, root fresh weight, root diameter, and total soluble solute of beetroot were significant. The highest root yield of beetroot was achieved from the combination of 66 666, 80 000, and 10 0000 plant ha−1 with 92 kg N ha−1, whereas the lowest root yield of beet was obtained from the combination of 0 kg N ha−1 with a planting density of 133 333 plants ha−1. The economic analysis showed that higher net benefit and marginal rate of return were obtained from the application of 92 kg N ha−1 with plant densities of 66 666 plants ha−1. In order to prevent excessive production costs, the use of 66 666 plants ha−1 combined with the application of 92 kg N ha−1 is recommended.


1968 ◽  
Vol 48 (1) ◽  
pp. 85-88 ◽  
Author(s):  
T. Lawrence ◽  
F. G. Warder ◽  
R. Ashford

The effects of six rates of N fertilizer and five frequencies of clipping on the nitrate content of forage from intermediate wheatgrass, Agropyron intermedium (Host.) Beauv., were studied throughout the 1965 growing season.The nitrate content of the forage increased with increasing rates of N fertilizer, and varied with date of harvest. Toxic levels of nitrates (> 2,000 ppm) were found during the period June 5 to July 17 in samples harvested from grass which had been fertilized with 300 and 375 kg/ha of N fertilizer in the spring. Toxic levels were not found in samples from grass fertilized at lower rates. There was an interaction between frequency of clipping and fertilizer rates. At low fertilizer rates the nitrate content of the forage increased as the frequency of clipping was increased, but at the 375-kg/ha rate of fertilizer the opposite was true.It is suggested that fertilizer rates’ in excess of 225 kg/ha N (200 lb/ac N) may result in toxic levels of nitrate in intermediate wheatgrass.


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