Significance of timing and method of N fertilizer application for the N-use efficiency in flooded tropical rice

1995 ◽  
Vol 42 (1-3) ◽  
pp. 129-138 ◽  
Author(s):  
H. F. Schnier
2013 ◽  
Vol 93 (6) ◽  
pp. 1073-1081 ◽  
Author(s):  
E. N. Johnson ◽  
S. S. Malhi ◽  
L. M. Hall ◽  
S. Phelps

Johnson, E. N., Malhi, S. S., Hall, L. M. and Phelps, S. 2013. Effects of nitrogen fertilizer application on seed yield, N uptake, N use efficiency, and seed quality of Brassica carinata . Can. J. Plant Sci. 93: 1073–1081. Ethiopian mustard (Brassica carinata A. Braun) is a relatively new crop in western Canada and research information on its response to N fertilizer is lacking. Two field experiments (exp. 1 at 3 site-years and exp. 2 at 4 site-years) were conducted from 2008 to 2010 in Saskatchewan and Alberta, Canada, to determine effect of N fertilizer application on Brassica carinata plant density, seed and straw yield, N uptake in seed and straw, N use efficiency (NUE), N fertilizer use efficiency (NFUE) and seed quality. N rates applied were 0 to 160 kg N ha−1 and 0 to 200 kg N ha−1 in exps. 1 and 2, respectively. Plant density was not affected by increasing N rate at 5 site-years but declined with high rates of N application at 2 site-years. Seed yield responded to applied N in 6 of 7 site-years, with the non-responsive site having a high total N uptake at the 0 kg N ha−1 rate (high Nt value). There were no sites where seed yields were maximized with the N rates applied. Response trends of straw yield and N uptake were similar to that of seed yield at the corresponding site-years. NUE and NFUE generally declined as N rate increased. Protein concentration in seed generally increased and oil concentration in seed decreased with increasing N rates. In conclusion, the responses of seed yield, total N uptake, NUE, and NFUE to applied N was similar to those reported in other Brassica species with the exception that a rate was not identified in which Brassica carinata yields were maximized.


Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Xiukang Wang ◽  
Yingying Xing

The purpose of this study is to investigate the interactions between irrigation and fertilizer treatments on soilNO3--N content and vertical distribution under drip fertigation in greenhouse tomatoes. Randomized block design with three replications and the treatments consisting of three levels of irrigation and three levels of N fertilizer were used. Three irrigation levels were W1 (100%  ET0), W2 (75%  ET0), and W3 (50%  ET0) and fertilizer levels were F1 (N240–P2O5120–K2O150 kg hm−2), F2 (N180–P2O590–K2O112.5 kg hm−2), and F3 (N120–P2O560–K2O75 kg hm−2). The result demonstrates that dynamics of soilNO3--N and its response to drip fertigation and levels of N moved toward the fore soil moist, and the average soilNO3--N content with W3 treatment was 1.23 times higher than that of the W1 treatment in 0–60 cm at 43 days after transplanting. The negative correlation between N use efficiency and levels of fertilizer N and the N recovery efficiency was increased with increases of N fertilizer application. The fertilizer nitrogen rate greatly significantly influenced soilNO3--N content. Avoiding N leaching through controlled matching N fertilizer application and controlled irrigation to tomato N demand is the key to maintain crop yield and improve N use efficiency.


Crop Science ◽  
2014 ◽  
Vol 54 (3) ◽  
pp. 1175-1183 ◽  
Author(s):  
Zhejun Liang ◽  
Kevin F. Bronson ◽  
Kelly R. Thorp ◽  
Jarai Mon ◽  
Mohammad Badaruddin ◽  
...  

2014 ◽  
Vol 11 (2) ◽  
pp. 215-220
Author(s):  
A Naznin ◽  
H Afroz ◽  
TS Hoque ◽  
MH Mian

An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during the aman season of 2012 to investigate the effects of prilled urea (PU), urea super granule (USG) and NPK briquette on NH4- N concentration in field water, yield and nitrogen (N) use efficiency (NUE) of BR22 rice under reduced water conditions. The experiment was laid out in a randomized complete block design with three replications. There were altogether eight treatment combinations viz. T1: Control (No N fertilizer), T2: 52 kg N ha-1 from USG, T3: 104 kg N ha-1 from USG, T4: 78 kg N ha-1 from PU, T5: 120 kg N ha-1 from PU, T6: 51 kg N ha-1 from NPK briquette, T7: 78 kg N ha-1 from USG and T8: 78 kg N ha-1 from NPK briquette. Water samples were collected from rice field for seven consecutive days after deep placement of USG and the first split application of PU and the samples were analyzed for NH4-N. The Highest concentration of NH4-N in water was observed at the second day of PU application followed by gradual decrease with time. The yield contributing characters like plant height, panicle length, number of effective tillers hill-1 and grains panicle-1 were significantly influenced by different treatments. The highest grain yield of 3.93 t ha-1 was recorded from 104 kg N ha-1 as USG (T3) and the lowest value of 2.12 t ha-1 was obtained from control. The N use efficiency was increased when the N was applied as USG. The overall results revealed that application of USG and NPK briquette may be practised for obtaining better yields in addition to increasing the efficiency of N fertilizer. DOI: http://dx.doi.org/10.3329/jbau.v11i2.19897 J. Bangladesh Agril. Univ. 11(2): 215-220, 2013


HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 214-217 ◽  
Author(s):  
S.B. Phillips ◽  
J.G. Warren ◽  
G.L. Mullins

Previous work suggests that `Beauregard' sweetpotato [Ipomoea batatas (L.) Lam.] has a much lower N requirement than other common cultivars. Over the past 10 years, `Beauregard' has become the premier sweetpotato cultivar grown in Virginia; however, N fertilizer recommendations have not been reassessed to consider the potentially lower N requirement of `Beauregard'. The objectives of this study were to evaluate the effects of N rate and application timing on root yield, quality, and N use efficiency for `Beauregard' sweetpotato production in Virginia. A field study was conducted each year from 2000 to 2002 at the Eastern Shore Agricultural Research and Extension Center, Painter, Va. Nitrogen fertilizer was applied at rates of 28, 56, and 84 kg·ha-1 either before transplanting, 2 to 3 weeks after transplanting (WAT), or 4 to 5 WAT. A check treatment that received no N fertilizer was also included. Optimum N rates varied annually; under normal precipitation, root yield was greatest at the 28-kg·ha-1 rate, while 56 kg·ha-1 was required for maximum yield in wet conditions. Of note is that this range of rates is considerably lower than the current N recommendation for Virginia sweetpotato production (56 to 84 kg·ha-1). Delaying N application until 2 to 3 WAT further increased marketable root yield compared with applying N before transplanting or 4 to 5 WAT. Crude protein and N uptake increased with increasing N rate up to 84 kg·ha-1; however, N use efficiency was highest (67%) when 28 kg·ha-1 was applied 2 to 3 WAT.


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