Root and shoot traits for rice varieties with higher grain yield and higher nitrogen use efficiency at lower nitrogen rates application

ABSTRACT The efficiency of nitrogen fertilizer in corn is usually low, negatively affecting plant nutrition, the economic return, and the environment. In this context, a variable rate of nitrogen, prescribed by crop sensors, has been proposed as an alternative to the uniform rate of nitrogen traditionally used by farmers. This study tested the hypothesis that variable rate of nitrogen, prescribed by optical sensor, increases the nitrogen use efficiency and grain yield as compared to uniform rate of nitrogen. The following treatments were evaluated: 0; 70; 140; and 210 kg ha-1 under uniform rate of nitrogen, and 140 kg ha -1 under variable rate of nitrogen. The nitrogen source was urea applied on the soil surface using a distributor equipped with the crop sensor. In this study, the grain yield ranged from 10.2 to 15.5 Mg ha-1, with linear response to nitrogen rates. The variable rate of nitrogen increased by 11.8 and 32.6% the nitrogen uptake and nitrogen use efficiency, respectively, compared to the uniform rate of nitrogen. However, no significant increase in grain yield was observed, indicating that the major benefit of the variable rate of nitrogen was reducing the risk of environmental impact of fertilizer.

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Effects of Nitrogen Levels on Growth, Yield And Nitrogen use Efficiency Of Some Newly Released Egyptian Rice Genotypes

Open Agriculture ◽

10.1515/opag-2018-0034 ◽

2018 ◽

Vol 3 (1) ◽

pp. 310-318 ◽

Cited By ~ 9

Author(s):

Adel M. Ghoneim ◽

Gewaily E.E. ◽

Marvet M.A. Osman

Keyword(s):

Grain Yield ◽

Nitrogen Use Efficiency ◽

Nitrogen Fertilizer ◽

Growth And Yield ◽

Rice Varieties ◽

Nitrogen Use ◽

Nitrogen Levels ◽

Growing Seasons ◽

Use Efficiency ◽

Rice Genotypes

Abstract Application of appropriate level of nitrogen fertilization is a major objective to increase nitrogen use efficiency by rice varieties. Field experiments were conducted during 2016 and 2017 growing seasons to evaluate the efficiency of varying nitrogen fertilizer rates on growth and yield parameters, along with nitrogen use efficiency of some newly released rice varieties (Sakha 108) and some promising lines GZ9399-4-1-1-3-2-2, GZ10101- 5-1-1-1 and GZ10154-3-1-1-1. Five nitrogen levels (i.e. 0, 55, 110, 165 and 220 kg N ha-1) were used. The results from both growing seasons indicated that, Sakha 108 recorded the highest grain yield while GZ10154 and GZ10101 recorded the lowest grain yields. A linear increase in grain yield was observed with continuous rate increase of nitrogen from 0 to 220 kg ha-1, while 220 kg N ha-1 treatment showed maximum grain yield followed by 165 kg N ha-1, with control as minimum. Agronomic nitrogen use efficiency (AE) for studied rice genotypes varied significantly, and ranged from 3.63 to 32.9 and from 2.72 to 34.12 kg grain yield produced per kg of nitrogen applied in 2016 and 2017 respectively. Across N levels, GZ9399 recorded the highest values of AE for the nitrogen fertilizer rate of 165 kg N ha-1 in both seasons.

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Yield and Nitrogen Use Efficiency of Locally Improved Rice Varieties in Rice Based Tidal Flooded Ecosystem of Bangladesh

Bangladesh Agronomy Journal ◽

10.3329/baj.v19i2.31851 ◽

2017 ◽

Vol 19 (2) ◽

pp. 39-49 ◽

Cited By ~ 3

Author(s):

MAA Mamun ◽

MM Haque ◽

QA Khaliq ◽

MA Karim ◽

AJMS Karim ◽

...

Keyword(s):

Grain Yield ◽

Nitrogen Use Efficiency ◽

Efficiency Index ◽

Rice Varieties ◽

Nitrogen Use ◽

Deep Placement ◽

Effective Option ◽

Use Efficiency ◽

Initiation Stage ◽

Planting Materials

An on farm field experiment was conducted to evaluate locally improved aman rice varieties in terms of nitrogen use efficiency and grain yield in southern region of Bangladesh. The treatments were: i. deep placement of urea (UDP) before panicle initiation stage and ii. farmers practice (FP/control). The locally popular rice varieties were used as planting materials. Higher panicles m-2 and grains panicle-1 was obtained from UDP application compared to FP. Nitrogen fertilization increases grain and straw nitrogen content significantly. Application of urea before panicle initiation stage gave considerable higher grain yield in all cultivated varieties. Cultivated aman varieties produced 2.0 to 2.5 t ha-1 grain without application of N fertilizer. But, cultivated local variety Razashail, Kutiagoni, Sadachikon, Sadapajam, Lalmota and Sadamota gave 3.0 to 3.5 t ha-1 grain in tidal prone areas with UDP. Hence, application of urea gave yield advantage by 0.5 to 1.0 t ha-1. The highest internal, agronomic, recovery and physiological efficiency; nitrogen harvest and grain yield efficiency index was obtained from Kutiagoni, Lalpayka, Sadachikon, Sadapajam, Moulata and Lalmota. Based on the yield and nitrogen fertilizer use efficiency, it could be concluded that UDP before panicle initiation stage is an effective option of urea application for rice cultivation in tidal prone areas.Bangladesh Agron. J. 2016 19(2): 39-49

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