Use efficiency of variable rate of nitrogen prescribed by optical sensor in corn

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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Effect of Nitrogen Rates and Varieties on Grain Yield and Nitrogen Use Efficiency of Bread Wheat (Triticum aestivum L.)

Greener Journal of Plant breeding and Crop Science ◽

10.15580/gjpbcs.2016.4.062816109 ◽

2016 ◽

Vol 4 (4) ◽

pp. 081-086

Author(s):

Tilahun Bergene ◽

◽

Alemayehu Balcha ◽

Keyword(s):

Triticum Aestivum ◽

Grain Yield ◽

Bread Wheat ◽

Nitrogen Use Efficiency ◽

Triticum Aestivum L ◽

Nitrogen Use ◽

Use Efficiency ◽

Nitrogen Rates

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Review of Active Optical Sensors for Improving Winter Wheat Nitrogen Use Efficiency

Agronomy ◽

10.3390/agronomy10081157 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1157

Author(s):

Lawrence Aula ◽

Peter Omara ◽

Eva Nambi ◽

Fikayo B. Oyebiyi ◽

William R. Raun

Keyword(s):

Winter Wheat ◽

Grain Yield ◽

Optical Sensors ◽

Nitrogen Use Efficiency ◽

Optical Sensor ◽

Management Practices ◽

N Uptake ◽

Nitrogen Use ◽

Use Efficiency ◽

N Management

Improvement of nitrogen use efficiency (NUE) via active optical sensors has gained attention in recent decades, with the focus of optimizing nitrogen (N) input while simultaneously sustaining crop yields. To the authors’ knowledge, a comprehensive review of the literature on how optical sensors have impacted winter wheat (Triticum aestivum L.) NUE and grain yield has not yet been performed. This work reviewed and documented the extent to which the use of optical sensors has impacted winter wheat NUE and yield. Two N management approaches were evaluated; optical sensor and conventional methods. The study included 26 peer-reviewed articles with data on NUE and grain yield. In articles without NUE values but in which grain N was included, the difference method was employed to compute NUE based on grain N uptake. Using optical sensors resulted in an average NUE of 42% (±2.8% standard error). This approach improved NUE by approximately 10.4% (±2.3%) when compared to the conventional method. Grain yield was similar for both approaches of N management. Optical sensors could save as much as 53 (±16) kg N ha−1. This gain alone may not be adequate for increased adoption, and further refinement of the optical sensor robustness, possibly by including weather variables alongside sound agronomic management practices, may be necessary.

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