Nitrogen Uptake and Use Efficiency in Upland Rice under Two Nitrogen Sources

作者：Fageria N K^*; Moreira A; Moraes L A C; Moraes M F

来源：Communications in Soil Science and Plant Analysis, 2014, 45(4): 461-469.

DOI：10.1080/00103624.2013.861907

• Oryza sativa L.
• utilization efficiency
• N concentration
• Agronomical efficiency

Upland rice is an important crop in South America, including Brazil. Nitrogen (N) is one of the most yield-limiting nutrients in upland rice production in Brazil. A greenhouse experiment was conducted to evaluate N uptake and use efficiency as influenced by N sources. The soil used in the experiment was an Oxisol. The N sources were ammonium sulfate and urea, and N rates were 0, 50, 100, 150, 300, and 400 mg kg(-1) of soil. Nitrogen concentrations in the root, shoot, and grain were significantly influenced by N sources. The N rate and N source significantly influenced the N uptake in root, shoot, and grain. Similarly, nitrogen rate by N source interaction was also significant for N uptake in the root, shoot, and grain, indicating N source has a significant influence on uptake of N. Overall, concentration (content per unit dry weight) of N was greater in the grain, followed by root and shoot. Agronomical efficiency, apparent recovery efficiency, and utilization efficiency of N were significantly influenced by N rate and varied with N sources. However, physiological and agrophysiological efficiencies were only influenced significantly by N sources. Overall, N recovery efficiency was 33% for ammonium sulfate and 37% for urea. Hence, the large amount of N lost from soil-plant system may be by denitrification or voltilization.

• 出版日期2014-2-21