Yield and Yield Components of Upland Rice as Influenced by Nitrogen Sources

Abstract

and urea are main sources of nitrogen (N) for annual crop production in developing countries. Two greenhouse experiments were conducted using ammonium sulfate and urea as N sources for upland rice grown on a Brazilian Oxisol. The N rates used were 0, 50, 100, 150, 3000, and 400 kg N kg −1 of soil. Yield and yield components were significantly increased in a quadratic fashion with increasing N rate. Ammonium sulfate X urea interaction was significant for grain yield, shoot dry matter yield, panicle number, plant height and root dry weight, indicating a different response magnitude of these plant parameters to two sources of N. Based on regression equation, maximum grain yield was achieved with the application of 380 mg N kg −1 by ammonium sulfate and 271 mg N kg −1 by urea. Grain yield and yield components were reduced at higher rates of urea (>300 mg kg N) but these plant parameters' responses to ammonium sulfate at higher rates was constant. In the intermediate N rate range (125 to 275 mg kg −1 ), urea was slightly better compared to ammonium sulfate for grain yield. Grain yield was significantly related with plant height, shoot dry weight, panicle number, grain harvest index and root dry weight. Hence, improving these plant characteristics by using appropriate soil and plant management practices can improve upland rice yield.

Growth, yield and agronomic efficiency of rice (Oryza sativa L.) cv. IAPAR 117 affected by nitrogen rates and sources

“…Similar results were obtained by Fageria et al (2011), working with upland rice. These authors observed higher plant height when using ammonium sulphate compared to urea at low N rates.…”

“…In Brazil, upland rice is sown mainly in Cerrado regions (Fageria & Baligar, 2005), where the soils are characterized by low natural fertility, high exchangeable aluminum, low organic matter content, low phosphorus availability and almost exclusive dependence of rainfall to supply the crop water requirements (Fageria, Moreira & Coelho, 2011;Fageria, Carvalho & dos Santos, 2014). Therefore, the yield of upland rice is low, contributing with only 41% of Brazilian production, despite having more than 60% of rice cultivation areas in Brazil (Alvarez, Crusciol & Nascente, 2014).…”

“…Some literature citations (Fageria, Moreira & Coelho, 2011;Fageria, Moreira, Moraes & Moraes, 2014), on the effects influence of N sources and N rates on yield of upland rice crop in Brazilian conditions are limited, especially for newly released genotypes. In that sense, continuous studies are necessary to adjust the aspects of nitrogen fertilization for new cultivation realities.…”

Produtividade de arroz de terras altas em função de reguladores de crescimento

“…No entanto, um dos grandes problemas do arroz de terras altas, quando se utilizam cultivares do tipo tradicional, ou do tipo intermediário, e se empregam doses elevadas de adubação, notadamente a nitrogenada, acompanhadas por práticas como a irrigação por aspersão, é o aumento da altura e, consequentemente, o acamamento de plantas (Soares et al, 2003;Nascimento et al, 2009;Fageria et al, 2011;Crusciol et al, 2012).…”

Upland rice yield as affected by previous summer crop rotation (soybean or upland rice) and glyphosate management on cover crops

“…The high rice grain yield on fallow straw may be due to the fact that rice is a crop that has slow initial growth and that shows great sensitivity to competition with other plants (Menezes et al, 2001;Fageria et al, 2011). Thus, the proper management of plants (weeds) and the desiccation process have favored the full development of culture without competition.…”