Nitrate Reductase, Micronutrients and Upland Rice Development as Influenced by Soil pH and Nitrogen Sources

Author(s)

Moro, Edemar ^[1] ; Costa Crusciol, Carlos Alexandre ^[2] ; Nascente, Adriano Stephan ^[3] ; Cantarella, Heitor ^[4] ; Broetto, Fernando ^[5] ; Moro, Adriana Lima ^[1]

Affiliation

^[1] Univ Oeste Paulista UNOESTE, Dept Agron, Campus 2, Presidente Prudente, SP - Brazil

^[2] Univ Estadual Paulista, Dept Prod Vegetal Agr, Fac Ciencias Agron, UNESP, Botucatu, SP - Brazil

^[3] Empresa Brasileira Pesquisa Agr, Embrapa Arroz & Feijao, Santo Antonio De Goias, Go - Brazil

^[4] Inst Agron Campinas, Ctr Solos & Recursos Ambientais, Campinas, SP - Brazil

^[5] Univ Estadual Paulista, Inst Biociencias, Dept Quim & Bioquim, UNESP, Botucatu, SP - Brazil

• Document type: Journal article
• Source: Communications in Soil Science and Plant Analysis; v. 48, n. 22, p. 2642-2651, 2017.
• Web of Science Citations: 2

Abstract

The average yield of upland rice under no-tillage system (NTS), a sustainable soil management, is lower than in conventional tillage (one plowing and two disking). One of the reasons given for this drop in crop grain yield would be the low-nitrate assimilation capacity of rice seedlings, due to the low activity of the nitrate reductase (NR) enzyme in the early development phase. A greenhouse experiment was conducted to evaluate the effects of the soil acidic and nitrogen source in the micronutrient concentrations, NR activity and grain yield of upland rice growing under NTS. The soil used in the experiment was an Oxisol. The experimental design was completely randomized in a factorial 3 x 4. Treatments consisted of three levels of soil acidity (high, medium, and low) combined with four nitrogen sources (nitrate, ammonium, ammonium + nitrification inhibitor, and control - without N fertilization). The reduction of soil acidity reduced the concentration of zinc and manganese in rice plants. Generally, the activity of the NR enzyme was higher in plants grown in soils with low acidity and fertilized with calcium nitrate. There was a greater response in growth and yield in rice plants grown in soils with high acidity. Under medium acidity, rice plants grown with ammonium sulfate were more productive (no differences were detected with the addition of the nitrification inhibitor). (AU)

• FAPESP's process: 08/05641-6 - COVER CROP AND NITROGEN SOURCES FOR UPLAND RICE IN NO-TILL SYSTEM
• Grantee: Carlos Alexandre Costa Crusciol
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/05573-0 - COVER CROP AND NITROGEN SOURCES FOR UPLAND RICE IN NO-TILL SYSTEM
• Grantee: Edemar Moro
• Support Opportunities: Scholarships in Brazil - Doctorate