Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

Edson Cabral Da Silva,Salatiér Buzetti,José Alberto Bendassolli,Orivaldo Arf,Takashi Muraoka,Vinícius Ide Franzini,Karuppan Sakadevan,Frederico Antônio Loureiro Soares

doi:10.1590/s0100-204x2016000600004

Abstract

Abstract: The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the 15N isotope dilution technique. The field experiment was carried out in the municipality of Selvíria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5x3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha-1 N at sowing; and 20 kg ha-1 N at sowing plus 60 kg ha-1 N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha-1 N as urea on rice yield.

Highlights

Rice (Oryza sativa L.) is the most important cereal for global food security, and Brazil is the world largest producer of upland rice, known as aerobic rice, which is grown mainly in Asia, Africa, and Latin America (Fageria et al, 2010)
Rice cultivation in no‐tillage cover crops is of great interest because of the nutrients released by the crop residue, such as N available as ammonium (Torres et al, 2008; Teixeira et al, 2009; Nascente et al, 2013a, 2013b), which is essential for the initial development of rice (Holzschuh et al, 2009; Nascente et al, 2013a; Pacheco et al, 2013)
The objective of this work was to evaluate the effects of cover crops on the yield of upland rice grown under no‐tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the 15N isotope dilution technique

Summary

Introduction

Rice (Oryza sativa L.) is the most important cereal for global food security, and Brazil is the world largest producer of upland rice, known as aerobic rice, which is grown mainly in Asia, Africa, and Latin America (Fageria et al, 2010). It is important to know the capacity of cover crops to supply N for crop production (Nascente et al, 2013b; Pacheco et al, 2013). Rice cultivation in no‐tillage cover crops is of great interest because of the nutrients released by the crop residue, such as N available as ammonium (Torres et al, 2008; Teixeira et al, 2009; Nascente et al, 2013a, 2013b), which is essential for the initial development of rice (Holzschuh et al, 2009; Nascente et al, 2013a; Pacheco et al, 2013)

Objectives

Methods

Results

Conclusion