Dados do Trabalho

Título

RESIDUAL EFFECT OF NITROGEN FERTILIZER (15N) ON IRRIGATED WHEAT IN CERRADO REGION UNDER NO-TILLAGE

Resumo

The soil, climate, and topography conditions favorable to the cultivation of wheat (Triticum aestivum L.), both rainfed and irrigated, at times and altitudes defined by the research, make Central Brazil a region of great potential for the expansion of this crop. Among the nutrients, nitrogen (N) can be considered one of the most yield-limiting factors for maximum yield. Nitrogen is the nutrient required in greater quantity and is the highest share cost in the production of wheat in Brazil. The objective of this study was to evaluate the residual effect of N applied to corn in the previous crop, on irrigated wheat grown in succession. The study was carried out in Selvíria, State of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Haplustox), under a no-tillage system, which had organic matter content of 23 g dm-3, before the experiment was set up. The experimental design was in randomized blocks, with four replicates. The treatments were four N rates 30, 60, 120 and 180 kg ha-1, as urea (15N), applied in topdressing to corn in the previous crop. The producer of crop residues (straw) by corn in previous crop was 7.13 t ha-1 of dry matter. In the wheat crop, 120 kg N ha-1 was applied in covering (tillering stage) in all the plots to distinguish the residual effect of N applied in the previous crop (corn). A center-pivot sprinkler irrigation system irrigated the experimental area. The wheat grain yield was not influenced by N rates (urea) applied to the previous crop. The average wheat grain yield was 5.05 t ha-1, while the straw yield (crop residues) was of 7.19 t ha-1. The N contents in wheat straw were 5.1 g kg-1, while in grain was 21.0 g kg-1, evidencing this is the main drain of this nutrient. Regardless of the N rate, the recovery of residual N from urea by subsequent wheat crops was, on average, 3.2% of the amount initially applied.

Palavras-chave

Triticum aestivum L.; urea-15N; N rate; Crop succession; Grain yield; Crop residues.

Instituição financiadora

FAPESP and CNPq

Agradecimentos

UNESP - Campus de Ilha Solteira