Effect of nitrogen, wheat residues, and compost rates on the growth and yield of sunflower

Abstract

<span lang="EN-US">In modern agriculture, precise integrated management of farmlands requires natural, sustainable and environmentally friendly inputs replacing chemical fertilizers application. A two-year (2015-2016) field experiment was conducted to determine the influence of integrated application of wheat (<em>Triticum aestivum</em> L</span><span lang="FA" dir="RTL">.</span><span lang="EN-US">) residues and compost accompanied by nitrogen (N) on growth, seed yield and yield components of sunflower (<em>Helianthus annuus</em> L.) at School of Agriculture, Shiraz University, Shiraz, Iran. </span><span lang="EN-US">The experiment was conducted at split plots arranged in randomized complete blocks design with three replications.<span> Treatments included four N (0, 60, 120, and 180 kg N ha<sup>-1</sup>) two wheat residues (1.5 and 3 t ha<sup>-1</sup>), two municipal compost (50 and 70 t ha<sup>-1</sup>) rates and control (no additives). The results showed that higher N rates increased seed yield, whereas it reduced its oil content. Application of wheat residues and compost increased growth, seed yield, and seed oil content compared to control. The effect of compost application on seed yield increase was more pronounced than crop residues. Therefore, for an environmentally andagronomically sound management strategy, high compost application (70 t ha<sup>-1</sup>) combined with proper N fertilization is recommended for sunflower production in the region. </span></span>