Zeolite influences on nitrate leaching, nitrogen-use efficiency, yield and yield components of canola in sandy soil

Abstract

With regard to the low cation-exchange capacity and large saturated hydraulic conductivity of sandy soils, a field experiment was carried out in 2006–2007 to determine the impact of zeolite on nitrogen leaching and canola production. Four nitrogen (N) rates (0, 90, 180, and 270 kg ha^–1) and three zeolite amounts (3, 6 and 9 t ha⁻¹) were included as treatments. The results demonstrated that the highest growth parameters and seed yield were attained with 270 kg N ha⁻¹ and 9 t zeolite ha⁻¹. However, the highest and the lowest seed protein percentage and oil content were obtained with 270 kg N ha⁻¹ accompanied by 9 t zeolite ha⁻¹, respectively. Nitrate concentration in drained water was affected by nitrogen and zeolite. The lowest and highest leached nitrate values were found in control without N and zeolite (N₀Z₀) and in treatments with the highest N supply without zeolite (N₂₇₀Z₀), respectively. In general, nitrogen-use efficiency decreased with an increase in N supply. Application of 9 t zeolite ha⁻¹ showed higher nitrogen use efficiency than other zeolite amounts. Also, application of more N fertilizer in soil reduced nitrogen uptake efficiency. In total, application of 270 kg N ha⁻¹ and 9 t zeolite ha⁻¹ could be suggested as superior treatment.

Keywords:

• canola
• nitrogen leaching
• sandy soil
• yield
• zeolite