Comparing Soil vs. Foliar Nitrogen Supply of the Whole Fertilizer Dose in Common Wheat

Abstract

Late-season N application through foliar spraying is recognized as an efficient agronomic practice for improving grain quality in common wheat, although the major part of N is still supplied by soil fertilization. This study assessed the impact of various N doses entirely applied by repeated foliar sprayings on wheat growth, yield and quality, in comparison with conventional soil fertilization management with a recommended dose of 160 kg N ha−1 as ammonium nitrate (C-M). Doses of 96, 104 and 120 kg N ha−1 as both UAN (urea-ammonium-nitrate) and urea applied by foliar spraying were evaluated in a 2-year field trial in Northern Italy in a silty loam soil with 1.7% organic matter. Here, it was demonstrated that the canopy greenness was similar in all treatments, with slight grain yield increases by the lowest foliar N dose vs. C-M. The higher N foliar doses mainly improved the grain protein content and both high- and low-molecular-weight glutenin subunits (HMW-GS, LMW-GS), particularly with urea. It is concluded that in our fertile soil, managing N fertilization exclusively through foliar spraying is feasible without compromising grain yield and ameliorating quality at the same time. Improved nutrient use efficiency and beneficial environmental effects are also expected by reducing the nitrogen load on the agricultural fields by 25–40%.

Leaf Scorching following Foliar Fertilization of Wheat with Urea or Urea–Ammonium Nitrate Is Caused by Ammonium Toxicity

“…Foliar N-fertilization has the potential to improve fertilizer-NUE. However, leaf scorching may occur after foliar N-fertilization [23,45,46], as was also observed and characterized in the present work (Figures 1 and 3). The scorching appeared as chlorosis of the leaf tip, where NH 4 + accumulation is driven by the transpiration stream [47].…”

Comparative Efficacy of Foliar Plus Soil Application of Urea versus Conventional Application Methods for Enhanced Growth, Yield, Agronomic Efficiency, and Economic Benefits in Rice

“…The result of the study is in agreement with that of Al-Amin who obtained the longest panicle length from the foliar spray of 3% urea solution and the shortest one from 2% urea solution. Higher doses of N increased the panicle length per plant . The longest panicle length was observed from 6 times foliar spray of urea solution .…”

“…Soil and foliar application of fertilizers also significantly increased the grains per spike of wheat. 37,38,41 Number of Sterile Grains Panicle −1 . Nitrogen fertilizer doses and application methods showed significant effects on the unfilled grains panicle −1 of rice.…”

Chemistry of wheat gluten proteins: Quantitative composition

“…The study showed that foliar N application with urea was preferable compared to urea‐ammonium‐nitrate. Quality‐related traits were similar in the wheats with conventional and foliar treatments, indicating that foliar N application allows a reduction of total N addition by 25%–40% (Ferrari et al, 2021).…”

“…In addition to the total amount of N and timing of N application, the N application strategy was studied for its impact on wheat quality‐related parameters. The impact of supplying the total amount of N by repeated foliar application was compared to conventional soil fertilization using one Italian wheat variety with high bread‐making quality grown in two seasons (Ferrari et al, 2021). All treatments received 32 kg N/ha at sowing and there was one control with no further fertilization.…”