Wheat nitrogen utilization efficiency and yield as affected by nitrogen management and environmental conditions

Abstract

Nitrogen (N) is the main nutrient for plant nutrition, however, its fertilization management is still very complex. To evaluate wheat N utilization efficiency (NUtE) and yield in response to N fertilization management considering the influence of environmental conditions, an experiment was carried out in three field conditions in Southern Brazil: Londrina in rainfed and irrigation conditions, and Ponta Grossa in rainfed. A complete (2 × 2 × 2) + 1 factorial arrangement evaluated two N rates (40 and 80 kg ha-1), two N sources (ammonium nitrate and urea), two N timings of fertilization (at sowing or at the beginning of plant tillering), and additional treatment without N fertilization. Agronomic characteristics related to wheat productivity and N plant nutrition were evaluated. Irrigation increased the density of fertile spikes and the N accumulated in the shoot dry matter at anthesis, which partially explained the better grain yield in the irrigated condition. The higher N accumulation in the shoot dry matter was essential for grain yield increase in the environments with lower water deficit, based on their higher NUtE for grain yield. Nitrogen fertilization reduced NUtE for grain yield in Londrina (in rainfed and irrigation conditions), and increased NUtE for shoot dry matter production in all environments. In a colder condition (i.e. Ponta Grossa), the use of a higher N rate at sowing provided greater grain yield, thousand-grain weight, and density of fertile spikes. Nitrogen rate can be reduced in warmer and wetter environmental conditions that favor the mineralization of soil organic matter and the decomposition of soybean straw. The choice for urea or ammonium nitrate can be based on economic criteria in environments with low water deficit and low potential for NH3 volatilization. Nitrogen fertilization carried out exclusively at wheat sowing may be suitable to supply spring wheat N requirements.

Assessment of stability for some yield components in wheat under different fertilizations on saline soil

“…The treatment with urea showed a superior effect compared to the other treatments especially under the conditions from 2023, characterized by a higher level of rainfall. These results are consistent with the findings that the fertilization with urea is more suitable for environments with higher water availability because its rapid solubilization and infiltration into the soil decreases the nitrogen losses due to ammonia volatilization (Ferreira et al, 2021).…”

Nitrogen fertilization and sowing density on yield and physiological quality of wheat seeds

“…On the other hand, soil acidity may have influenced the nutrient availability and plant root growth. Soil pH was between 4.6 and 5.2 (medium acidity level) in the three environments and at both soil depths, minimizing N losses by volatilization, which is higher in the pH range from neutral to alkaline (Ferreira et al, 2021). The concentrations of Al 3+ in the soil were low (< 0.32 cmol c .dm −3 ), and the potential acidity (H+Al) was medium (between 2.5 and 5.0 cmol c .dm −3 ), not representing a significant hindering for root growth of the two wheat genotypes, which were selected by a genetic improvement program that considers the plant tolerance to soil acidity as one of the main selection criteria (M.C.…”

Evaluation of potential and rate of the germination of wheat seeds (Triticum aestivum L) treated with bifunctional growth regulators under water stress

“…Abiotic stresses such as drought, extreme temperatures, salinity, flooding, lack of or high light levels, imbalances in inorganic nutrients, anthropogenic toxic compounds and oxidative stress result in crop losses annually (Ferreira et al, 2021;Seleem et al, 2021). Water stress (drought), being the second major factor in yield decline after diseases, alters the physiological, morphological, biochemical and molecular traits of plants (Rijala et al, 2021;Dhankher and Foyer, 2018;Dutta et al, 2016).…”