Nitrogen release from different polymer‐coated urea fertilizers in soil is affected by soil properties

Abstract

The use of urea as nitrogen (N) fertilizer in agriculture needs to consider environmental, economic and resource conservation aspects because of low N‐use efficiency (NUE). Polymer‐coated urea (PCU) offers an effective way to improve the NUE of urea and to reduce its environmental trade‐offs. However, we lack information on the impact of climate and soil properties on N release from PCU. Therefore, this study was performed to quantify the effects of soil texture, moisture and temperature on the release kinetics of N from PCU. We designed a test system for soil incubation experiments and investigated three fertilizers with different release patterns, five topsoils, three moisture levels and two temperatures over 48 days. We analysed the concentrations of inorganic N ( and ) in the soil and estimated N release rates using the unified Richards model. Soil texture did not change the N release patterns, but release rates varied significantly among the investigated soils. Changes in soil moisture for a given soil had no effect on N release from PCU and urea when fertilizers were incorporated into the soil at conditions supportive of crop growth. Lowering soil temperatures, however, decreased N release rates from PCU by 16%–49% but only in silt loam and not in sandy loam. We conclude that PCU improves the N residence time in soil, but predictions on N release from PCU must be adapted to the prevailing environmental conditions and cannot be generalized across differently textured soils.

Mechanochemical Synthesis of Nitrogen-Efficient Zn- and Cu-Sulfate Urea Cocrystals from Carbonate Minerals

“…Therefore, in our study, we employed a unified methodology based on the Richards model, initially proposed in 2010 for evaluating organism growth, to analyze nitrogen release from fertilizers . This method facilitates the comparison of different fertilizers, enabling us to assess varied N-release curves without requiring any additional adjustments or conversions. The unified Richards model, as presented by Tjo̷rve and Tjo̷rve in 2010, is defined in eq : W ( t ) = A true( 1 + ( ( W o A ) 1 − d − 1 ) · e xp ( − k · t d d / 1 − d ) true) 1 / 1 − d In eq , W ( t ) represents the amount of nitrogen (%) released at a time ( t , days), A denotes the upper asymptote (the maximum or end point of net N released, %), W o is the initial value at the beginning of the observation period (%), k refers to the slope at the inflection point (the point where the rate of N release is highest), and d is the parameter that determines the shape of the curve.…”

“…39 Therefore, in our study, we employed a unified methodology based on the Richards model, initially proposed in 2010 for evaluating organism growth, to analyze nitrogen release from fertilizers. 40 This method facilitates the comparison of different fertilizers, 41 enabling us to assess varied Nrelease curves without requiring any additional adjustments or conversions. The unified Richards model, as presented by Tjo̷ rve and Tjo̷ rve in 2010, 40 is defined in eq 2:…”

“…Urea acid cocrystal materials, such as urea phosphate or urea sulfate, are already manufactured on a large scale but are utilized chiefly as aqueous solutions. Solubility of urea phosphate in the broad temperature range between 277 and 345 K was reported in water and phosphoric acid solutions, 41 and liquid fertilizers have been made. 49 Early granulation attempts have been reported 50 suggesting the engineering feasibility of solid fertilizers.…”

“…42 To ensure comparability among the release curves, the parameter W o was standardized to zero across all curves, establishing a consistent initial reference point. 41 Pot Experiment. A study was conducted in a greenhouse at the US Arid Land Agricultural Research Center, USDA, Arizona.…”

Sustainable Rehabilitation of Post-Bauxite Mining Land for Albizia falcata Cultivation Using Specific Location Amelioration Technology

“…The contribution of nitrogen from air fixation in the soil is relatively low, around 117 kg/ha/year [48]. Organic fertilizers undergo hydrolysis, mineralization, and nitrification processes, reaching maximum accumulation of N-NO3-after 14 days of incubation [49][50][51]. Figure 3 depicts the effect of the combination of red mud and cow manure on total soil nitrogen.…”