Addition of Urease Inhibitor Has No Effect on Ammonia Volatilization Following Soil Application of Poultry Litter or Organomineral Fertilizer, Unlike Urea

Abstract

Quantification of ammonia volatilization after addition of animal residues and nitrogen (N) mineral fertilizers to the soil is important for N management in fertilization programs. The objective of this study was to evaluate the effect of adding a urease inhibitor to N fertilizers to minimize ammonia losses following soil application. The experiment was carried out in a laboratory with samples of a Brazilian Oxisol containing 790 g kg -1 clay and 23 g kg -1 organic matter. Treatments consisted of addition of poultry litter (PL), organic mineral fertilizer (OMF) and urea to the soil, with and without the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT), plus a control with no fertilizer. We applied the fertilizers over the soil surface, with no soil incorporation, at a rate of 200 mg kg -1 N. Experimental units consisted of PVC tubes with a diameter of 0.15 m, containing 1.0 kg of soil (dry basis). Ammonia volatilization was measured for 56 days following fertilizer application to the soil using sponge discs impregnated with phosphoric acid and glycerin, which were fitted inside the tubes 0.15 m above the soil surface. Ammonia volatilization peaks varied according to the fertilizer, and most of them occurred in the first 15 days following application to the soil. Total ammonia volatilized from the soil treated with PL or OMF had no influence on the urease inhibitor, probably because the losses were small, attaining a maximum of 2.5 and 9 % of the total N applied, respectively. In the treatment that received urea, NBPT delayed the peak of volatilization by three weeks and decreased the loss of ammonia from 22 to 9 % of the N applied. Use of urease inhibitor does not always decrease ammonia volatilization, especially when mixed with fertilizers in which urea is not the only source of N.

Agronomic efficiency of organomineral fertilizer in sequential grain crops in southern Brazil

“…Fertilizations that exceed plant demand reflect in increased nutrient content in the soil, especially of P (Tian et al, 2019), which is susceptible to soil fixation (Barrow, 2015) and losses by runoff (Fischer et al, 2018). Nitrogen and K surpluses also tend to be lost from the soil system; N by volatilization or leaching (Lourenço et al, 2016), and K by leaching (Rosolem et al, 2018).…”

“…The correction of organic or mixed sources, which also leads to higher operational efficiency of fertilization. However, the high solubility of mineral fertilizers may cause nutrient losses, mainly N, because of volatilization and/or leaching (Lourenço, Ernani, Corrêa, Dal Molin, & Lourenço, 2016), P fixation (Borges et al, 2019), and leaching of K (Rosolem, Almeida, Rocha, & Bacco, 2018). Organic fertilizers are an alternative to soluble fertilizers, especially those originating from animal production (waste or manure) whose main characteristics are low nutrient concentration and slow rate of nutrient release (Antille, Sakrabani, & Godwin, 2014).…”

Contribution of enzymes to soil quality and the evolution of research in Brazil

“…Because of this, numerous strategies can be developed to reduce its effects, including producing urea granules coated with materials that limit dissolution and urea derivatives that are more slowly hydrolyzed by soil urease and using soil urease inhibitors applied with urea. These techniques decrease N losses by volatilization and improve urea-based fertilizer efficiency (Mota et al, 2015;Viero et al, 2015;Cancellier et al, 2016;Lourenço et al, 2016).…”