Search Results (38)

Organo-mineral fertilizers can slow N release to plants, reducing N losses to the environment and enhancing N use efficiency (NUE). Yet, this greater NUE is not always coupled to greater crop yields, which warrants further investigation. Here, we assessed the relationship between N-NH₃ losses from volatilization and wheat (Triticum aestivum L.) biomass and N status. The following treatments were tested: conventional urea (U, 45% N), urea treated with NBPT (N-(n-butyl) thiophosphoric triamide) (U + NBPT, 45.6% N), S-coated urea (U + S; 37% N), Se-coated urea (U + Se; 45% N), organo-mineral fertilizer Azoslow 29 (OMF, 29% N + 50% Azogel^®). The above treatments and non-fertilized control were tested in two soils (LVd and LVAd, 71 and 25% clay, respectively). Semi-open static collectors were used to determine N-NH₃ volatilization 1, 2, 4, 8, 11, 15, 18, 23, 29, and 36 days after application of treatments. Wheat was cultivated for 35 days, and shoot dry mass and total leaf N were determined after harvest. Cumulative N-NH₃ losses from OMF (27 and 32% of N applied in the LVd and LVAd soils, respectively) did not differ from U and (26–32%) and U + Se (24–31%), likely due to organic matter inputs enhancing urease activity in soils. Nevertheless, OMF resulted in 2–4 times greater wheat dry matter than U, U + Se, and U + S, with similar dry mass of U + NBPT for LVAd soils. OMF application enhanced total N removal in wheat leaves relative to the unfertilized control and most N sources. N-NH₃ losses did not reduce biomass yield, but were negatively linked to N accumulation in wheat. The OMF enhanced wheat biomass and nutrition while sustaining environmental quality and promoting circularity in agroecosystems. Full article

Ammonia (NH₃) volatilization caused by urea application has negative implications for human health, environmental quality, and the value of nitrogen fertilizers. It remains to be investigated how management strategies should be adopted to not only reduce NH₃ volatilization but also improve nitrogen use efficiency (NUE) in the agriculture industry at present. Hence, a two-year field trial, including subplots, was conducted to simultaneously evaluate the effects of mulching treatments (NM: non-mulching; SM: straw mulching) and different fertilizer treatments (U: urea; U + NBPT: urea plus 1% N-(n-butyl) thiophosphoric triamide; U + CRU: the mixture of urea and controlled-release urea at a 3:7 ratio; U + OF: urea plus commercial organic fertilizer at a 3:7 ratio) on NH₃ volatilization, crop production, and NUE in an oilseed rape–maize rotation system in the sloping farmland of purple soil in southwestern China between 2021 and 2023. Compared with NM + U, NH₃ volatilization losses under the NM + U + NBPT, NM + U + CRU, and NM + U + OF treatments decreased, on average, by 64.13%, 17.39%, and 15.09% during the oilseed rape growing season but by 64.01%, 11.67%, and 10.13% during the maize growing season, respectively. An average increase in NH₃ volatilization of 35.65% for the straw-mulching treatment was recorded during the oilseed rape season, while during the maize season, this parameter showed an increase of 10.69%, in comparison to NM + U. With the combination of urea with NBPT, CRU, and organic fertilizer, contrastingly, a reduction in NH₃ volatilization was achieved under the SM + U + NBPT, SM + U + CRU, and SM + U + OF treatments. When compared with NM + U, the difference in the NUE between the NM + U + NBPT, NM + U + CRU, and NM + U + OF treatments was not significant in the oilseed rape season. The NUE was around 4.27% higher under NM + U + NBPT during the maize season (p < 0.05). Compared with NM + U, under the NM + U + NBPT, NM + U + CRU, and NM + U + OF treatments, consistently lower values of yield-scaled NH₃ volatilization were noted: 13.15–65.66% in the oilseed rape season and 10.34–67.27% in the maize season. Furthermore, SM + U, SM + U + NBPT, SM + U + CRU, and SM + U + OF showed average annual emission factors (AEFs) of 14.01%, 5.81%, 12.14%, and 11.64%, respectively. Overall, straw mulching, along with the application of the mixture of NBPT and urea, was found to be the optimal strategy to effectively reduce the NH₃ emissions in the purple soil areas of southern China. Full article

While previous studies have suggested that biochar, nitrification inhibitors, and urease inhibitors may reduce soil greenhouse gas emissions, their effectiveness in soils irrigated with alternative water resources remains unclear. To compensate for this, reclaimed water and livestock wastewater were utilized as alternative water resources alongside groundwater control. Nitrapyrin and N-(n-butyl) thiophosphoric triamide and biochar were applied to the soil either individually or in combination, and a no-substance treatment (NS) was included for comparison. The results revealed that reclaimed water and livestock wastewater irrigation exacerbated the global warming potential. Compared to the NS, all exogenous substance treatments suppressed nitrous oxide (N₂O) emissions while increasing carbon dioxide (CO₂) emissions, and affecting methane (CH₄) emissions varied across treatments irrespective of the water types. Interestingly, the additional biochar reduced the inhibitory effect of the inhibitors on the greenhouse effect. Using nitrification inhibitors reduced the global warming potential by 48.3% and 50.1% under reclaimed water and livestock wastewater irrigation, respectively. However, when nitrification inhibitors were applied in combination with biochar, the global warming potential was increased by 52.1–83.4% compared to nitrification inhibitors alone, and a similar trend was also observed in the scenario of urease inhibitors, with increases ranging from 8.8 to 35.1%. Therefore, the combined application of biochar and inhibitors should be approached cautiously, considering the potential for increased greenhouse gas emissions. Full article

Relative to soluble N sources, enhanced-efficiency fertilizers (EEFs) support steady turfgrass growth and dense canopy quality while abating N loss as nitrate, ammonia, and/or N₂O from turfgrass systems. Modern EEFs provide turfgrass managers greater operational effect and versatility in their nutrient management efforts and compel field characterization of their temporal response. Likewise, field confirmation of commercial EEF nutrient recovery helps stakeholders select the appropriate EEF for their specific application. Our research objective was to quantify the temporal response of Kentucky bluegrass growth/yield, canopy density and color, and fertilizer N recovery to a practical application of conventional urea or an enhanced-efficiency granular fertilizer. In May 2014 and June 2018, Kentucky bluegrass plots were fertilized by granules of conventional urea, N-(n-butyl) thiophosphoric triamide (NBPT)-, and dicyandiamide (DCD)-stabilized urea, or polymer-/sulfur-coated urea (PSCU) at a N rate of 43.9 kg ha⁻¹ (0.9 lbs/1000 sq. ft.). The dependent variable response over the two growing seasons was highly affected by efficiency enhancement. Following the repeated 16.5-week evaluations, the mean percent of fertilizer N recovered from conventional urea, stabilized urea, and PSCU totaled 57.5, 68.4, and 89.1%, respectively. In the 23 to 51 days from treatment (DFT), recovery of PSCU-N significantly exceeded that from conventional or stabilized urea. Full article

The aim of this study was to economically estimate the effect of inoculation with Azospirillum brasilense (A. brasilense) associated with enhanced efficiency nitrogen fertilizers on corn yield cultivated in the Brazilian Amazon. The experimental design used was completely randomized, in a 2 × 3 × 5 factorial scheme, resulting from the combination of the presence and absence of seeds inoculated with A. brasilense, three sources of N (conventional urea, urea with NBPT, N-(n-butyl)thiophosphoric triamide, and polymer-coated urea), and five doses of N (0; 50; 100; 150; and 200 kg ha⁻¹ of N), with six replications. Inoculation with A. brasilense promoted profit in corn, regardless of dose and the source of N applied. The urea with NBPT provided better economic return compared to polymer-coated urea and conventional urea sources, and doses of N applied in topdressing that promoted the highest economic return were 100 and 150 kg ha⁻¹ of N, with an estimated increase of 62.33 and 135.53 bags ha⁻¹ and increase of BRL 3253.76 and BRL 7074.88 respectively, compared to the control treatment. Full article

The excessive application of nitrogen fertilizer aggravated the loss of nitrogen in farmland and exerted detrimental effects on the soil and water environment. Examining the effects of N-(n-Butyl)thiophosphoric triamide (NBPT) and nitrification inhibitor dicyandiamide (DCD) on nitrification and crop yield in wheat-corn double cropping systems would provide valuable insights for improving nitrogen efficiency and ensuring a rational application of inhibitors. A field experiment lasting one and a half years was performed in the winter wheat–summer maize double agroecosystem in North China. The four treatments that were applied included (I) conventional fertilization without inhibitors (CK), (II) conventional fertilization with 0.26 g/m² NBPT (NBPT), (III) conventional fertilization with 1.00 g/m² DCD (DCD), and (IV) conventional fertilization with 0.26 g/m² NBPT and 1.00 g/m² DCD (NBPT + DCD). The results demonstrated that the combined use of NBPT and DCD exerted better effects in reducing NO₃⁻-N leaching. Nitrification could be inhibited for up to 95 days by combining NBPT and DCD, while 21 days by DCD. Ammonia-oxidizing archaea (AOA) (R² = 0.07159, p < 0.01) along with ammonia-oxidizing bacteria (AOB) (R² = 0.09359, p < 0.01), rather than a complete ammonia oxidizer (comammox), were significantly and positively correlated with NO₃⁻-N content, which indicated that the ammoxidation process was mainly regulated by AOA and AOB, instead of comammox in the winter wheat–summer maize double agroecosystem in North China. Full article

Enhanced efficiency fertilizers, such as urea treated with a urease inhibitor, controlled-release fertilizers (CRFs), and fertilizer blends, compose important strategies for improving efficiency in nitrogen (N) use by plants and mitigating ammonia (N-NH₃) emissions. The physical mixture of fertilizers in blends can favor synchronization of N-release from the fertilizers and N-uptake by coffee plants and also dilute the costs of acquiring a pure CRF, making fertilizer blends more accessible to growers. To investigate this, a field experiment was conducted over two consecutive crop years with Coffea arabica with the aim of evaluating nitrogen fertilizer technologies at application rates ranging from 0 to 450 kg N ha⁻¹. The fertilizers were characterized, and analyses were performed to quantify N-release from the fertilizers, ammonia volatilization, and nutritional and yield aspects of the coffee plant. The fertilizers used were urea (UCon), urea treated with N-(n-butyl) thiophosphoric-triamide (UNBPT), urea-coated with polymer of the E-Max technology (with 41%N (EMax41) or 43%N (EMax43)), and blends of UNBPT with E-Max (Blend41–Blend43). The cumulative N-release for EMax41 always remained below that for EMax43, just as occurred for Blend41 in relation to Blend43. Over the two crop years, the greatest volatilization of N-NH₃ occurred with UCon (~25%) and the least with EMax41 (9%). The results indicate that the technologies mitigated the N-NH₃ emissions in relation to UCon [EMax41 (63% mitigation) > Blend41 (43%) > EMax43 (32%) > UNBPT (28%) > Blend43 (19%)]. Crop management affects coffee yield. The yield increase went from 20% in the first crop year to 75% in the second, with better results from fertilizers containing CRF. We present information that can assist fertilizer producers and coffee growers, and, above all, we seek to contribute to environmental action for the reduction of agricultural NH₃, clarifying potential strategies for mitigation of these emissions and strategies that generate advances in research on technologies for coffee growing. Full article

The adoption of technologies for N fertilization has become essential for increasing the N use efficiency in no-till (NT) systems in Brazil. Thus, this study aimed to quantify ammonia losses, N removal in grains, and second crop season yield in no-till and conventional (T) areas that received the application of different N fertilizers and their technologies. Ammonia volatilization, N extraction in grains, and corn yield in response to the application of conventional fertilizers were compared to urea treated with urease inhibitors in NT and conventional systems. The treatments were: no-N (Control); Prilled urea (PU); urea + N-(n-Butyl) thiophosphoric triamide (U_NBPT); urea + Cu + B (U_CuB); ammonium nitrate (AN), and ammonium sulfate (AS). In the NT system, the N-NH₃ losses were 49% higher than in the conventional; without differences in corn yield. The fertilizers AN and AS had the lowest N-NH₃ losses, regardless of the tillage system. U_NBPT reduced the mean N-NH₃ loss by 33% compared to PU. U_NBPT (1200 mg kg⁻¹) and U_NBPT (180 mg kg⁻¹) reduced the N-NH₃ losses by 72% and 22%, respectively, compared to PU in the NT system. We noticed that the NBPT concentration to be used in soils under NT should be adjusted, and a reduction of N-NH₃ losses does not directly reflect an increase in yield and N extraction by corn. Full article

Nitrification inhibitor (NI) and urease inhibitor (UI) with fertilizer have the potential to reduce nitrogen (N) loss as well as improve grain yields. Urea–ammonium nitrate (UAN) solution as liquid fertilizer is superior to conventional solid nitrogen (N) fertilizer in terms of fertilizer efficiency, energy savings, environmental pollution reduction and economic benefits. However, comprehensive assessments of UAN with inhibitors from an environmental and agronomy perspective, including insights into the mechanisms of UAN with inhibitors, are lacking. In a field trial, three single-inhibitor and two double-inhibitor (DI) treatments were set to quantify the grain yield, the N losses and the N recovery efficiency of maize treated with urea supplemented with dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP) and N-(n-buty_l) thiophosphoric triamide (NBPT). Compared with the UAN treatment, the supply of urease inhibitors reduced NH₃ emission by 13.0% but increased N₂O emission by 13.0%. The supply of nitrification inhibitors delayed the conversion of ammonium N to nitrate N and improved NH₃ emission by 23.5–28.7%, but reduced N₂O emission by 31.4% and significantly increased the maize yield by 21.3%. The combined use of NBPT and DCD were not compatible in UAN and cannot achieve the maximum potential for optimizing yields and reducing nitrogen losses. Considering the grain yield, the N use efficiency and the N losses, the combined use of NBPT and DMPP in maize production system significantly improved the grain yield and N use efficiency, as well as reduced N losses. Full article

Both, 3,4-dimethylpyrazole phosphate (DMPP) and N-(n-butyl) thiophosphoric triamide (NBPT) are commonly used as nitrogen (N) stabilizers, and are often used in agriculture to reduce nitrogen (N) loss from soils by inhibiting soil nitrification and by slowing down urea hydrolysis, respectively. The current knowledge gap concerns how soil microbial communities involved in N cycling are affected by the long-term use of DMPP and NBPT. The present field study explored the inter-annual variation of nitrous oxide (N₂O) emissions and the responses of ammonia oxidizers (AOA, AOB encoded by the amoA gene), nitrite-oxidizing bacteria (NOB, encoded by the nxrA and nxrB genes), and denitrifier (encoded by the narG and nosZ genes) populations following a long-term (8 years) addition of DMPP and NBPT. The results showed that the reduction in N₂O emissions by DMPP and NBPT increased year on year. The AOB population diversity significantly increased (p < 0.05) after a long-term urea application but decreased after DMPP addition. The long-term application of urea increased the potential nitrification rate (PNR) by the enrichment of the genera with a high ammonia oxidation capacity in the AOB population. In contrast, DMPP addition weakened this effect and formed a population with a low ammonia oxidation capacity. Variations in the NOB population were mainly associated with fertilizer-induced changes in substrate NO₂⁻, whereas DMPP and NBPT had minor impacts on the NOB population. Additionally, the change in the denitrification population was indirectly affected by the soil ammonium (NH₄⁺) content with a long-term N stabilizer application. These findings provide a new interpretation related to the response mechanisms of the nitrifier and denitrifier populations for the long-term use of N stabilizers in soils. Full article

The use of mineral nitrogen (N) fertilizers is associated with significant nitrogen loss through the volatilization. Ammonia (NH₃) emissions are common from fertilizers with amide (NH₂) and ammonium (NH₄) nitrogen forms applied to the soil surface without incorporation. The objective of the laboratory and greenhouse pot experiments was to verify the hypothesis that liquid mineral fertilizers and fertilizer solutions containing N-NH₂ and N-NH₄ applied to the soil surface in combination with natural hydroabsorbents (NHAs) will reduce the volatilization of nitrogen. The effect of NHAs addition to urea ammonium nitrate (UAN) fertilizer and urea, ammonium nitrate (AN) and ammonium sulphate (AS) solutions was evaluated in a laboratory experiment. The effect of the two types of NHAs (acidic and neutral) was compared with the control (UAN) and its mixture with the commercially used urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). The proportion of volatilized NH₃ of the total N from the examined fertilizers applied to the soil surface was determined by the titration method. Subsequently, the effect of fertilization with UAN and its mixture with NHAs and NBPT on the growth of maize under the drought conditions was verified in a greenhouse pot experiment. While the addition of NBPT resulted in a reduction of NH₃ emission for the fertilizers containing NH₂ (UAN, urea solution), a decrease in volatilization after the addition of both acidic and neutral NHA was observed especially for UAN. A reduction in ammonia emission was also observed for AS after the addition of acidic NHA. The addition of both NHAs and NBPT to UAN increased the utilization of nitrogen from the applied fertilizer, which was reflected by an increase in chlorophyll content and increased CO₂ assimilation by maize plants grown under the drought stress. UAN fertilizer combined with acidic NHA and NBPT significantly increased aboveground biomass production and root system capacity of maize. Significant increases in UAN nitrogen recovery were observed for all examined additives (UI and both types of NHAs). In addition to the known effects of hydroabsorbents, especially their influence on soil physical and biological properties and soil water retention, the effect of NHAs application in combination with UAN and AS solutions on the reduction of gaseous N loss, maize plant growth and fertilizer nitrogen recovery was found. Full article

Urea granule dissolution in soil and soil urease activity are essential parameters for the accurate prediction of nitrogen dynamics after urea application, but both are scarcely studied. The response of urease activity to temperature is unclear under the addition of urease or nitrification inhibitors. In this study, we conducted laboratory incubation trials using glass jars with 100 g soil to quantify urea granule dissolution. Urease activity after urease and nitrification inhibitor addition were investigated in plastic bottles (5 g soil) under different temperatures. Inhibitor N-(2-nitrophenyl) phosphoric triamide (2-NPT), and a mixture of dicyandiamide and 1 H-1,2,4-triazol (DCD/HZ) were tested as urease and nitrification inhibitors separately and in combination. The dynamics of urease activity was fitted with Michaelis–Menten kinetics combined with the Van’t Hoff equation. At low soil moisture contents close to air-dry conditions (4–8% w/w water content), soil moisture was the dominant factor, but at higher soil moisture contents (28% and 48% w/w), temperature controlled the dissolution process. Dissolution could take several days or even longer at very dry soil conditions, while it was completed between a few hours and 24 h at high soil moisture levels. Urea with urease inhibitor formulation dissolved significantly slower at a moisture level of 28% (w/w). In the studied soil, urease activity varied between 2.9 and 54.4 mg NH₄⁺-N kg⁻¹ h⁻¹. Across all urea concentrations, the addition of urease inhibitor 2-NPT significantly reduced urease activity. The relationship between urease activity and urea addition rate could be accurately described with Michaelis–Menten kinetics, and urease inhibitor addition reduced the temperature sensitivity of urease activity by 7%, while the nitrification inhibitor increased it by 4%. Parameter estimates and process characterization for urea granule dissolution and urea hydrolysis in this study are meaningful for and helpful in agricultural practice and the model simulation of soil nitrogen dynamics. Full article

Metabolic syndrome is a set of risk factors that consist of abdominal obesity, arterial hypertension, alterations in the lipid profile, and hyperglycemia. The current therapeutic strategy includes polypharmacy, using three or more drugs to control each syndrome component. However, this approach has drawbacks that could lead to therapeutic failure. Multitarget drugs are molecules with the ability to act on different targets simultaneously and are an attractive alternative for treating complex diseases such as metabolic syndrome. Previously, we identified a triamide derivative of 5-aminoanthranilic acid that exhibited hypoglycemic, hypolipemic, and antihypertensive activities simultaneously. In the present study, we report the synthesis and in combo evaluation of new derivatives of anthranilic acid, intending to identify the primary structural factors that improve the activity over metabolic syndrome-related parameters. We found that substitution on position 5, incorporation of 3,4-dimethoxyphenyl substituents, and having a free carboxylic acid group lead to the in vitro inhibition of HMG-CoA reductase, and simultaneously the diminution of the serum levels of glucose, triglycerides, and cholesterol in a diet-induced in vivo model. Full article

A series of eleven benzylated intermediates and eleven target compounds derived from salicylanilide were tested against Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 as reference strains and against three clinical isolates of methicillin-resistant S. aureus (MRSA) and three isolates of vancomycin-resistant E. faecalis. In addition, the compounds were evaluated against Mycobacterium tuberculosis H37Ra and M. smegmatis ATCC 700084. The in vitro cytotoxicity of the compounds was assessed using the human monocytic leukemia cell line THP-1. The lipophilicity of the prepared compounds was experimentally determined and correlated with biological activity. The benzylated intermediates were found to be completely biologically inactive. Of the final eleven compounds, according to the number of amide groups in the molecule, eight are diamides, and three are triamides that were inactive. 5-Chloro-2-hydroxy-N-[(2S)- 4-(methylsulfanyl)-1-oxo-1-{[4-(trifluoromethyl)phenyl]amino}butan-2-yl]benzamide (3e) and 5-chloro-2-hydroxy-N-[(2S)-(4-methyl-1-oxo-1-{[4-(trifluoromethyl)phenyl]amino)pentan-2-yl)benzamide (3f) showed the broadest spectrum of activity against all tested species/isolates comparable to the used standards (ampicillin and isoniazid). Six diamides showed high antistaphylococcal activity with MICs ranging from 0.070 to 8.95 μM. Three diamides showed anti-enterococcal activity with MICs ranging from 4.66 to 35.8 μM, and the activities of 3f and 3e against M. tuberculosis and M. smegmatis were MICs of 18.7 and 35.8 μM, respectively. All the active compounds were microbicidal. It was observed that the connecting linker between the chlorsalicylic and 4-CF₃-anilide cores must be substituted with a bulky and/or lipophilic chain such as isopropyl, isobutyl, or thiabutyl chain. Anticancer activity on THP-1 cells IC₅₀ ranged from 1.4 to >10 µM and increased with increasing lipophilicity. Full article

After evaluating the ecological and economic aspects, it is predicted that the use of urease inhibitors and biological preparations should reduce the risk of nutrient leaching by using fertilizers containing amide, ammonium, and nitrate forms of nitrogen and would increase nitrogen use efficiency. Moreover, with lower nitrogen fertilizer rates, it would be possible to achieve or even increase planned maize biomass yield. The field experiment was performed in 2019–2021 at the Experimental Station of Vytautas Magnus University Agriculture Academy. The soil of the experimental field was Endohipogleyic-Eutric Planasol. The aim of this study was to investigate the effect of urease inhibitors and biological preparations in combination with nitrogen fertilizers on the productivity of aboveground maize (Zea mays L.) biomass. A two-factor experiment was carried out: factor A included nitrogen fertilizer rates of (1) 100 kg N ha⁻¹, (2) 140 kg N ha⁻¹, and (3) 180 kg N ha⁻¹; and factor B included the use of preparations of (1) no use of urease inhibitors (UIs) and biological preparations (BPs) (control), (2) the urease inhibitor ammonium thiosulphate (UI ATS), (3) the urease inhibitor (UI URN)—N-Butyl-thiophosphorus triamide (NBPT), (4) the biological preparation of suspension of humic and fulvic acids (BP HUM); and (5) the biological preparation (BP FIT) of suspension of Ascophyllum nodosum The studies showed that the dry matter yield of maize was significantly increased not only by increasing nitrogen fertilizer rates but also by the use of UIs and BPs. The highest dry matter yield of maize (24.1 t ha⁻¹) was obtained with N₁₈₀ fertilizer and UI ATS. UI ATS significantly increased the dry matter yield of the aboveground maize in all nitrogen fertilization backgrounds. The UIs and BPs tested had a greater and significant (p < 0.05) effect on the dry matter yield of maize at lower rates of N₁₀₀ and N₁₄₀ nitrogen fertilizer. Increasing nitrogen fertilizer rates up to N₁₈₀ had a positive significant effect on dry matter yields of the aboveground part of maize, its cobs, leaves, and stems. Positive, moderate, strong, and very strong correlations were found in most cases between the latter variables. These correlations were statistically significant (r² = 0.62–0.98). The UIs and BPs increased the efficiency of nitrogen fertilizer; therefore, the lower rates of nitrogen fertilizer (N₁₀₀ and N₁₄₀) could be used to produce maize productivity the same as that obtained with a high rate of nitrogen fertilizer (N₁₈₀). Full article