Annual Nitrogen Balance from Dairy Barns, Comparison between Cubicle and Compost-Bedded Pack Housing Systems in the Northeast of Spain

The aim of this study was to determine N recovery and irreversible losses (i.e., through NH3-N volatilization) from manure in two different housing systems throughout a year using an N mass balance approach. Dietary, milk, and manure N were monitored together with outside temperatures in six dairy barns during six months, comprising two different seasons. Three barns were designed as conventional free stalls (cubicle, CUB) and the other three barns as compost-bedded packs (CB). All the barns were located in the Ebro’s valley, in the northeast of Spain. Mass N balance was performed simultaneously in the six barns, during two three-month periods (Season I and II) and sampling at a 15-day interval. Results of ANOVA analysis showed that annual N retained in manure (kg/head per year) from cows housed in CUB barns was significantly higher than in manure from cows housed in CB (133.5 vs. 70.9, p < 0.001), while the opposite was observed for N losses (26.9 vs. 84.8, for CUB and CB barn, respectively; p < 0.005). The annual mean proportion of irreversible N loss from manure in relation to N intake was much lower in barns using conventional free-stall cubicles than the mean ratio registered in bedded pack systems barns.

Different Zn loading in Urea–Formaldehyde influences the N controlled release by structure modification

Nitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its high concentration and affordability. Nevertheless, urea fast solubilization leads to frequent losses and lower agronomic efficiency. The modification of urea structure by condensation with formaldehyde has been proposed to improve nutrient uptake by plants and to reduce environmental losses. Herein we show that the co-formulation with Zn strongly modifies the N release (in lab conditions) and, more important, the Zn source—ZnSO4 or ZnO—has a critical role. Urea–formaldehyde (UF) served as a matrix for the zinc sources, and chemical characterizations revealed that Zn particles influenced the length of the polymeric chain formation. Release tests in an aqueous medium showed that the UF matrix favors ZnO release and, on the other hand, delays ZnSO4 delivery. Soil incubation with the fertilizer composites proved the slow-release of N from UF, is ideal for optimizing nutritional efficiency. Our results indicated that the ZnO-UF system has beneficial effects for both nutrients, i.e., reduces N volatilization and increases Zn release.

Different Zn Loading in Urea-Formaldehyde Influences the N Controlled Release by Structure Modification

Nitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its high concentration and affordability. Nevertheless, urea fast solubilization leads to frequent losses and lower agronomic efficiency. The modification of urea structure by condensation with formaldehyde has been proposed to improve nutrient uptake by plants and to reduce environmental losses. Herein we show that the co-formulation with Zn strongly modifies the N release (in lab conditions) and, more important, the Zn source – ZnSO4 or ZnO – has a critical role. Urea-formaldehyde (UF) served as a matrix for the zinc sources, whose chemical characterizations revealed that Zn particles influenced the length of the polymeric chains' formation. Release tests in an aqueous medium showed that the UF matrix favors ZnO release and, on the other hand, delays ZnSO4 delivery. Soil incubation with the fertilizer composites proved the slow-release of N from UF, ideal for optimizing nutritional efficiency. Our results indicated that ZnO: UF system has beneficial effects for both nutrients, i.e., reduces N volatilization and increases Zn release.

The Effect of Untreated and Acidified Biochar on NH3-N Emissions from Slurry Digestate

The development of new options to reduce ammonia (NH3) emissions during slurry manure storage is still required due to the shortcomings of the current technologies. This study aimed to identify to what extent untreated and acid-treated biochar (BC) and pure acids could reduce ammonia nitrogen (NH3-N) volatilization and increase nitrogen retention in slurry digestate. The NH3-N emissions were effectively reduced by H2SO4 and H3PO4 acids, untreated BC when applied mixed into the digestate and acidified BC treatments applied on the surface of the digestate. Acidification increased the specific surface area and number of O-containing surface functional groups of the BC and decreased the pH, alkalinity and the hydrophobic property. Compared to untreated BC, the ability of BC to reduce NH3-N emissions was greater when it was acidified with H2SO4 and applied to the digestate surface. The effect on digestate pH of acidified BC when applied mixed into the digestate was not different, except for H2O2, from that of the addition of the respective pure acid to digestate. The total N concentration in digestate was not significantly correlated with NH3-N emissions. These findings indicate that acidified BC could be an effective conditioner to reduce NH3-N emissions from slurry digestate storage.

Avaliação de fertilizantes de eficiência aumentada aplicados em cobertura sem incorporação nos parâmetros morfológicos e produtivos na cultura do café

O equilíbrio nutricional das plantas é fundamental para se evitar perdas de produtividade. O N é o nutriente que proporciona maior resposta em termos de produção na cultura do café, e a fonte nitrogenada mais utilizada é a ureia, sendo sujeita a perdas de N por volatilização de amônia quando aplicada sem incorporação. Para evitar tais perdas, fontes nitrogenadas de eficiência aumentada têm sido comercializadas como eficientes na redução da volatilização do N. Assim sendo, objetivou-se, com este estudo, avaliar as fontes nitrogenadas aplicadas em cobertura na cultura do café. O trabalho foi desenvolvido no Instituto Federal de Educação, Ciência e Tecnologia de Minas Gerais (IFMG) - Campus Bambuí, em área de cafeeiro do cultivar Rubi, em espaçamento 3 x 0,8m, em um Latossolo Vermelho. O experimento foi realizado em blocos casualizados, com quatro repetições; os tratamentos incluíram sete fontes nitrogenadas, e foram realizadas quatro adubações, por dois anos, com intervalos mensais. As parcelas experimentais foram compostas por 10 plantas; contudo, somente oito foram avaliadas quanto ao diâmetro de copa, altura, número de ramos e produtividade, um mês após a cobertura. Foram analisados o IRCF da clorofila A (IRCA), da clorofila B (IRCB) e a clorofila total (IRCT). O uso dos adubos ureia + Cu + B e ureia + NBPT demonstrou, em modificações fisiológicas, que pode gerar um melhor desempenho de crescimento devido a uma maior capacidade fotossintética, posto que o adubo cinco proporcionou aumento na produtividade do cafeeiro. Palavras-chave: Amônia. Clorofila. Produtividade. Evaluation of increased efficiency fertilizers applied in coverage without incorporation in the morphophysiological and productive parameters in coffee culture Abstract The nutritional balance of the plants is fundamental to avoid losses of productivity. N is the nutrient that provides the greatest production response in the coffee crop. The most used nitrogen source is urea, which is subject to N losses by volatilization of ammonia when applied without incorporation. In order to avoid such losses, nitrogen sources of increased efficiency have been commercialized as efficient in the reduction of N volatilization. Thus, this work aimed to evaluate the nitrogen sources applied in the coffee crop. The work was developed at the Federal Institute of Education, Science and Technology of Minas Gerais (IFMG) – Bambuí Campus, in a coffee area of the Rubi cultivar, spaced 3 x 0.8 m in a Red Latosol. The experiment was performed in a randomized complete block with four replicates, treatments included seven nitrogen sources and four fertilizations were performed for two years with monthly intervals. The experimental plots were composed of 10 plants, however, only eight were evaluated for crown diameter, height, number of branches and productivity one month after coverage. IRCF of chlorophyll A (IRCA), chlorophyll B (IRCB) and total chlorophyll (IRCT) were analyzed. The use of fertilizers urea + Cu + B and urea + NBPT translated into physiological modifications that can generate a better growth performance due to a greater photosynthetic capacity, since the fertilizer five provided an increase in coffee productivity. Keywords: Ammonia. Chlorophyll. Productivity.

Additives incorporated into urea to reduce nitrogen losses after application to the soil

The objective of this work was to develop urea-based fertilizers with internal incorporation of urease inhibitors and other additives in the granule. The effects of the incorporation of NBPT, copper (Cu+2), boric acid (H3BO3), elemental sulphur (Sº), and a clay mineral from the zeolite group in powder urea - with ten different combinations of these additives - were evaluated as to N losses by volatilization and leaching. The losses in laboratory-developed formulations were compared with those of commercial fertilizers coated with the same additives (Super N, FH Nitro Mais, and FH Nitro Gold). The evaluations were made in greenhouse conditions, using a Ultisol accommodated in PVC columns. Nitrate and ammonium leaching was evaluated in the solution percolated through the soil columns. Ammonia volatilization was measured with a semi-open static chamber. The incorporation of urease inhibitors (NBPT, H3BO3, and Cu+2) into the urea granules was efficient to reduce N volatilization. Ammonia volatilization in the laboratory-developed ureas was lower than in commercial fertilizers coated with the same additives, while ammonium sulfate losses by leaching were similar. The addition of zeolite does not reduce N volatilization. Mineral N leaching in the soil profile is not affected by urease inhibitors.

Ammonia volatilization losses in Tanzania grass fertilized with urea

<p>Gaseous losses are the main factors affecting the efficiency of nitrogenous fertilizers in pastures. To evaluate NH₃-N volatilization losses in Tanzania grass fertilized with urea in autumn, spring and summer, a completely randomized design with repeated measurements over time and fifteen replicates was used. Plots were represented by urea levels (50; 100 and 150 kg ha^-1 N) and subplots by time after fertilization (1; 2; 3; 6; 9; 12 and 15 days). The interaction between fertilization leveland time after urea application was significant for the accumulated NH₃-N volatilization. Urea application leads to higher percentage N losses in the first three days after application. The average cumulative NH₃-N loss for the three occasions (different seasons of the year) was 28%, 20% and 16% of N applied for fertilizer doses of 50; 100 and 150 kg ha^-1of N, respectively. The season of the year influenced NH₃-N loss pattern and volume, with the lowest values recorded in spring, followed by summer and autumn. The cumulative NH₃-N volatilization loss varies from 78 to 90% up to the third day after application of the total N-NH3 loss.</p>

Effects of lignosulfonate-fertilizer applications on soil respiration and nitrogen dynamics

Lignosulfonate (LS) has been used as a carrier for micronutrients and has the potential to improve macronutrient fertilizer efficiency, but little is known about the behaviour of LS fertilizer mixtures in soil. A laboratory study was conducted using ammonium lignosulfonate (2.67% wt wt−1) in combination with diammoniumphosphate (DAP), urea (U) and U+DAP incubated in a silty clay loam soil. The experiment monitored CO2 evolution and NH3–N volatilization for 69 d and extractable soil N periodically for 38 d. Addition of LS initially increased CO2 evolution, but only a small proportion (10–22%) of the LS-C was evolved as CO2. Lignosulfonate decreased urea hydrolysis slightly and reduced the proportion of added N volatilized from the LS+U treatment. Lignosulfonate treatments accumulated N in the form of [Formula: see text], suggesting that LS may inhibit nitrification. A larger proportion of added inorganic N was recovered in the LS + fertilizer treatments, indicating that LS may increase fertilizer N availability. Key words: Lignosulfonate, urea, diammonium phosphate, ammonia volatilization, nitrification, fertilizer efficiency