Replacement Of Urea Research Articles

The Synergistic Optimization of Rice Yield, Quality, and Profit by the Combined Application of Organic and Inorganic Nitrogen Fertilizers

The replacement of urea with polymer-coated urea (PCU) fertilizer and the application of organic fertilizers (OFs) are effective strategies for reducing N loss in farmland and preventing soil degradation. However, limited research has been conducted on the synergistic effects of OF combined with inorganic N fertilizer, particularly PCU, on rice yield, quality, and profit. To address this issue, a two-year field experiment was conducted involving five fertilization treatments: no nitrogen fertilizer (0N), urea applied at the full local rate of 270 kg N ha−1 (CK), PCU at a reduced rate of 240 kg N ha−1 (T1), a combination of 70% PCU and 30% urea at 240 kg N ha−1 (T2), and T2 supplemented with 4500 kg ha−1 of OF (T3). The results showed that, compared with CK, the T1 treatment improved the appearance quality and taste value but slightly reduced the other quality indices. In contrast, the T2 and T3 treatments enhanced the grain yield, especially for T3, with an advantage in the tiller number, shoot dry weight, and leaf area index, which promoted the panicle number, filled grain, and grain weight, thereby significantly increasing the yield. The T2 improved the processing, appearance, and taste qualities by reducing the protein content, increasing the amylose content and gel consistency, and optimizing the starch viscosity characteristics (increasing the peak viscosity and breakdown while reducing the setback and consistency), with the addition of OF (T3) further expanding the benefits. Furthermore, the nutritional quality was also enhanced by optimizing the protein components and increasing the protein yield. Although the agricultural inputs in the T2 and T3 treatments were higher, the profit from the increased grain yield could cover these inputs, thereby maintaining profit with T3 or increasing profit with T2. In summary, the combined application of PCU with urea and OF can synergistically improve the rice yield, quality, and profit.

Ammonia loss potential and mitigation options in a wheat-maize rotation system in the North China Plain: A data synthesis and field evaluation

The North China Plain (NCP) is an intensive agricultural area and ammonia (NH3) emission hotspot in China. Urgent mitigation actions are needed to reduce its environmental impact. A field trial was conducted, and results combined with a synthesis of existing data to assess the NH3 loss and mitigation potentials in a wheat-maize double-crop rotation, a dominant crop production system in the NCP. Ammonia volatilization losses from N fertilizer applied to summer maize and winter wheat were 9.1% and 5.0%, respectively, based on the data synthesis, and were significantly affected by fertilizer application method and N fertilizer type. From the field trial, optimized reduction in N application rate, compared with conventional practice, had great efficiency for NH3 mitigation. Despite their high NH3 reduction potential, the higher input costs associated with the use of controlled-release fertilizers, replacement of urea with calcium ammonium nitrate or inclusion of double inhibitors (urease and nitrification inhibitors) with urea limited their applicability from an economic perspective. The inclusion of a urease inhibitor with urea achieved over 70% reduction in NH3 emission and also gave a significant improvement in grain yield, net income and N use efficiency. Future adoption of NH3 mitigation options in the NCP should focus on establishing a reduction target and consider the cost-benefits of simultaneous implementation of multiple mitigation techniques.

VALUE ADDED FERTILIZERS AMELIORATE GRAIN YIELD AND NUTRITIONAL QUALITY OF MAIZE CROP

A field trial was conducted to gauge the impact of value added NPK fertilizer,Zarkhez Plus, (N:08%;P:23%; K;18%) and biologically activated Zinc coated Urea (BAZU) maize.Treatments consisted; Control (T1), Straight Fertilizers (DAP, MoP, Urea) (T2), Zarkhez Plus + BAZUas 1/3rd replacement of Urea (T3), Zarkhez Plus + BAZU as 2/3rd replacement of Urea (T4), andZarkhez Plus + BAZU as 1/3rd replacement of Urea (T5). Results suggested that plant height, stemgirth, rows cob-1, grains row-1, grains cob-1, thousand seed weight were significantly improved by theapplication of Zarkhez Plus and BAZU. Grain yield was increased upto 30% with the application ofZarkhez Plus and BAZU compared to straight fertilizers. Application of BAZU beyond 1/3rd of thetotal N requirement did not increase the grain yield significantly but improved grain quality withhigher Zn and K contents. Maize grain yield can be significantly increased with the application ofZerkhez Plus and replacing 1/3rd in-season N requirement with BAZU.

Nutrient Utilisation in Ram Lambs Fed with Coated Slow Release Non-protein Nitrogen Sources

Background: Urea is commonly used as source of non protein nitrogen for ruminants. However, the fact that the rate of release of NH3-N must coincide with the rate of digestion of carbohydrates or else lead to toxicity, this has led the industry to seek the development of compounds with a slow release urea (SRU), which have less risk of toxicity in animals. Methods: A study was conducted on 30 ram lambs (1-2 month old; 14.73±0.49 kg body weight) randomly allotted to 5 dietary treatments with 6 animals in each group in a completely randomized design to evaluate the effect of supplementation of SRNPN products on nitrogen balance, plane of nutrition and nutrient utilisation. Five maize stover based complete diets (2190kcal ME/kg and 14.6% CP) were prepared viz. control diet with SBM as major protein source (45% CP) and without any NPN supplement, positive control diet, having urea (46% N) around 1% of dietary DM and in other 3 diets, urea was totally replaced with FCU, CFCU and HMCCU. Result: Supplementation of SRNPN products did not affect the intake of nutrients viz. DM, OM, CP, CF, NFE, NDF, ADF, hemicellulose and cellulose and the digestibilities of DM, OM, NFE and ADF. While, CP digestibility (%) reduced (P less than 0.01) with feeding of urea (78.52) based diet compared to control diet (84.34) and replacement of urea with FCU (85.24) improved the CP digestibility (%) and was comparable to control. Incorporation of urea in the diets decreased (P less than 0.01) the CF and cellulose digestibility compared to control, while incorporation of FCU or CFCU in diets improved (P less than 0.01) CF, NDF and hemicellulose digestibilities. The N intake, excretion and balance (g/d) was though comparable among the dietary groups, the retention in lambs fed urea diets was lower by 14.71% compared to control group, while in FCU, CFCU and HMCCU fed lambs, N retention improved by 18.17, 10.05 and 7.84%, respectively compared to urea diet fed lambs.

Optimization of an IgG1 CIEF separation by using narrow-range ampholytes and DMSO as protein solubilizer.

CIEF is a powerful separation tool utilized in the characterization and relative quantitation of therapeutic mAb charged isoforms. However, one CIEF method is not capable of separating all mAbs with high resolution and reproducibility. Optimization of sample composition and separation parameters is expected when developing a CIEF method for a specific mAb. This paper summarizes a root cause investigation into why a validated CIEF separation method for MAK33 (a type of IgG1) was no longer reproducible. In addition, this paper introduces the concept of sample focusing volume, which is defined as the actual capillary volume occupied by the sample after focusing and explains why there is less protein precipitation and aggregation when using narrow-range ampholytes than broad-range ampholytes. The use of DMSO as protein solubilizer and possible replacement of urea is also explored in this work. Finally, this paper demonstrates that a new optimized CIEF method can achieve over 100 reproducible high-resolution separations of MAK33 per neutral-coated capillary.

Effects of Nitrate Supplementation on Nutrition, Performance and Methane Mitigation in Ruminants: A Review

Nitrate supplementation is a viable option to mitigate enteric methane emission and also to improve animal performance. It is a well established fact that bacteria from the rumen are able to use nitrate as electron acceptors, instead of carbon dioxide and when nitrate is used as an alternative electron acceptor, methane production is reduced. The reduction of nitrate to ammonia, consumes eight electrons and each mole of nitrate reduced could thus lower methane production by 1 mole. In addition, to inhibiting methane production, the end product of nitrate production ammonia, is an essential nutrient for the rumen microbial population for protein synthesis and for the growth of microbial cells. Microbial protein in turn is the source of amino acids, absorbed and used for animal growth, reproduction and milk production. Urea, which is quickly converted to ammonia in the rumen, is often included in ruminant diets as a nitrogen supplement. The replacement of urea with nitrates in ruminant diets is feasible, subject to the management of nitrate supplementation. A further useful feature of nitrate supplementation is that, small amounts of nitrogen oxides produced during the nitrate metabolism in the rumen inhibit the activities of some methanogens, potentially increasing the level of inhibition of methane production where nitrate is only a proportion of the total fermentable nitrogen in a diet.

Management opportunities to mitigate greenhouse gas emissions from Chinese agriculture

Agriculture accounts for approximately 11% of China’s national greenhouse gas (GHG) emissions. Through adoption of region-specific best management practices, Chinese farmers can contribute to emission reduction while maintaining food security for its large population (>1300 Million). This paper presents the outcome of a bottom–up assessment to quantify technical potential of mitigation measures for Chinese agriculture using meta-analysis of data from 240 publications for cropland, 67 publications for grassland and 139 publications for livestock, and provides the reference scenario for the cost analysis of identified mitigation measures. Management options with greatest mitigation potential for rice, or rice-based cropping systems are conservation tillage, controlled irrigation; replacement of urea with ammonium sulphate, nitrogen (N) inhibitor application, reduced N fertilizer application, integrated rice-fish-duck farming and biochar application. A 15% reduction in current average synthetic N fertilizer application for rice in China i.e., 231kg N ha−1, would result in 12% decrease in direct soil nitrous oxide (N2O) emissions. Combined application of chemical and organic fertilizer, conservation tillage, biochar application and reduced N application are possible measures that can reduce overall GHG emissions from upland cropping systems. Conventional fertilizer inputs for greenhouse vegetables are more than 2–8 times the optimal crop nutrient demand. A 20–40% reduction in N fertilizer application to vegetable crops can reduce N2O emissions by 32–121%, while not negatively impacting the yield. One of the most important mitigation measures for agricultural grasslands could be conversion of low yielding cropland, particularly on slopes, to shrub land or grassland, which is also a promising option to decrease soil erosion. In addition, grazing exclusion and reduced grazing intensity can increase SOC sequestration and decrease overall emissions while improving the largely degraded grasslands. For livestock production, where poor quality forage is commonly fed, improving grazing management and diet quality can reduce methane (CH4) emissions by 11% and 5%, on average. Dietary supplements can reduce CH4 emissions further, with lipids (15% reduction) and tannins or saponins (11% reduction) showing the greatest potential. We also suggest the most economically cost-effective mitigation measures, drawing on related work on the construction of marginal abatement cost curves for the sector.

Highly efficient oxygen reduction on porous nitrogen-doped nanocarbons directly synthesized from cellulose nanocrystals and urea

This study displays an easy preparation of high-performance electrocatalyst from cellulose nanocrystals for oxygen reduction reaction (ORR) that occurs at cathode of fuel cells. Through a direct pyrolysis of cellulose nanocrystals and urea, porous nitrogen-doped carbon nanosheets (NCN) are successfully synthesized without involving any catalysts or post treatments. As-prepared NCN displays very high specific surface area (∼1362.36m2g−1), large pore volume (∼3.36cm3g−1) and high graphitic-/pyridinic-N proportion (∼80% in total N content). This metal-free material demonstrates a superior catalytic performance in terms of a comparable electrocatalytic activity, a better tolerance to the methanol crossover effect and an improved long-term durability toward ORR in the alkaline media when compared with the commercial Pt/C catalyst. Interestingly, the addition of FeCl3 catalyst to the reaction system does not benefit ORR activity of the resultant material; the replacement of urea by NH3 gas brings about much poorer material features of morphology, structure and catalytic activity. It is suggested that urea is irreplaceable during this catalyst-free synthesis of nitrogen-doped nanocarbons while cellulose nanocrystal is an unique choice for preparing high performance ORR electrocatalyst. The study herein contributes a very promising Pt-alternative cathode catalyst and also a facile and practical preparation of advanced carbon materials.

Digestibilidade total e parcial e balanço nitrogenado em bovinos em pastejo no período das águas recebendo suplementos com nitrogênio não-proteico e/ou proteína verdadeira

Objetivou-se avaliar o efeito de diferentes relações entre proteína verdadeira e nitrogênio não-proteico sobre a digestibilidade, a síntese de proteína microbiana e o balanço de compostos nitrogenados em bovinos em pastejo durante o período das águas. Foram utilizados cinco novilhos mestiços Holandês × Zebu, castrados, com peso vivo inicial de 335±35 kg fistulados no rúmen e no abomaso. Os tratamentos foram: controle (somente pasto); e suplementos com ureia; com 2/3 de compostos nitrogenados oriundos da ureia e 1/3 de compostos nitrogenados oriundos da albumina; com 1/3 de compostos nitrogenados oriundos da ureia e 2/3 de compostos nitrogenados oriundos da albumina; e com albumina. Foram fornecidos 200 g/dia de proteína bruta (PB) a partir dos suplementos. O experimento foi conduzido segundo delineamento em quadrado latino 5 × 5, com cinco períodos experimentais, cada um de 15 dias. A suplementação não afetou os coeficientes de digestibilidade total nem o teor de nutrientes digestíveis totais da dieta; elevou as estimativas do coeficiente de digestibilidade aparente ruminal da PB, que migraram de negativa, no tratamento controle, para positivas, porém não diferentes de zero, nos tratamentos envolvendo suplementação. O fornecimento de suplementos elevou a concentração de nitrogênio amoniacal ruminal. O balanço de compostos nitrogenados aumentou com a suplementação. A substituição de ureia por albumina influenciou de forma cúbica o balanço de compostos nitrogenados, cuja estimativa foi maior para o suplemento com 1/3 de PB oriunda da ureia. A eficiência de síntese microbiana no rúmen não foi influenciada pelo fornecimento ou pela composição dos suplementos. A suplementação de bovinos em pastejo com fontes de compostos nitrogenados degradáveis durante o período das águas amplia a eficiência de uso do pasto, principalmente por ampliar a retenção de compostos nitrogenados no organismo.

Consumo e dinâmica ruminal da fibra em detergente neutro em bovinos em pastejo no período das águas recebendo suplementação com nitrogênio não-proteico e/ou proteína verdadeira

Objetivou-se avaliar o efeito de diferentes relações entre proteína verdadeira e nitrogênio não-proteico sobre o consumo e a dinâmica de trânsito e degradação ruminal da fibra em detergente neutro (FDN) da forragem em bovinos em pastejo durante o período das águas. Foram utilizados cinco novilhos mestiços Holandês × Zebu, castrados, com peso corporal inicial de 335±35 kg fistulados no rúmen e no abomaso. Os tratamentos foram: controle (somente pasto); e suplementos com ureia; com 2/3 de compostos nitrogenados oriundos da ureia e 1/3 de compostos nitrogenados oriundos da albumina; com 1/3 de compostos nitrogenados oriundos da ureia e 2/3 de compostos nitrogenados oriundos da albumina; e com albumina. Foram fornecidos 200 g/dia de proteína bruta (PB) a partir dos suplementos. O experimento foi conduzido segundo delineamento em quadrado latino 5 × 5, com cinco períodos experimentais de 15 dias. Não foram observados efeitos da suplementação sobre o consumo voluntário, com exceção do consumo de PB, que aumentou com a suplementação. A substituição da ureia por albumina nos suplementos teve efeito linear sobre o consumo de PB. Os consumos dos demais componentes da dieta não foram afetados pela composição dos suplementos. Nenhum efeito foi observado sobre a taxa de passagem ruminal de compostos fibrosos. O fornecimento de suplementos ampliou, em média, a estimativa da taxa comum de latência e degradação da FDN. Contudo, não houve efeito da alteração na composição dos suplementos sobre este parâmetro. A suplementação de bovinos com fontes de compostos nitrogenados degradáveis no rúmen proteicos ou não-proteicos durante o período das águas não afeta o consumo voluntário de pasto.

Responses to graded replacement of urea by maize steep liquor in diets for intensively fed lambs for meat production

Urea is a common ingredient of the diets of intensively fed lambs, but is increasingly required for industrial processes. Maize steep liquor (MSL) is a by-product of maize grain degradation to produce starch that may be a suitable replacement. Fifty growing lambs were fed on equinitrogenous diets in which between 0% and 80% of the urea was replaced by MSL; their growth and metabolism were recorded over 70 days. Increasing replacement of urea by MSL increased feed intake and nutrient digestibilities, leading to increased growth rates, more efficient feed conversion, and increased nitrogen retention. Concentrations of triiodothyroxin, thyroxin, glucose, and methionine were increased by replacement of urea by liquor, and plasma urea was reduced. This study suggests that MSL is a suitable replacement for up to 80% of urea in the diet of rapidly growing lambs.

Adubação nitrogenada em cobertura para o milho cultivado após aveia preta no sistema plantio direto

A field experiment was carried out on a red dystrophic loam oxisol from Tibagi, Parana State, Brazil, to assessing whether surface-applied urea affects corn development and yield as a result of N-NH 3 losses by volatilization, and whether the partial or full replacement of urea by ammonium sulfate increases the effectiveness of nitrogen fertilization as sidedressing, without incorporation. A randomized complete block design was used, with three replications, in a split-plot experiment. The plots received four rates of N applied as top dressing: 30, 60, 90 and 120kg ha -1 . The subplots were constituted by four application forms: surface-applied urea, incorporated urea, surface-applied ammonium sulfate and surface-applied urea + ammonium sulfate. The N rates led to a linear increase in corn yield, number of grains per ear, ear weight per plant, grain weight per ear, and weight of 1000 grains. Urea, surface-applied or incorporated, and surface-applied ammonium sulfate performed similarly in nutrition and corn grain yield.

Desempenho e desenvolvimento ponderal de novilhas leiteiras alimentadas com dietas à base de cana de açúcar

O objetivo deste trabalho foi avaliar o desempenho e o desenvolvimento ponderal de novilhas alimentadas com dietas à base de cana-de-açúcar suplementadas com fontes de nitrogênio não-protéico (NNP) (uréia ou cama de frango, em substituição parcial da uréia) e, ou, adição de probióticos (sem probiótico, levedura ou microbiota ruminal). O custo e a margem bruta do uso destas dietas também foram analisados. Vinte e quatro novilhas, com idade e peso médio inicial de 15 meses e 247 kg PV, respectivamente, foram mantidas em baias individuais e alimentadas durante o período experimental de 84 dias. Os animais foram distribuídos em delineamento inteiramente casualisado, em esquema fatorial 2 x 3 (fonte de NNP vs fonte de probiótico), com quatro repetições. As novilhas foram pesadas e o perímetro torácico e a altura de cernelha e garupa foram determinados no início e no final do período experimental e a cada 28 dias. Os níveis de N-uréia plasmáticos das novilhas foram determinados em amostras de sangue coletadas imediatamente antes do fornecimento diário de alimento, zero hora, e às duas, quatro, seis e oito horas após a alimentação. Não houve interação entre fontes de nitrogênio e fontes de probióticos, para qualquer característica estudada. A suplementação da cana-de-açúcar com fontes NNP não apresentou diferença no ganho de peso diário dos animais. Entretanto, a adição de levedura ou microbiota ruminal promoveu ganhos semelhantes, porém superiores à sem adição de probióticos. A substituição parcial da uréia pela cama de frango não influenciou o desempenho das novilhas, mas as dietas suplementadas com levedura ou microbiota ruminal apresentaram maiores ganho de peso e desenvolvimento ponderal.

Comportamento ingestivo de novilhas leiteiras alimentadas com dietas à base de Cana-de-açúcar

O objetivo deste trabalho foi avaliar o comportamento ingestivo de novilhas mestiças Holandês x Zebu alimentadas com dietas à base de cana-de-açúcar suplementadas com fontes de nitrogênio não-protéico [NNP] (uréia e cama de frango, em substituição parcial da uréia) e, ou, adição de probióticos (sem probiótico, com levedura ou com microbiota ruminal). Vinte e quatro novilhas, com idade e peso médio inicial de 15 meses e 247 kg, respectivamente, foram mantidas em baias individuais e alimentadas à vontade, durante o período experimental de 84 dias. Os animais foram distribuídos em delineamento inteiramente casualisado, em esquema fatorial 2 x 3 (fontes de NNP vs fontes de probiótico), com quatro repetições. O comportamento ingestivo de cada novilha foi determinado visualmente, a cada 28 dias, a intervalos de 10 minutos, durante 24 horas. Não houve diferença no tempo despendido em alimentação, ruminação e mastigação total, em min/dia, das novilhas alimentadas com diferentes fontes de NNP e probióticos. O tempo médio de ruminação, em min/kg de MS e FDN, foi maior para os animais alimentados com uréia. O comportamento ingestivo das novilhas não foi influenciado pelas fontes de nitrogênio ou pela adição de probiótico.

Osmotic work across inner medullary collecting duct accomplished by difference in reflection coefficients for urea and NaCl.

To demonstrate that osmotic work can be accomplished across the inner medullary collecting duct (IMCD) by the difference in reflection coefficients for urea and NaCl, phenomenological coefficients for urea and NaCl transport were determined in isolated segments of the hamster IMCD perfused in vitro. Arginine vasopressin at 100 microU/ml increased urea permeability from 11.5 +/- 2.9 to 31.7 +/- 4.2 x 10(-7) cm2 s-1 in the middle IMCD but not in the upper IMCD. Urea transport in the middle IMCD consisted of two components, transport with saturable kinetics and simple passive diffusion. Permeability to Na+ was very low (2 x 10(-7) cm2 s-1). Reflection coefficients as measured by the equiosmolality method, with raffinose being a reference solute, were 0.87 +/- 0.05 and 0.71 +/- 0.04 for urea and 1.03 +/- 0.07 and 0.91 +/- 0.04 for NaCl in the upper and the middle IMCD, respectively. Reflection coefficient for urea in the middle IMCD was 0.68 when determined by the zero volume flux method. When the middle IMCD was perfused with bicarbonate Krebs-Ringer (BKR) solution containing 200 mmol/l urea, the replacement of urea in the bathing fluid with equisomolal NaCl caused large volume flux (3.81 +/- 0.45 nl mm-1 min-1) associated with dilatation of intercellular space. The existence of vasopressin in the bath was essential for this phenomenon. This effect was inhibited by 5 x 10(-4) M phloretin in the bath, suggesting that the vasoressin-stimulated urea transport is responsible for this phenomenon. From these observations, we conclude that transport parameters of the middle IMCD are appropriate for accomplishment of osmotic work across this segment in the absence of physicochemical osmotic gradients.

The effect of high levels of molasses in combinations with hay on digestibility of organic matter, microbial protein synthesis and volatile fatty acid production in vitro

Fermentation in vitro of 0 100 , 10 90 , 40 60 and 70 30 cane molasses/hay mixtures in media containing urea, trace minerals and vitamins showed a progressive improvement of digestible organic matter in vitro (INVDOM) of hay as the level of molasses increased. Replacement of urea by soya bean meal induced a lower INVDOM of hay in the mixture with 70% molasses. Structural carbohydrates (hay) induced higher microbial synthesis per unit digestible organic matter (DOM) than simple sugars (molasses). The results observed emphasized the importance of adding urea to molasses for improved digestion of hay and a higher percentagge of propionic acid in the rumen. The effect of formulation of molasses/hay rations with soya bean meal or urea on the pattern of fermentation is discussed.

O 2 Consumption and K +/Na + balance of elasmobranch kidney slices after replacement of urea by thiourea or acetamide

1. 1. O 2 consumption, potassium and sodium concentrations were measured in kidney slices of the dogfish, Scyliorhinus canicula, incubated in normal dogfish medium containing urea and in media in which urea was replaced by thiourea (thiourea medium) or acetamide (acetamide medium). 2. 2. In thiourea medium O 2 consumption and K + concentration were decreased and Na + concentration was increased compared with the values obtained in urea medium. 3. 3. In acetamide medium O 22 consumption, K + and Na + concentrations were the same as in urea medium. 4. 4. These results support the idea that the high urea concentrations in elasmobranch tissues mainly exert a relatively unspecific osmotic effect rather than a specific biochemical effect. Thiourea appears to be toxic.