Nitrogen Absorption Research Articles

Nutritivne strategije u ishrani koka nosilja u svetlu rešavanja izazova u zaštiti životne sredine smanjivanjem izlučivanja azota

This research aimed to assess the impact of incorporating Castanea sativa powder (CSP) into laying hens diets, examining reduced crude protein (CP) levels and their effects on production performance, haematological parameters, nutrients and mineral digestibility and environmental pollution by nitrogen (N) absorption and excretion. For that, a 6-week trial was developed, with 90 Lohmann Brown laying hens aged 51 weeks, raised in digestibility cages, divided into three groups with 30 hens each. The diets were composed as follows: a control group fed with 17.50% crude protein (CON), an experimental group with a reduced CP level of 15.50% (RPL), and a similar reduced CP group supplemented with 0.5% CSP (RPC) as tannin additive. The limiting amino acids (lysine, methionine, and threonine) were supplemented to maintain constant equal amino acid concentrations in all experimental diets. Throughout the feeding trial, the laying rate was higher in the RPC group (94.12%), followed by RLP (93.65%) and CON (91.11%). However, CON hens produced heavier eggs compared to RPL and RPC groups. Average daily feed intake and feed conversion ratio showed no significant differences (p>0.05) between the groups. Results from blood samples showed a significant increase (p<0.05) in RPL group on monocytes and uric acid compared with CON and RPC groups with tendencies for leucocytes, lymphocytes, heterophiles. Notably, excreted N levels were significantly reduced (up to 30%) in RPL (0.33 mg N/100g) and RPC (0.30 mg N/100g) groups compared to the CON (0.42 mg N/100g) group, showing a promising way of reducing N pollution. The RPC group had significantly higher (p<0.05) N content and coefficient of apparent N absorption compared with RPL group. On the other hand, the CP excretion was significantly lower (p<0.05) in the RPL (2.06 mg CP/100g) and RPC (1.94 mg CP/100g) groups compared with CON group (2.63 mg CP/100g). The lowest CP absorption was determined in the RPL group, while the RPC group (88.24%), had the highest coefficient of apparent absorption, compared with both CON (86.18%) and RPL (86.22%) groups. No significant effect on mineral excretion content was observed.

Effects of Nitrogen Reduction at Different Growth Stages on Maize Water and Nitrogen Utilization under Shallow Buried Drip Fertigated Irrigation

A field experiment of drip fertigated nitrogen reduction was set up in a typical Maize planting area in the Xiliao River Basin in 2018 and 2019. Different phased nitrogen reductions were set up under shallow buried drip irrigation during the growth period to explore ways to improve nitrogen use efficiency (NUE) by understanding the Maize regulation of nitrogen absorption and utilization. The recommended nitrogen application in the early stage (Nopt, total nitrogen 240 kg·hm−2) had the highest grain nitrogen uptake and total nitrogen uptake, followed by nitrogen reduction before the maximum canopy mulching (Nde-I, total nitrogen 180 kg·hm−2), nitrogen reduction after the maximum canopy mulching (Nde-II, total nitrogen 180 kg·hm−2) and no nitrogen application (N0). Without nitrogen application, the leaves were thin, green and yellow. The total nitrogen uptake was 38.54~41.31% lower than the recommended nitrogen application in the early stage. When nitrogen fertilizer was reduced in the maximum canopy mulching, grain nitrogen absorption was affected. Grain nitrogen absorption fell by 15.07% to 17.51% when nitrogen was reduced in the maximum canopy mulching compared to the recommended nitrogen application. The harvest index of nitrogen reduction before the maximum canopy coverage was 9.65~11.52% higher than that in the later stage, indicating that the nitrogen absorption between Maize grain, stem, and leaf was better regulated. Maize evapotranspiration water consumption was reduced throughout the growth cycle when nitrogen was reduced at various stages. Nitrogen reduction before maximum canopy mulching boosted water use efficiency (WUE) by 3.44% to 6.12% compared to the recommended nitrogen application in the early stage. The nitrogen fertilizer agronomic efficiency increased by 11.17% to 13.87%. The nitrogen use efficiency rose by 10.99~3.15% (5.24~6.60 percentage points). A total of 25% of nitrogen fertilizer was saved with the yield declining by only about 5%, resulting in increased NUE while maintaining the yield stability. Under shallow buried drip fertigated irrigation, the appropriate reduction in nitrogen fertilizer during the period from Maize sowing to the maximum canopy development ensured the nitrogen supply during tasseling–silking stage and filling stage, which can be used as a regulation method and a way to improve the Maize fertilizer use efficiency.

Nitrogenous Porosity and Ways to Prevent it Under Conditions of Arc Surfacing in a Nitrogen-containing Atmosphere

Pores coming to the surface can cause a violation of the tightness of the valve when the valve is closed, as well as be a focus of erosive destruction, especially in conditions of high-speed flows of the medium. Pores also contribute to the corrosive destruction of metals, since under the influence of certain aggressive media, they increase in size and cause a breach of the tightness of the gate. In the presence of carbon dioxide, nitrogen absorption by the weld pool metal increases and the tendency of the deposited metal to form pores decreases. The introduction of carbon dioxide of at least 30% to nitrogen makes it possible to obtain a dense deposited metal due to its better absorption of nitrogen. A significant factor reducing the formation of pores from nitrogen in the deposited metal 10X17H8X5G2T is the content of ferrotitane in the charge of the PP-AN 133 powder wire. The titanium content in the deposited metal should be within 0.2...0.4%. A further increase in the concentration of titanium leads to a deterioration in the formation of the deposited metal and to an increase in the amount of slag on the surface of the deposited layer

Responses of root characteristics and nitrogen absorption and assimilation to different pH gradients of winter wheat at seedling stage.

Nitrogen (N) and rhizosphere pH are the two main factors restricting the growth of winter wheat (Triticum aestivum L.) in North China Plain. Soil nutrient availability is affected by soil acidity and alkalinity. In order to understand the effect of rhizosphere pH value on wheat nitrogen metabolism and the response of wheat growth to pH value at seedling stage, winter wheat varieties 'Aikang 58' (AK58) and 'Bainong 4199' (BN4199) were tested in hydroponics under three pH treatments (pH = 4.0, 6.5, and 9.0). The results showed that the accumulation of dry matter in root and above ground under pH 4.0 and pH 9.0 treatments was lower than that under pH 6.5 treatments, and the root/shoot ratio increased with the increase of pH value. Regardless of pH value, 'BN4199' had higher root dry weight, root length, root surface area, root activity and root tip than 'AK58'. Therefore, wheat that is tolerant to extreme pH is able to adapt to the acid-base environment by changing root characteristics. At pH 4.0, the net H+ outflow rate of wheat roots was significantly lower than that of the control group, and the net NO3- flux of wheat roots was also low. The net H+ outflow occurred at pH 6.5 and 9.0, and at the same time, the net NO3- flux of roots also increased, and both increased with the increase of pH. The activity of nitrate reductase (NR) in stem of pH 9.0 treatment was significantly higher than that of other treatments, while the activity of glutamine synthetase (GS) in root and stem of pH 6.5 treatment was significantly higher than that of other treatments. Under pH 4.0 and pH 9.0 treatments, the activities of NR and GS in 'BN4199' were higher than those in 'AK58', The root respiration of 'BN4199' was significantly higher than that of 'AK58' under pH 4.0 and pH 9.0 treatment, and 'BN4199' had higher NO3- net flux, key enzyme activity of root nitrogen metabolism and root respiration. Therefore, we believe that 'BN4199' has strong resistance ability to extreme pH stress, and high root/shoot ratio and strong root respiration can be used as important indicators for wheat variety screening adapted to the alkaline environment at the seedling stage.

Evaluation of Nutrient Levels, Optical Sensors and Decision Support Tools for Nitrogen Optimization in Rice during Dry Season

Background: Improving the efficiency of nitrogen utilization in rice is vital for achieving significant crop yields with minimum harm to the environment. To tackle this challenge, various portable optical sensors and decision-support tools have been emerging in recent times. However, there is currently a lack of comprehensive assessment and comparison of these tools with different levels of fertilizer recommendation with and without additional supplementation of nano urea. Methods: The current study was carried out during the dry season of 2021 and 2022 at the P.G. Experimental Farm of Centurion University of Technology and Management. The investigated treatments encompassed the following: T1: Absolute control, T2: 90-45-45 (N-P2O5-K2O kg/ha), T3: 120-60-60 (RDF), T4: 150-75-75, T5: T2+NU @ 2 ml/L at panicle initiation, T6: T3+NU @ 2 ml/L at panicle initiation, T7: N application at LCC d™ 3, T8: N application at LCC d™4, T9: N application at SI less than 90%, T10: Nutrient Expert (TY: 5.5 t/ha), T11: Rice crop manager (TY: 5.5t/ha) which were allocated in randomized block design with three replications. Result: The findings showed that implementing nitrogen (N) application when the sufficiency index (SI) is below 90% led to a significant 16.85% boost to grain yield of rice compared to the application of 120-60-60 at fixed intervals as per the standard recommendation. In the former approach, 150 kg N/ha was applied in four splits. However, N application at a leaf color chart (LCC) value of 4 or less was considered efficient, with maximum agronomic efficiency (18.22 and 19.22 kg grain/kg N applied) and recovery efficiency (43.27% and 50.25%) observed in 2021 and 2022, respectively since, this approach resulted in a comparable yield increase and nitrogen absorption with a reduced nitrogen input.

Transcriptome analysis revealed regulatory mechanisms of light and culture density on free-living sporangial filaments of Neopyropia yezoensis (Rhodophyta)

Previous research indicated that free-living sporangial filament keep hollow morph under high-culture density and form bipartite cells under low-culture density, while the following conchospore release was inhibited by high light. Here, we further explored the molecular bases of these affects caused by light and culture density using a transcriptome analysis. Many differentially expressed genes (DEGs) related to carbon dioxide concentration and fixation, photosynthesis, chlorophyll synthesis and nitrogen absorption were upregulated under high-light conditions compared with low-light conditions, indicating the molecular basis of rapid vegetative growth under the former. The stress response- and ion transport-related DEGs, as well as the gene encoding the vacuole formation–brefeldin A-inhibited guanine nucleotide exchange protein (BIG, py05721), were highly expressed under high-density conditions, indicating the molecular basis of the hollow morph of free-living sporangial filaments under high-culture density conditions. Additionally, the brefeldin A treatment indicated that the hollow morph was directly influenced by vacuole formation-related vesicle traffic. Others DEGs related to cell wall components, zinc-finger proteins, ASPO1527, cell cycle and cytoskeleton were highly expressed in the low density with low-light group, which might be related to the formation and release of conchospores. These results provide a deeper understanding of sporangial filaments in Neopyropia yezoensis and related species.

The mechanism of melatonin promotion on cucumber seedling growth at different nitrogen levels

The supply level of exogenous nitrogen has a very important influence on the growth and development of cucumber. Insufficient or excessive nitrogen application will lead to metabolic disorders in the body and affect the formation of yield. Therefore, it is of great scientific and practical significance to explore the corresponding mitigation measures. Melatonin (MT) is a multi-regulatory molecule with pleiotropic effects on plant growth and development. A large number of studies have shown that the appropriate amount of melatonin supplementation is beneficial to plant growth and development by promoting root development, delaying leaf senescence, and improving fruit yield. However, the study of MT function combined with a detailed physiological analysis of nitrogen (N) absorption and metabolism in cucumber plants needs further strengthening. We performed hydroponic tests at different nitrogen levels to determine the metabolic processes associated with the enhanced tolerance to nitrogen in melatonin-treated cucumber (Cucucumis sativus L.) seedlings. Cucumber seedlings were sprayed with 100 μM melatonin or water and treated with different nitrogen in the growth chamber for 7 days. Nitrogen deficiency significantly inhibited seedling growth, and this growth inhibition was partially alleviated by melatonin. The expression analysis of related carbon and nitrogen genes showed that the genes whose expression was significantly altered by melatonin were mainly related to carbon (C) and nitrogen (N) metabolism. By enzyme activity and reactive oxygen content data analysis, melatonin-treated cucumber seedlings showed relatively stable carbon and nitrogen levels compared to untreated ones. In conclusion, MT can repair the impaired growth and development situation by regulating the nitrogen assimilation capacity and the balance between oxidation and oxidative metabolism and carbon metabolism in the cucumber under different nitrogen levels.

Trichoderma asperellum boosts nitrogen accumulation and photosynthetic capacity of wolfberry (Lycium chinense) under saline soil stress.

Trichoderma can promote plant growth under saline stress, but the mechanisms remain to be revealed. In this study, we investigate photosynthetic gas exchange, photosystem II (PSII) performance, nitrogen absorption and accumulation in a medicinal plant wolfberry (Lycium chinense) in saline soil supplemented with Trichoderma biofertilizer (TF). Larger nitrogen and biomass accumulation were found in plants supplemented with TF than with organic fertilizer (OF), suggesting that Trichoderma asperellum promoted plant growth and nitrogen accumulation under saline stress. T. asperellum strengthened root nitrogen (N) absorption according to greater increased root NH4+ and NO3- influxes under supplement with TF than OF, while nitrogen assimilative enzymes such as nitrate reductase, nitrite reductase and glutamine synthetase activities in roots and leaves were also stimulated. Thus, the elevated N accumulation derived from the induction of T. asperellum on nitrogen absorption and assimilation. Greater increased photosynthetic rate (Pn) and photosynthetic N-use efficiency under supplement with TF than OF illustrated that T. asperellum enhanced photosynthetic capacity and N utilization under saline stress. Although increased leaf stomatal conductance contributed to carbon (C) isotope fractionation under TF supplement, leaf 13C abundance was significantly increased by supplement with TF rather than OF, indicating that T. asperellum raised CO2 assimilation to a greater extent, reducing C isotope preference. Trichoderma asperellum optimized electron transport at PSII donor and acceptor sides under saline stress because of lower K and J steps in chlorophyll fluorescence transients under supplement with TF than OF. The amount of PSII active reaction centers was also increased by T. asperellum. Thus, PSII performance was upgraded, consistent with greater heightened delayed chlorophyll fluorescence transients and I1 peak under supplement with TF than OF. In summary, TF acted to increase N nutrient acquisition and photosynthetic C fixation resulting in enhanced wolfberry growth under saline soil stress.

MATHEMATICAL MODELS OF METHANE CONSUMPTION BY SOILS: A REVIEW

MATHEMATICAL MODELS OF METHANE CONSUMPTION BY SOILS: A REVIEW

Mixed cropping enhances the nitrogen and phosphorus purification efficiency of sewage in wetland ecosystems

Although the water purification performance of individual species and their removal mechanisms have been thoroughly documented, the potential enhancement of sewage nitrogen and phosphorus removal rates through the combined effects of different plant species has yet to be comprehensively investigated. This study opted for Canna indica and Thalia dealbata, two characteristic wetland plants from the Three Gorges Reservoir Area, as the test subjects. The impact of cropping patterns (single-cropping and mixed-cropping) on the efficiency of nitrogen and phosphorus removal from sewage at varying concentrations was explored. The findings unveiled that the mixed-cropping pattern considerably heightened the total nitrogen (TN) absorption of plants in sewage environments, though it did not appreciably affect total phosphorus absorption. Moreover, sewage concentration influenced the nitrogen and phosphorus absorption patterns of plants, potentially exhibiting a threshold phenomenon. Mixed cropping significantly augmented the removal rates of sewage nitrogen and phosphorus. Under the single cropping arrangement, C. indica displayed superior pollutant removal performance in comparison to T. dealbata. Furthermore, the wetland plants significantly diminished the TN content of the soil matrix. The results indicated that the mixed planting pattern enhanced the purification efficiency of effluent nitrogen and phosphorus in the artificial wetland, probably due to the better purification by mixed species under competition for nutrients or the dilution effect of multiple species on effluent nitrogen and phosphorus nutrient salts following mixed planting. These results should guide planting selection for efficient and sustainable wastewater purification in wetland ecosystems.

Transcriptome analysis of growth and quality response of chrysanthemum to co-inoculation with Bacillus velezensis and Pseudomonas aeruginosa

The inoculation of plants with plant growth-promoting rhizobacteria (PGPR) has been increasingly discussed as a way to sustainably promote plant growth and soil health. Although some promising results have been achieved in the laboratory, the applications of microbial inoculants in chrysanthemum production greenhouses and co-inoculation with PGPRs in ornamental planting systems have been less investigated. Here, greenhouse experiments were conducted to study the integrated effect of bioagents (Bacillus velezensis and Pseudomonas aeruginosa) on chrysanthemum nutrient use efficiency, plant growth, and quality. The growth-promoting mechanisms were further elucidated by transcriptome analysis. Co-inoculation with the two PGPRs increased the absorption and utilization of nitrogen, phosphorus, and potassium. The quality and growth of chrysanthemum were significantly higher than those of single PGPR inoculation or soil conditioner application. Transcriptome analysis revealed that differentially expressed genes (DEGs) were co-expressed at 30, 60, and 90 days after chrysanthemum co-inoculation with the two PGPRs. DEGs were primarily enriched in metabolic and signal transduction pathways. PDC encoding pyruvate decarboxylase in the glycolysis pathway and SAUR32 and SAUR36 encoding auxin were upregulated in chrysanthemum during the PGPRs inoculation period. Notably, the transcription factors WRKY70 and BHLH35 belonging to signal transduction and defense responses were both upregulated, demonstrating that chrysanthemum system and disease resistance were activated. The results of this study could help to elucidate the mechanism of 2 PGPRs on chrysanthemum growth and development at the transcriptome level, which could lay a theoretical foundation for the highly efficient cultivation of cut chrysanthemum “Qinhuai Yulian”.

Portable Disc Granulator Machine

This work presents the design of a portable disc granulator machine to produce granule shape fertilizer from a powdered mixture. The industry demands granular fertilizer made from chemical substances due to the benefits that can be obtained compared to fine powder fertilizer. It has a longer lifespan of up to 9 months and a slow rate of nitrogen absorption from fertilizer because of its granular form. Granular fertilizers are easy to store and do not settle out over time, or salt out in cold weather. Fertilizer plays the role of a plant food element and is crucial to maintaining the health of plants for their growth. The pharmaceutical method is frequently used by farmers to create fertilizer in the form of granules which are wet granulation and dry granulation process. Wet granulation was employed in this project since it involves the addition of liquids like molasses or water. The portable disc granulator machine is designed to turn fertilizer into granule shapes, which are subsequently used as the product's base material. However, the fertilizer must be produced a uniform ±5 mm diameter of granular shape for bio-organic fertilizer. Solidification has been made to improve the fertilizer’s granular shape to create a consistent ±5 mm diameter in the disc that rotates automatically with an angle of 48°. A disc granulator machine should first be filled with bio-organic fertilizer. Then, use brown sugar solution or cornstarch to form a granule shape. The disc will be rotating at a speed of 11 to 15 rpm. To assess the machine's ability to create granules with a diameter of about 5 mm, evaluation, and analysis were performed using a vernier caliper. The result demonstrated that the machine could produce ±5 mm with a tolerance of 1 mm and uniformity will be constant.

Genome-Wide Identification and Characterization of Long Non-Coding RNAs in Roots of Rice Seedlings under Nitrogen Deficiency

Long non-coding RNAs (lncRNAs) regulate gene expression in eukaryotic organisms. Research suggests that lncRNAs may be involved in the regulation of nitrogen use efficiency in plants. In this study, we identified 1628 lncRNAs based on the transcriptomic sequencing of rice roots under low-nitrogen (LN) treatment through the implementation of an integrated bioinformatics pipeline. After 4 h of LN treatment, 50 lncRNAs and 373 mRNAs were significantly upregulated, and 17 lncRNAs and 578 mRNAs were significantly downregulated. After 48 h LN treatment, 43 lncRNAs and 536 mRNAs were significantly upregulated, and 42 lncRNAs and 947 mRNAs were significantly downregulated. Moreover, the interaction network among the identified lncRNAs and mRNAs was investigated and one of the LN-induced lncRNAs (lncRNA24320.6) was further characterized. lncRNA24320.6 was demonstrated to positively regulate the expression of a flavonoid 3′-hydroxylase 5 gene (OsF3′H5). The overexpression of lncRNA24320.6 was shown to improve nitrogen absorption and promote growth in rice seedlings under LN conditions. Our results provide valuable insights into the roles of lncRNAs in the rice response to nitrogen starvation.

Nitrogen absorption and mineralization change with cover crop types and greenhouse vegetable planting years in fluvo-aquic soil

Nitrogen absorption and mineralization change with cover crop types and greenhouse vegetable planting years in fluvo-aquic soil

Dry shrinkage and micro-structure of alkali-activated fly ash/slag pastes incorporated with silane coupling agent modified MWCNTs

In this study, functionalized Multi-Walled Carbon Nanotubes (MWCNTs) grafted with a silane coupling agent (MS) at concentrations of 0.1 %, 0.2 %, 0.3 %, and 0.4 % were used as additives to investigate their impact on the reaction kinetics, working performance, mechanical strength, and drying shrinkage of alkali-activated fly ash/slag (AAFS) pastes. Additionally, various micro-structure techniques, including X-ray Diffraction (XRD), Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), nitrogen (N2) absorption, and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), were employed to examine the morphology, chemical composition, and mineralogy of AAFS pastes. The experimental findings indicate that all the modified AAFS pastes exhibit prolonged setting time and increased flowability compared to the control AAFS pastes, with the enhancement of these properties being proportional to the MS content. Specifically, with the addition of 0.3 wt% MS, the compressive strength and flexural strength of LGMS-0.3 % were 41.2 MPa and 6.4 MPa, respectively, at the 28-day curing age, representing a 15.7 % and 39.1 % increase compared to the control AAFS pastes. Simultaneously, significant reductions in mass loss and drying shrinkage of over 70 % and 90 % were observed, respectively, in comparison to the control AAFS pastes. Micro-structural analysis reveals that the inclusion of MS leads to an increase in the quantity of reaction products without affecting their type. Furthermore, the incorporation of MS decreases the total porosity and the proportion of capillary pores with diameters ranging from 2 nm to 50 nm, resulting in the refinement of the overall pore structure of AAFS pastes. Notably, the three-dimensional interpenetrating network formed by MWCNTs and the silane coupling agent positively influences the mitigation of drying shrinkage and the enhancement of the mechanical strength of AAFS pastes.

Intra- and interspecific ecophysiological responses to waterlogging stress in two contrasting waterlogging-tolerant arbor species.

At present, establishing planted forests, typically composed of not more than two tree species, to avoid forest losses has received increasing attention. In addition, investigating the impact of environmental stress such as waterlogging on different planting patterns is essential for improving wetland ecosystem resilience. Knowledge about the impact of waterlogging on planted forests is crucial for developing strategies to mitigate its adverse effects. Here, we conducted experimentally a simulated pure and mixed planting system composed of two contrasting WL-tolerant species (Cleistocalyx operculatus and Syzygium cumini) to determine their ecophysiological responses based on the type of interaction. Results showed that the aboveground growth performance of S. cumini was better than that of C. operculatus under well-watered conditions regardless of the planting model, which is contrary to the belowground accumulation that was significantly improved in C. operculatus. Intra- and interspecific interactions in different planting models facilitated the growth performance of C. operculatus while provoking a significant competition in S. cumini under waterlogging. Such phenomenon was explained through the remarkable ability of C. operculatus to naturally increase its root network under stress on non-stress conditions compared with S. cumini. In this study, two main factors are proposed to play key roles in the remarkable performance of C. operculatus compared with S. cumini following the planting model under waterlogging. The high level of nitrogen and phosphor absorption through C. operculatus primary roots and the significant starch biosynthesis constituted the key element that characterized the facilitation or competition within the intra- or interspecific interactions shown in C. operculatus compared with S. cumini. Furthermore, the intraspecific competition is more pronounced in S. cumini than in C. operculatus when grown in a pure planting pattern, particularly when subjected to waterlogging. However, when the two species are planted together, this competition is alleviated, resulting in enhanced waterlogging tolerance.

PSII-23 Effect of Protein Supplementation Level and Degradability on N Balance in Steers Consuming Low-Quality Forage: Ii.Bos Taurus Indicus

Abstract Low-quality forage lacks the nitrogen (N) necessary for optimal forage utilization and animal performance. Supplemental protein improves forage utilization by increasing ruminally available N and energy supply to the animal. Together these two are expected to increase N absorption and balance. Therefore, our objective was to determine the effect of ruminal degradability and level of protein supplementation on N balance in Bos taurus indicus steers. Accordingly, six ruminally cannulated Brahman steers (BW 369 ± 51 kg) were used in a 5 × 5 Latin square to evaluate the interaction between level and degradability of protein supplementation when consuming King Ranch Bluestem hay (3.5% CP, 71.0% NDF). Treatments were arranged as a 2 × 2 factorial with steers receiving protein supplements (43% CP) with two ruminal degradable protein levels; 35% RDP (35%; 58% corn gluten meal and 42% soybean hulls) and 70% RDP (70%; 100% soybean meal). Supplements were fed at two levels, providing 1.26 or 2.53 g of supplement/kg BW (LOW and HIGH). A control (CON) provided no supplement. Five, 14-d periods, consisted of 9 d adaptation and 4 d to measure intake, digestion, and N balance, and 1 d for ruminal fermentation. No degradability × level interactions were significant (P > 0.10) for any measures of N balance. Forage organic matter intake increased (P < 0.01) in response to supplementation, forage N intake tended to increase (P = 0.06). Supplemental N intake increased with increased supplementation, as designed, (P < 0.01) resulting in a significant increase in total N intake (P < 0.01). Degradability tended (P = 0.09) to affect supplement N intake with 70% RDP being greater than 35% RDP. Fecal N excretion increased 50% for LOW and 68% for HIGH (P < 0.01) compared with CON but did not differ (P = 0.24) between RDP levels. Urinary N excretion increased with increasing level (P < 0.01) and degradability (P < 0.01) of the protein supplement. Urinary N excretion increased 250% for the 70% HIGH supplement and 84% for the 35% HIGH supplement. Nitrogen absorption increased from -3.8 g N/d for unsupplemented steers to 38.8 and 48.8 g N/d for the 35% HIGH and 70% HIGH, respectfully (P < 0.01). Nitrogen retention increased (P = 0.03) with level of supplementation from -19.1 g N/d for unsupplemented steers to 10.6 and 9.7 g N/d for 35% HIGH and 70% HIGH, respectfully. Providing supplemental N to Bos taurus indicus increased N intake, excretion, absorption, and retention. Level of ruminal degradability did not affect the amount of N retained or absorbed suggesting that protein supplementation regardless of ruminal N degradability will improve N balance in Bos taurus indicus consuming low-quality forage.

PSII-22 Effect of Protein Supplementation Level and Degradability on N Balance By Steers Consuming Low-Quality Forage: I.Bos Taurus Taurus

Abstract Globally, cattle convert low-quality forage to beef and milk; therefore, understanding protein utilization in Bos taurus taurus is critical to enhancing sustainability as over and under-supplementation of protein are economically and environmentally costly. Low-quality forage lacks the N necessary for proper utilization and metabolic function. Supplemental protein improves low-quality forage utilization and is expected to increase N absorption and retention. Accordingly, our objective was to determine the effect of ruminal degradability and level of protein supplementation on N balance in Bos taurus taurus steers. To achieve this objective, six ruminally cannulated Angus steers (BW 294 ± 37.7 kg) were used in a 5 × 5 Latin square to evaluate the interaction between level and degradability of protein supplementation when consuming King Ranch Bluestem hay (3.5% CP, 71.0% NDF). Treatments were arranged as a 2 × 2 factorial steers receiving protein supplements (43% CP) with two ruminal degradable protein levels; 35% RDP (35%; 58% corn gluten meal and 42% soybean hulls) and 70% RDP (70%; 100% soybean meal). Supplements were fed at two levels, providing 1.26 or 2.53 g of supplement/kg BW (LOW and HIGH, respectively). A control (CON) provided no supplement. Five, 14-d periods, consisted of 9 d adaptation and 4 d to measure intake, digestion, and N balance, and 1 d for ruminal fermentation. No significant (P ≥ 0.14) degradability × level interactions were detected for any measures of N balance. Although forage organic matter intake increased (P < 0.01) in response to supplementation, forage N intake was not improved. Supplemental N intake increased linearly (P < 0.01) with increased supplementation, as designed, resulting in a significant linear (P < 0.01) increase in total N intake. In addition, 70% RDP supplement resulted in greater supplemental N intake than the 35% RDP supplement. Fecal N excretion increased linearly with supplementation. Supplementation at the HIGH level increased (P < 0.01) fecal N excretion 90% compared with CON. There was no significant (P = 0.94) effect of ruminal degradability. Urinary N excretion was greater (P < 0.01) when the 70% RDP supplement was fed than the 35% RDP. Nitrogen absorption linearly increased with supplementation (P < 0.01). Similarly, nitrogen retention linearly increased (P < 0.01) with level of supplementation but was not significantly affected by degradability (P = 0.87). In conclusion, providing supplemental N to Bos taurus taurus increased N intake, excretion, absorption, and retention. Level of ruminal degradability did not affect N retention or absorption suggesting that protein supplementation regardless of ruminal N degradability improves N balance in Bos taurus taurus consuming low-quality forage.

Transcriptomics and metabolomics reveal the primary and secondary metabolism changes in Glycyrrhiza uralensis with different forms of nitrogen utilization.

The roots and rhizomes of Glycyrrhiza uralensis Fisch. represent the oldest and most frequently used herbal medicines in Eastern and Western countries. However, the quality of cultivated G. uralensis has not been adequate to meet the market demand, thereby exerting increased pressure on wild G. uralensis populations. Nitrogen, vital for plant growth, potentially influences the bioactive constituents of plants. Yet, more information is needed regarding the effect of different forms of nitrogen on G. uralensis. G. uralensis seedlings were exposed to a modified Hoagland nutrient solution (HNS), varying concentrations of nitrate (KNO3), or ammonium (NH4)2SO4. We subsequently obtained the roots of G. uralensis for physiology, transcriptomics, and metabolomics analyses. Our results indicated that medium-level ammonium nitrogen was more effective in promoting G. uralensis growth compared to nitrate nitrogen. However, low-level nitrate nitrogen distinctly accelerated the accumulation of flavonoid ingredients. Illumina sequencing of cDNA libraries prepared from four groups-treated independently with low/medium NH4 + or NO3 - identified 364, 96, 103, and 64 differentially expressed genes (DEGs) in each group. Our investigation revealed a general molecular and physiological metabolism stimulation under exclusive NH4 + or NO3 - conditions. This included nitrogen absorption and assimilation, glycolysis, Tricarboxylic acid (TCA) cycle, flavonoid, and triterpenoid metabolism. By creating and combining putative biosynthesis networks of nitrogen metabolism, flavonoids, and triterpenoids with related structural DEGs, we observed a positive correlation between the expression trend of DEGs and flavonoid accumulation. Notably, treatments with low-level NH4 + or medium-level NO3 - positively improved primary metabolism, including amino acids, TCA cycle, and glycolysis metabolism. Meanwhile, low-level NH4 + and NO3 - treatment positively regulated secondary metabolism, especially the biosynthesis of flavonoids in G. uralensis. Our study lays the foundation for a comprehensive analysis of molecular responses to varied nitrogen forms in G. uralensis, which should help understand the relationships between responsive genes and subsequent metabolic reactions. Furthermore, our results provide new insights into the fundamental mechanisms underlying the treatment of G. uralensis and other Glycyrrhiza plants with different nitrogen forms.

Optimizing root system architecture to improve root anchorage strength and nitrogen absorption capacity under high plant density in maize

Optimizing root system architecture to improve root anchorage strength and nitrogen absorption capacity under high plant density in maize