Nitrogen Supply Research Articles

Storage protein activator controls grain protein accumulation in bread wheat in a nitrogen dependent manner

The expression of cereal grain storage protein (GSP) genes is controlled by a complex network of transcription factors (TFs). Storage protein activator (SPA) is a major TF acting in this network but its specific function in wheat (Triticum aestivum L.) remains to be determined. Here we generated an RNAi line in which expression of the three SPA homoeologs was reduced. In this line and its null segregant we analyzed GSP accumulation and expression of GSP and regulatory TF genes under two regimes of nitrogen availability. We show that down regulation of SPA decreases grain protein concentration at maturity under low but not high nitrogen supply. Under low nitrogen supply, the decrease in SPA expression also caused a reduction in the total quantity of GSP per grain and in the ratio of GSP to albumin-globulins, without significantly affecting GSP composition. The slight reduction in GSP gene expression measured in the SPA RNAi line under low nitrogen supply did not entirely account for the more significant decrease in GSP accumulation, suggesting that SPA regulates additional levels of GSP synthesis. Our results demonstrate a clear role of SPA in the regulation of grain nitrogen metabolism when nitrogen is a limiting resource.

Nutrient intake, digestibility, and utilization in goats fed graded levels of hempseed cake finisher diets

Globally, the price of soybean meal, the most common proteinaceous ingredient in livestock diets, has become highly expensive prompting a search for alternative ingredients. Hemp seed cake is a promising alternative but could be limited by its high neutral detergent fiber and ether extract contents which impede nutrient intake and digestibility. However, some ruminant species such as goats have superior ability to digest high fiber and ether extract diets. Thus, the current research evaluated nutrient intake and digestibility, rumen fermentation, and microbial protein synthesis of goats fed hempseed cake as a substitute for soybean meal in finisher diets. A total of 25 Kalahari Red castrates (27 ± 3 kg, 4–5 months old) were assigned to five dietary treatments (5 goats/ diet) in a completely randomized design. A maize-lucerne-based finishing diet was formulated with hempseed cake substituting soybean meal as the primary protein ingredient at 0, 25, 50, 75, or 100 g/kg dry matter. Ether extract intake exhibited a positive linear trend (P ≤ 0.05) while crude protein intake and microbial nitrogen supply exhibited a negative linear trend (P ≤ 0.05) with dietary inclusion of hempseed cake. However, feeding hempseed cake did not influence (P > 0.05) apparent nutrient digestibility, rumen fermentation parameters and nitrogen use efficiency. In conclusion, the substitution of soybean meal for hempseed cake decreased crude protein intake and microbial nitrogen supply in goat finisher diets without compromising nutrient digestibility and nitrogen use efficiency. The study recommends partial or full replacement of soybean meal with hempseed cake in goat finisher diets.

The exceptional form and function of the giant bacterium Ca. Epulopiscium viviparus revolves around its sodium motive force.

Epulopiscium spp. are the largest known heterotrophic bacteria; a large cigar-shaped individual is a million times the volume of Escherichia coli. To better understand the metabolic potential and relationship of Epulopiscium sp. type B with its host Naso tonganus, we generated a high-quality draft genome from a population of cells taken from a single fish. We propose the name Candidatus Epulopiscium viviparus to describe populations of this best-characterized Epulopiscium species. Metabolic reconstruction reveals more than 5% of the genome codes for carbohydrate active enzymes, which likely degrade recalcitrant host-diet algal polysaccharides into substrates that may be fermented to acetate, the most abundant short-chain fatty acid in the intestinal tract. Moreover, transcriptome analyses and the concentration of sodium ions in the host intestinal tract suggest that the use of a sodium motive force (SMF) to drive ATP synthesis and flagellar rotation is integral to symbiont metabolism and cellular biology. In natural populations, genes encoding both F-type and V-type ATPases and SMF generation via oxaloacetate decarboxylation are among the most highly expressed, suggesting that ATPases synthesize ATP and balance ion concentrations across the cell membrane. High expression of these and other integral membrane proteins may allow for the growth of its extensive intracellular membrane system. Further, complementary metabolism between microbe and host is implied with the potential provision of nitrogen and B vitamins to reinforce this nutritional symbiosis. The few features shared by all bacterial behemoths include extreme polyploidy, polyphosphate synthesis, and thus far, they have all resisted cultivation in the lab.

OPTIMIZATION OF NITROGEN FERTILIZATION FOR AGRICULTURAL CROPS UPON ADDITIONAL APPLICATION OF FRESH ORGANIC MATTER TO THE SOIL

Objective. Using biological testing, determine the environmental appropriate rates of mineralnitrogen, applied in the background of effect and aftereffect of straw and biomass of intermediatelupine green manure, in the fertilization system of potatoes and spring barley. Methods. Field experiment (growing crops in crop rotation in the conditions of a long-term (since 2009) stationaryexperiment on leached chornozem); gas chromatographic (to determine the potential nitrogenfixing (nitrogenase) and potential denitrifying activities in the rhizosphere soil of plants dependingon the fertilizer); statistical. Results. With the systematic application of fresh organic matter to thesoil in the form of 5.0 t/ha of straw and 5.3 t/ha of dry biomass of intermediate lupine green manure, the excess of nitrogen mineral compounds is metabolically bound (immobilized) by microorganisms, the process of nitrogen fixation is restored, the emission of N2O decreases, and the ratesof mineral fertilizers not exceeding N80P80K80 become environmentally appropriate when growingpotatoes. At the same time, the introduction of straw does not require additional provision of mineral nitrogen to optimize the C/N ratio. The highest rate of mineral fertilizers N120P120K120 in theexperiment, even when combined with organic matter for a long time is environmentally inappropriate — only at the end of the growing season, the studied indicators demonstrate its acceptability.When growing spring barley on leached chornozem, the optimization of the processes of biologicaltransformation of nitrogen compounds is achieved if mineral fertilizers are applied on the background of aftereffect of organic matter in a rate not exceeding N60P60K60. Systemic application ofN90P90K90 suppresses the activity of nitrogen fixation and ensures significant losses of nitrous oxide.This rate of fertilizers should be applied only on the condition that it is applied against the background of the aftereffect of straw and green manure mass, which contributes to the mitigation ofenvironmental consequences. Conclusion. The use of mineral fertilizers against the backgroundof systematic application of winter wheat straw and intermediate lupine green manure biomass tothe soil contributes to the optimization of the biological state of the leached chornozem. The improvement of environmental indicators contributes to the growth of the yield of agricultural crops.

Effect of Different Macronutrient Supply Levels on the Drought Tolerance of Rainfed Grass Based on Biomass Production, Water Use Efficiency and Macroelement Content

Water shortage, one of the main limiting factors for plant growth and development, can be alleviated by an adequate nutrient supply. The effect of different nitrogen (N), phosphorus (P) and potassium (K) supply levels and their combinations was examined in different rainfall supply periods (wet, normal, dry) on a grass sward in a field experiment. Dry and fresh aboveground biomass production were primarily increased by the N–rainfall supply interaction, from 0.739 to 6.51 and from 1.84 to 21.8 t ha−1, respectively, but the P–rainfall supply and N–P interactions and K treatment all had significant effects. Dry matter content was primarily influenced by the N–rainfall supply interaction, increasing in response to N in dry periods and declining in wet periods. Water use efficiency (WUE) was increased by the N–rainfall supply interaction from 28.3 to 127 kg ha−1 mm−1, but the N–P interaction had a similarly strong effect, and K treatment increased it in the dry period. The N, P and K contents of the aboveground biomass were increased by treatment with the corresponding element, but were also influenced by rainfall supply. The increase in biomass, mainly due to N treatment, caused the dilution of the P and K contents in grass in treatments poorly supplied with P and K. Biomass production and WUE were significantly improved up to a dose of 200 kg ha−1 year−1 of N, up to a supply level of 153 mg kg−1 of P2O5, and 279 mg kg−1 of K2O measured in the soil. Treating grass with the N, P and K macroelements may effectively increase biomass production and water use efficiency, but above a certain level their application is unnecessary.

Identification of the regularities of the thermohydraulic processes of the cooling system of an experimental device based on a mathematical model

The article is devoted to the study of a nitrogen supply system for cooling an experimental device designed for testing in a pulsed reactor with a graphite moderator. To analyze emergency situations caused by disruption of the nitrogen supply system in the cooling paths of the fuel assembly cover and the experimental device power housing, a mathematical model has been developed to describe thermodynamic processes in a system of interconnected tanks that simulate individual sections of the experimental device hydrodynamic cooling system in a pulsed graphite reactor and implemented in the mathematical interactive package for engineering calculations in MATLAB/Simulink. To study the normal operation of the system and analyze possible emergencies, the cooling system of the experimental device was presented in the form of groups of interconnected sections of the hydrodynamic system-tanks, with specified volumes and hydraulic resistances of pipelines connecting these tanks. Verification of the model, calculations of the experimental device cooling system normal operation mode, calculations of emergency situations caused by a violation of the nitrogen supply system normal operation in the cooling paths of the fuel assembly cover were carried out, in particular, it was found that for the cooling system of the experimental device WF-2, the breakdown of the gearbox P-12 can cause depressurization of the fuel assembly cover and an increase in pressure in the power housing, the opening of the safety valve prevents exceeding the pressure limit in the housing, the device maintains integrity even in emergency situations, without being subjected to destruction of the power elements of the structure at a pressure of up to 8 MPa

Effects of nitrogen supply on hydrogen-oxidizing bacterial enrichment to produce microbial protein: Comparing nitrogen fixation and ammonium assimilation

To investigate the effects of nitrogen source supply on microbial protein (MP) production by hydrogen-oxidizing bacteria (HOB) under continuous feed gas provision, a sequencing batch culture comparison (N2 fixation versus ammonium assimilation) was performed. The results confirmed that even under basic cultivation conditions, N2-fixing HOB (NF-HOB) communities showed higher levels of CO2 and N2 fixation (190.45 mg/L Δ CODt and 11.75 mg/L Δ TNbiomass) than previously known, with the highest biomass yield being 0.153 g CDW/g COD-H2. Rich ammonium stimulated MP synthesis and the biomass accumulation of communities (increased by 7.4 ～ 14.3 times), presumably through the enhancement of H2 and CO2 absorption. The micro mechanism may involve encouraging the enrichment of species like Xanthobacter and Acinetobacter then raising the abundance of nitrogenase and glutamate synthase to facilitate the nitrogen assimilation. This would provide NF-HOB with ideas for optimizing their MP synthesis activity.

The Effectiveness and Performance of BT Cotton's Insecticidal Properties under Various Abiotic Stresses: A Review

Over the past two decades, biotechnology has yielded Bt cotton, a huge success in the field of agriculture. In a number of countries, commercial Bt crop production has proven successful. The global food scarcity crisis has been alleviated by transgenic Bt crops, which have improved agricultural productivity. The Bt cotton crop displays variable levels of insect resistance to several environmental abiotic circumstances, including high temperatures, salt in the soil, water logging and scarcity, inadequate nitrogen supply, and humidity. It has been demonstrated that these components lessen the transgenic crop's endotoxin protein level, which in turn reduces the insecticidal efficacy of the crop. In unfavourable climatic conditions, plants have altered nitrogen metabolism and pain in their physiological systems. This article has discussed some of the primary stresses that Bt cotton encounters as well as the underlying mechanisms that explain its variable insecticidal efficacy under both single and combination pressures. While several important elements are covered in this study, such as gene silencing, post transcriptional changes, and protein breakdown, the most important aspect of this field that still need investigation is nitrogen metabolism. A thorough meta-analysis table provides an overview of the several significant research that have been carried out to examine the impacts of stress. A comprehensive study technique is needed to clarify the metabolic and physiological changes that transpire in transgenic cotton crops under high stress. In order to increase the production and performance of the cotton crop worldwide, more research is needed to address the unpredictable insect resistance of Bt crops.

Upcycling of the industrial waste as a sustainable source of axenic fungal strain (Aspergillus oryzae) for scale up enzymatic production with kinetic analysis and Box–Behnken design application

Abstract The utilization of industrial waste for valuable product synthesis is essential for mitigating the environmental impact of climate change and managing waste disposal challenges. Industrial waste is always a big challenge for global warming. In this study, a novel fungus strain was isolated, and identified as Aspergillus oryzae (AKMS), from the oily surface of industrial effluent from an oil industry. Submerged fermentation was exploited to achieve maximum lipases production. A sequence of batch experiments was performed, altering five primary components: sucrose (for carbon), molasses (constituting nutrient mix), yeast extract (as nitrogen supply), sunflower oil (used as an activating agent), and Tween-80 (functioning as an emulsifying agent). These elements are recognized for their substantial impact on the proliferation of microorganisms and, consequently, the synthesis of lipases. The maximum lipase activity for each ingredient was determined, with sucrose showing 2.4 ± 0.539 U/mL at 0.15 g/L, molasses at 1.499 ± 0.291 U/mL at 0.25 g/L, Tween 80 % at 3.33 ± 0.484 U/mL at 0.25 g/L, sunflower oil at 7.49 ± 0.282 U/mL at 1 % v/v, and yeast extract at 4.165 ± 0.841 U/mL at 0.075 % v/v. The optimization of the lipase production and activity was done by using RSM (Box–Behnken design) with the 41st run yielding the maximum activity of 9 U/mL, while the 25th run showed the minimum activity of 4 U/mL, enzyme estimation (U/mL and U/g), glucose (g/L), and dry cell mass estimation (g/L) were monitored up to 120 h of fermentation in a custom-made fermenter with a working volume of 7 L. The highest production of extracellular and intracellular lipases (27.4 ± 0.378 U/mL and 25.4 ± 0.208 U/g, respectively) was observed at the 40 h interval, with the highest value of dry cell mass at 20 g/L. Glucose concentration initially peaked and subsequently decreased over time. A. oryzae exhibited the capability to produce triacyl glycerol acyl hydrolases, demonstrating its potential significance in biotechnological applications. These novel findings shed light on the efficient utilization of oil industry waste soil for isolation of microorganism for sustainable lipase production and highlight the biotechnological promise of the novel isolated fungal strain, which was reported first time in this study.

Novel coating of slow-release nitrogen fertilizers: Characterization and assessment

Developing novel fertilizers that reduce nitrogen release rate receives worldwide interest as a potential means for improving nitrogen utilization efficiency. Making these fertilizers sustainable, this work introduces various attempts to prepare slow-release nitrogen using different materials comprised of agro-industrial wastes such as sugarcane (SC) and beet filter cakes (mud) besides, sulfur, gypsum, and zeolite to cover two nitrogen sources. The prepared coated nitrogen fertilizers were characterized using SEM-EDX. Afterward, an incubation trial was conducted to appraise the produced slow-release fertilizers via mixing with three soils (from Egypt and Sudan) at various incubation periods. The tested coating process enhanced the surface morphology of the fertilizer grains, in which the surface became smoother and all the cracks and cavities were filled with the coating material, which is critical for the physical barrier property and preventing moisture penetration into the core. ANOVA analysis indicated that the released values of N were significantly varied according to the soil type, source of N, and the coating material. Zeolite was effective as a coating material for all nitrogen fertilizers. The coated granules by SC material provided a steady, adequate nitrogen supply throughout the incubation. Beet mud treatments showed the lowest N release among all coating materials, but the liberation of N gradually increased with time elapsed. The beet and sugarcane mud can be considered promising covering materials for developing environmentally friendly and cost-effective slow-release fertilizers. The results showed continuous release of N in the soils from all prepared coated fertilizers til the end of the incubation, enhancing the feasibility for agricultural application.

The Impact of Fertilizer Type on Dry Matter, Nitrogen Partitioning, and Yield of Spring Maize with Film-Side Sowing

Dry matter (DM) and nitrogen (N) transport from nutritive organs to the grain is critical for cereal crop yield and protein content. There is limited research on the effects of slow-release or controlled-release fertilizers on dry matter and nitrogen partitioning in the nutrient organs of spring corn. A field trial was conducted in the National Corn Industry Technology System Xinzhou Comprehensive Experiment Station, China. The effects of different fertilizer management on yield, photosynthetic capacity, and nutrient partitioning of spring maize were studied. We modeled local farmers’ planting and management practices (T3). Based on T3, we added a slow-release compound fertilizer (T2), which does not require a follow-up fertilizer, and a controlled-release formulated fertilizer (T1), which is highly efficient and has low carbon emissions. The net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) were 23%, 18.5%, 18%, 10.5% and 19%, 10.9%, 7%, and 5.5% higher in T1 compared to those of T3 and T2, respectively, at the ripening stage. The contribution of post-flowering DM transport to the kernel of T1 was 46% and 41.4% higher than that of T3 and T2, respectively. The nitrogen content of the kernel of T1 was 35.2% and 18.5% higher than that of T3 and T2, respectively. After a comprehensive analysis, T1 prolonged the photosynthetic effect through adequate nitrogen supply, provided nutrients to the kernel, promoted maize nitrogen uptake and utilization, and ultimately improved yield.

Sustainable Management for oat Grain Yield and Quality Based on Nitrogen Supply and Seeding Density

Purpose: The objective of this study is to evaluate a sustainable management for oat crops with high nitrogen use efficiency combined with high seeding density to improve grain yield and quality while increasing oat competitive ability against ryegrass. Method/design/approach: The experiment was carried out in the years 2020, 2021 and 2022, with an experimental design of randomized blocks with four replications, in a 4 x 3 factorial arrangement, for sowing densities (100, 300, 600 and 900 viable seeds m-2) and form of nutrient supply: [single dose, (100%) at phenological stage V4 (fourth expanded leaf); fractional (70/30%) at the V4/V6 phenological stage (fourth and sixth expanded leaves) and; fractionated (70/30%) at phenological stage V4/R1 (beginning of anthesis)], respectively. Indicators of productivity and chemical quality of oat grains were analyzed, and lodging and ryegrass inflorescences exposed on oat plants were analyzed in the field. Results and conclusion: The application of a single dose of nitrogen at the V4 stage resulted in higher grain and oat straw yields, without changes in the crude protein and crude fiber content of the grains. The combination of this nitrogen application method with a sowing density of 490 seeds m-2 increased the competitive capacity of white oat plants, reducing the number of ryegrass inflorescences. Originality/value: This study contributes to more sustainable management practices in the use of nitrogen and the contribution of plant density in promoting competitive ability, reducing dependence on agrochemicals in ryegrass control and promoting food security and environmental protection.

Genome‐wide identification of nitrate transporter 1/peptide transporter family (NPF) in cassava (Manihot esculenta) and functional analysis of MeNPF5.4 and MeNPF6.2 in response to nitrogen and salinity stresses in rice

AbstractNitrogen is a major driving force for the improvement of crop yield worldwide but brings detrimental effects on ecosystems. Therefore, enhancing nitrogen use efficiency (NUE) is vital for sustainable agriculture. The nitrate transporter (NRT1/NPF) family associated with nitrogen uptake and utilization is indispensable to the improvement of NUE in crops. As an important food security crop, cassava (Manihot esculenta) produces an acceptable yield in nutrient‐deficient soil. Here, we identified and systematically analyzed the NPF gene family in cassava, including phylogenetic relationship, chromosome location, gene duplication, and gene expression in response to different nitrogen supplies. The stem is involved in nitrogen transportation and remobilization. Gene expression analysis revealed that MeNPF5.4 and MeNPF6.2 were specifically expressed in the stem, and have diverse expression in different nitrogen conditions. To facilitate the functional analysis of MeNPF5.4 and MeNPF6.2, we constructed their overexpression (OE) lines in rice. A NO3− flux assay showed that MeNPF5.4 and MeNPF6.2 OE lines exhibited a marked decrease in NO3− efflux and significant NO3− influx compared with WT, which suggests that they might have contributed to the NUE improvement of rice. Notably, overexpressing MeNPF5.4 showed increased grain size, grain number, and grain weight per panicle. More importantly, the MeNPF5.4 OE line contributed to salt tolerance. Nevertheless, an obvious reduction in grain number and grain weight per panicle was detected in the MeNPF6.2 OE line compared with WT. Strikingly, the MeNPF6.2 OE line showed higher salt stress tolerance than WT in LN conditions. Taken together, our results demonstrated that MeNPF5.4 can potentially improve the NUE and salt stress tolerance of rice, which reveals valuable breeding targets to improve crop yield and stress tolerance.

Leaf trait relationships with species ecological optimum and sustainability across wetland plants

Structural and functional parameters of leaves were studied in 19 dominant and abundant species growing in shallows and wet riversides at the mouth of the Maksimikha River (Barguzinsky district, Republic of Buryatia). To evaluate the species ecological optimum Tsyganov’ scales were used (Tsyganov, 1983). To assess the resistance, the potential ecological valence of the species on the illumination scale, as well as the climatic and soil tolerance indices of the species were applied (Zhukova et al., 2010). It was shown that the index of climatic tolerance of the species was negatively correlated with the leaf mass per area (LMA) (r = -0,68) and positively with the chlorophyll photosynthetic activity of (r = 0,51). A tendency was revealed to decrease in LMA and leaf dry matter content (LDMC) and increase in the chlorophyll photosynthetic activity in more thermophilic wetland plants. Leaf area positively correlated with the scores of the species optimum on the soil moisture and acidity scales (r = 0,59 and r = 0,72, respectively). LMA, the content and photosynthetic activity of chlorophyll correlated with the optimum scores on the soil nitrogen supply scale (r = -0,53, r = -0,50 and r = 0,72, respectively). The tolerance index of the species to soil factors was associated only with the content of chlorophylls (r = 0,68) and carotenoids (r = 0,55) per unit leaf area. The potential ecological valence of the species to illumination was positively correlated with leaf density and LDMC (r = 0,58 and r = 0,57, respectively). It was concluded that the thermoclimatic optimum of species of wetland plants, as well as their climate sustainability, are associated with changes in the LMA and chlorophyll photosynthetic activity. Edaphic factors had a greater influence on the structural and functional parameters of leaves than climatic ones, which manifested in a large number of relationships between soil scales and leaf traits. Wetland plant tolerance to a wider range of edaphic conditions was associated with a high content of chlorophylls and carotenoids.

Aboveground antagonists mitigate belowground plant–antagonist interactions but not affect plant–mutualist interactions

Species interactions exert important influences on biodiversity and ecosystem stability. In complex natural communities, species interactions have gone beyond pairwise mechanisms, as interactions between two species can be regulated by one or more other species (higher-order species interactions). However, few studies consider higher-order interactions among organisms that are indirectly contacted, particularly under high soil nutrient conditions. Here, we performed a common garden experiment to investigate how natural herbivory (aboveground weevil) and simulated herbivory (leaf clipping) affect plant (Triadica sebifera) interactions with soil antagonists (root-knot nematodes) and mutualists (arbuscular mycorrhizal fungi; AMF) under nitrogen and phosphorus addition. We also tested the effects of nitrogen, phosphorus, and herbivory-stimuli on T. sebifera leaf extrafloral nectary (EFN) production. We found that T. sebifera can compensate for biomass loss caused by clipping or weevil feeding, moreover, high nitrogen availability caused plant biomass to outpace herbivory-stimuli. Plant–antagonist (root-knot nematodes) interactions were not affected by clipping or weevil feeding under ambient nitrogen condition but were reduced by clipping or weevil feeding under high nitrogen supply, however, we did not find the same pattern under phosphorus addition. Aboveground herbivory-stimuli did not affect plant–mutualist (AMF) interactions, whether fertilized or not. In addition, nitrogen addition stimulated plants to secrete more EFN against clipping but did not increase EFN production against weevil feeding. Clipping and weevil feeding exhibited consistent effects on both plant–antagonist (root-knot nematodes) interactions and plant–mutualist (AMF) interactions. These results suggest that aboveground antagonists mainly mitigate belowground plant–antagonist interactions but not affect plant–mutualist interactions, and higher-order species interactions depend on nitrogen addition but not phosphorus addition.

Effects of water and nitrogen rate on grain-filling characteristics under high-low seedbed cultivation in winter wheat

A high-efficiency mode of high-low seedbed cultivation (HLSC) has been listed as the main agricultural technology to increase land utilization ratio and grain yield in Shandong province, China. However, little information is available on the optimized water and nitrogen management for yield formation, especially the grain filling process, under HLSC mode. A three-year field experiment with four nitrogen rates and three irrigation rates of HLSC was conducted to reveal the response of grain-filling parameters, grain weight percentage of spike weight (GPS), spike moisture content (SMC), and yield of winter wheat to water and nitrogen rates. The four nitrogen rates were N1 (360 kg ha-1 pure N), N2 (300 kg ha-1 pure N), N3 (240 kg ha-1 pure N), and N4 (180 kg ha-1 pure N), and three irrigation quotas were W1 (120 mm), W2 (90 mm) and W3 (60 mm). Results showed that the determinate growth function generally performed well in simulating the temporal dynamics of grain weight (0.989<R2<0.999, where R2 is the determination coefficient). The occurrence time of maximum filling rate (Tmax) and active grain-filling period (AGP) increased with the increase in the water or nitrogen rate, whereas the average grain filling rate (Gmean) had a decreasing trend. The final thousand-grain weight (FTGW) increased and then decreased with the increase in the nitrogen rates and increased with the increase in the irrigation rates. The GPS and SMC had a highly significant quadratic polynomial relationship with grain weight and days after anthesis. Nitrogen, irrigation, and year exerted highly significant effects on the Tmax, AGP, Gmean, and FTGW. Particularly, the AGP and FTGW were insignificantly different between high seedbed (HLSC-H) and low seedbed (HLSC-L) across the water and nitrogen levels. Moreover, the moderate water and nitrogen supply was more beneficial for grain yield as well as spike number and grain number per hectare. The principal component analysis indicated that the combination of 240-300 kg N ha-1 and 90-120 mm irrigation quota could improve grain filling efficiency and grain yield for the HLSC-cultivated winter wheat.

Carbon and nutrient colimitations control the microbial response to fresh organic carbon inputs in soil at different depths

Despite the potential of subsoil carbon (C) to buffer or amplify climate change impacts, how fresh C and nutrients interact to control microorganismal effects on the C balance in deep soil horizons has yet to be determined. In this study, we aimed to estimate the impact of fresh C input at different soil depths on soil microbial activity. To conduct this study, Mediterranean soils from 3 layers (0–20, 20–50 and 50–100 cm of depth) were incubated over 28 days. Carbon and nutrient fluxes were measured after the addition of an amount of C equivalent to the postharvest root litter derived-C of a barley crop (4.3 atom% 13C), with and without nitrogen and phosphorus supply. We found that the microbial mineralization was C limited in the topsoil, while C and N colimited in the subsoil. These variations in stoichiometric constraints along the soil profile induced different microbial responses to C and/or nutrient addition. A stronger priming effect was observed in the topsoil than in the subsoil, and the sole C addition induced a negative C balance. Conversely, subsoil showed a positive C balance following fresh C addition, changing to critical soil C losses when nutrients were supplied with C. Our results show that fresh C input to subsoil (e.g., through deep-rooting crops) might foster soil C sequestration, but this positive effect can be reversed if such C inputs are combined with high nutrient availability (e.g., through fertilization), alleviating microbial limitation at depth.

Nitrogen Supply of Crops and Type of Fertilization and Their Impact on the Soil Case Study of Apulia Region

Nitrogen (N) is one of the fundamental elements for plant development: it plays a very important role in biochemical processes, such as chlorophyll photosynthesis, the production of amino acids and proteins, but it is also the most critical element in fertilization. When nitrogen is administered to the soil, in its more complex forms, organic and ureic, it transforms into increasingly simple forms such as Ammonia (NH) and Nitric (NO3) and becomes assailable by plants. Due to its agronomic function, nitrogen represents an element that must be appropriately integrated into the crop cycle through careful fertilization and a careful balance between withdrawals, losses and contributions. The choice of the nitrogen fertilization strategy must obviously aim to guarantee the availability of the element to the crops in the phases in which they need it most, avoiding losses that can represent a threat to the environment or to the crop economic balance. This article has the main purpose of highlighting the impact of the main fertilizations used in the regional agricultural context, in relation to the concentration of nitrogen in its various forms which remains in the soil, thus becoming part of a potential environmental impact both of the matrix itself and of the aquifers. Below, through the analysis of the main crop types. The conclusion is the impact of the main crop type and them fertilization on the soil in particular for the nitrogen compounds.

Improving Determination of Pigment Contents in Microalgae Suspension with Absorption Spectroscopy: Light Scattering Effect and Bouguer-Lambert-Beer Law.

The Bouguer-Lambert-Beer (BLB) law serves as the fundamental basis for the spectrophotometric determination of pigment content in microalgae. Although it has been observed that the applicability of the BLB law is compromised by the light scattering effect in microalgae suspensions, in-depth research concerning the relationship between the light scattering effect and the accuracy of spectrophotometric pigment determination remains scarce. We hypothesized that (1) the precision of spectrophotometric pigment content determination using the BLB law would diminish with increasing nonlinearity of absorbance, and (2) employing the modified version of the BLB (mBLB) law would yield superior performance. To assess our hypotheses, we cultivated Phaeodactylum tricornutum under varying illumination conditions and nitrogen supplies in controlled indoor experiments, resulting in suspensions with diverse pigment contents. Subsequently, P. tricornutum samples were diluted into subsamples, and spectral measurements were conducted using different combinations of biomass concentrations and path lengths. This was carried out to assess the applicability of the BLB law and the nonlinearity of absorbance. The chlorophyll a and fucoxanthin contents in the samples were analyzed via high-performance liquid chromatography (HPLC) and subsequently used in our modeling. Our findings confirm our hypotheses, showing that the modified BLB law outperforms the original BLB law in terms of the normalized root mean square error (NRMSE): 6.3% for chlorophyll a and 5.8% for fucoxanthin, compared to 8.5% and 7.9%, respectively.

Unlocking the secrets of peptide transport in wine yeast: insights into oligopeptide transporter functions and nitrogen source preferences.

Limited nitrogen supply can prevent the completion of alcoholic fermentation. Supplementation through peptides as an alternative, natural source of nitrogen for yeast offers an interesting solution for this issue. In this work, the S. cerevisiae peptide transporters of the Opt and Fot families were studied. We demonstrated that Fot and Opt2 have a broader peptide length preference than previously reported, enabling yeasts to acquire sufficient nitrogen from peptides without requiring additional ammonia or amino acids to complete fermentation. On the contrary, Opt1 was unable to consume any peptide in the given conditions, whereas it has been described elsewhere as the main peptide transporter for peptides longer than three amino acid residues in experiments in laboratory conditions. This controversy signifies the need in applied sciences for approaching experimental conditions to those prevalent in the industry for its more accurate characterization. Altogether, this work provides further evidence of the importance of peptides as a nitrogen source for yeast and their consequent positive impact on fermentation kinetics.