Nitrogen Supplementation Research Articles

Carotenoid Production by Rhodosporidium paludigenum Using Orange Peel Extract as Substrate

Carotenoids are fat-soluble pigments that have various benefits in health and beauty. The demand and market of carotenoids are increasing; thus, the faster and cheaper biological production of these pigments using microorganisms is desired. In this study, the optimum medium pH and nitrogen concentration for carotenoid production by Rhodosporidium ( R. ) paludigenum using orange peel extract as substrate were determined. The soluble sugars from orange peels were extracted using distilled water at 100 °C. The yeast inoculum was cultivated in Yeast Peptone Dextrose (YPD) media before fermentation. The independent variables in the fermentation factorial design included initial medium pH (5; 6; and 7) and nitrogen concentration (0; 1; and 1.75 g/L urea in the medium). The decrease in reducing sugar concentration and the increase in biomass dry weight during fermentation demonstrated carbon source consumption by R. paludigenum for growth and carotenoid production. On the sixth day of fermentation (D6), the culture was harvested for the total carotenoid extraction and determination. The highest total carotenoid yield (107.63 µg/g) was achieved by the treatment group with an initial medium pH of 6 without nitrogen supplementation. This result indicated the orange peel extract potential as a substrate for carotenoid production using R. paludigenum as a workhorse. This was the first reported research in natural carotenoid generation using R. paludigenum (strain InaCC Y-236) locally isolated in Indonesia as the producer and orange peel extract as the substrate. Thus, this research would enrich the microbial carotenoid exploration and waste valorization to value-added products at the same time. The study can then be developed further and upscaled for industrial applications.Â

Fermentation of Sweet Sorghum Syrup Under Reduced Pressure for Bioethanol Production

Background:Production of bioethanol from sweet sorghum (Sorghum saccharatum) is a promising “green” energy source that can help to reduce energy dependence on petroleum products, to decrease greenhouse gas emissions, and fight environmental pollution. As an additional benefit, it can promote the exploitation of new uncultivated agricultural lands and favor establishing integrated agro-industrial energy independent enterprises. The alcoholic fermentation under reduced pressure may prevent the accumulation of high ethanol concentrations in the cultured broth and thus may create favorable conditions for the highest productivity of yeastSaccharomyces cerevisiae.Objective:Elaboration of optimal conditions for sweet sorghum syrup fermentation under reduced pressure.Aim:To determine the parameters of sweet sorghum syrup fermentation byS. cerevisiaeunder the conditions of constant and periodic reduced pressure for the highest bioethanol production efficiency.Methods:The sweet sorghum was grown in a temperate continental climate region of Northern Ukraine. The parameters of diluted stem syrup andS. cerevisiaefermentation under reduced and atmospheric pressure were established and controlled by chemical, biochemical and physicochemical methods. The yeast cells were dyed with methylene blue and counted using a microscope and a Neubauer counting chamber. The obtained data have been statistically analyzed.Results:It has been established that a periodic vacuum extraction with short-term heating of the medium to the boiling point is the most promising procedure for bioethanol production. Periodically reduced pressure fermentation of sweet sorghum diluted syrup resulted in 55% higher bioethanol productivity compared to atmospheric pressure fermentation. Such treatment enables to maintain the concentration of ethanol in the medium below 5.5% vol., which does not significantly inhibit the productivity of industrial yeast strains and allows adding a nutrient with the subsequent continuation of the cultivation process. The resulting distillate requires less energy for further dehydration.Conclusion:The sweet sorghum syrup does not contain substances that inhibit yeast cells although nitrogen and phosphorus supplements are required to support efficientS. cerevisiaegrowth. The optimal technology, elaborated in this research, consists of repeated cycles of fermentation under reduced pressure (to the level of vacuum) for boiling the cultured broth. This technology provides the highest bioethanol output, high efficiency, and productivity of the overall process.

Impact of Feedlot Manure and Nitrogen Additions on Forage Yields, Nutrient Balance and Soil Nitrate, Phosphate and Salinity

ABSTRACT Safe disposal of feedlot manure is an increasing problem throughout the world. A field experiment was established on a duplex sandy loam soil (Alfisol) in Northern NSW, Australia to determine the dry matter (DM) crop response and the fate of nutrients derived from cattle feedlot manure and inorganic fertilizer applications. The five treatments imposed over a three year period were no manure or inorganic fertilizer (NM), a moderate annual manure application (20–25 t DM ha−1) -/+ N (MA, MAN) a high initial application in year 1 (60 t DM ha−1 + N, HIN) and an inorganic fertilizer treatment (single superphosphate, KCl, urea, I) applied in each year. Vegetative yields of forage sorghum (Sorghum bicolor cv. Super-Dan) and triticale (Triticosecale spp. cv. Madonna) were recorded in crops grown in sequence over a three-year period. A mass balance approach was used to quantify nutrient gains to, and losses from the system. Total crop yield was 14.22 t dry matter (DM) ha−1 in the NM treatment with an approximate threefold increase with HIN and I. Removal of nutrients (kg ha−1) in harvested forage was highest for N, K and S in the I treatment (767 N, 1447 K, 76 S) and highest for P in the HIN treatment (189 P). There was no accumulation of NO3 in the soil layers to the B horizon in the manure treatments which contrasts with I. In the manure treatments there was a 6 to 8 fold increase over the initial value in Colwell bicarbonate extractable P in the 0–10 cm soil horizon in the MAN and HIN treatments, a decline in exchangeable K, an increase in EC and a loss of P sorption capacity. Supplemental inorganic nitrogen has been found to increase the nutrient benefits of feedlot manure. Accumulation of soil phosphate and salts, and a decline in soil K was found and needs to be closely monitored to maintain productivity and the environment.

Assessment of optimal growth conditions for specific carotenoids production by Chlorella vulgaris

Exploration of regional microalgae for carotenoids production under optimized cultural conditions is a sustainable economic and technical perspective. This study details comprehensive research on the influence of growth conditions on microalgal carotenoids. Carotenoid triggering factors were optimized to identify suitable growth conditions to produce specific carotenoids by Chlorella vulgaris. Media optimization and cultivation conditions were the factors considered and the results revealed the optimum growth conditions for carotenoid production by C. vulgaris was pH 8, 35°C temperature, 0.04 M salinity and 160 µE\m²\sec light intensity. Among the nutrient sources, potassium nitrate and potassium phosphate were suitable for nitrogen and phosphorous supplements. The results indicated optimizing the culture conditions and nutrient sources help to attain desirable carotenoid production by C. vulgaris. Specific carotenoids were extracted from the algal extract and were identified by high-performance liquid chromatography in which lutein (8.8%) was present as major carotenoid followed by astaxanthin (4.6%) and ?-carotene (3.9%). This study revealed that that carotenoid production by C. vulgaris could be enhanced by manipulating culture conditions thereby attain desirable carotenoid production.

The effect of molasses nitrate lick blocks on supplement intake, bodyweight, condition score, blood methaemoglobin concentration and herd scale methane emissions in Bos indicus cows grazing poor quality forage

Context The Australian government has approved a greenhouse gas (GHG) offset method that requires cattle to consume nitrate in the form of a lick block. Field studies demonstrating the effectiveness of this methodology have not been previously reported. Aims This experiment was conducted to determine the effects on productivity and health when nitrate lick blocks were provided as a supplement to grazing beef cattle. We hypothesised that beef cattle given access to nitrate lick blocks would have similar productivity compared with cattle offered urea lick blocks. Methods Bos indicus breeding cows (n = 76) grazed a 467-ha paddock near Charters Towers, Queensland, between May and November 2014. A two-way remote automatic drafting system enabled allocation of cattle to different treatments while grazing in a common paddock. Treatments were 30% urea lick blocks (30U), or molasses nitrate lick blocks (MNB). At monthly intervals liveweight (LW), body condition score (BCS), and blood methaemoglobin concentration were recorded. Estimates of individual supplement intake were made on three separate occasions using a lithium marker technique. Results Mean daily supplement intake (±s.e.m.) of 30U (122 ± 13 g) was greater (P < 0.001) than MNB (67 ± 8 g). Lesser MNB intake was associated with greater variability for individual supplement intake, a greater proportion of non-consumers of supplement during July (P < 0.05) and reduced voluntary supplement intake until October (P < 0.001). Increasing MNB consumption during October and November was accompanied by elevated blood methaemoglobin concentration (P < 0.001). It was estimated that cattle offered MNB had insufficient supplementary nitrogen intake throughout the study to resolve rumen degradable nitrogen deficiency from grazed forage. Consequently, cattle provided access to MNB demonstrated conceptus free liveweight loss and lesser BCS compared with cattle treated with 30U (P < 0.001). Conclusion Nitrate lick blocks were ineffective as a dual-purpose non-protein nitrogen supplement and methane mitigant for beef cattle grazing poor quality forage. Further field experiments are required to determine if there may be situations where this GHG offset methodology is efficacious. Implications Caution is advised in implementing GHG mitigation methods that involve the use of nitrate lick blocks.

Revalorization of untreated Brewer’s spent grain: novel and versatile feedstock to produce cellulases, lipases, and yeast biomass in a biorefinery approach

Brewer’s spent grain (BSG) is the main by-product of the beer production industry. BSG is rich in valuable compounds, so it can be used as feedstock for the production of high value-added products. BSG was revalorized as a cost-effective, versatile, and novel media to produce lipases, cellulases, and yeast biomass. The microorganisms used were the yeasts Yarrowia lipolytica, Saccharomyces cerevisiae, Rhodotorula mucilaginosa, Hanseniaspora uvarum, and two recently isolated fungi identified as Aspergillus fumigatus and Penicillium sp. The BSG-based media allowed the production of both enzymes and yeast biomass. Y. lipolytica strains displayed similar or better lipase activity with the BSG-based media, showing that BSG can be used as carbon and nitrogen source and lipid inducer in lipases production. The highest cellulase activity on submerged fermentation was 0.354 ± 0.046 and 0.232 ± 0.004 U/mL with BSGw medium for A. fumigatus and Penicillium sp., respectively, after 72 h. On solid-state fermentation, the cellulase activity was 7.5 ± 0.039 (11 days) and 8.3 ± 0.278 (14 days) U/g BSGw for A. fumigatus and Penicillium sp., respectively. In yeast biomass production, S. cerevisiae had a better response in the BSG syrup production medium than R. mucilaginosa and H. uvarum, since these two strains were highly dependent on nitrogen supplementation. These results demonstrate that BSG can be used without pretreatment, as substrate for the growth of various microorganisms and as potential raw material for biorefineries, allowing the production of enzymes and single-cell biomass.

Oat genotypic requirement for intercropping with vetch under Mediterranean conditions

AbstractOat (Avena spp. L.) intercropped with common vetch (Vicia sativa L.) has shown high forage yield and crude protein content (CP) in rainfed Mediterranean environments of Greece. The objective was to study the oat genotypic interactions for yield, quality and agronomic traits of four oat accessions (cv. Flega and lines B2, B3 and B4) grown as intercrops with a common vetch cultivar (Pegasus) and as monocrops without or with nitrogen (N) supplementation (100 kg N/ha). In all mixtures, the land equivalent ratio exceeded the unit indicating that there was a yield advantage. Intercrops produced, on average, 5.0% less dry matter (DM) and 38.9% more crude protein yield (CPY) compared to monocropped oats with N fertilization and 3.4% more DM and 75.5% more CPY compared to monocropped oats without N fertilization. The DM, CP and quality differences between the intercropped and monocropped oats were attributed to oats by vetch cultivar interactions. The oat B2 intercropped was the shortest, the latest flowering and the less vigorous early in the season, a trait that allowed common vetch to dominate in the intercrop (vetch participation 770 g/kg). The high vetch fragment in the intercrop contributed to high CP, CPY, acid detergent lignin, total digestible nutrients, relative feeding value, relative forage quality, net energy for lactation and to low neutral detergent fibre, acid detergent fibre and hemicellulose. The replacement value index indicated that the intercrop was 21% more economically viable in comparison to the fertilized monocrop.

Coupling of Biochar with Nitrogen Supplements Improve Soil Fertility, Nitrogen Utilization Efficiency and Rapeseed Growth

Compensating nitrogen input and increasing nitrogen utilization efficiency (NUtE) are necessary for sustainable crop production. Research studies on the co-application of biochar and nitrogen to promote rapeseed growth, soil fertility, and improve nutrient utilization efficiency are found to be limited. This study aims to examine the integral effects of biochar and nitrogen over soil fertility, rapeseed growth and nitrogen utilization efficiency. The experiment was conducted in a completely randomized design to assess various morphological, physiological and biochemical traits of rapeseed and soil chemical properties under the application of four nitrogen levels (0, 75, 225, and 450 kg ha−1 equivalent to 0, 133, 400 and 800 mg nitrogen pot−1) and four biochar levels (0, 5, 10, and 15 MT ha−1 equivalent to 0, 10, 20 and 30 g biochar pot−1 soil by weight basis). The results of this study showed that the integral application of biochar at 30 g pot−1 and nitrogen at 800 mg pot−1 at 45 days after sowing (DAS) and 60 days after sowing (DAS) compensated the amount of nitrogen and increased soil organic carbon (SOC 69%), total nitrogen accumulation (TNA) (93% and 62%), leaf biomass (60% and 33%), stem biomass (20% and 22%) and photosynthesis (20% and 17%) at 45 DAS and 60 DAS, respectively as compared to a single application of nitrogen. However, under the conditions of no nitrogen or 75 kg ha−1 nitrogen application, the application of biochar to promote the growth of rapeseed plants is limited due to the less nitrogen supply. In contrast, the application of nitrogen at 800 mg pot−1 and biochar at 10 or 20 g pot−1 showed that the growth of early seedlings was adversely affected due to high nitrogen concentration in soil. The findings of the present study imply that within the appropriate nitrogen application range, the interaction of biochar and nitrogen might have an economical approach towards better utilization of nitrogen and sustainable crop production.

Nutrients Supplementation through Organic Manures Influence the Growth of Weeds and Maize Productivity.

Declining rate of productivity and environmental sustainability is forcing growers to use organic manures as a source of nutrient supplement in maize farming. However, weed is a major constraint to maize production. A field study was carried out over two seasons to evaluate various integrated nutrient and weed management practices in hybrid maize. The treatment combinations comprised of supplementation of inorganic fertilizer (25% nitrogen) through bulky (Farmyard manure and vermicompost) and concentrated (Brassicaceous seed meal (BSM) and neem cake (NC)) organic manures and different mode of weed management practices like chemical (atrazine 1000 g ha−1) and integrated approach (atrazine 1000 g ha−1 followed by mechanical weeding). Repeated supplementation of nitrogen through concentrated organic manures reduced the density and biomass accumulation of most dominant weed species, Anagalis arvensis by releasing allelochemicals into the soil. But organic manures had no significant impact on restricting the growth of bold seeded weeds like Vicia hirsuta and weed propagated through tubers i.e., Cyperus rotundus in maize. By restricting the weed growth and nutrient removal by most dominating weeds, application of BSM enhanced the growth and yield of maize crop. Repeated addition of organic manures (BSM) enhanced the maize grain yield by 19% over sole chemical fertilizer in the second year of study. Application of atrazine as pre-emergence (PRE) herbicide significantly reduced the density of A. arvensis, whereas integration of mechanical weeding following herbicide controlled those weeds which were not usually controlled with the application of atrazine. As a result, atrazine at PRE followed by mechanical weeding produced the highest maize grain yield 6.81 and 7.10 t/ha in the first year and second year of study, respectively.

Optimization of biomass and some metabolites productivity of Merismopedia tenuissima and Spirulina (Arthrospira) platensis grown under stress conditions

The attention to using cyanobacteria as a nutrient supplement has increased due to their nutritional value and high bioactive metabolites contents. The reason behind designing such a study is to illustrate and clarify stress conditions effects like nitrogen and phosphorus supplementation and deficiency, salinity stress, and different pH values on the biomass, lipid, protein, amino acid, and carbohydrate productivities of Merismopedia tenuissima and Spirulina (Arthrospira) platensis.  The obtained results revealed that an increase in sodium nitrate by 100% caused an improvement in biomass, protein, and amino acid’s productivity of S. platensis  and M. tenuissima by 7.02 % and 7.05, 9.2% and 47.5%, 11.8% and19.5, respectively while 100% nitrogen deficiency enhanced lipid productivity of S. platensis  and M. tenuissima to 41% and 94%. Moreover, phosphorus limitation led to a reduction in biomass, protein, amino acid, and carbohydrate S. platensis to 24.3%, 21.1%, 43.3%, and 28.1%, respectively. However, phosphorus-free medium showed an increase in lipid productivity of S. platensis and M. tenuissima by 46.8% and 81.8%, respectively. The addition of 0.05 M NaCl concentration to S. platensis  medium stimulates the biomass, protein, and carbohydrate productivity by 6%, 7.75%, and 18.1%, respectively, whilst, among all concentration, zero M NaCl (control) resulted in increasing biomass, protein, and amino acids, whilst, high concentration (0.3M) of NaCl enhanced lipid productivity to 125.9% and 153.5% at S. platensis  and M. tenuissima, respectively. Applications of high alkalinity (pH 9) increased the productivities of all studied metabolites in S. platensis and reduction of all mention metabolites in M. tenuissima.

The Influence of Three Years of Supplemental Nitrogen on Above- and Belowground Biomass Partitioning in a Decade-Old Miscanthus × giganteus in the Lower Silesian Voivodeship (Poland)

Because of the different opinions regarding nitrogen (N) requirements for Miscanthus × giganteus biomass production, we conducted an experiment with a set dose of nitrogen. The objective of this study was to examine the effects of nitrogen fertilization on the biomass yield, water content, and morphological features of rhizomes and aboveground plant parts in various terms during a growing season over the course of three years (2014–2016) in Lower Silesia (Wroclaw, Poland). The nitrogen fertilization (dose 60 kg/ha and control) significantly affected the number of shoots (p = 0.0018), the water concentration of rhizomes (p = 0.0004) and stems (p = 0.0218), the dry matter yield of leaves (p = 0.0000), and the nitrogen uptake (p = 0.0000). Nitrogen fertilization significantly affected the nitrogen uptake in all plant parts (p = 0.0000). Although low levels of nitrogen appeared to be important in maintaining the maximum growth potentials of mature Miscanthus × giganteus, the small reductions in the above- and belowground biomass production are unlikely to outweigh the environmental costs of applying nitrogen. More studies should use the protocols for the above- and belowground yield determination described in this paper in order to create site- and year-specific fertilizer regimes that are optimized for quality and yield for autumn (green) and spring (delayed) harvests.

Efficacy of Supplemental Irrigation and Nitrogen Management on Enhancing Nitrogen Availability and Urease Activity in Soils with Sorghum Production

The soil nitrogen (N) availability and urease activity (UA) in a humid ecosystem with variable rainfall distribution and poor soil fertility are not well understood. A complete appreciation of N cycling in the soil–water–plant continuum is needed to better manage N and water in regions that will be strongly affected by climate change. A sorghum (Sorghum bicolor L.) study located in Florence, South Carolina, USA, was conducted using a variable-rate pivot system. We hypothesized that supplemental irrigation (SI) and N would enhance UA and N uptake while minimizing the concentration of N in porewater (TINW). The aim of the study was to assess the impact of SI (0, 50, and 100%) and N fertilization (0, 85, and 170 kg N ha−1) on: UA; total N (TNS); total inorganic N (TINS); TINW; and N uptake of sorghum. Results support our research hypothesis. The greatest UA was from 0% SI and 170 kg ha−1 (18.7 µg N g−1 ha−1). Porewater N (mg L−1), when averaged across SI and N showed a significantly lower concentration at lower soil depth (9.9 ± 0.7) than the upper depth (26.1 ± 2.4). The 100% SI had the greatest biomass N uptake (NUPB) of 67.9 ± 31.1 kg ha−1 and grain N uptake (NUG) of 52.7 ± 20.5 kg ha−1. The greatest NUPB (70.9 ± 30.3 kg ha−1) and NUG (55.3 ± 16.5 kg ha−1) was from the application of 170 kg N ha−1. Overall, results showed that proper use of water and N enhanced soil N dynamics, and improved biomass productivity and N uptake of sorghum.

Pentose-rich hydrolysate from oil palm empty fruit bunches for β-glucan production using Pichia jadinii and Cyberlindnera jadinii

Pentose-rich hydrolysate obtained from dilute acid pretreatment of oil palm empty fruit bunches was successfully consumed by pentose-consuming yeasts: Cyberlindnera jadinii (Cj) and Pichia jadinii (Pj). Nitrogen supplementation and no additional detoxification step were required. Pj produced 5.87 g/L of biomass using a C/N ratio of 14 after 120 h of fermentation, with xylose consumption of 71%. Cj produced 10.50 g/L of biomass after 96 h of fermentation with C/N ratio of 11.5, with maximum xylose consumption of 85%. β-glucans, high value-added macromolecules, were further extracted from the yeast biomass, achieving yields of 3.1 and 3.0% from Pj and Cj, respectively. The isolated polysaccharides showed a chemical structure of β-(1,3)-glucan with residues of other molecules. Additionally, β-(1,6) branches seems to have been broken during isolation process. Further studies assessing β-glucans production at industrial scale should be carried out looking for nitrogen sources and optimizing the β-glucan isolation method.

Nitrogen supplementation for the production of Chlorella vulgaris biomass in secondary effluent from dairy industry

• Secondary effluent from dairy industry was used for Chlorella vulgaris cultivation. • Nitrogen was supplemented for achieving N:P = 1.72:1. • Biomass productivity with effluent was the same as that with standard medium. In this study, secondary effluent from dairy industry was employed for the cultivation of Chlorella vulgaris in a bench-scale tubular photobioreactor. We sought to evaluate the biomass production, the consumption of nitrogen in the medium, and the final biomass composition. Considering the need of nitrogen supplementation, we evaluated the nitrogen:phosphorus ratio: the same proportion found in Bold basal medium (N:P = 1.71:1) and Redfield ratio (N:P = 16:1), comparing with no nitrogen supplementation and Bold Basal Medium. The results showed that nitrogen supplementation improves biomass growth (up to 2824.93 mg.L −1 ), also granting efficient nutrients consumption (up to 98 % of nitrogen removal). Nitrogen supplementation following the Bold medium ratio was the most suitable protocol, since it requires less nitrogen addition without impairment in biomass productivity (Px =259.90 mg.L −1 .d −1 ), in comparison with cultures with supplementation following Redfield ratio (Px =296.73 mg.L −1 .d −1 ) or control culture (Px =221.02 mg.L −1 .d −1 ). In addition, the final biomass showed satisfactory amounts of proteins (up to 21.92 %) and lipids (up to 35.75 %), besides presenting a profile with high concentrations of saturated (C16:0) and monounsaturated fatty acids (C18:1).

Phenotypic and transcriptional analysis of Saccharomyces cerevisiae during wine fermentation in response to nitrogen nutrition and co-inoculation with Torulaspora delbrueckii

Nitrogen content of grape musts strongly impacts on fermentation performance and wine metabolite production. As nitrogen is a limiting nutrient in most grape musts, nitrogen supplementation is a common practice that ensures yeast growth during fermentation. However, preferred nitrogen sources -as ammonium- repress the genes related to alternative nitrogen sources consumption, usually involved in aromatic compounds production. Here, we describe the effect of high ammonium doses in Saccharomyces cerevisiae fermentation performance and wine properties, and how it is affected by yeast co-inoculation in mixed (S. cerevisiae + Torulaspora delbrueckii) fermentations. In addition, an RNA-seq analysis allowed us to study the S. cerevisiae transcriptional response to ammonium nutrition and yeast interaction, demonstrating that T. delbrueckii presence affects the global S. cerevisiae transcriptional response, reducing ammonium effects at both phenotypic -fermentation kinetics and metabolite production- and transcriptional levels, under experimental conditions.

Organic nutrient management in aromatic rice-rice sequence: A critical review

The field experiment was conducted to evaluate the “Effect of soil and foliar supplementation of nitrogen, boron and salicylic acid on growth and yield of cucumber (Cucumis sativus L.) in alfisols of Konkan (M.S.)” at Research and Education Farm, Department of Agricultural Botany, College of Agriculture, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, Dist. Ratnagiri (M.S.) during the Summer season of 2018. The experiment was laid out in Randomized Block Design (RBD) comprising ten treatment combinations replicated thrice, where the effect of soil and foliar supplementation of nitrogen, boron and salicylic acid either alone or in combinations applied along with the recommended dose of fertilizers (135:60:30 NPK kg ha-1) and an absolute control (to judge the fate of native nutrients) were studied. The study further revealed that the treatment receiving the application of recommended dose of fertilizer (135:60:30 kg ha-1) + Foliar spray of nitrogen through urea (1%) + Soil application of boron through borax @ 2 kg ha-1+ Foliar spray of salicylic acid (0.2%) was recorded the highest fruit yield (231.22 q ha-1) and yield attributing characters like number of fruits per vine (7.00) and weight of fruit i.e., 1.98 kg per vine as well as growth parameters viz. vine length (407.00 cm) and number of branches per vine (14.22) of Cucumber in alfisols of Konkan (M.S.).

Lower Nitrogen Availability Enhances Resistance to Whiteflies in Tomato.

Soil nitrogen (N) supplementation via fertilizers may increase crop yields substantially. However, by increasing tissue N content, added N can make plants more attractive to herbivores, effectively reducing their resistance to herbivores (ability to avoid herbivore damage). In turn, greater pest infestation may cause more severe reductions in fruit production than a moderate N scarcity. In this study, we tested whether lower N supplementation results in greater resistance to whiteflies and lower fruit production in four tomato varieties. We assessed the effects of N availability on tolerance to herbivores (degree to which fitness is affected by damage) and tested for the long-hypothesized trade-off between resistance and tolerance. Plants grown at half of an agronomically recommended amount of N had greater resistance without a significant drop in fruit production. Tomato varieties differed in resistance and tolerance to whiteflies, and showed a clear trade-off between these modes of defense. Root:shoot ratios were greater at lower N, but had no clear relation to tolerance. We estimated that the economic benefit of decreasing N addition almost fully compensates for losses due to lower tomato production. Additionally, lower fertilization rates would contribute to reduce environmental costs of large-scale use of agrochemicals.

Azospirillum brasilense increases corn growth and yield in conventional low input cropping systems

AbstractThe supplementation of nitrogen can be increased by the use of nitrogen-fixing, diazotrophic bacteria such as Azospirillum brasilense. These bacteria can act to promote plant growth in various plant species, including corn (Zea mays L.). However, there is a need to understand the behavior of these bacteria in different agricultural systems. The objective of this study was to evaluate the effect on the growth and yield of corn inoculated with A. brasilense, and to identify the type of farming system which benefited most from the use of A. brasilense-based inoculants. The experiment conducted over two corn crop seasons was arranged in a 6 × 2 factorial scheme, consisting of six farming systems and the presence or absence of inoculation with the bacteria A. brasilense. The farming systems were derived from a long-term experiment with different fertilization systems that has been conducted since 1984. Among these systems, there were three conventional systems (CNT1: conventional no-till without fertilizer; CNT2: conventional no-till with 150 kg ha−1 of mineral fertilizer + 50 kg ha−1 of urea; CNT3: conventional no-till with 300 kg ha−1 of mineral fertilizer + 100 kg ha−1 of urea), and three organic systems (ONT1: organic no-till with 40 m3 ha−1 of organic compost; ONT2: organic no-till with 20 m3 ha−1 of organic compost; ONT3: organic no-till with 40 m3 ha−1 of organic compost and intercropped with Canavalia ensiformis). Although the Azospirillum population in the soil before planting was the same for all six systems, the count in the rhizospheric soil was higher in the organic systems, and there was no increase in that count due to inoculation. In this study, the only difference observed was within the CNT1 system, between the inoculated (CNT1-I) and uninoculated (CNT1-NI) treatments. In this system, inoculation resulted in an increase in plant height, in addition to higher concentrations of foliar N and P, and a higher plant survival rate, which culminated in higher yield. Corn inoculated with A. brasilense in the CNT1-I treatment showed a significant increase in yield—2839 kg ha−1 higher than that recorded for CNT1-NI. This study shows that, in the conventional low input treatment CNT1-I, inoculation with A. brasilense resulted in an increase in corn growth and yield.

Nitrogen Sources Added to Must: Effect on the Fermentations and on the Tempranillo Red Wine Quality

Nitrogen supplementation in musts or during the alcoholic fermentation is a common practice to promote fermentations. In this study, the impact of the supplementation of two different sources of nitrogen during Tempranillo red wine elaboration was studied. Mineral and organic nitrogen was added after the exponential yeast growth phase and during winemaking, examining its impact on the alcoholic and malolactic fermentation development, on the aromatic wine composition and on the nitrogenous wine composition. The nitrogen supplementation did not provide neither significant advantages in kinetics and fermentations time, nor differences in the chemical wine composition. The aromatic composition of the wines improved with the addition of inorganic nitrogen, although its organoleptic evaluation was not favored. Moreover, the concentration of amino acids in wines increased slightly after the malolactic fermentation and significantly during the stabilization time, especially with organic nitrogen addition. However, the synthesis of biogenic amines did not increase in wines neither after the malolactic fermentation, nor after the storage period.

Nattokinase production from Bacillus subtilis using cheese whey: Effect of nitrogen supplementation and dynamic modelling

In this study, cheese whey – a nutrient-rich industrial waste was utilized as a low-cost fermentation medium for the growth of Bacillus subtilis and nattokinase production. The nattokinase yield (caseinolytic activity) using cheese whey (789.93 U ml−1) was 5 %–7 % less compared to glucose- or lactose-based synthetic media (833.44 and 850.84 U ml−1, respectively). Effect of nitrogen supplementation (yeast extract, tryptone, and peptone) on nattokinase yield was tested adopting an L9 (33) Taguchi experimental design, which revealed yeast extract as the best nitrogen source. Yeast extract supplementation (10 g l-1) to cheese whey increased the caseinolytic activity to 833.43 U ml−1, making it comparable to lactose- and glucose-based synthetic media, while lowering the medium cost by 55–60 %. A dynamic model incorporating logistic growth, substrate utilization and Luedeking-Piret product formation kinetics across all carbon-sources offered good agreement (R2 > 0.93). The estimated maximum specific growth rate on lactose-based synthetic medium (0.204 h−1), or yeast extract supplemented cheese whey medium (0.201 h−1) were better than that of the glucose-based synthetic medium (0.122 h−1). A similar observation on the growth associated product formation parameters offers insight on medium selection process. Overall, this study suggested that cheese whey could be utilized as a low-cost medium for nattokinase production.