Effect of nitrogen-sulphur nutrition and inhibitors of nitrification on the yield and quality of maize grain

Increasing the productivity of cereals such as maize while protecting the environment remains a fundamental impetus of healthy food production systems. The use of biostimulants is one of the sustainable strategies to achieve this balance, although the ability of biostimulants to enhance maize productivity varies. Moreover, research on the efficacy of biostimulants is ubiquitous with limited comprehensive global analysis. In this context, this systematic review evaluated the sole and interactive effects of biostimulants on the yield and quality of maize grain from a global perspective. Changes in yield (t ha-1), protein content (%), starch content (%) and oil content (%) of maize grain were assessed. Results revealed that sole and combined application of biostimulants significantly improved grain yield. Irrespective of the region, the highest and the lowest grain yields ranged between 16-20 t ha-1 and 1-5 t ha-1, respectively. In sole application, the promising biostimulants were chicken feather (16.5 t ha-1), and endophyte Colletotrichum tofieldiae (14.5 t ha-1). Sewage sludge × NPK (15.4 t ha-1), humic acid × control release urea (12.4 t ha-1), Azospirillum brasilense or Bradyrhizobium japonicum × maize hybrids (11.6 t ha-1), and Rhizophagus intraradices × earthworms (10.0 t ha-1) had higher yield for the interactive effects. The effects of biostimulants on grain quality were minimal, and all attributes improved in the range from 0.1 to 3.7%. Overall, biostimulants had a distinct improvement effect on yield, rather than on the quality of grain. As one way of maximising maize productivity, soil health, and the overall functioning of crop agroecosystems, the integrated application of synergistic microbial and non-microbial biostimulants could provide a viable option. However, the ability to produce consistent yield and quality of grain improvement remains a major concern.

The field experiment was performed in 2019–2021 at the Experimental Station of Vytautas Magnus University Agriculture Academy (54°52′ N, 23°49′ E). The soil of the experimental field was Endohipogleyic-Eutric Planasol. The studied factors were: Factor A—different nitrogen fertilizer rates: (1) 100 kg N ha−1; (2) 140 kg N ha−1; (3) 180 kg N ha−1; Factor B—the use of urease inhibitors (UI) and biological preparations (BP): (1) urease inhibitors (UI) and biological preparations (BP) were not used; (2) Urease inhibitor (UI ATS)—ammonium thiosulfate—[(NH4)2S2O3 12-0-0-26S]; (3) Urease inhibitor (UI URN)—N-butyl-thiophosphorus triamide (NBPT) and N-propyl-thiophosphorus triamide (NPPT); (4) Biological preparation (BP HUM)—suspension of humic and fulvic acids; (5) Biological preparation (BP FIT)—Ascophyllum nodosum suspension. Our studies showed that the highest yield of maize grain (8.9–12.0 t ha−1) was obtained by fertilizing with N180 and using the urease inhibitor ammonium thiosulfate (ATS). ATS significantly increased corn grain yield in all backgrounds of nitrogen fertilization. The investigated urease inhibitors and biologics had a higher and more significant (p < 0.05) effect on maize grain yield when fertilized with N100 nitrogen. The increase in nitrogen fertilizer rates had an effect on maize grain yield, with the largest increase in yield being found in the increase in nitrogen rate from N100 to N140, and the increase in rate to N180 was less effective. The maximum mass of 1000 grains (323.5 g) was determined in 2019 by fertilization with N180 and use of the urease inhibitor UI URN. The urease inhibitor UI ATS was more effective when fertilized with lower rates of N100 and N140. Positive, moderate, strong and very strong, statistically significant correlations (r2 = 0.48–0.91) were most often found between the latter indicators and nitrogen fertilizer rates throughout the study year. The largest amount of grain (497 units) in the cob was determined in 2019, using fertilization with N140 and UI ATS, but no significant differences were found between the different fertilizer rates and the tested preparations. These results suggest that urease inhibitors and biologics can reduce dependence on nitrogen fertilizers and increase maize yield, a technology that should be practiced by maize growers.

Aim. The study of the effect of nitrogen fertilization on the yield and quality of winter wheat grain on meadow‐chestnut soil.Methods. Analyses of soil samples were carried out using generally accepted standard techniques. Assessment of the biological yield of grain and its structure was carried out according to the "Methodology of the State Variety Testing of Agricultural Crops". Tillage for winter crops after stubble predecessors was carried out according to the irrigation halfsteam system.Results. With an increase in the hydrothermal coefficient, a more elastic gluten is formed. Studies have shown that as the dose of nitrogen fertilizing increases, the indicators of the sowing qualities of seeds and the baking qualities of winter wheat grain of the Grom variety improve. In the best variant N90P90, the following indicators were obtained: seed germination energy – 99%, germination – 100%, weight of 1000 grains – 34.7 g, protein content – 14.8%, gluten 27.4%, which represent respectively 4%; 4%; 3.9 g; 1.3% and 6.1% more than in the control variant without the use of mineral fertilizers and higher than in the variants N30P90 and N60P90.Conclusion. The research area determines the use of the high‐intensity Thunder variety, which helps to stabilise productivity and improve product quality. The use of nitrogen top dressing (N30, N60 and N90) against the background of P90 increases the yield of winter wheat grain from 6.25 to 7.90 t / ha and improves the main indicators of baking qualities of grain: protein – 14.3–14.8% and gluten – 22.1–27.4%, the best option with nitrogen top dressing being a dose of N90 (N30 in autumn + N60 in spring).

The purpose of this study was to evaluate the effects of liquid manure to increase the yield of green manure in winter season, and to investigate the effect of green manure incorporation to increase the yield of maize grain and nutrient balance improvement in upland soil. The green manure used in this experiment was barley and hairy vetch with a mixed ratio of barley and hairy vetch (75:25), respectively. Liquid manure applied 0, 26, 52, 78, and 104 Mg ha-1, respectively, and the half of the total amount was applied as basal fertilizer, and the other half was topdressing. Nitrogen inputs through liquid manure were 0, 7.1, 15.6, 21.5 and 28.4 kg ha-1, respectively, and the phosphorus inputs were 0, 11.3, 22.6, 33.9 and 45.2 kg ha-1, respectively. The yield of green manure crops increased significantly with the increase of liquid manure application, but the yield of hairy vetch decreased. In the summer season, the green manure crops were incorporated, and the compost was used in the conventional treatment. The yield of maize grain increased with increasing green manure yield. The yield of maize grain of green manure crops incorporation treatments was up to 81% compared to conventional cultivation treatment, however the two-year experiments showed an increase on maize grain yields in green manure incorporation treatment. In addition, the incorporation of green manure crops greatly improved the phosphorus balance in compared to conventional cultivation. Therefore, productivity improvement of green manure crops by utilizing liquid manure is thought to have significantly contributed to the improvement of maize grain yield and nutrient balance. The effect of green manure incorporation on the maize grain yield with different rate of liquid manure application for two years. The maize grain yield of PM4 treatment was 759 kg 10a-1, and up to 81% in compared with the NPK treatment in 2017. However, the maize yield of incorporation green manure treatment in 2017 tended to increase in compared with that of in 2016.

Urea fertilizer‐induced N2O emissions from soils might be reduced by the addition of urease and nitrification inhibitors. Here, we investigated the effect of urea granule (2–3 mm) added with a new urease inhibitor, a nitrification inhibitor, and with a combined urease inhibitor and nitrification inhibitor on N2O emissions. For comparison, the urea granules supplied with or without inhibitors were also used to prepare corresponding supergranules. The pot experiments without vegetation were conducted with a loess soil at (20 ± 2)°C and 67% water‐filled pore space. Urea was added at a dose of 86 kg N ha–1 by surface application, by soil mixing of prills (<1 mm) and granules, and by point‐placement of supergranules (10 mm) at 5 cm soil depth. A second experiment was conducted with spring wheat grown for 70 d in a greenhouse. The second experiment included the application of urea prills and granules mixed with soil, the point‐placement of supergranules and the addition of the urease inhibitor, and the combined urease plus nitrification inhibitors at 88 kg N ha–1. In both experiments, maximum emissions of N2O appeared within 2 weeks after fertilization. In the pot experiments, N2O emissions after surface application of urea were less (0.45% to 0.48% of total fertilization) than from the application followed by mixing of the soil (0.54% to 1.14%). The N2O emissions from the point‐placed‐supergranule treatment amounted to 0.64% of total fertilization. In the pot experiment, the addition of the combined urease plus nitrification inhibitors, nitrification inhibitor, and urease inhibitor reduced N2O emissions by 79% to 87%, 81% to 83%, and 15% to 46%, respectively, at any size of urea application. Also, the N2O emissions from the surface application of the urease‐inhibitor treatment exceeded those of the granules mixed with soil and the point‐placed‐supergranule treatments receiving no inhibitors by 32% to 40%. In the wheat growth experiment, the N2O losses were generally smaller, ranging from 0.16% to 0.27% of the total fertilization, than in the pot experiment, and the application of the urease inhibitor and the combined urease plus nitrification inhibitors decreased N2O emissions by 23% to 59%. The point‐placed urea supergranule without inhibitors delayed N2O emissions up to 7 weeks but resulted in slightly higher emissions than application of the urease inhibitor and the urease plus nitrification inhibitors under cropped conditions. Our results imply that the application of urea fertilizer added with the combined urease and nitrification inhibitors can substantially reduce N2O emissions.

The use of CO2 sensors has been reported as an effective tool in the early detection of signs of deterioration, allowing good accuracy in decision-making about the quality of stored grains. The objective of this study was to quantify the CO2 levels produced by maize grains stored at ambient temperature in a prototype silo, with initial moisture contents of 14, 16 and 18% w.b., and to evaluate the quality of the product over time and the technical breakage. Analyses of moisture content, ash, proteins, lipids, Hue Angle (color), germination and electrical conductivity were performed. Inside the silos, the amount of CO2, relative air humidity and temperature were monitored every hour. Grain quality evaluations were carried out at four storage times (0, 30, 60 and 90 days). A completely randomized design in a 3 × 4 factorial scheme with six replicates was used. Grains with higher moisture contents showed higher technical breakage and losses associated with CO2 emissions. Moisture content, protein, lipids, germination, bulk density, lightness and chroma decreased over time, while the electrical conductivity increased, resulting in greater damage to membranes and loss of quality of maize grains. Monitoring of CO2 in the grain mass is a good tool to assess the quality of grain, and higher initial moisture content caused greater level of CO2 emission and reduction in quality of maize grains.

The aim of this study was to assess the bromatological quality and the content of essential amino acids in maize grains produced using two different cropping systems: organic and conventional. The experimental area was 4 hectares, divided into 2 hectares per system. In the conventional management, agrochemicals from conventional maize production were used. In the organic management, inputs permitted by the current Brazilian legislation on organic production were used. For each system, 10 plots of 9 m² each were established, from which experimental samples were harvested. The method described by Silva & Queiroz (2002) was used to determine bromatological quality. Near-infrared reflectance spectroscopy (NIRS) was used to quantify essential amino acids. A significant difference was found in the bromatological quality of maize grains. The conventional management provided greater crude protein content. Significant changes were also found in the following amino acids: methionine, threonine, arginine, isoleucine, leucine, valine, histidine, and phenylalanine, which showed lower levels in the organic management. The results confirm the need to determine food composition before diet formulation, since using preestablished food compositions probably leads to differences between what was formulated and what was actually given to poultry. The type of management influenced the quality of maize grains. The management of plant nutrition in the organic system should be refined to adequately supply nitrogen, thus improving bromatological and amino acid quality of the grains.

The article presents the results of the studies of the effect of the combined paw coulter for multilevel sowing of grain crops and the simultaneous introduction of a starting dose of mineral fertilizers on the quality and yield of grain of soft spring wheat Omskaya 36 carried out in 2019-2020. When sowing using the SKP-2.1M seeder, which was reequipped with combined coulters, where mineral fertilizers were applied below the seeds of spring wheat, the yield increase in the experiments carried out in 2019 by 14 % average in comparison with the control sowing with the SKP-2.1 seeder with serial coulters, where mineral fertilizers were applied to the same soil horizon with seeds. The conducted field experiment in 2020 confirmed the previously obtained results of the coulter performance; the increase in grain when using the combined coulters on the SPK-2.1M seeder was 12,5 %. The difference in grain yield happened due to the different weather conditions in 2019 and 2020. The qualitative indicators of spring soft wheat when sowing with combined openers in comparison with a serial seeder gave an average increase in protein by 7,9 and 4,7 %, and the highest gluten values on the control seeder were in the range of 25,8-27,1 %, and on the experimental SKP-2.1M seeder it was 26,1-28,5 % in 2019-2020, respectively. Thus, according to the results of the laboratory field studies carried out over two years, it was found that the proposed design of the combined coulter for sowing and applying mineral fertilizers below the sowing of seeds is efficient and it contributes to an increase in yield and quality of grain of soft spring wheat.

Nitrification inhibitors are used to decrease the rate of nitrification process so it can decreases the nitrate losses. The objective of this study was to investigate the improvement of urea effectiveness by using urease and nitrification inhibitors on shallot. The study was conducted at Blubuk Village, Tanjung, Brebes District, Central Java, Indonesia from December 2017 to April 2018. The experiment was arranged in a randomized block design with 8 treatments and 3 replications. The treatments were untreated group (P0), 100% dose of Urea without inhibitor (control) (P1), (3) 100% dose of Urea + Urease Inhibitor (P2), 100% dose of Urea + Nitrification Inhibitor (P3), 100% dose of Urea + Urease Inhibitor + Nitrification Inhibitor (P4), 80% dose of Urea + Urease Inhibitor (P5), 80% dose of Urea + Nitrification Inhibitor (P6), and 80% dose of Urea + Urease Inhibitor + Nitrification Inhibitor (P7). The results showed that 100% dose of Urea + Urease inhibitor, 80% dose of Urea + Urease inhibitor, 80% dose of Urea + Nitrification inhibitor, and 80% dose of Urea + Urease inhibitor + Nitrification inhibitor treatments significantly produced higher plants heights, number of leaves, and more number of tillers compared to control treatment (100% Urea without inhibitors), without affecting the yield and yield components.

Intercropping maize (Zea mays L.) with cover crops (Crotalaria spectabilis and Urochloa ruziziensis) is a sustainable cultivation strategy that can generate ecological benefits combined with grain yield (GY). However, cover crops may require nitrogen (N) fertilization management to be adjusted to obtain a high GY in intercropping systems. This study was carried out over 2 years in southeastern Brazil using randomized complete block design in a split-plot scheme. The plots were composed of three cropping systems: sole maize, maize + U. ruziziensis and maize + C. spectabilis. The subplots consisted of four N levels: 0, 70, 140 and 210 kg/ha. The GY of the maize + U. ruziziensis may be reduced by 13% compared to the sole maize. The GY of the sole maize increased up to 11.3 Mg/ha for 95 kg/ha of N in the first year and 6.7 Mg/ha for 169 kg/ha of N in the second year. The GY of the maize + U. ruziziensis intercropping system showed linear increments of 120 kg/ha for every 10 kg/ha of N applied. In the maize + C. spectabilis intercropping, GY increased up to 9.8 Mg/ha for 201 kg/ha of N in the first year, without any variation during the second year. The land equivalent ratio (LER) of intercropping was increased by more than 35% compared to that of sole maize, and N fertilization increased the LER of the sole maize and maize + U. ruziziensis intercropping. Maize intercropping had higher LER values with greater demand for nitrogen to obtain similar yields compared to sole maize cropping.

NITROGEN NUTRITION AS A REGULATOR OF BIOSYNTHESIS OF STORAGE PROTEINS IN MAIZE (ZEA MAYS L.) GRAIN

Background: Lowering the nitrogen demand is the most cost effective and sustainable option to increase grain yield of maize in poor fertility soil.
 Aim: This study was conducted to estimate the variability and inter-traits’ association of white and yellow hybrid maize in soil nitrogen-nutritional stress and optimal conditions.
 Materials and Methods: 150 white and 66 yellow single cross hybrid maize were evaluated in contrasting soil (stress and optimal) N conditions in Ibadan in 2014 and 2015. The trial for the white maize was laid out in 19 × 8 lattice design while the yellow maize was experimented in randomized complete block design. Each trial was replicated three times. Data were collected on days to anthesis (DTA), days to silking (DTS), plant height (PH), ear height (EH), anthesis-silking-interval (ASI) and grain yield (GY) were estimated while leaf senescence (LS), plant aspect (PASP) and ear aspect (EASP) were scored. Data collected were subjected to analysis of variance while variances and broad sense heritability were calculated and rated.
 Results: Greater variability existed among white maize than the yellow maize for the traits. Inheritance of the traits can be predicted in optimal N than stress condition. Additive genes action was responsible for inheritance of DTA and DTS while both additive and non-additive control the GY, PH, EH and LS of the white maize in both N conditions. For yellow maize, the DTA and DTS were controlled by additive genes action in both N conditions. The GY, ASI, PH, EH and LS were governed by both additive and non-additive genes actions in N stress condition. Additive genes action is responsible for inheritance of PH and EH while both additive and non-additive actions govern inheritance of GY, ASI and LS in optimal condition. The GY had positive relationship with the DTA, DTS and LS in both N conditions for the white maize while the GY positively correlated with PH, EH and LS in N stress, but with ASI only in optimal condition for the yellow maize.
 Conclusion: Grain yield, flowering, height and leaf senescence can be used in selecting maize for nitrogen-use-efficiency.

A soil tillage system adjusted to the soil type and agro-ecological conditions, together with the optimal nutrient supply, is a prerequisite for high maize (Zea mays L.) yield. However, there is little knowledge about the influence of soil tillage and nitrogen (N) rates on maize grain quality. A study was initiated in 1978 in Zemun Polje, Belgrade, Serbia, on the chernozem soil type. The effects of three N rates—0, 180 and 240 kg N ha−1—within three tillage practices—no-tillage, reduced and conventional tillage—and their influence on grain yield (GY) and the content of proteins, starch, oil, total tocopherols and carotenoids, phytic phosphorus (Phy), glutathione (GSH), phenols and inorganic P (Pi) in maize grain were analysed in the period 2016–2018. Differences in maize GY were 2.57 and 3.01 t ha−1 for reduced- or no-tillage, respectively, in comparison to conventional tillage. Conventional tillage and higher N rates contributed to the increase in maize yield and the grain nutritional quality with regard to the increased level of proteins, GSH and Phy. On the other hand reduced inputs were beneficial only for grain quality, in relation to the increase in tocopherols and phenols.

Purpose. To identify the features of pea productivity as affected by application of organic and mineral fertili­zers and plant growth regulators under the conditions of the Forest-Steppe of Ukraine.Methods. The objects of the study were two leafless pea varieties ‘Uliublenets’ and ‘Yulii’. At the stage of budding, the plants were fed with organic and mineral fertilizers “Biovit” and “Freia-Akva Bobovi” and treated with growth regulators “Rehoplant” and “Ahrostymulin”, both separately and in one pass, with the fertilization rates recommended by manufacturers.Results. A relation of the yield components formation (number of plants survived through vegetation period per unit area, number of beans per plant, number of seeds in beans and seeds per plant, as well as the 1000 kernel weight and seed weight per the plant) and the varietal peculiarities, treatments and weather conditions of the year was found. The most significant effect on the crop productivity had plant density, seed number per plant and seed weight per plant. A clear pattern was observed regarding the efficiency of organic and mineral fertilizers and plant growth regulators combination on the formation of yield components, and consequently, on the yield and quality of pea grain. Moreover, this pattern was not affected by adverse environmental conditions in both varieties under study and was observed in all years of the experiment. The highest yield and quality of grain (content of crude protein, fat, etc.) were recorded in complex treatments.Conclusions. Application of fertilizers and plant growth regulators in pea sowings is an important and effective factor in the realization of crop yield potential. The characteristics of individual plant productivity, grain yield, and quality determined in the experiment can be used to improve the model of cultivation technology for pea under the conditions of the Forest-Steppe of Ukraine

ABSTRACTImproved plant N utilization and partitioning is critical for future improvements in maize (Zea mays L.) grain yield (GY). The overall research objective was to gain understanding of the physiological mechanisms underpinning biomass (BM), N uptake partitioning, and GY processes during the reproductive period for two maize hybrids grown at varying plant density (PD) (low is 54,000 plant ha−1, medium is 79,000 plants ha−1, and high is 104,000 plants ha−1) and N inputs (low is 0 kg N ha−1, medium is 112 kg N ha−1, and high is 224 kg N ha−1) over four site–years. At the community level, maize GY was maximized in both genotypes at the medium PD and highest N rate. At maturity, grain harvest index improved as the whole‐plant N uptake increased following a linear‐plateau model and, for N allocation, both grain and shoot N concentrations increased similarly as BM increased. Around flowering (±15 d), dry mass and N partitioning rates were unmodified by treatment factors. Treatment factors only marginally influenced potential kernel number near flowering. Allometric analyses confirmed a lack of treatment impact on whole‐plant N uptake and N remobilization coefficients. Greater reproductive‐stage N uptake was associated with superior ear strength (kernel number and weight) and late shoot N remobilization, but GY was also positively related to vegetative‐stage N uptake. Future research should identify genotypic variation for overcoming the documented N uptake trade‐off mechanisms (vegetative‐stage N uptake vs. shoot N remobilization) as related to the maize GY improvement process.