Need For Nitrogen Fertilization Research Articles

Influence of Basic Tillage Technologies on the Transformation of Nitrogen-Containing Organic Compounds in Agrochernozem and the Activity of Nitrogen Cycle Enzymes

The influence of dump and minimal agrochernozem processing technologies on the activity of nitrogen cycle enzymes and their role in the transformation of nitrogen-containing organic compounds was evaluated. The most significant differences in the seasonal dynamics of the fraction content of difficult-to-hydrolyze nitrogen compounds were found in the soil of the barley agrocenosis in all types of tillage. When using surface disking, the dynamics of their content was determined by the activity of protease. The high availability of the soil with easily hydrolyzable nitrogen was revealed, which indicated that there was no need for nitrogen fertilizers. The dependence of the dynamics of the content of easily hydrolyzable nitrogen compounds on the activity of protease was ambiguous. Under conditions of minimal tillage, the formation of easily hydrolyzable nitrogen compounds was inversely dependent on the proteolysis process. The plane-cutting method of loosening caused an increase in the level of urease activity relative to dump plowing and surface disking.

Widely conserved AHL transcription factors are essential for NCR gene expression and nodule development in Medicago

Symbiotic nitrogen fixation by Rhizobium bacteria in the cells of legume root nodules alleviates the need for nitrogen fertilizers. Nitrogen fixation requires the endosymbionts to differentiate into bacteroids which can be reversible or terminal. The latter is controlled by the plant, it is more beneficial and has evolved in multiple clades of the Leguminosae family. The plant effectors of terminal differentiation in inverted repeat-lacking clade legumes (IRLC) are nodule-specific cysteine-rich (NCR) peptides, which are absent in legumes such as soybean where there is no terminal differentiation of rhizobia. It was assumed that NCRs co-evolved with specific transcription factors, but our work demonstrates that expression of NCR genes does not require NCR-specific transcription factors. Introduction of the Medicago truncatula NCR169 gene under its own promoter into soybean roots resulted in its nodule-specific expression, leading to bacteroid changes associated with terminal differentiation. We identified two AT-Hook Motif Nuclear Localized (AHL) transcription factors from both M. truncatula and soybean nodules that bound to AT-rich sequences in the NCR169 promoter inducing its expression. Whereas mutation of NCR169 arrested bacteroid development at a late stage, the absence of MtAHL1 or MtAHL2 completely blocked bacteroid differentiation indicating that they also regulate other NCR genes required for the development of nitrogen-fixing nodules. Regulation of NCRs by orthologous transcription factors in non-IRLC legumes opens up the possibility of increasing the efficiency of nitrogen fixation in legumes lacking NCRs.

Digital imaging of coffee leaves under different nitrogen concentrations applied to soil

Brazil is the largest Coffea arabica L. producer and exporter in the world market. In view of the need for nitrogen fertilization, the objective of this work was to evaluate the use of digital images of coffee leaves as a function of nitrogen concentration and cultivars, as well as to evaluate the most adequate sampling of this technique to predict leaf nitrogen. The experiment was set in a greenhouse, at UNESP - Experimental Campus of Registro-SP, using 12L pots with medium sand. A completely randomized design was adopted, in a 4 x 2 factorial scheme, with four concentrations of N (0, 50, 100 and 200 mg dm-3), and two coffee cultivars (Mundo Novo and Obatã), with ten replications. The variables evaluated were: hue, dark green color index (DGCI), leaf area and leaf nitrogen content. The hue and DGCI were influenced by N concentration, cultivar and are dependent on the day after treatment application and the number of leaves used. The use of five leaves per replication was more adequate to estimate leaf N content. Hue, DGCI and leaf area were higher in Obatã depending on the day after application of the treatment and N concentration.

The Sustainability Crisis . . . Again

The Sustainability Crisis . . . Again

Economics and Feasibility of Legume Inclusion in Southeastern Perennial Grass-Based Systems

Abstract Perennial grass pastures provide the basis for beef production systems across the Southeast United States. One common management practice that is widely recommended among agronomists is interseeding cool-season legumes. Legumes can serve as a complementary resource for filling in production gaps, reducing supplemental feedstuffs, reducing the need for nitrogen fertilization, increasing the nutritional quality of forage available, increase biomass production, improve animal performance, and can reduce the toxic effects of endophyte-infected tall fescue through dilution. A simulated economic analysis was developed to further the economic understanding of the cost of implementation, the subsequent animal and forage performance benefits, and net returns from the inclusion of legumes over many research trials and years. Data from 15 peer-reviewed papers was used to simulate the economic benefits of implementing this production practice. Cost of production and revenue for each paper were calculated using the 10-year average from 2010 to 2019. This analysis provides users with a further understanding of the net returns, critical breakeven areas, and return on investment that is necessary in order to successfully implement the inclusion of cool-season legumes in perennial grass-based systems.

Incorporating Alfalfa into Warm-season Grass Systems in the Southeast

Abstract Bermudagrass is the primary warm season perennial forage crop grown in the Southeast (~20 million acres) for livestock and forage operations. While prominent in the region, bermudagrass requires large amounts of fertility and forage quality is moderate relative to other options. There has been great success and a growing interest in interseeding alfalfa into existing bermudagrass stands in the region. This combination eliminates the need for nitrogen fertilization, increases relative forage quality (RFQ) better meeting the nutritional needs of livestock, and decreases the need for supplemental feed. In recent years, research evaluations have been conducted across the Southeast to evaluate the use of alfalfa when incorporated into warm-season grass forage systems under various management strategies. Three projects conducted from 2016–2020 at the University of Georgia Tifton campus evaluated ‘Bulldog 805’ alfalfa interseeded into Tifton-85 bermudagrass (1) when harvested as baleage, (2) under grazing management and(3) in a clipping study to better define defoliation management recommendations. Overall findings from this work observed that alfalfa-bermudagrass mixtures provide greater seasonal herbage accumulation, extend the growing season by three to four months annually, and increase forage DM digestibility and CP compared to bermudagrass alone. Steers on ABG managed under rotational stocking had greater total gain/ha (~%33 increase) due to a higher stocking density throughout the growing season than a bermudagrass monoculture. Results indicate that interseeding alfalfa into bermudagrass is a viable option for southeastern forage systems and can be an effective way to improve forage quality, extend the grazing season, and reduce the need for additional supplementation when fed to livestock.

Abiotic and Biotic Limitations to Nodulation by Leguminous Cover Crops in South Texas

Many farms use leguminous cover crops as a nutrient management strategy to reduce their need for nitrogen fertilizer. When they are effective, leguminous cover crops are a valuable tool for sustainable nutrient management. However, the symbiotic partnership between legumes and nitrogen fixing rhizobia is vulnerable to several abiotic and biotic stressors that reduce nitrogen fixation efficiency in real world contexts. Sometimes, despite inoculation with rhizobial strains, this symbiosis fails to form. Such failure was observed in a 14-acre winter cover crop trial in the Rio Grande Valley (RGV) of Texas when three legume species produced no signs of nodulation or nitrogen fixation. This study examined the role of nitrogen, phosphorus, moisture, micronutrients, and native microbial communities in the nodulation of cowpea (Vigna unguiculata L. Walp) and assessed arbuscular mycorrhizal fungi as an intervention to improve nodulation. Results from two controlled studies confirm moisture and native microbial communities as major factors in nodulation success. Micronutrients showed mixed impacts on nodulation depending on plant stress conditions. Nitrogen and phosphorus deficiencies, however, were not likely causes, nor was mycorrhizal inoculation an effective intervention to improve nodulation. Inoculation method also had a major impact on nodulation rates. Continued research on improved inoculation practices and other ways to maximize nitrogen fixation efficiency will be required to increase successful on-farm implementation.

Effect of acid–chlorite pretreatment on Miscanthus harvesting date for biosugar production

Miscanthus (Geodae-Uksae in Korean, GU) is a promising source of biomass for biosugar production due to its superior mass yield and minimal need for nitrogen fertilizer and herbicides. In this study, the biomass productivity, chemical composition, and physical properties of Miscanthus were investigated for two harvest dates. The total biomass of early harvest GU (EH-GU; 20.1 t DM/ha) was greater than that of the delayed-harvest GU (DH-GU; 18.0 t DM/ha). There was no noticeable difference in the carbohydrate content between the EH-GU and DH-GU, while the lignin content remarkable decreased after pretreatment. The enzymatic conversion rates of GU to biosugar increased after pretreatment, to approximately 86 to 90%. After enzymatic hydrolysis, 381 g and 147 g of glucose and xylose were produced, respectively. Consequently, 528 g of biosugar was obtained from 1 kg of EH-GU. Determining the optimal harvest date of Miscanthus has enabled a more efficient enzymatic hydrolysis and higher biosugar yields.

Productivity and crude protein concentration of Tifton 85 pasture-based mixed with pinto peanut

ABSTRACT Mixed pasture grass-legume systems balance forage supply and minimize environmental impacts by reducing the need for nitrogen fertilization. Pinto peanut (Arachis pintoi Krap. and Greg. “Amarillo”) has several traits that are suitable for mixed pastures but have not yet been adequately explored. The aim of this study was to evaluate a mixture of Tifton 85 bermudagrass (Cynodon dactylon) and pinto peanut and evaluate forage yield, crude protein, and stocking density. A two-year study of three grazing systems was used with the following treatment combinations: (a) Tifton 85 (T) + 100 kg N ha-1 yr-1 + pinto peanut (T + PP+100); (b) T + 100 kg N ha-1 yr-1 (T + 100; control, pure grass); and (c) T + 200 kg N ha-1 yr-1 (T + 200; positive control, pure grass). In this study, forage yield, pasture characteristics and responses of lactating cows were evaluated. The experimental design was completely randomized with three treatments (grazing systems), three replicates (paddocks), and repeated measures (grazing cycles within seasons). Forage accumulation, crude protein concentration, and stocking rate were 15.1; 11.3 and 14.1 t DM ha-1 yr-1; 17%, 16%, and 17%; and 5.3; 4.9 and 6.1 AU ha-1 day-1, respectively. The grass-legume system yielded the best results.

Inoculation with Azospirillum brasilense on corn yield and yield components in an integrated crop-livestock system

Inoculation of corn with diazotrophic bacteria reduces the need for nitrogen fertilization and mitigates environmental contamination risks due to the bacteria’s biological nitrogen-fixation capacity. The aim of the present study was to evaluate the effect of corn seed inoculation with Azospirillum brasilense under different nitrogen levels and post-grazing residual heights. The experiment was performed in two growing seasons and conducted in an integrated crop-livestock system for the 2014/15 and 2015/16. A factorial randomized block experimental design with sub-divided plots and three factors. The main plots varied in post-grazing residual height (0.10, 0.20, 0.30 m, continuous grazing, or no grazing), the subplots varied in inoculation (with or without seed inoculation), and the sub-subplots varied in nitrogen level (0, 75, 150, 225, or 300 kg ha -1 of N). The higher post-grazing residual height associated an A. brasilense and nitrogen fertilization resulted in increased corn biomass and production and yield. At the 300 kg dose of N, the highest grain yield was obtained under different post-grazing heights (10.15 Mg ha -1 ) and in the absence of the bacterium (10.00 Mg ha -1 ). Azospirillum brasilense helps plant growth and yield but does not replace the effect of N fertilization.

Some Aspects of Nitrogen Management and Its Real Time Application in Direct Seeded Rice Using Leaf Color Chart

Proper application of nitrogen (N) fertilizer is vital to improve the growth and grain yield of rice crop. As there prevails more aerobic period in direct seeded rice, nitrogen loss is generally more in such environment. Therefore, nitrogen recommendation for direct seeded rice is slightly higher (22.5-30 Kg ha-1) than that under the transplanted rice. Insufficient and/or inappropriate nitrogen fertilizer application is highly critical to the crops. Optimal nitrogen management strategies aim at matching the nitrogen fertilizer supply to the actual crop demand. Leaf color is generally used as a visual and subjective indicator of the rice crop need for nitrogen fertilizer. The Leaf Color Chart is a simple and inexpensive tool for real time nitrogen management in rice. It helps farmers to improve their decision-making process in nitrogen management. It provides the idea of when and how much nitrogen fertilizer to apply based on relative greenness of the rice leaf. In overall, LCC based nitrogen management improves productivity and profitability of the rice crop by nitrogen saving and ensuring its higher use efficiency.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 81-86

Growing Azolla to produce sustainable protein feed: the effect of differing species and CO2 concentrations on biomass productivity and chemical composition.

BACKGROUNDSince available arable land is limited and nitrogen fertilizers pollute the environment, cropping systems ought to be developed that do not rely on them. Here we investigate the rapidly growing, N2‐fixing Azolla/Nostoc symbiosis for its potential productivity and chemical composition to determine its potential as protein feed.RESULTSIn a small production system, cultures of Azolla pinnata and Azolla filiculoides were continuously harvested for over 100 days, yielding an average productivity of 90.0–97.2 kg dry weight (DW) ha−1 d−1. Under ambient CO2 levels, N2 fixation by the fern's cyanobacterial symbionts accounted for all nitrogen in the biomass. Proteins made up 176–208 g kg−1 DW (4.9 × total nitrogen), depending on species and CO2 treatment, and contained more essential amino acids than protein from soybean. Elevated atmospheric CO2 concentrations (800 ppm) significantly boosted biomass production by 36–47%, without decreasing protein content. Choice of species and CO2 concentrations further affected the biomass content of lipids (79–100 g kg−1 DW) and (poly)phenols (21–69 g kg−1 DW).CONCLUSIONSBy continuous harvesting, high protein yields can be obtained from Azolla cultures, without the need for nitrogen fertilization. High levels of (poly)phenols likely contribute to limitations in the inclusion rate of Azolla in animal diets and need further investigation. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

English

The objective was to evaluate the agronomic efficiency in the field of the inoculant Fluid and Turfoso containing the bacterium Azospirillum brasiliense, strains AbV5 and AbV6 applied by treatment of seeds in the corn crop associated with nitrogen fertilization in different localities. Four experiments were carried out in different sites involving two in Parana and one each from Mato Grosso do sul and Santa Catarina. The design was randomized blocks with 6 treatments: T1- 0 kg ha-1 of nitrogen (N), without inoculation (control); T2 - 80 kg ha-1 of N, without inoculation; T3 - 160 kg ha-1 of N, without inoculation; T4 - 80 kg ha-1 of N + seed inoculation AzoTotal® 'Liquid'; T5 - 80 kg ha-1 of N + seed inoculation Nitro 1000 Gramines 'Liquid'; T6 - 80 kg ha-1 of N + seed inoculation Nitro 1000 'Peat' grasses. The evaluations were composed of nutrient content in leaves and grains, and at the end of the cycle length and ear diameter, number of rows of grains and grains per row, mass of one thousand grains and productivity. The results showed that the inoculation of the seeds, regardless of the physical nature of the inoculant, was efficient for the maize crop, reducing the use of mineral nitrogen in all evaluated sites. It is concluded that the use of inoculation with A. brasilense regardless of the physical nature of the inoculant reduces the need for nitrogen fertilization of the corn crop by 50%, without reducing the final yield of the crop. Key words: Zea mays, biological nitrogen fixation, productivity, Azospirillum brasilense, sustainable agriculture.

PENGARUH NAUNGAN DAN PEMUPUKAN NITROGEN TERHADAP KARAKTERISTIK MORFOLOGIS RUMPUT GAJAH DWARF (Pennisetum purpureum cv Mott)

THE EFFECT OF SHADING AND NITROGEN FERTILIZATION ON MORPHOLOGICAL CHARACTERISTICS OF DWARF ELEPHANT GRASS (Pennisetum purpureum cv. mott). This study was conducted to determine the responses of Dwarf Elephant grass (P. purpureum cv. Mott.) fertilized with different nitrogen levels and at different shading areas. A Completely Randomized Design (CRD) in a Factorial arrangement with 2 factors of nitrogen levels and shading areas arranged as follows: factor A = fertilization levels of P1 = without fertilization (0%); P2 = 200 kg urea/ha; P3 = 400 kg urea/ha; and P4 = 800 kg urea/ha; whereas factor B = shasing areas of N1 = no shading area (0%), and N2 = 70% shading area. Variables measured were including leaf length, number of mature leaves, and plant height. Research results showed that plants needed about 200 kg urea/ha in order to achieve maximum leaf length in shaded area; whereas plants within no shading area needed about 800 kg urea/ha to achieve maximum leaf length. To achieve maximum number of mature leaves in open area without shading plants needed about 800 kg urea/ha, and no need for nitrogen fertilization in shading area for plants to achieve such a maximum number of mature leaves. The highest plant height was achieved at the level of 400 kg urea/ha fertilization at open area (no shading), and there was no need of nitrogen fertilization for plants in shaded area in order to achieve their maximum height. It can be concluded that shading positively contributed to the availability of nitrogen to be used by Dwarf Elephant grass (P. purpureum cv. Mott.). In open area without shading, plants need more nitrogen in the form of urea to produce leaf length, number of mature leaves, and plant height compared to shaded area.Keywords: Fertilization, Shading, Elephant Grass, Plant morphology.

In Winter Wheat, No-Till Increases Mycorrhizal Colonization thus Reducing the Need for Nitrogen Fertilization

Arbuscular mycorrhizal fungi (AMF) play a major role in the uptake of nutrients by agricultural plants. Nevertheless, some agricultural practices can interrupt fungal-plant signaling and thus impede the establishment of the mycorrhizal symbiosis. A field experiment performed over a 5-year period demonstrated that both the absence of tillage and of nitrogen (N) fertilization improved AMF colonization of wheat roots. Moreover, under no-till conditions, N uptake and aboveground biomass production did not vary significantly between N-fertilized and N-unfertilized plots. In contrast, both N uptake and above ground biomass were much lower when N fertilizer was not added during conventional tillage. This finding strongly suggests that for wheat, no-till farming is a sustainable agricultural system that allows a gradual reduction in N fertilizer use by promoting AMF functionality and at the same time increasing N uptake.

Receptive to infection

Rhizobium bacteria infect the roots of legumes, where they induce the formation of nitrogen-fixing root nodules. This symbiotic relationship is of agricultural importance as it reduces the need for nitrogen fertilizers. But how do legumes recognize these beneficial partners among thousands of incompatible soil bacteria they encounter? It is known that exopolysaccharides on the surface of bacteria are important for interactions of these microorganisms with multicellular organisms and here Jens Stougaard and coworkers identify an exopolysaccharide receptor (EPR3) that mediates recognition of rhizobia in the wild legume Lotus japonicus. EPR3 expression is induced upon perception of bacterial signalling molecules known as Nod factors. The receptor recognizes compatible exopolysaccharides, thus controlling the symbiotic infection.

Key applications of plant metabolic engineering.

Great strides have been made in plant metabolic engineering over the last two decades, with notable success stories including Golden rice. Here, we discuss the field's progress in addressing four long-standing challenges: creating plants that satisfy their own nitrogen requirement, so reducing or eliminating the need for nitrogen fertilizer; enhancing the nutrient content of crop plants; engineering biofuel feed stocks that harbor easy-to-access fermentable saccharides by incorporating self-destructing lignin; and increasing photosynthetic efficiency. We also look to the future at emerging areas of research in this field.

Agronomic performance ofAzospirillum brasilenseon wheat crops

The use of nitrogen-fixing diazotrophs bacteria in grasses is a recent alternative that which allows reducing the use of agricultural inputs. In this aspect the Azospirillum brasilense has emerged as a viable alternative in reducing nitrogen application in field crops. The objective of this review was to gather information regarding the agronomic performance in the use of A. brasilense in wheat crops. Besides the obvious reduction in the need for nitrogen fertilization, is noteworthy that the inoculation allows obtaining agronomic results similar to those obtained with fertilizers, that is, presents efficiency in several important agronomic attributes. Generally it is observed increase in productivity as the crop is inoculated. The best results were obtained with the use of diazotrophic bacteria associated to nitrogen fertilizer, underscoring the fact that the bacterium does not completely replace the fertilization. The increase in productivity is attributed to the improved translocation of biomass to grains and in the increased photosynthetic activity, justified by the increase in green tissues and its root system, occasioned by the plant symbiosis.

Monitoring and evaluation of need for nitrogen fertilizer topdressing for maize leaf chlorophyll readings and the relationship with grain yield

The study was carried out for two years in maize in succession to the wheat using no tillage system in a distroferric Red Latosol (Hapludox). Methods of management nitrogen fertilizer (120 kg ha-1) with ammonium sulphate were studied; the fertilizer was applied in maize sowing or in maize topdressing, and N with previous application in wheat sowing. In addition, leaf chlorophyll reading was used as an indicator for the need for topdressed nitrogen fertilizer. Nitrogen supply index (NSI) was shown to be effective at predicting need for topdressed nitrogen fertilizer for maize. The application of N improved the yield of the maize independent of the management system. The flowering stage was carried out at the appropriate time in order to estimate the nitrogen nutrition state and yield of maize using the relative chlorophyll level (RIC).

Weed Control for Winter Faba Bean Cover Crop in South Florida

Faba bean is an important leguminous winter crop in warm temperate and subtropical areas that has been cultivated for more than 10,000 years as a source of protein in human and livestock diets. It is also grown to enhance yields of other crops. Faba bean provides nitrogen in agricultural systems through the unique process of biological fixation of atmospheric nitrogen by symbiosis with Rhizobium bacteria. This substantially reduces the need for nitrogen fertilizers, which contribute to both carbon dioxide and nitrous oxide emissions. This 2-page fact sheet written by D.C. Odero provides weed control recommendations. Published by the UF Department of Agronomy, April 2011. SS-AGR-345/AG355: Weed Control for Winter Faba Bean Cover Crop in South Florida (ufl.edu)