Different characteristics of nitrogen utilization between lupin and soybean: can lupin utilize organic nitrogen in soils?

It is well known that lupin forms cluster roots, which help in dissolving insoluble P in soils. In nonleguminous species, cluster roots also appear to contribute to the utilization of organic N in soils. In white lupin ( Lupinus albus L.), however, the characteristics of its organic N utilization have not been studied. Therefore, we examined whether white lupin can utilize organic N in soils. Soybean ( Glycine max (L.) Merr.), which does not form cluster roots, was used as a control plant. Seedlings of lupin and soybean were cultivated in soils with different N sources (non-N, ammonium sulphate, ammonium sulphate plus cattle farmyard manure, or cattle farmyard manure). The rate of glycine uptake by excised roots was determined in a hydroponic experiment to investigate the ability of lupin and soybean to directly utilize amino acids. Nitrogen accumulation in soybean corresponded to the decrease in inorganic N in the soils. In contrast, N accumulation in lupin was higher than the decrease in inorganic N in the soil, especially with the cattle farmyard manure treatment, indicating that lupin derived more N from an organic N source. Wheat ( Triticum aestivum L.) cultivated with lupin in a pot accessed more available N than wheat with soybean or wheat in monoculture, suggesting that lupin roots themselves or the lupin rhizosphere microorganisms were able to decompose organic N in soils. Excised roots of lupin, especially cluster roots, exhibited higher rates of glycine uptake than roots of soybean. In conclusion, lupin decomposed organic N in the rhizosphere and was able to absorb amino acids from decomposition in addition to any inorganic N produced by further microbial decomposition.

Download Full-text

Arabidopsis and Lobelia anceps access small peptides as a nitrogen source for growth

Functional Plant Biology ◽

10.1071/fp11077 ◽

2011 ◽

Vol 38 (10) ◽

pp. 788 ◽

Cited By ~ 25

Author(s):

Fiona M. Soper ◽

Chanyarat Paungfoo-Lonhienne ◽

Richard Brackin ◽

Doris Rentsch ◽

Susanne Schmidt ◽

...

Keyword(s):

Amino Acids ◽

Nitrogen Source ◽

Biomass Accumulation ◽

Organic N ◽

Amino Acid Residues ◽

Growth Responses ◽

Small Peptides ◽

Inorganic N ◽

Metabolic Products ◽

Species Specific

While importance of amino acids as a nitrogen source for plants is increasingly recognised, other organic N sources including small peptides have received less attention. We assessed the capacity of functionally different species, annual and nonmycorrhizal Arabidopsis thaliana (L.) Heynh. (Brassicaceae) and perennial Lobelia anceps L.f. (Campanulaceae), to acquire, metabolise and use small peptides as a N source independent of symbionts. Plants were grown axenically on media supplemented with small peptides (2–4 amino acids), amino acids or inorganic N. In A. thaliana, peptides of up to four amino acid residues sustained growth and supported up to 74% of the maximum biomass accumulation achieved with inorganic N. Peptides also supported growth of L. anceps, but to a lesser extent. Using metabolite analysis, a proportion of the peptides supplied in the medium were detected intact in root and shoot tissue together with their metabolic products. Nitrogen source preferences, growth responses and shoot–root biomass allocation were species-specific and suggest caution in the use of Arabidopsis as the sole plant model. In particular, glycine peptides of increasing length induced effects ranging from complete inhibition to marked stimulation of root growth. This study contributes to emerging evidence that plants can acquire and metabolise organic N beyond amino acids.

Download Full-text

Interactions between uptake of amino acids and inorganic nitrogen in wheat plants

Biogeosciences Discussions ◽

10.5194/bgd-8-11311-2011 ◽

2011 ◽

Vol 8 (6) ◽

pp. 11311-11335 ◽

Cited By ~ 4

Author(s):

E. Gioseffi ◽

A. de Neergaard ◽

J. K. Schjoerring

Keyword(s):

Amino Acids ◽

Nutrient Solution ◽

Inorganic Nitrogen ◽

N Uptake ◽

Organic N ◽

Arable Soils ◽

Inorganic N ◽

N Losses ◽

Total N ◽

N Source

Abstract. Soil-borne amino acids may constitute a nitrogen (N) source for plants in various terrestrial ecosystems but their importance for total N nutrition is unclear, particularly in nutrient-rich arable soils. One reason for this uncertainty is lack of information on how the absorption of amino acids by plant roots is affected by the simultaneous presence of inorganic N forms. The objective of the present study was to study absorption of glycine (Gly) and glutamine (Gln) by wheat roots and their interactions with nitrate (NO3–) and (NH4+) during uptake. The underlying hypothesis was that amino acids, when present in nutrient solution together with inorganic N, may lead to down-regulation of the inorganic N uptake. Amino acids were enriched with double-labelled 15N and 13C, while NO3– and NH4+ acquisition was determined by their rate of removal from the nutrient solution surrounding the roots. The uptake rates of NO3– and NH4+ did not differ from each other and were about twice as high as the uptake rate of organic N when the different N forms were supplied separately in concentrations of 2 mM. Nevertheless, replacement of 50 % of the inorganic N with organic N was able to restore the N uptake to the same level as that in the presence of only inorganic N. Co-provision of NO3– did not affect glycine uptake, while the presence of glycine down-regulated NO3– uptake. The ratio between 13C and 15N were lower in shoots than in roots and also lower than the theoretical values, reflecting higher C losses via respiratory processes compared to N losses. It is concluded that organic N can constitute a significant N-source for wheat plants and that there is an interaction between the uptake of inorganic and organic nitrogen.

Download Full-text

Potential organic and inorganic N uptake by six Eucalyptus species

Functional Plant Biology ◽

10.1071/fp06045 ◽

2006 ◽

Vol 33 (7) ◽

pp. 653 ◽

Cited By ~ 51

Author(s):

C. R. Warren

Keyword(s):

Amino Acids ◽

N Uptake ◽

N Cycling ◽

Organic N ◽

Eucalyptus Species ◽

Inorganic N ◽

South Eastern ◽

Eastern Australia ◽

Relative Abundances ◽

South Eastern Australia

There are no published studies of organic N uptake by species of south-eastern Australia (e.g. Eucalyptus) despite several studies of ecosystem N cycling. This study examines uptake of nitrate, ammonium and glycine (an amino acid) by six species of 16-year-old Eucalyptus growing at two plantations (‘common gardens’). By using two plantations, one xeric / oligotrophic and one mesic / eutrophic, I was able to disentangle genotypic from phenotypic differences in preference for N forms. Measurements were made on three separate occasions during spring. N uptake was examined in situ with attached roots placed in uptake solutions containing equimolar 100 μmol L–1 concentrations of 15N-nitrate, 15N-ammonium and 2-13C215N-glycine. Water and KCl extracts were used to determine the relative abundances of nitrate, ammonium and amino acids at the two plantations. Nitrate dominated at the eutrophic site, but was nearly absent at the oligotrophic site. N at the oligotrophic site was dominated by ammonium and amino acids which were present in similar concentrations. The rate of uptake of ammonium (6.3 ± 0.4 μmol g h–1; mean ± s.e., n = 108), was faster than glycine (3.4 ± 0.2), which was faster than nitrate (0.62 ± 0.07). Plant ‘preference’ for N forms did not vary between sites despite large differences in the relative abundances of N forms (nitrate v. ammonium v. amino acids). Hence, there was little evidence for acclimation of Eucalyptus species to differences in the relative availability of N forms. This study suggests the possibility for considerable organic N uptake in the field. Previous studies of ecosystem N cycling in south-eastern Australia have only examined inorganic N. The N cycle in south-eastern Australia needs to be revisited with a new perspective, one that considers inorganic N and organic N.

Download Full-text

Soil nitrogen transformations on a subantarctic island

Antarctic Science ◽

10.1017/s0954102092000099 ◽

1992 ◽

Vol 4 (1) ◽

pp. 41-50 ◽

Cited By ~ 9

Author(s):

V. R. Smith ◽

Marianna Steenkamp

Keyword(s):

Growth Period ◽

Organic N ◽

Nitrogen Transformations ◽

Inorganic N ◽

Biological Fixation ◽

Available N ◽

Grassland Community ◽

Soil Macroinvertebrates ◽

Soil Nitrogen Transformations

The vascular vegetation of a mire-grassland community on Marion Island (47°S, 38°E) takes up c. 158 mg N m−2 d−1 in summer. Bryophytes take up c. 36 mg N m−2 d−1 during their peak growth period. Since inputs of N through precipitation and biological fixation are negligible, mineralization of organic N must have supplied the bulk of this N. From changes in peat inorganic N levels and rates of uptake by the vegetation we estimate mean mineralization rates of 178 mg N m−2 d−1 in summer and 55 mg N m−2d−1 in winter. In situ incubation of peat give a maximum mineralization rate of 48 mg N m−2 d−1. At this rate the small (700 mg m−2) pool of available N in the upper 25 cm of peat would be depleted by the vascular vegetation in about seven days and bryophytes would deplete the available N pool in the top 25 mm in two days. Hence the rate of N mineralization measured by incubation is much too low to account for the fluctuations in concentrations of inorganic N in the peat and the amounts taken up by the vegetation. This may be due to losses through denitrification or to the fact that soil macroinvertebrates were excluded from the incubation.

Download Full-text

Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method

Canadian Journal of Soil Science ◽

10.4141/cjss-2014-109 ◽

2015 ◽

Vol 95 (4) ◽

pp. 305-319 ◽

Cited By ~ 2

Author(s):

D. V. Ige ◽

S. M. Sayem ◽

O. O. Akinremi

Keyword(s):

Nitrogen Mineralization ◽

Growing Season ◽

Organic N ◽

Pig Manure ◽

Inorganic N ◽

Available N ◽

Amended Soils ◽

Anion Resin ◽

Resin Method ◽

Fertilizer Equivalence

Ige, D. V., Sayem, S. M. and Akinremi, O. O. 2015. Nitrogen mineralization in beef- and pig-manure-amended soils measured using anion resin method. Can. J. Soil Sci. 95: 305–319. A major challenge facing the widespread use of manure is the uncertainty about its fertilizer equivalence. This study was carried out to determine the fertilizer equivalence of locally available manures in two soils in Manitoba. A randomized complete block design was adopted with six treatments [nitrogen fertilizer, a liquid swine manure (LSM), three solid beef manures (SBM) and a control] and four replicates. Each treatment was applied to a cylindrical soil column installed at the site at the rate of 100 kg ha−1of “available N”, and leached NO3-N was captured by resin bags at the bottom of the cylinder. The soils and resin bags removed from the cylinders were sampled at 0, 1, 2, 4, 6, 8, 10, 14, and 18 wk following treatment application. Ammonium nitrogen in the amendments was nitrified within the first 2 to 3 wk with significant build-up of NO3-N in the soil above the control (P<0.05). The greatest available N was in the fertilizer treatment, followed by the LSM and the smallest was in the SBM. The available N in the three SBM was statistically similar (P>0.05). Approximately 50% of the inorganic N in LSM was available during the growing season, while 68 to 100% of SBM inorganic N was available. Between 4 and 25% of the organic N in the three SBM was mineralized during the growing season. High soil moisture hindered N mineralization and enhanced N loss in the clay soil. LSM has the greatest fertilizer equivalence, with a mean of 65 to 68%, of the four manure types used. The fertilizer equivalence of the three SBM ranged between 42 and 59% and was influenced by the manure C:N ratio and the soil environmental conditions. Our study suggests the need to revise the assumptions regarding manure N availability by considering soil environmental factors in the estimation of available N.

Download Full-text

Nitrogen Dynamics Associated with Organic and Inorganic Inputs to Substrate Commonly Used on Rooftop Farms

HortScience ◽

10.21273/hortsci.50.6.806 ◽

2015 ◽

Vol 50 (6) ◽

pp. 806-813 ◽

Cited By ~ 5

Author(s):

Angela Y.Y. Kong ◽

Cynthia Rosenzweig ◽

Joshua Arky

Keyword(s):

The United States ◽

Organic N ◽

N Availability ◽

Inorganic N ◽

Available N ◽

Nutrient Runoff ◽

Swiss Chard ◽

Rooftop Farming ◽

N Input ◽

Synthetic Fertilizer

Employing rooftops for the cultivation of crops in limited urban space has garnered interest in densely populated cities in the United States, where there is a growing demand for locally sourced vegetable products. Fertility management recommendations for rooftop farming, however, are scant. With insufficient research on nutrient cycling within rooftop farming systems, which tend to use soilless substrates with low organic matter content, the potential tradeoffs between the negative impacts (e.g., nutrient runoff) and the benefits (e.g., increased locally produced vegetables, stormwater retention, etc.) associated with rooftop farms are unclear. The objective of this study was to evaluate the effects of organic and inorganic nitrogen (N) inputs on the N dynamics within substrate typically used on rooftop farms. Substrate without added N inputs (control) was compared with substrates receiving N sources that are both realistic for and/or reflective of amendments currently applied on urban rooftop farms: a synthetic fertilizer (Osmocote® 14N–4.2P–11.6K), and three organic N inputs—composted poultry manure, municipal green waste (MGW) compost, and vermicompost. Aboveground crop biomass and yields of Beta vulgaris (swiss chard), along with inorganic N availability (ammonium: and nitrate: ), potentially mineralizable nitrogen (PMN), leachate-inorganic N concentrations, and pH and electrical conductivity (EC) levels were measured during an 8-week greenhouse experiment. Despite differences in carbon-to-nitrogen ratios (C:N), few differences in N cycling and yields were found among the treatments receiving organic N inputs. Crop yields from the synthetic fertilizer and MGW compost treatments were higher than the other organic N input treatments. Inorganic N levels in the synthetic fertilizer treatment decreased from 129 mg N/L at the start of the season to 113 mg N/L at the end of the season, while nearly 10-fold decreases of inorganic N concentrations in the substrate of the control and organic N input treatments from week 0 (79.5–117.8 mg N/L) to week 8 (12.8–16.6 mg N/L) were observed. Greater N availability at critical periods during the season may have promoted greater crop N uptake efficiency and, therefore, higher yields in the system receiving synthetic fertilizer. However, the greatest losses of and via leachate were also measured from this treatment. Our results show that the type of N input influenced plant-available N and yields and that the MGW compost treatment best achieved the balance between higher yields and reduced N losses to potential roof runoff. Furthermore, additional N inputs to these systems, particularly to the treatments receiving organic composts, will likely be necessary if a high N-demanding crop (such as swiss chard) is to be grown in the same substrates for more than 8 weeks. Rooftop farming is an emergent component of urban agriculture; regulations and guidelines for nutrient management of rooftop farms are necessary to optimize productivity and long-term benefits and to minimize negative environmental impacts.

Download Full-text

Effects of long-term soil warming on nitrogen fluxes in forest soils

10.5194/egusphere-egu2020-7551 ◽

2020 ◽

Author(s):

Erich Inselsbacher ◽

Jakob Heinzle ◽

Andreas Schindlbacher

Keyword(s):

Amino Acids ◽

Global Warming ◽

Soil Temperature ◽

Organic N ◽

Soil N ◽

Inorganic N ◽

Soil Warming ◽

N Fluxes

Forests are the main contributors to the global terrestrial carbon (C) sink but several studies suggest that global warming could significantly reduce their CO2 mitigation potential. The capacity of forest plants to sequester C is closely linked to soil nitrogen (N) availability, a major control of plant growth and ecosystem functioning. An increase of soil temperature caused by global change is critically affecting soil N supply rates, both directly by increasing diffusive N fluxes in the soil solution and indirectly by accelerating soil N turn-over rates. In recent short-term laboratory incubation studies, an increase in soil temperature has not only led to a significant increase in diffusive N fluxes but also to a concomitant shift in N quality available for plant uptake towards a higher portion of inorganic N forms compared to small organic N forms such as amino acids. However, until now long-term effects of soil warming on soil N fluxes have not been studied. Here, we present first results from a study on soil N availabilities at the long-term soil warming experimental site Achenkirch (Austria) in the Limestone Alps. This site is one of the few in situ climate manipulation experiments operational for more than 10 years and has already provided a wealth of novel insights into the potential effects of global warming on forest ecosystem responses. Applying in situ microdialysis, we estimated diffusive fluxes of inorganic N and amino acids along the growing season in soils warmed by resistance heating cables since 2005 (+4 &#176;C compared to control plots) and control soils. Fluxes of all N forms were highly variable within each subplot (2 x 2 m) and reflected the high heterogeneity of soils at this forest site. Interestingly, fluxes of amino acids were less variable than of nitrate or ammonium throughout the year, indicating comparably stable protein depolymerization rates. In summary, long-term soil warming affected diffusive N fluxes but less than other factors operating on smaller (< 1 cm) scales.

Download Full-text

Drought tolerance and acclimation in Pinus ponderosa seedlings: the influence of nitrogen form

Tree Physiology ◽

10.1093/treephys/tpaa052 ◽

2020 ◽

Vol 40 (9) ◽

pp. 1165-1177 ◽

Cited By ~ 1

Author(s):

José A Sigala ◽

Mercedes Uscola ◽

Juan A Oliet ◽

Douglass F Jacobs

Keyword(s):

Amino Acids ◽

Drought Tolerance ◽

Pinus Ponderosa ◽

Drought Resistance ◽

Physiological Traits ◽

Organic N ◽

Nitrogen Form ◽

Inorganic N ◽

Drought Acclimation ◽

Proline Concentration

Abstract Drought is a limiting factor to forest regeneration and restoration, which is likely to increase in intensity and duration under future climates. Nitrogen (N) nutrition is related to drought-resistance mechanisms in trees. However, the influence of chemical N form (inorganic and organic N) on physiological traits related to drought resistance has been sparsely studied in conifer seedlings. We investigated the effect of N forms on morpho-physiological traits of Pinus ponderosa Dougl. ex Laws. seedlings and subsequent influences in drought tolerance and acclimation. One-year-old seedlings were fertilized during 10 weeks at 9 mM N with different N forms [either NH4+, NO3− or organic N (amino acids mixture)] in their second year of growth. After fertilization, we measured traits associated with intrinsic drought tolerance (shoot water relations, osmotic regulation, photosynthesis and cell membrane stability). Seedlings were then subjected to an 8-week drought period at varying drought intensities to evaluate plant acclimation mechanisms. We demonstrated that P. ponderosa seedlings could efficiently use amino acids as a primary N source, showing similar performance to those grown with inorganic N forms. Nitrogen form influenced mainly drought-acclimation mechanisms rather than intrinsic drought tolerance. Osmotic potential at saturation (Ψπsat) was marginally affected by N form, and a significant relationship between proline concentration in needles and Ψπsat was found. During acclimation, seedlings fertilized with organic N minimized needle senescence, retained more nutrients in the oldest needles, had maximum increments in proline concentration and hastened the development of water-use efficiency mechanisms compared with those fertilized with inorganic N sources. Our results suggest an improved physiological drought acclimation of organic N-fertilized seedlings.

Download Full-text

C and N mineralization of composted and anaerobically stored ruminant manure in differently textured soils

The Journal of Agricultural Science ◽

10.1017/s0021859699008096 ◽

2000 ◽

Vol 135 (2) ◽

pp. 151-159 ◽

Cited By ~ 46

Author(s):

INGRID K. THOMSEN ◽

JØRGEN E. OLESEN

Keyword(s):

N Mineralization ◽

Storage Period ◽

Clay Content ◽

Organic N ◽

Net N Mineralization ◽

Turnover Rates ◽

Inorganic N ◽

Available N ◽

C Pools ◽

Anaerobic Storage

Three animal manures cross-labelled with 15N in either the urine, faeces or straw fractions were prepared. After a storage period of 86 days when the manures were exposed to either composting or to anaerobic storage, portions of the manures were incubated in six differently textured soils with clay contents ranging from 11 to 45%. Evolved CO2-C was determined during a 266 day incubation and inorganic N and 15N in soil were measured at the termination of the incubation. The mineralization of C was analysed using first-order kinetics, and two C pools with fast (P1) and slow (P2) turnover rates were estimated. The total conversion of added C (Ps) was estimated as Ps=P1+P2.The cumulated CO2 production was considerably higher from soils incubated with anaerobically stored manure compared with soils amended with composted manure. CO2 production levelled off after c. 60 days in the three sandier soils whereas CO2 continued to be produced throughout the incubation from the three soils with the highest clay content. More C was assigned to the easily decomposable P1 pool in the sandiest soils whereas the more recalcitrant P2 pool was larger in the soils with higher clay content. Because of the different relationships between soil texture and C pools, Ps ended up being similar for five of the six soils. When taking C losses during the preceding storage into account, the accumulated C losses during storage and after incubation in soil accounted for 60 and 54% of C initially present in the composted and anaerobically stored manure, respectively.Net N mineralization which averaged 16% of applied organic N took place in all soils amended with composted manure. Soils with anaerobically stored manure showed net immobilization after the 266 days of incubation. The amount of N immobilized accounted for up to 30% of the inorganic N applied with the manure. As anaerobically stored manure generally loses less inorganic N during storage, it may contain more inorganic N than composted manure at the time of field application. Because of the immobilization that takes place after application of anaerobically stored manure to soil, the immediate levels of plant available N in soil may not be as different from soil supplied with composted manure as could be expected from the inorganic N content in the two types of manure. However, when considering the manure as a N resource, anaerobic storage is superior to composting.

Download Full-text

Co-occurrence of organic and inorganic N sources influences asparagine uptake and internal amino acid profiles in white clover

10.1101/577114 ◽

2019 ◽

Author(s):

Weronika Czaban ◽

Jim Rasmussen

Keyword(s):

Amino Acids ◽

Amino Acid ◽

White Clover ◽

Uptake Rate ◽

Essential Amino Acids ◽

Organic N ◽

Inorganic N ◽

Total N ◽

Amino Acid Profiles ◽

N Status

AbstractDirect plant uptake of organic nitrogen (N) is important for plant N nutrition, but we lack knowledge of how the concentration of external N forms (organic and inorganic) -influence organic N uptake and plant N status. We investigated the uptake of the amino acid asparagine (Asn) in white clover in the presence of different nitrate (NO3-), Asn, and total N concentrations. White clover seedlings were for one week exposed to combinations of NO3-(3-30 µmol N kg-1sand DW) and Asn (3-30 µmol N kg-1sand DW), where after the Asn uptake rate was determined by addition of13C4-Asn. Shoot and root Asn content and amino acid profiles were also analyzed. Increasing external NO3-and total N concentrations decreased13C4-Asn uptake rates and internal clover Asn content. Furthermore, total N affected clover amino acid profiles from non-essential amino acids at low N doses to the dominance of essential amino acids at increasing N doses. Asn uptake rate in white clover is reduced by increasing inorganic N, but not by increasing organic N concentrations. Furthermore, plant amino acid profiles are likely to be a more sensitive indicator of N supply and descriptor of the N status.

Download Full-text