scholarly journals Role of root exudates and root turnover in the below-ground N transfer from Canavalia ensiformis (jackbean) to the associated Musa acuminata (banana)

2009 ◽  
Vol 60 (3) ◽  
pp. 289 ◽  
Author(s):  
Jorge Sierra ◽  
Lucienne Desfontaines
Keyword(s):  
Root Exudates ◽  
N Uptake ◽  
Root Traits ◽  
Box Model ◽  
Root Turnover ◽  
Nitrogen Transfer ◽  
N Transfer ◽  
Donor Plant ◽  
Feeding Method ◽  
N Release

Jackbean is an annual legume frequently used as green manure in tropical intercropping systems with bananas. Although the beneficial effect of nitrogen (N) release from above-ground residues on banana nutrition is well known, little information is available on the N transfer from jackbean roots before and after the above-ground harvest. The aim of this study was to assess the relative contribution of exudates and root turnover in the N transfer from jackbean to banana in a greenhouse experiment. Nitrogen transfer was studied in a 6-month trial using the 15N leaf feeding method, and estimated with a box model of 15N dilution based on the observed data of 15N content in exudates and decomposing roots. For the sowing–harvest period, the amount of N transferred from jackbean exudates represented 16% of banana N uptake and 0.7% of jackbean N uptake. Therefore, the N transfer flux via exudates was 23 times higher in terms of N input for the recipient plant than in terms of N output for the donor plant. This value, which is an index of the effectiveness of N transfer, was lower than those reported previously for other soil–plant systems in greenhouse conditions. This would be due to differences in root traits of the recipient plants. The amount of transferred N from root turnover after jackbean harvest represented 52% of banana N uptake in that period. The box model described N transfer from both legume N sources adequately (r2 = 0.92). For the whole experiment, 38% of banana N uptake was derived from jackbean (6% from exudates and 32% from root turnover), and 62% from soil N. The results indicated that N transfer from root exudates of jackbean would be a useful but minor process compared with N release from root turnover in soil. The experimental and theoretical approach proposed in this study may be useful in screening studies to assess the capability of herbaceous legumes to transfer N.

scholarly journals Nitrogen Transfer Play an Important Role of Differentially Expressed Protein of Roots in Eucalyptus Urophylla × E. grandis and Dalbergia Odorifera Nursery Seedlings Intercropping System

2020 ◽  
Author(s):  
Xianyu Yao ◽  
Liangning Liao ◽  
Yongzhen Huang ◽  
Ge Fan ◽  
Mei Yang ◽  
...  
Keyword(s):  
Root Growth ◽  
Nitrogen Assimilation ◽  
Molecular Mechanisms ◽  
Field Experiments ◽  
N Uptake ◽  
Nitrogen Compound ◽  
Differentially Expressed ◽  
Nitrogen Transfer ◽  
N Transfer ◽  
Differentially Expressed Protein

Abstract Background: The mixing of Eucalyptus with N2-fixing trees is a frequently successful and sustainable cropping practice. In this study, we evaluated nitrogen transfer and conducted a proteomic analysis on seedlings of Eucalyptus and a N2-fixing tree, Dalbergia (D.) odorifera, from intercropping and monocropping systems, to elucidate the physiological effecting and the molecular mechanisms on N transfer of Eucalyptus mixed with D. odorifera. Results: We demonstrated the following: (1) Nitrogen transfer occurred from D. odorifera to E. urophylla × E. grandis by 14.6 %. Interspecific facilitation of N uptake and root growth in E. urophylla × E. grandis was increased in the intercropping system, but the root growth and N absorption of D. odorifera were inhibited. (2) Among differentially expressed proteins was greater than 1.5 times, E. urophylla × E. grandis were found to be up-regulated several proteins for the nitrogen assimilation and enhancing the nitrogen competition, such as the proteins related to tricarboxylic acid/organic transformation, nitrogen metabolism and nitrogen assimilation; it also up-regulated the expression of stress resistant protein for its adaptability. However, the assimilation and metabolism of nitrogen was promoted in D. odorifera through the up-regulation of amino acid metabolism related proteins, and increased the key enzyme abundance of glycolysis pathway in D. odorifera. (3) Importantly, E. urophylla × E. grandis was the beneficiary in the process of N transfer, there were more different proteins involved in the synthesis pathway than that of the metabolic pathway, but there were more functional proteins involved in metabolic degradation in D. odorifera. Additionaly, the two groups of nitrogen compound transporter were found in E. urophylla × E. grandis, i.e. the molecular mechanism of the N transfer from D. odorifera to E. urophylla × E. grandis was explained by proteomics. Conclusions: Our study suggests that N transfer occurred from D. odorifera to E. urophylla × E. grandis and it was affected by the variations in the differentially expressed protein. We anticipate the result can be verified in field experiments for the sustainable development of Eucalyptus plantations.

scholarly journals Morphological and Physiological Root Traits and Their Relationship with Nitrogen Uptake in Wheat Varieties Released from 1915 to 2013

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1149
Author(s):  
Guglielmo Puccio ◽  
Rosolino Ingraffia ◽  
Dario Giambalvo ◽  
Gaetano Amato ◽  
Alfonso S. Frenda
Keyword(s):  
Durum Wheat ◽  
Root System ◽  
N Uptake ◽  
Specific Root Length ◽  
Root Traits ◽  
Wheat Breeding ◽  
N Availability ◽  
Wheat Varieties ◽  
Uptake Efficiency ◽  
Positive Effects

Identifying genotypes with a greater ability to absorb nitrogen (N) may be important to reducing N loss in the environment and improving the sustainability of agricultural systems. This study extends the knowledge of variability among wheat genotypes in terms of morphological or physiological root traits, N uptake under conditions of low soil N availability, and in the amount and rapidity of the use of N supplied with fertilizer. Nine genotypes of durum wheat were chosen for their different morpho-phenological characteristics and year of their release. The isotopic tracer 15N was used to measure the fertilizer N uptake efficiency. The results show that durum wheat breeding did not have univocal effects on the characteristics of the root system (weight, length, specific root length, etc.) or N uptake capacity. The differences in N uptake among the studied genotypes when grown in conditions of low N availability appear to be related more to differences in uptake efficiency per unit of weight and length of the root system than to differences in the morphological root traits. The differences among the genotypes in the speed and the ability to take advantage of the greater N availability, determined by N fertilization, appear to a certain extent to be related to the development of the root system and the photosynthesizing area. This study highlights some variability within the species in terms of the development, distribution, and efficiency of the root system, which suggests that there may be sufficient grounds for improving these traits with positive effects in terms of adaptability to difficult environments and resilience to climate change.

scholarly journals Differences in fine root traits between Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) – A case study in the Kysucké Beskydy Mts

2009 ◽  
Vol 55 (No. 12) ◽  
pp. 556-566 ◽  
Author(s):  
B. Konôpka
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Fagus Sylvatica ◽  
Seasonal Dynamics ◽  
Fine Roots ◽  
Fine Root ◽  
Root Traits ◽  
European Beech ◽  
Root Turnover ◽  
Mortality Ratio

Interspecific comparisons of the fine root “behaviour” under stressful situations may answer questions related to resistance to changing environmental conditions in the particular tree species. Our study was focused on Norway spruce (<I>Picea abies</I> [L.] Karst.) and European beech (<I>Fagus sylvatica</I> L.) grown in an acidic soil where acidity was caused by past air pollution in the Kysucké Beskydy Mts., North-Western Slovakia. Between April and October 2006, the following fine root traits were studied: biomass and necromass seasonal dynamics, vertical distribution, production, mortality, fine root turnover and production to mortality ratio. Sequential soil coring was repeatedly implemented in April, June, July, September, and October including the soil layers of 0–5, 5–15, 15–25, and 25–35 cm. Results indicated that spruce had a lower standing stock of fine roots than beech, and fine roots of spruce were more superficially distributed than those of beech. Furthermore, we estimated higher seasonal dynamics and also higher turnover of fine roots in spruce than in beech. The production to mortality ratio was higher in beech than in spruce, which was hypothetically explained as the effect of drought episodes that occurred in July and August. The results suggested that the beech root system could resist a physiological stress better than that of spruce. This conclusion was supported by different vertical distributions of fine roots in spruce and beech stands.

scholarly journals Root Contact between Maize and Alfalfa Facilitates Nitrogen Transfer and Uptake Using Techniques of Foliar 15N-Labeling

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 360 ◽  
Author(s):  
Zeqiang Shao ◽  
Xinyu Wang ◽  
Qiang Gao ◽  
Hualiang Zhang ◽  
Hailing Yu ◽  
...  
Keyword(s):  
Growth Period ◽  
Crop Productivity ◽  
Nitrogen Transfer ◽  
N Transfer ◽  
Total N ◽  
N Source ◽  
N Utilization ◽  
Root Barrier ◽  
15N Labeling ◽  
Root Contact

Belowground nitrogen (N) transfer from legumes to non-legumes provides an important N source for crop yield and N utilization. However, whether root contact facilitates N transfer and the extent to which N transfer contributes to crop productivity and N utilization have not been clarified. In our study, two-year rain shelter experiments were conducted to quantify the effect of root contact on N transfer in a maize/alfalfa intercropping system. N transfer occurred mainly one direction from alfalfa to maize during the growth period. Following the N0 treatment, the amount of N transfer from alfalfa to maize was 204.56 mg pot−1 with no root barrier and 165.13 mg pot−1 with a nylon net barrier, accounting for 4.72% and 4.48% of the total N accumulated in maize, respectively. Following the N1 treatment, the amount of N transfer from alfalfa to maize was 197.70 mg pot−1 with no root barrier and 139.04 mg pot−1 with a nylon net barrier, accounting for 3.64% and 2.36% of the total N accumulated in the maize, respectively. Furthermore, the amount of N transfer without no root barrier was 1.24–1.42 times higher than that with a nylon net barrier regardless of the level of N addition. Our results highlight the importance and the relevance of root contact for the enhancement of N transfer in a maize/alfalfa intercropping system.

Nitrogen dynamics under growth chamber conditions as influenced by method of alfalfa termination 2. Plant-available N release

1998 ◽  
Vol 78 (2) ◽  
pp. 261-266 ◽  
Author(s):  
R. M. Mohr ◽  
H. H. Janzen ◽  
M. H. Entz
Keyword(s):  
Nitrogen Uptake ◽  
N Uptake ◽  
Soil Surface ◽  
Growth Chamber ◽  
Nitrogen Accumulation ◽  
Herbicide Application ◽  
Hordeum Vulgare L ◽  
Available N ◽  
N Release ◽  
Barley Crop

Herbicide application has been proposed as an alternative to tillage for termination of established alfalfa (Medicago sativa L.) stands but it may alter the pattern and amount of N released from alfalfa residues. A controlled environment study was conducted to investigate the effect of termination technique on the availability of N to four barley (Hordeum vulgare L.) crops. Four treatments consisting of a factorial combination of two termination methods (chemical, mechanical) and two methods of residue placement (surface, incorporated) were established. Nitrogen uptake by the four consecutive crops of barley was measured during a 125-d period after termination. Termination method, particularly residue placement, strongly affected N release from alfalfa residues. Nitrogen accumulation by the initial barley crop accounted for >60% of cumulative N uptake in incorporated treatments compared with 39% and 24% for herbicide and tillage treatments in which alfalfa residue was surface applied. Herbicide application also slightly increased N uptake by the initial barley crop. Nitrogen uptake by subsequent barley crops was not affected by termination method; however, cumulative N uptake remained substantially greater for incorporated treatments throughout the 125 d experiment. Effects of residue particle size on N release from alfalfa residues were small. These results suggest that herbicide termination in which residue is retained on the soil surface may reduce the short-term plant-available N supply. Provided that mineralization is sufficient to meet the N needs of subsequent crops, maintaining a smaller reservoir of soil inorganic N may be beneficial in reducing the potential for leaching or denitrification losses. Key words: Plant-available N, termination method, alfalfa, herbicide, tillage, growth chamber

scholarly journals A Comparison of Nitrogen Transfer and Transformation in Traditional Farming and Rice-Duck Farming System by N15 Tracer Method

2018 ◽  
Author(s):  
Tchister Morrel Ebissa ◽  
Bo Yang ◽  
Yuanqing Guan ◽  
Bingchang Tan ◽  
Peizhen Chen ◽  
...  
Keyword(s):  
Organic Fertilizer ◽  
N Uptake ◽  
Distribution Patterns ◽  
Farming System ◽  
Crop Productivity ◽  
Chemical Fertilizer ◽  
N Use Efficiency ◽  
Nitrogen Transfer ◽  
Use Efficiency ◽  
N Use

A field experiment was conducted in Ninghe, Tianjin, China, using 15N isotope method to evaluate the application of organic fertilizer on N distribution patterns of labelled and unlabeled N fertilizer, ammonium sulfate -15N uptake by rice, N use efficiency (NUE), and the fate of (15NH4)2SO4 applied. The experiment included eight treatments: CK-N (control + no-duck), CK-D (control + ducks), CF-N (chemical fertilizer + no-ducks), CF-D (chemical fertilizer + ducks), CM-N (chemical fertilizer + organic fertilizer + no-ducks), CM-D (chemical fertilizer + organic fertilizer + ducks), CD-N (chemical fertilizer 30% off + organic fertilizer + no-ducks), and CD-D (chemical fertilizer 30% off + organic fertilizer + ducks). The results showed that the application of organic fertilizer whether CM or CD significantly increased N and P concentrations over control (CK) and chemical fertilizer (CF). Moreover, no-significant differences were found in 15N fresh grain and husk concentration. Both organs ranged of 14.2-14.4 g kg-1 and 6.2-6.3 g kg-1, respectively. N derived from the fertilizer and soil significantly affected fresh grain compared to fresh husk. However, N uptake and N use efficiency did not show any differences. We concluded that organic fertilizer has a significant influence on rice growth and promote crop productivity.

scholarly journals Seasonal Variation in Growth, Nitrogen Uptake and Allocation by Container-grown Evergreen and Deciduous Rhododendron Cultivars

HortScience ◽  
2007 ◽  
Vol 42 (6) ◽  
pp. 1440-1449 ◽  
Author(s):  
Carolyn F. Scagel ◽  
Guihong Bi ◽  
Leslie H. Fuchigami ◽  
Richard P. Regan
Keyword(s):  
Nitrogen Uptake ◽  
Leaf Growth ◽  
Stem Elongation ◽  
N Uptake ◽  
Root Turnover ◽  
Total Biomass ◽  
N Availability ◽  
N Losses ◽  
Total N ◽  
N Storage

Growth, nitrogen (N) uptake, and N storage were assessed in transplanted 1-year-old rhododendron liners. Two evergreen cultivars, Rhododendron ‘P. J. Mezitt Compact’ (PJM) and R. ‘English Roseum’ (ER), and one deciduous cultivar, R. ‘Gibraltar’ (AZ), were transplanted into 1-gal. pots and given liquid fertilizer with (+N) or without (–N) N. Increased N availability increased growth after July (ER, PJM) or August (AZ), and resulted in three to five times more total biomass. Biomass continued to increase after stem elongation and leaf production ceased. Nitrogen uptake was correlated with growth of all plant structures on AZ, whereas N uptake was only correlated with stem and leaf growth on evergreen cultivars. The rate of N uptake was highest before July for AZ (1.9 mg·d−1) and in August and September for the evergreen cultivars (≈5 mg·d−1). Thirteen percent to 16% of total N uptake from between May and February occurred after N fertilization ceased at the beginning of September. Plants contained the most N in October (AZ), November (PJM), or December (ER). Biomass loss after November accounted for a loss of 14% to 48% of the maximum total plant N content. Nitrogen demand by roots and stems increased from May to February in all cultivars. The role of new and old leaves in N storage on evergreen cultivars varied with cultivar and time. Differences in N storage between the evergreen cultivars occurred primarily in their roots and leaves. Over the winter, PJM stored more N in its roots, whereas ER stored more N in its leaves. Changes in N concentrations and contents in different plant structures after November indicate that, during early winter, N stored in other structures moves to roots and old stems of PJM, old stems of ER, and roots and new and old stems of AZ. These results suggest that fertilizer application strategies for transplanted liners of these cultivars should include low N availability after transplanting followed by high N availability in mid to late summer. This type of strategy will not only improve N uptake efficiency from fertilizer, but also will minimize N loss from the containers. The results also demonstrated that N uptake in the autumn may play an important role in supplementing plant N reserves required for growth during the next season as well as for balancing N losses incited by leaf abscission, root turnover, and maintenance functions that occur over winter.

scholarly journals Plant Nitrogen Uptake From Insect Frass Is Affected by the Nitrification Rate as Revealed by Urease and Nitrification Inhibitors

2021 ◽  
Vol 5 ◽  
Author(s):  
Conor Watson ◽  
Timo Preißing ◽  
Florian Wichern
Keyword(s):  
Microbial Biomass ◽  
Nutrient Uptake ◽  
N Mineralization ◽  
N Uptake ◽  
Italian Ryegrass ◽  
Organic N ◽  
Nutrient Concentrations ◽  
Nitrite Accumulation ◽  
Nitrification Inhibitors ◽  
N Release

Insect protein production is considered a sustainable alternative to livestock protein which furthermore utilizes waste streams. Its production can have positive but also potentially negative environmental effects, which require evaluation. Frass, the byproduct of insect production, is regarded an efficient organic fertilizer or soil amendment. However, several studies report negative frass effects on plant growth and nitrogen (N) cycling. Therefore, a pot trial was carried out which sought to understand N release from frass and subsequent growth and nutrient uptake of Italian ryegrass. Mealworm frass (MWF) or buffalo worm frass (BFW) was applied at two rates (1.5 and 3% w/w) to a soil-sand mix. To evaluate N release processes, frass was applied alone, with a nitrification inhibitor (NI), a urease inhibitor (UI), or both (NI+UI). Plant N, nutrient uptake and soil inorganic N were measured at the experiment's end. To gauge whether altered N fluxes induced changes in the microbial community, soil microbial biomass, bacterial/archaeal abundances and ergosterol content as a fungal biomarker, were determined. Both frass types and application rates stimulated microbial growth and N mineralization. The 3% rate inhibited seed germination, possibly due to salinity or ammonia toxicity. At the 1.5% rate, both frass types were effective fertilizers. MWF led to higher biomass and nutrient uptake, owing to its higher extractable nutrient concentrations. The 3% rate caused nitrite accumulation in the absence of NI. NI improved plant biomass, nutrient uptake, stimulated archaeal and bacterial abundances and prevented nitrite accumulation. UI reduced N mineralization, showing that a substantial fraction of frass organic N is ureic. UI enhanced fungal contribution to the microbial biomass, revealing the importance of bacteria in frass N mineralization processes when UI is not applied. NI and UI combined, induced greater N release from frass than UI or NI alone. Our study demonstrated the usefulness of NI and UI in studying N release from frass. NI can improve plant N uptake and minimize N losses following frass application, reducing its potentially negative effects. UI can retard N release from frass, allowing its application as a slow-release fertilizer, but should not be used concurrently with NI.

scholarly journals Bidirectional Nitrogen Transfer and Plant Growth in a Mixed Plantation of N2-Fixing Species and Eucalyptus urophylla × E. grandis under Different N Applications

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1171
Author(s):  
Xianyu Yao ◽  
Uromi Manage Goodale ◽  
Mei Yang ◽  
Liangning Liao ◽  
Sufang Yu ◽  
...  
Keyword(s):  
Management Practice ◽  
Application Rate ◽  
Pot Experiment ◽  
Nitrogen Transfer ◽  
Eucalyptus Urophylla ◽  
N Transfer ◽  
N Content ◽  
Stand Productivity ◽  
Mixed Plantations ◽  
Dalbergia Odorifera

N2-fixing species play a crucial role in mixed-plantations as they improve stand productivity. To quantify the N transfer from N2-fixing species to Eucalyptus (Eucalyptus urophylla × E. grandis) in N2-fixing species/Eucalyptus plantations, we established a pot experiment and confirmed the occurrence of this process under natural conditions. The 15N was traced in labeled species as well as in neighboring tree species after labeling, and the growth was evaluated in short-term natural trials. Our results showed that a bidirectional N transfer occurred. The amount of net N transfer was 21.8–127.0 mg N plant−1, which was equal to 1.5–21.2% of the total nitrogen (TN) that accumulated in Eucalyptus plants under pot conditions, was transferred from Dalbergia odorifera to Eucalyptus. The amount of N transferred significantly decreased with the increasing N application rate but increased with time after labeling. Compared with the results for the Eucalyptus monocrop, the soil N concentration (including NO3−-N and NH4+-N) greatly improved when D. odorifera was introduced together with Eucalyptus under both field and pot conditions. Furthermore, the results under field conditions were consistent with the results of the pot experiment. The dry matter (DM) yield (14.5–16.4%) and the N content (5.1–9.6%) in Eucalyptus increased when mixed together with D. odorifera, but the N content in and DM yield of D. odorifera slightly decreased. It is concluded that the N transfer between Eucalyptus and D. odorifera is a much more important dynamic process than previously recognized, and Eucalyptus and legume intercropping is a successful management practice because N transfer provides a significant amount of N required for Eucalyptus productivity.

scholarly journals Biological nitrification inhibition by root exudates of native species,Hibiscus splendensandSolanum echinatum

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4960 ◽  
Author(s):  
Chelsea K. Janke ◽  
Laura A. Wendling ◽  
Ryosuke Fujinuma
Keyword(s):  
Plant Species ◽  
Root Exudates ◽  
Native Species ◽  
N Uptake ◽  
Nitrification Inhibition ◽  
Native Plant ◽  
Native Plant Species ◽  
Potential Nitrification ◽  
Australian Native Plant ◽  
Biological Nitrification

Australian native species grow competitively in nutrient limited environments, particularly in nitrogen (N) limited soils; however, the mechanism that enables this is poorly understood. Biological nitrification inhibition (BNI), which is the release of root exudates into the plant rhizosphere to inhibit the nitrification process, is a hypothesized adaptive mechanism for maximizing N uptake. To date, few studies have investigated the temporal pattern and components of root exudates by Australian native plant species for BNI. This study examined root exudates from two Australian native species,Hibiscus splendensandSolanum echinatum,and contrasted with exudates ofSorghum bicolor, a plant widely demonstrated to exhibit BNI capacity. Root exudates were collected from plants at two, four, and six weeks after transplanting to solution culture. Root exudates contained three types of organic acids (OAs), oxalic, citric and succinic acids, regardless of the species. However, the two Australian natives species released larger amount of OAs in earlier development stages thanS. bicolor. The total quantity of these OAs released per unit root dry mass was also seven-ten times greater for Australian native plant species compared toS. bicolor. The root exudates significantly inhibited nitrification activity over six weeks’ growth in a potential nitrification assay, withS. echinatum(ca. 81% inhibition) >S. bicolor(ca. 80% inhibition) >H. splendens(ca. 78% inhibition). The narrow range of BNI capacity in the study plants limited the determination of a relationship between OAs and BNI; however, a lack of correlation between individual OAs and inhibition of nitrification suggests OAs may not directly contribute to BNI. These results indicate that Australian native species generate a strongly N conserving environment within the rhizosphere up to six weeks after germination, establishing a competitive advantage in severely N limited environments.

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