scholarly journals Optimization of Nitrogen Demand in Vegetables by Different Impacts on Autotrophic and Heterotrophic Nitrification

Author(s):  
Xiaoqian Dan ◽  
Lei Meng ◽  
Mengqiu He ◽  
Xiaoxiang He ◽  
Chang Zhao ◽  
...  

Abstract Aims The understanding of the interactions between N transformations and N uptake by plants in greenhouse soils with large N accumulation is still not clear. The aim is to understand the plant- soil interactions (vegetables) on N transformations with respect to N supply. Methods 15N tracing studies were conducted in two greenhouse soils to simultaneously quantify soil gross N transformation and plant N uptake rates using the Ntraceplant tool. Results There were significant feedbacks between vegetable N uptake and soil gross N transformation rates, whether soil N accumulation occurred or not. Plant NO3– uptake rates (UNO3) were higher than the NH4+ uptake rates (UNH4), which is consistent with the NO3–-preference of the vegetable plants studied. While UNH4 was still responsible for 6-49% of total N uptake rates, significantly negative relationships between UNH4 and NH4+ immobilization rate and autotrophic nitrification rate (ONH4) were observed. ONH4 was significantly inhibited in the presence of plants and decreased with time. ONH4 (1.11 mg N kg-1 d-1) was much lower than UNO3 (8.29 mg N kg-1 d-1) in the presence of plants. However, heterotrophic nitrification rate (ONrec), which ranged from 0.10 to 8.11 mg N kg-1 d-1 was significantly stimulated and was responsible for 5-97% of NO3– production in all plant treatments, providing additional NO3– to meet N requirements of plants and microorganisms.Conclusions The management of organic N fertilizers should be improved to stimulate inorganic N production via heterotrophic nitrification in greenhouse cultivation.

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 894
Author(s):  
Xiaoqian Dan ◽  
Zhaoxiong Chen ◽  
Shenyan Dai ◽  
Xiaoxiang He ◽  
Zucong Cai ◽  
...  

Soil temperature change caused by global warming could affect microbial-mediated soil nitrogen (N) transformations. Gross N transformation rates can provide process-based information about abiotic–biotic relationships, but most previous studies have focused on net rates. This study aimed to investigate the responses of gross rates of soil N transformation to temperature change in a subtropical acidic coniferous forest soil. A 15N tracing experiment with a temperature gradient was carried out. The results showed that gross mineralization rate of the labile organic N pool significantly increased with increasing temperature from 5 °C to 45 °C, yet the mineralization rate of the recalcitrant organic N pool showed a smaller response. An exponential response function described well the relationship between the gross rates of total N mineralization and temperature. Compared with N mineralization, the functional relationship between gross NH4+ immobilization and temperature was not so distinct, resulting in an overall significant increase in net N mineralization at higher temperatures. Heterotrophic nitrification rates increased from 5 °C to 25 °C but declined at higher temperatures. By contrast, the rate of autotrophic nitrification was very low, responding only slightly to the range of temperature change in the most temperature treatments, except for that at 35 °C to 45 °C, when autotrophic nitrification rates were found to be significantly increased. Higher rates of NO3− immobilization than gross nitrification rates resulted in negative net nitrification rates that decreased with increasing temperature. Our results suggested that, with higher temperature, the availability of soil N produced from N mineralization would significantly increase, potentially promoting plant growth and stimulating microbial activity, and that the increased NO3− retention capacity may reduce the risk of leaching and denitrification losses in this studied subtropical acidic forest.


2014 ◽  
Vol 152 (S1) ◽  
pp. 137-149 ◽  
Author(s):  
M. ERNFORS ◽  
F. P. BRENNAN ◽  
K. G. RICHARDS ◽  
K. L. MCGEOUGH ◽  
B. S. GRIFFITHS ◽  
...  

SUMMARYNitrification inhibitors are used in agriculture for the purpose of decreasing nitrogen (N) losses, by limiting the microbially mediated oxidation of ammonium (NH4+) to nitrate (NO3−). Successful inhibition of nitrification has been shown in numerous studies, but the extent to which inhibitors affect other N transformations in soil is largely unknown. In the present study, cattle slurry was applied to microcosms of three different grassland soils, with or without the nitrification inhibitor dicyandiamide (DCD). A solution containing NH4+and NO3−, labelled with15N either on the NH4+or the NO3−part, was mixed with the slurry before application. Gross N transformation rates were estimated using a15N tracing model. In all three soils, DCD significantly inhibited gross autotrophic nitrification, by 79–90%. Gross mineralization of recalcitrant organic N increased significantly with DCD addition in two soils, whereas gross heterotrophic nitrification from the same pool decreased with DCD addition in two soils. Fungal to bacterial ratios were not significantly affected by DCD addition. Total gross mineralization and immobilization increased significantly across the three soils when DCD was used, which suggests that DCD can cause non-target effects on soil N mineralization–immobilization turnover.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 750
Author(s):  
Jianwei Zhang ◽  
Yan Zhou ◽  
Weiwei Li ◽  
Muhammad Y. Nadeem ◽  
Yanfeng Ding ◽  
...  

Straw-derived N (Straw-N) is an important organic N source, but its distribution in soil–rice systems regulated by water management and N fertilization is poorly understood. Therefore, a pot experiment using 15N-labeled wheat residue was conducted with conventional flooded irrigation (CF) and alternate wetting/drying irrigation (AWD) both with and without N fertilization. Results showed that the whole-plant straw–N recovery rate and the soil residue rate were 9.2–11.9% and 33.5–43.1%, and 10.2–13.8% and 33.7–70.2% at panicle initiation stage (PI) and mature stage (MS), respectively. There was no interaction between water management and N fertilization. Compared to CF, AWD did not affect whole-plant straw-N absorption and significantly changed its distribution in various plant parts, such as increasing the straw-N accumulation in roots at PI and decreasing it at MS. N fertilization addition markedly promoted the transfer of straw-N to the plant but reduced the contribution rate of N uptake by the plant. Furthermore, AWD or N fertilization addition allowed more straw-N to remain in the soil, and a positive interaction effect on the straw-N loss mitigation was found. These results suggest that AWD combined with N fertilization addition is a great measure to improve the efficient utilization of straw-N and avoid the risk of environmental pollution in a soil–rice system.


2016 ◽  
Author(s):  
Anne B. Jansen-Willems ◽  
Gary J. Lanigan ◽  
Timothy J. Clough ◽  
Louise C. Andresen ◽  
Christoph Müller

Abstract. Over the last century an increase in mean soil surface temperature has been observed and it is predicted to increase further in the future. To evaluate the legacy effects of increased temperature on both nitrogen (N) transformation rates in the soil and nitrous oxide (N2O) emissions, an incubation experiment was conducted with soils taken from a long term in situ warming experiment on temperate permanent grassland. In this experiment the soil temperature was elevated by 0 (control), 1, 2 or 3 °C (4 replicates per treatment) using IR-lamps over a period of 6 years. The soil was subsequently incubated under common conditions (20 °C and 50 % humidity) and labelled with NO315NH4 Gly, 15NO3NH4 Gly or NO3NH4 15N-Gly. Both inorganic N (NO3−NH4+) and NO32− contents were higher in soil subjected to the +2 and +3 °C temperature elevations. Analyses of N transformations using a 15N tracing model, showed that, following incubation, gross organic (and not inorganic) N transformation rates decreased in response to the prior soil warming treatment. This was also reflected in reduced N2O emissions associated with organic N oxidation and denitrification. A newly developed source partitioning model showed the importance of oxidation of organic N as a source of N2O. Concluding, long term soil warming can cause a legacy effect which diminishes organic N turn over and the release of N2O from organic N and denitrification.


2020 ◽  
Vol 11 ◽  
Author(s):  
Xuan Jia ◽  
Chaohe Huangfu ◽  
Dafeng Hui

Plant species may acquire different forms of nitrogen (N) to reduce competition for the same resource, but how plants respond to neighbors with different densities in their N uptake is still poorly understood. We investigated the effects of competition regime on the uptake of different N forms by two hygrophytes, Carex thunbergii and Polygonum criopolitanum, by conducting a hydroponic test of excised roots and an in situ experiment in a subtropical wetland ecosystem. The two species were grown either in monocultures or mixtures with various neighbor densities. Root functional traits and N uptake rates of different N forms were measured. Our results showed that N uptake was mainly determined by N form, rather than species identity. Both species were able to use organic N sources, but they took up relatively more N supplied as NO3- than as NH4+ or glycine, irrespective of competition treatments. Both species preferred NO3- when grown in monoculture, but in the presence of competitors, the preference of fast-growing C. thunbergii persisted while P. criopolitanum acquired more NH4+ and glycine, with stronger responses being observed at the highest neighbor density. The hydroponic test suggested that these divergences in N acquisition between two species might be partially explained by different root functional traits. To be specific, N uptake rates were significantly positively correlated with root N concentration and specific root length, but negatively correlated with root dry matter content. Our results implicated that C. thunbergii has a competitive advantage with relatively more stable N acquisition strategy despite a lower N recovery than P. criopolitanum, whereas P. criopolitanum could avoid competition with C. thunbergii via a better access to organic N sources, partly mediated by competition regimes.


2012 ◽  
Vol 9 (4) ◽  
pp. 1509-1518 ◽  
Author(s):  
E. Gioseffi ◽  
A. de Neergaard ◽  
J. K. Schjoerring

Abstract. Soil-borne amino acids may constitute a source of nitrogen (N) 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 ammonium (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, thereby resulting in similar total N uptake rates. 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 generally 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 N.


2014 ◽  
Vol 80 (19) ◽  
pp. 6013-6022 ◽  
Author(s):  
Tara L. Connelly ◽  
Steven E. Baer ◽  
Joshua T. Cooper ◽  
Deborah A. Bronk ◽  
Boris Wawrik

ABSTRACTHow Arctic climate change might translate into alterations of biogeochemical cycles of carbon (C) and nitrogen (N) with respect to inorganic and organic N utilization is not well understood. This study combined15N uptake rate measurements for ammonium, nitrate, and urea with15N- and13C-based DNA stable-isotope probing (SIP). The objective was to identify active bacterial and archeal plankton and their role in N and C uptake during the Arctic summer and winter seasons. We hypothesized that bacteria and archaea would successfully compete for nitrate and urea during the Arctic winter but not during the summer, when phytoplankton dominate the uptake of these nitrogen sources. Samples were collected at a coastal station near Barrow, AK, during August and January. During both seasons, ammonium uptake rates were greater than those for nitrate or urea, and nitrate uptake rates remained lower than those for ammonium or urea. SIP experiments indicated a strong seasonal shift of bacterial and archaeal N utilization from ammonium during the summer to urea during the winter but did not support a similar seasonal pattern of nitrate utilization. Analysis of 16S rRNA gene sequences obtained from each SIP fraction implicated marine group ICrenarchaeota(MGIC) as well asBetaproteobacteria,Firmicutes, SAR11, and SAR324 in N uptake from urea during the winter. Similarly,13C SIP data suggested dark carbon fixation for MGIC, as well as for several proteobacterial lineages and theFirmicutes. These data are consistent with urea-fueled nitrification by polar archaea and bacteria, which may be advantageous under dark conditions.


Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 261 ◽  
Author(s):  
Lu Yang ◽  
Jinshun Bai ◽  
Jia Liu ◽  
Naohua Zeng ◽  
Weidong Cao

Green manure is a promising, at least partial, substitution for chemical fertilizer in agriculture, especially for nitrogen (N), which in soil can be radically changed by exogenous input. However, it is not well understood how, after green manure incorporation, soil N changes coordinate with crop N uptake and consequently contribute to fertilizer reduction in a maize–green manure rotation. A four-year field study was performed consisting of (1) control, no fertilization; (2) F100, recommended inorganic fertilization alone; (3) G, green manure incorporation alone; (4) F70 + G (70% of F100 plus G); (5) F85 + G; and (6) F100 + G. The results show that treatments with 15–30% reduction of inorganic fertilizer (i.e., F70 + G and F85 + G) had similar grain yield, dry matter (DM) accumulation, and N uptake as F100 treatment. F100 + G maize had 17% greater DM and 15% more N uptake at maturity relative to F100. Of the five soil N fractions examined, dissolved organic N (DON) and mineral N (Nmin) explained over 70% of the variation of maize DM and N accumulation. Partial least squares path modeling further revealed that soil N fractions had positive indirect effects on DM production through N uptake, which might be coordinated with improved DON and Nmin status at both early and mid-late stages of maize growth. Overall, the results highlight enhanced maize production with reduced fertilizer inputs based on green manure incorporation in temperate regions.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 595
Author(s):  
Shama Naz ◽  
Qiufang Shen ◽  
Jonas Lwalaba Wa Lwalaba ◽  
Guoping Zhang

Nitrogen (N) availability and form have a dramatic effect on N uptake and assimilation in plants, affecting growth and development. In the previous studies, we found great differences in low-N tolerance between Tibetan wild barley accessions and cultivated barley varieties. We hypothesized that there are different responses to N forms between the two kinds of barleys. Accordingly, this study was carried out to determine the response of four barley genotypes (two wild, XZ16 and XZ179; and two cultivated, ZD9 andHua30) under 4Nforms (NO3−, NH4+, urea and glycine). The results showed significant reduction in growth parameters such as root/shoot length and biomass, as well as photosynthesis parameters and total soluble protein content under glycine treatment relative to other N treatments, for both wild and cultivated barley, however, XZ179 was least affected. Similarly, ammonium adversely affected growth parameters in both wild and cultivated barleys, with XZ179 being severely affected. On the other hand, both wild and cultivated genotypes showed higher biomass, net photosynthetic rate, chlorophyll and protein in NO3− treatment relative to other three N treatments. It may be concluded that barley undisputedly grows well under inorganic nitrogen (NO3−), however in response to the organic N wild barley prefer glycine more than cultivated barely.


2021 ◽  
Author(s):  
Robert Reuter ◽  
Olga Ferlian ◽  
Mika Tarkka ◽  
Nico Eisenhauer ◽  
Karin Pritsch ◽  
...  

Abstract Mycorrhizal fungi play an important role for the nitrogen (N) supply of trees. The influence of different mycorrhizal types on N acquisition in tree-tree interactions is, however, not well understood, particularly with regard to the competition for growth-limiting N. We studied the effect of competition between temperate forest tree species on their inorganic and organic N acquisition in relation to their mycorrhizal type (i.e., arbuscular mycorrhiza or ectomycorrhiza). In a field experiment, we quantified net N uptake capacity from inorganic and organic N sources using 15N/13C stable isotopes for arbuscular mycorrhizal tree species (i.e., Acer pseudoplatanus L., Fraxinus excelsior L., and Prunus avium L.) as well as ectomycorrhizal tree species (i.e., Carpinus betulus L., Fagus sylvatica L., and Tilia platyphyllos Scop.). All species were grown in intra- and interspecific competition (i.e., monoculture or mixture). Our results showed that N sources were not used complementarily depending on a species´ mycorrhizal association, but their uptake rather depended on the competitor indicating species-specific effects. Generally, ammonium was preferred over glutamine and glutamine over nitrate. In conclusion, our findings suggest that inorganic and organic N acquisition of the studied temperate tree species is less regulated by mycorrhizal association, but rather by the availability of specific N sources in the soil as well as the competitive environment of different tree species.


Sign in / Sign up

Export Citation Format

Share Document