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2022 ◽  
Author(s):  
yiwen cao ◽  
Yonghui Pan ◽  
Tianheng Liu ◽  
Min Wang ◽  
Shiwei Guo

The relationship between nitrogen (N) sources and photosynthetic capacity of leaf differs between species. However, the leaf anatomical variabilities related to photosynthesis (A) of shrubs under different forms of N remain imperfectly known. Here, Lonicera Japonica (a shrub) was grown hydroponically in the presence of three forms of N (sole NH4+, 50%/50% NH4+/NO3– and sole NO3–). A and photosynthetic N use efficiency significantly decreased under sole NH4+ supply, in parallel with down-regulated stomatal conductance (gs), mesophyll conductance (gm), and electron transfer rate (J). Up to the total A decline of 41.28% in sole NH4+ supply (compare with sole NO3–), the gm attributed to 60.3% of the total limitations. Besides, the decreased internal air space explained the increase of gas-phase resistance, and the increased liquid-phase resistance in sole NH4+ supply was ascribed to the thicker cell wall thickness (Tcw) and decreased chloroplasts exposed surface area per unit leaf area (Sc/S). The discrepancy of Sc/S could be interpreted by the altered chloroplasts numbers and the distance between adjacent chloroplasts (Dchl-chl). These results indicate the alteration of Tcw and chloroplast numbers were the main causes of the difference in gm in coping with varied N sources.


2021 ◽  
Author(s):  
Zahid Hussain ◽  
Cheng Tang ◽  
Muhammad Irshad ◽  
Riaz A. Khattak ◽  
Chen Yao ◽  
...  

Abstract Nitrate (NO3) leaching from soils results in lower soil fertility, reduced crop productivity and groundwater pollution. The present study determined NO3 leaching from bentonite [0, 2 and 4% (m/m)] treated sandy soil, under three N sources (calcium nitrate [Ca(NO3)2], ammonium chloride [NH4Cl], urea [CO(NH2)2] @ 300 kg N ha-1) with a leaching fraction of 0.3-0.4. Bentonite markedly reduced NO3 release in leachate, while 4% bentonite retained higher NO3 in soil. The NO3 leaching varied with N sources as Ca(NO3)2>NH4Cl>(CO(NH2)2. This study indicated that soil amendment with bentonite could efficiently mitigate NO3 leaching from soil and hence prevent N fertilizer losses and groundwater pollution.


2021 ◽  
pp. 153560
Author(s):  
Ana Isabel González Hernández ◽  
Loredana Scalschi ◽  
Pilar Troncho ◽  
Pilar García-Agustín ◽  
Gemma Camañes

Nitrogen ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 378-391
Author(s):  
Arati Sapkota ◽  
Moha Dutta Sharma ◽  
Hom Nath Giri ◽  
Bishal Shrestha ◽  
Dinesh Panday

Economic use of organic and inorganic fertilizers following their availability is necessary for livestock-based Nepalese farming systems. However, how best to integrate these fertilizers in an appropriate manner is not yet clear. Thus, this study was conducted in the horticulture farm of the Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal from November 2018 to February 2019 to evaluate the effect of organic and inorganic sources of nitrogen (N) on growth, yield, and quality of beetroot (Beta vulgaris L.) varieties. The experiment was laid out in a two factorial randomized complete block design with four replications consisting of two beetroot varieties, i.e., Madhur and Ruby Red, and five N source combinations, i.e., N1: 100% poultry manure (PM), N2: 50% PM + 50% urea, N3: 100% farmyard manure (FYM), N4: 50% FYM + 50% urea, and N5: 100% urea (120:80:40 kg NPK ha−1). Results of this study indicated a significant impact of N sources and varieties on the assessed parameters. During harvest, a significantly higher plant height (41.84 cm), number of leaves per plant (14.68), leaf length (34.56 cm), leaf width (11.38 cm), and beetroot diameter (72.15 mm) were observed in the N2 treatment. Likewise, higher economic (49.78 t ha−1) and biological yields (78.69 t ha−1) were also recorded in the N2 compared to other N sources. Out of the two varieties, the Madhur variety was significantly better in most growth and yield parameters. Similarly, the Madhur variety showed a significantly higher economic (44.49 t ha−1) and biological yields (69.79 t ha−1) compared to the Ruby Red variety. However, the physiological weight loss was higher in the Ruby Red variety. Therefore, the current study suggests that an integration of poultry manure along with the combination of N fertilizer and the Madhur variety is the best combination for quality beetroot production in the Terai region of Nepal.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254182
Author(s):  
Pouwedeou Mouloumdema Potcho ◽  
Nnaemeka Emmanuel Okpala ◽  
Tchalla Korohou ◽  
Muhammad Imran ◽  
Nabieu Kamara ◽  
...  

Many studies have been carried out on N sources effect on fragrant rice; however, their impact on rice grain quality is largely unclear. In this study, we evaluated the effects of different types of N sources on rice growth, yield, 2-acetyl-1-pyrroline (2AP), amylose and cooked rice elongation. Two indica rice cultivars, Basmati 385 (B385), Xiangyaxiangzhan (XYXZ) and two japonica cultivars, Yunjingyou (YJY), Daohuaxiang (DHX) were grown in experimental pots with six replications under four N sources: Potassium nitrate (KNO3), ammonium bicarbonate (NH4HCO3), urea (H2NCONH2) and sodium nitrate (NaNO3) in 2019 and 2020 early seasons. Our results showed that N dynamics regulated the number of panicles, 1000-grain weight, grain yield, 2-acetyl-1-pyrroline, amylose and cooked rice elongation across all the four treatments. The NH4HCO3 treatment significantly increased the number of panicles and grain yield across the four rice varieties compared with KNO3, H2NCONH2 and NaNO3 N sources in both 2019 and 2020 early season, The KNO3 treatment significantly showed higher 1000-grain weight in B-385, YJY, XYXZ and DHX compared to other N sources. Compared with other N sources treatment, the NH4HCO3 treatments significantly increased the 2AP contents in heading stage leaves, matured leaves and grains of B-385, YJY, XYXZ and DHX respectively. Cooked rice elongation percentage also showed significant difference in all treatments studied with KNO3 recorded the highest across the four varieties. Analysis of major enzymes and compounds such as P5C, P5CS, PDH, Pyrroline, proline and Methylglyoxal showed remarkable differences in each cultivar at heading and maturity stages with higher activity in NH4HCO3 and H2NCONH2 treatments. Similarly, in all treatments, we also observed significant increase in amylose content percentage, with NH4HCO3 having greater percentage of amylose.


2021 ◽  
Author(s):  
CANDACE G CARTER ◽  
Meagan E. Schipanski

Abstract Aims Improving crop utilization of N from soil organic matter (SOM) has received limited attention despite evidence that half of field crop N is often derived from SOM mineralization. We explored the effects of rapeseed (Brassica napus) genotypic diversity on N uptake from organic and inorganic N sources. Methods In a greenhouse study, we applied dual 15N labeled ammonium-nitrate fertilizer to examine N uptake patterns of rapeseed in different N environments. Ten varieties were grown in a full factorial experiment with four treatments, including combinations of high and low N fertilizer and SOM. Results While we found limited varietal differences in N uptake dynamics, SOM was an important N source across all varieties even as N fertilizer availability increased. High SOM/High Fertilizer treatment plants obtained 64% of N from SOM, while plants grown with High SOM/Low Fertilizer obtained 89% of total N from SOM. High N fertilizer additions increased overall N uptake from SOM by 42% relative to low N fertilizer treatments. In contrast, microbial enzyme activity related to nutrient mineralization was suppressed by 16–58% in high N fertilizer relative to low fertilizer treatments. Conclusions Integrating plant reliance on SOM-N sources into crop breeding and system management has the potential to improve productivity and overall N use efficiency.


2021 ◽  
pp. 1-9
Author(s):  
Travis Wayne Shaddox ◽  
Joseph Bryan Unruh

Numerous nitrogen (N) sources are used in turfgrass management and vary from soluble to slow-release. Determining the least expensive N source can be confusing for consumers. Price per ton and price per pound N are common price comparison methods. An improved approach could use longevity of the N source to balance the price. The objective of this study was to determine the longevity of turfgrass response to N sources and to determine the cost to achieve such responses. This study was conducted in Ft. Lauderdale and Jay, FL, from 1 Jan. to 31 Dec. 2018 on ‘Riley’s Super Sport’ (Celebration®) bermudagrass (Cynodon dactylon). Treatments included nontreated turfgrass, urea, ammonium sulfate, stabilized urea, methylene urea, ureaformaldehyde, two natural organics, sulfur-coated urea, and two polymer-coated urea fertilizers. Treatments were arranged in a split-plot design with N sources as whole plots and N rate (N applied at 49 and 98 kg·ha−1 every 4 months) as subplots. Turf quality was recorded on a scale of 1 to 9, where 1 = dead/brown turf and quality, 6 = minimal acceptable, and 9 = optimal healthy/green turf. Turf quality ratings were recorded weekly and used to determine response longevity (days quality ≥6.0) and area under the turfgrass response curve (AUTRC). Urea resulted in response longevity greater than or equal to other N sources during each season except when applied at 98 kg·ha−1 of N during the fall fertilizer cycle in Jay. Natural organics were ≈6-fold more expensive than urea in Jay and Ft. Lauderdale using turfgrass response longevity and AUTRC. Urea and sulfur-coated urea were the least expensive soluble and slow-release N source, respectively, using dollars per pound N, dollars per acre per day, and dollars per acre per quality-day during each fertilizer cycle and annual average in Jay and Ft. Lauderdale. No evidence was found supporting the use of turfgrass response as a more effective method of determining fertilizer cost than dollars per pound N.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Xulun Zhou ◽  
Ang Wang ◽  
Erik A. Hobbie ◽  
Feifei Zhu ◽  
Xueyan Wang ◽  
...  

Abstract Background Conifers partition different N forms from soil, including ammonium, nitrate, and dissolved organic N (DON), to sustain plant growth. Previous studies focused on inorganic N sources and specific amino acid forms using 15N labelling, but knowledge of the contribution of DON to mature conifers’ N uptake is still scarce. Here, we quantified the contribution of different N forms (DON vs. NH4+ vs. NO3−) to total N uptake, based on 15N natural abundance of plant and soil available N, in four mature conifers (Pinus koraiensis, Pinus sylvestris, Picea koraiensis, and Larix olgensis). Results DON contributed 31%, 29%, 28%, and 24% to total N uptake by Larix olgensis, Picea koraiensis, Pinus koraiensis, and Pinus sylvestris, respectively, whereas nitrate contributed 42 to 52% and ammonium contributed 19 to 29% of total N uptake for these four coniferous species. Conclusions Our results suggested that all four conifers could take up a relatively large proportion of nitrate, while DON was also an important N source for the four conifers. Given that DON was the dominant N form in study soil, such uptake pattern of conifers could be an adaptive strategy for plants to compete for the limited available N sources from soil so as to promote conifer growth and maintain species coexistence.


2021 ◽  
Vol 13 (6) ◽  
pp. 31
Author(s):  
Vinícius Almeida Oliveira ◽  
Eliana Paula Fernandes Brasil ◽  
Welldy Gonçalves Teixeira ◽  
Felipe Corrêa Veloso dos Santos ◽  
Atila Reis da Silva

While over-use of N fertilizers can suppress microbial biomass, application of urease inhibitors is known to be a potential way to rebuilt microbial diversity and improve soil functions. However, the hypothesis of this study is that the application of N fertilizers regardless of the source would increase soil microbial biomass and reduce soil respiration. A two-year field experiment was conducted to assess the effects of enhanced-efficiency N sources on soil microbial biomass, and soil respiration. The experiment was set up in a randomized block design in a 3 × 4 + 1 factorial scheme, with four replicates. Treatments comprised three sources (conventional uncoated urea, NBPT (N-(n-butyl) thiophosphoric triamide)-treated urea, and polymer-coated urea) and four rates (30, 60, 90 and 120 kg ha-1) of N, in addition to a control treatment (no fertilizer application). Microbial biomass C (MBC) and microbial biomass N (MBN), and soil respiration (C-CO2 and qCO2) were determined in upland rice rhizosphere in each crop season. Responses of soil microbial properties to N fertilization were dependent on the N rates, but no significant effect of the N sources was observed. All measured parameters, except MBC in the first season and C-CO2 in the second season, were increased with increasing N rates. However, the application of N higher than 60 kg ha-1 suppressed soil microbial biomass, as well as soil respiration.  Therefore, the lack of response by added urease inhibitors to the N sources indicate that optimizing N rates for upland rice production is a far more effective option for improving soil microbial community than using enhanced-efficiency N sources.


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