Cooperation of earthworm and arbuscular mycorrhizae enhanced plant N uptake by balancing absorption and supply of ammonia

2018 ◽  
Vol 116 ◽  
pp. 351-359 ◽  
Author(s):  
Xinxing He ◽  
Yuanqi Chen ◽  
Shengjie Liu ◽  
Anna Gunina ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizae ◽  
N Uptake ◽  
Plant N Uptake

scholarly journals Effect of biofertilizers on soil microbial count, nutrient availability and uptake under november sown onion

2017 ◽  
Vol 9 (1) ◽  
pp. 55-59
Author(s):  
Dilpreet Talwar ◽  
Kulbir Singh ◽  
Jagdish Singh
Keyword(s):  
Nutrient Availability ◽  
Arbuscular Mycorrhizae ◽  
N Uptake ◽  
Nutrient Status ◽  
Recommended Dose ◽  
Available Phosphorus ◽  
Microbial Count ◽  
Available Nitrogen ◽  
Soil Microbial ◽  
The Impact

Biofertilizers improves the soil microbial content, Soil nutrient status and nutrient uptake by plant. In an experiment, fifteen treatments comprised of various combinations of biofertilizers, organic manures and chemical fertilizers were compared to access the impact of different sources of nutrient on performance of onion. The highest soil organic carbon (0.40%) was observed in the treatments T12 (Farm Yard Manure (FYM) @ 20 t/ha) and T11 (FYM myctes count (29.9 X 104) was recorded in T11 (FYM @ 20 t/ha + Azotobacter + VAM) treatment while highest fungal @ 20 t/ha + Azotobacter + Vesicular-Arbuscular Mycorrhizae (VAM)). Highest bacterial (24.5 X 106) and actino-count (17.5 X 103) was observed in T3 (Azospirillium+ Recommended dose of NPK) treatment. At the time of harvesting, available nitrogen (N), available phosphorus (P) and available potassium (K) were higher in treatment T3 (Azospirillium + Recommended dose of NPK), T9 (Azotobacter+ VAM + Recommended dose of NPK) and T13 (Poultry treatment (162.6 Kg ha-1) as compared to all other treatments except T1 and T9 treatments while P uptake (13.6 Kg ha-Manure @ 5t/ha) treatments respectively than that in other treatments. Azospirillum and Azotobacter application along with recommended dose of N, P and K improved the fertility status of soil. The N uptake was significantly higher in T3 treatments. The present study highlights the need of use of biofertilizers along with organic and inorganic 1) was significantly higher in T9 treatment than that in other treatments except T1, T3, T5 and T7 treatments. The K uptake was significantly higher in T3 treatment (126.9 Kg ha-1) as compare to all other treatments except T1 and T9 manures/fertilizer to enhance the nutrient availability and improve soil health.

scholarly journals Nitrogen Uptake and Use Efficiency in Sweet Basil Production under Low Tunnels

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 429-435 ◽  
Author(s):  
Tej P. Acharya ◽  
Mark S. Reiter ◽  
Greg Welbaum ◽  
Ramón A. Arancibia
Keyword(s):  
Open Field ◽  
N Uptake ◽  
Dry Weight ◽  
N Fertilizer ◽  
Plant N Uptake ◽  
Available N ◽  
Sweet Basil ◽  
Total Plant ◽  
Use Efficiency ◽  
Low Tunnels

Low tunnels (LTs) enhance vegetative growth and production in comparison with open field, but it is not known whether nitrogen (N) requirements and use efficiency increase or decrease for optimal crop performance. Therefore, the purpose of this study was to determine differences in N requirement, uptake, and use efficiency in basil grown under LTs compared with open field. The experimental design each year was a split plot with four replications. The main effect (plots) was N fertilizer application rate (0, 37, 74, 111, 148, and 185 kg·ha−1) and the secondary effect (subplots) was production system (LTs covered with spun-bonded rowcover vs. open field). Plant height and stem diameter were greater under LT than open field; however, they were unaffected by N fertilizer rate. Total fresh and dry weight increased with LT by 61% and 58% and by 50% and 48% in 2017 and 2018, respectively. Optimum N rates for fresh weight (98% of peak yield) were 124 and 104 kg·ha−1 N under LT and open field, respectively. Leaf N concentration decreased under LT, but total plant N uptake increased because of increased dry weight. Without fertilization, soil available N use efficiency (SNUE) for dry weight increased by 45% and 66% in 2017 and 2018, respectively. Mixed results were obtained for N fertilizer use efficiency (NFUE) in response to N rate. In conclusion, LT increased summer production of sweet basil, total plant N uptake, and SNUE.

NO3- uptake and C exudation – do plant roots stimulate or inhibit denitrification?

2020 ◽  
Author(s):  
Pauline Sophie Rummel ◽  
Reinhard Well ◽  
Birgit Pfeiffer ◽  
Klaus Dittert ◽  
Sebastian Floßmann ◽  
...  
Keyword(s):  
Soil Moisture ◽  
N Uptake ◽  
Root Exudation ◽  
Soil Surface ◽  
N Fertilization ◽  
Plant N Uptake ◽  
Mineral N ◽  
Double Labeling ◽  
Total N ◽  
Organic C

<p>Growing plants affect soil moisture, mineral N and organic C (C<sub>org</sub>) availability in soil and may thus play an important role in regulating denitrification. The availability of the main substrates for denitrification (C<sub>org</sub> and NO<sub>3</sub><sup>-</sup>) is controlled by root activity and higher denitrification activity in rhizosphere soils has been reported. We hypothesized that (I) plant N uptake governs NO<sub>3</sub><sup>-</sup> availability for denitrification leading to increased N<sub>2</sub>O and N<sub>2</sub> emissions, when plant N uptake is low due to smaller root system or root senescence. (II) Denitrification is stimulated by higher C<sub>org</sub> availability from root exudation or decaying roots increasing total gaseous N emissions while decreasing their N<sub>2</sub>O/(N<sub>2</sub>O+N<sub>2</sub>) ratios.</p><p>We tested these assumptions in a double labeling pot experiment with maize (Zea mays L.) grown under three N fertilization levels S / M / L (no / moderate / high N fertilization) and with cup plant (Silphium perfoliatum L., moderate N fertilization). After 6 weeks, all plants were labeled with 0.1 g N kg<sup>-1</sup> (Ca(<sup>15</sup>NO<sub>3</sub>)<sub>2</sub>, 60 at%), and the <sup>15</sup>N tracer method was applied to estimate plant N uptake, N<sub>2</sub>O and N<sub>2</sub> emissions. To link denitrification with available C in the rhizosphere, <sup>13</sup>CO<sub>2</sub> pulse labeling (5 g Na<sub>2</sub><sup>13</sup>CO<sub>3</sub>, 99 at%) was used to trace C translocation from shoots to roots and its release by roots into the soil. CO<sub>2</sub> evolving from soil was trapped in NaOH for δ<sup>13</sup>C analyses, and gas samples were taken for analysis of N<sub>2</sub>O and N<sub>2</sub> from the headspace above the soil surface every 12 h.</p><p>Although pots were irrigated, changing soil moisture through differences in plant water uptake was the main factor controlling daily N<sub>2</sub>O+N<sub>2</sub> fluxes, cumulative N emissions, and N<sub>2</sub>O production pathways. In addition, total N<sub>2</sub>O+N<sub>2</sub> emissions were negatively correlated with plant N uptake and positively with soil N concentrations. Recently assimilated C released by roots (<sup>13</sup>C) was positively correlated with root dry matter, but we could not detect any relationship with cumulative N emissions. We anticipate that higher C<sub>org</sub> availability in pots with large root systems did not lead to higher denitrification rates as NO<sub>3</sub><sup>-</sup> was limited due to plant uptake. In conclusion, plant growth controlled water and NO<sub>3</sub><sup>-</sup> uptake and, subsequently, formation of anaerobic hotspots for denitrification.</p>

scholarly journals Aridity and plant uptake interact to make dryland soils hotspots for nitric oxide (NO) emissions

2016 ◽  
Vol 113 (19) ◽  
pp. E2608-E2616 ◽  
Author(s):  
Peter M. Homyak ◽  
Joseph C. Blankinship ◽  
Kenneth Marchus ◽  
Delores M. Lucero ◽  
James O. Sickman ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
N Uptake ◽  
N Deposition ◽  
N Availability ◽  
Plant N Uptake ◽  
N Loss ◽  
Atmospheric N Deposition ◽  
Soil Microbial ◽  
California Grassland ◽  
No Emissions

Nitric oxide (NO) is an important trace gas and regulator of atmospheric photochemistry. Theory suggests moist soils optimize NO emissions, whereas wet or dry soils constrain them. In drylands, however, NO emissions can be greatest in dry soils and when dry soils are rewet. To understand how aridity and vegetation interact to generate this pattern, we measured NO fluxes in a California grassland, where we manipulated vegetation cover and the length of the dry season and measured [δ15-N]NO and [δ18-O]NO following rewetting with15N-labeled substrates. Plant N uptake reduced NO emissions by limiting N availability. In the absence of plants, soil N pools increased and NO emissions more than doubled. In dry soils, NO-producing substrates concentrated in hydrologically disconnected microsites. Upon rewetting, these concentrated N pools underwent rapid abiotic reaction, producing large NO pulses. Biological processes did not substantially contribute to the initial NO pulse but governed NO emissions within 24 h postwetting. Plants acted as an N sink, limiting NO emissions under optimal soil moisture. When soils were dry, however, the shutdown in plant N uptake, along with the activation of chemical mechanisms and the resuscitation of soil microbial processes upon rewetting, governed N loss. Aridity and vegetation interact to maintain a leaky N cycle during periods when plant N uptake is low, and hydrologically disconnected soils favor both microbial and abiotic NO-producing mechanisms. Under increasing rates of atmospheric N deposition and intensifying droughts, NO gas evasion may become an increasingly important pathway for ecosystem N loss in drylands.

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