Effect of N fertilisers and soil moisture levels on the N-gaseous losses and the plant N uptake in a maize pot experiment

Growing plants affect soil moisture, mineral N and organic C (Corg) availability in soil and may thus play an important role in regulating denitrification. The availability of the main substrates for denitrification (Corg and NO3-) is controlled by root activity and higher denitrification activity in rhizosphere soils has been reported. We hypothesized that (I) plant N uptake governs NO3- availability for denitrification leading to increased N2O and N2 emissions, when plant N uptake is low due to smaller root system or root senescence. (II) Denitrification is stimulated by higher Corg availability from root exudation or decaying roots increasing total gaseous N emissions while decreasing their N2O/(N2O+N2) ratios.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-1 (Ca(15NO3)2, 60 at%), and the 15N tracer method was applied to estimate plant N uptake, N2O and N2 emissions. To link denitrification with available C in the rhizosphere, 13CO2 pulse labeling (5 g Na213CO3, 99 at%) was used to trace C translocation from shoots to roots and its release by roots into the soil. CO2 evolving from soil was trapped in NaOH for &#948;13C analyses, and gas samples were taken for analysis of N2O and N2 from the headspace above the soil surface every 12 h.Although pots were irrigated, changing soil moisture through differences in plant water uptake was the main factor controlling daily N2O+N2 fluxes, cumulative N emissions, and N2O production pathways. In addition, total N2O+N2 emissions were negatively correlated with plant N uptake and positively with soil N concentrations. Recently assimilated C released by roots (13C) was positively correlated with root dry matter, but we could not detect any relationship with cumulative N emissions. We anticipate that higher Corg availability in pots with large root systems did not lead to higher denitrification rates as NO3- was limited due to plant uptake. In conclusion, plant growth controlled water and NO3- uptake and, subsequently, formation of anaerobic hotspots for denitrification.

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Biochar addition indirectly affects N2O emissions via soil moisture and plant N uptake

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2012.10.035 ◽

2013 ◽

Vol 58 ◽

pp. 99-106 ◽

Cited By ~ 122

Author(s):

S. Saarnio ◽

K. Heimonen ◽

R. Kettunen

Keyword(s):

Soil Moisture ◽

N Uptake ◽

N2o Emissions ◽

Plant N Uptake

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Nitrate and water uptake, rather than rhizodeposition, control denitrification in the presence of growing plants

10.5194/egusphere-egu21-1223 ◽

2021 ◽

Author(s):

Pauline Sophie Rummel ◽

Reinhard Well ◽

Birgit Pfeiffer ◽

Klaus Dittert ◽

Sebastian Floßmann ◽

...

Keyword(s):

Soil Moisture ◽

Water Uptake ◽

Plant Root ◽

Oxygen Deficiency ◽

N Uptake ◽

Root Exudation ◽

Root Systems ◽

Plant N Uptake ◽

N Losses ◽

Double Labeling

The main prerequisites for denitrification are availability of nitrate (NO3-) and easily decomposable organic substances, and oxygen deficiency. Growing plants modify all these parameters and may thus play an important role in regulating denitrification. Previous studies investigating plant root effects on denitrification have found contradictive results. Both increased and decreased denitrification in the presence of plants have been reported and were associated with higher Corg or lower NO3- availability, respectively. Accordingly, it is still unclear whether growing plants stimulate denitrification through root exudation or restrict it through NO3- uptake. Furthermore, reliable measurements of N2 fluxes and N2O/(N2O+N2) ratios in the presence of plants are scarce.Therefore, we conducted a double labeling pot experiment with either maize (Zea mays L.) or cup plant (Silphium perfoliatum L.) of the same age but differing in size of their shoot and root systems. The 15N gas flux method was applied to directly quantify N2O and N2 fluxes in situ. To link denitrification with available C in the rhizosphere, 13CO2 pulse labeling was used to trace C translocation from shoots to roots and its release by roots into the soil.Plant water uptake was a main factor controlling soil moisture and, thus, daily N2O+N2 fluxes, cumulative N emissions, and N2O production pathways. However, N fluxes remained on a low level when NO3- availability was low due to rapid plant N uptake. Only when both N and water uptake were low, high NO3- availability and high soil moisture led to strongly increased denitrification-derived N losses.Total CO2 efflux was positively correlated with root dry matter, but there was no indication of any relationship between recovered 13C from root exudation and cumulative N emissions. We anticipate that higher Corg availability in pots with large root systems did not lead to higher denitrification rates, as NO3- was limiting denitrification due to plant N uptake. Overall, we conclude that root-derived C stimulates denitrification only when soil NO3- is not limited and low O2 concentrations enable denitrification. Thus, root-derived C may stimulate denitrification under small plants, while N and water uptake become the controlling factors with increasing plant and root growth.

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Optimizing Irrigation of Fresh Market Tomato Grown in the Mid-Atlantic United States

HortTechnology ◽

10.21273/horttech.23.6.859 ◽

2013 ◽

Vol 23 (6) ◽

pp. 859-867 ◽

Cited By ~ 1

Author(s):

Catherine S. Fleming ◽

Mark S. Reiter ◽

Joshua H. Freeman ◽

Rory Maguire

Keyword(s):

Soil Moisture ◽

N Uptake ◽

Cost Effective ◽

Residual Soil ◽

Soil Nitrate ◽

Fresh Market ◽

Plant N Uptake ◽

Irrigation Rate ◽

Growing Seasons ◽

Effective Water

Determining irrigation requirements for fresh market tomato (Solanum lycopersicum) production is essential to obtain optimum yields, cost-effective water use, and minimize nitrate leaching. The objective of this study was to determine the appropriate irrigation rate for polyethylene-mulched fresh market tomato grown in Virginia. This study investigated irrigation regimes by applying water based on evapotranspiration (ET) calculations in three spring and three fall seasons. Plants were grown using 0.0 × ET, 0.5 × ET, 1.0 × ET, 1.5 × ET, and 2.0 × ET. Additional irrigation treatments involved tensiometers installed at 12-inch depth in the bed, programmed to irrigate at soil moisture set points of −20, −40, and −60 kPa. Tensiometer treatments were able to irrigate up to nine times per day if soil moisture fell below the designated moisture set point. Measurements included fruit yield, plant and fruit nitrogen (N) uptake, and inorganic soil nitrate-N (NO3-N) at 0 to 10-, 10 to 20-, and 20 to 30-inch depths. Overall, the 0.5 × ET treatment provided optimum yields in all growing seasons except Spring 2010, which was unseasonably hot and dry. A tensiometer treatment (−40 kPa) provided optimum yields in all growing seasons, and was able to adjust irrigation in a hot and dry season. Residual soil NO3-N at 0 to 10 inches generally exhibited an inverse relationship with yield; greater yields resulted in less residual soil NO3-N. In most treatments throughout the duration of this study, plant N uptake + fruit N uptake accounted for most of the N fertilizer applied (68% to 151%). In conclusion, an irrigation rate of 0.5 × ET and a tensiometer treatment (−40 kPa) provided minimal irrigation inputs to obtain optimum marketable yields while also minimizing residual soil nitrate that may be prone to leaching after the season.

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Increased soil moisture content increases plant N uptake and the abundance of 15N in plant biomass

Plant and Soil ◽

10.1007/s11104-007-9477-0 ◽

2007 ◽

Vol 302 (1-2) ◽

pp. 263-271 ◽

Cited By ~ 16

Author(s):

Feike A. Dijkstra ◽

Weixin Cheng

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Soil Moisture Content ◽

Plant Biomass ◽

N Uptake ◽

Plant N Uptake

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Transformation of Nitrogen Fertilizers in Greenhouse Experiments

Agrokémia és Talajtan ◽

10.1556/agrokem.51.2002.1-2.18 ◽

2002 ◽

Vol 51 (1-2) ◽

pp. 147-156 ◽

Cited By ~ 2

Author(s):

Erika Nótás ◽

K. Debreczeni ◽

K. Fischl ◽

Keyword(s):

Soil Moisture ◽

Difference Method ◽

N Uptake ◽

First Year ◽

Fertilizer N ◽

Plant N Uptake ◽

Mineral N ◽

After Effect ◽

Gaseous Loss ◽

The Difference

The primary (1 st year) and the after-effects (2 nd , 3 rd year) of N fertilizers (KNO 3 , NH 4 Cl) on the soil-plant-atmosphere system were studied in a three-year greenhouse pot experiment with and without maize plants. The two- and three-year balances of the fertilizer N uptake and gaseous N losses were also analyzed. The cumulative values of the gaseous losses showed a similar trend in all years, significant differences were not obtained. On the basis of the three-year balance, the gaseous loss in the planted and unplanted pots was 18-22% and about 37-39%, respectively. Consequently, there was a 50% decrease in denitrificated gaseous losses of fertilizer N due to plant N uptake. The cumulative gaseous loss, calculated by the difference method, was significantly higher in cases of KNO 3 applications than in NH 4 Cl treatments, as an assumed consequence of the intensive denitrification. It was found that the gaseous loss was not influenced by soil moisture. In contrast to the gaseous losses, the values of plant N uptake and soil mineral N content showed significant differences in the years studied, as a result of the quick transformation of mineral N to organic N, the non-complete homogenization of the total soil amount, the seasonal climatic differences in the greenhouse during the years studied, and consequently the different microbiological activity. The plant N uptake was found to depend significantly on the fertilizer N form. Results obtained by the difference method and the 15 N-tracer technique were very similar. In the case of KNO 3 treatment and higher soil moisture (WHC = 80%) plant N uptake was more intensive, ranging between 48-57% (calculated by the difference method), and 35-51% (calculated by the 15 N- tracer method) in the first year (1993). It can be concluded that 60-100% of the fertilizer N was used from the soil by plant uptake and gaseous losses, which depends mainly on the treatments and the soil moisture during the first year. These values changed between 7-17% in the 1 st year after-effect and between 1-5% in the 2 nd year after-effect.

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Decomposition of 15N-labelled catch-crop residues in soil: evaluation of N mineralization and plant-N uptake potentials under controlled conditions

European Journal of Soil Science ◽

10.1111/j.1365-2389.1995.tb01818.x ◽

1995 ◽

Vol 46 (1) ◽

pp. 115-123 ◽

Cited By ~ 22

Author(s):

B. NICOLARDOT ◽

D. DENYS ◽

B. LAGACHERIE ◽

D. CHENEBY ◽

M. MARIOTTI

Keyword(s):

N Mineralization ◽

Crop Residues ◽

N Uptake ◽

Catch Crop ◽

Plant N Uptake ◽

Soil Evaluation ◽

Controlled Conditions

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

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2017.10.038 ◽

2018 ◽

Vol 116 ◽

pp. 351-359 ◽

Cited By ~ 10

Author(s):

Xinxing He ◽

Yuanqi Chen ◽

Shengjie Liu ◽

Anna Gunina ◽

Xiaoli Wang ◽

...

Keyword(s):

Arbuscular Mycorrhizae ◽

N Uptake ◽

Plant N Uptake

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Soil characteristic and shallot growth with gypsum and zeolite amendments in irrigated saline Alfisol and Inceptisol

Journal of Degraded and Mining Lands Management ◽

10.15243/jdmlm.2021.083.2801 ◽

2021 ◽

Vol 8 (3) ◽

pp. 2801-2808

Author(s):

Rahayu Rahayu ◽

Jauhari Syamsiyah ◽

Livia Dewi

Keyword(s):

Electric Conductivity ◽

N Uptake ◽

Sodium Adsorption Ratio ◽

Pot Experiment ◽

Soil Types ◽

Soil Characteristic ◽

Saline Irrigation ◽

The Third ◽

Randomized Design ◽

Completely Randomized Design

Salinity of soil and irrigation is a factor that may cause a decrease in shallot productivity, so it requires efforts with amendments. This research aimed to determine the effect of gypsum and zeolite amendments on soil and shallot growth with saline irrigation. A pot experiment was conducted in the field using a completely randomized design with three factors. The first factor was two soil types (Alfisol and Inceptisol); the second factor was three shallot cultivars (Brebes, Purbalingga, and Pemalang); and the third factor was two types of soil amendments. The results showed that gypsum and zeolite reduced pH, sodium adsorption ratio (SAR), electric conductivity paste (ECp) and Na of the soils studied. Gypsum and zeolite increased the uptake of N, P and K by shallot plants. The increase of N uptake by applying gypsum on Inceptisol was more effective to Brebes and Purbalingga cultivars than Pemalang cultivar. Gypsum increased the diameter and number of bulbs in Inceptisol. Zeolite and gypsum increased bulb weight of Purbalingga cultivar in Alfisol.

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Fertilizer Placement Effects on Soil Nitrogen and Use by Drip-irrigated and Plastic-mulched Tomatoes

HortScience ◽

10.21273/hortsci.25.7.767 ◽

1990 ◽

Vol 25 (7) ◽

pp. 767-769 ◽

Cited By ~ 4

Author(s):

Wilton P. Cook ◽

Douglas C. Sanders

Keyword(s):

Soil Moisture ◽

N Uptake ◽

Fruit Size ◽

Infiltration Rate ◽

Moisture Level ◽

Plastic Mulch ◽

Fertilizer Placement ◽

Total N ◽

Soil Moisture Level ◽

N Concentration

The effects of fertilizer placement and soil moisture level on soil N movement, uptake, and use by tomato plants (Lycopersicon esculentum Mill) grown with drip irrigation and plastic mulch were evaluated at two locations on two types of sandy soils. Broadcast or band fertilizer placement had no effect on fruit size, fruit number, or total yield. Fruit size was increased at one location, and the incidence of blossom-end rot was decreased by increased frequency of irrigation. Nitrate-N distribution within the bed was not affected by initial N placement. In the soil with a rapid infiltration rate, NO3-N levels in the center of the bed were always low, with highest concentration observed in the areas of the bed most distant from the drip tube. In the soil with the slower infiltration rate, NO3-N concentrations were more uniform throughout the bed, with highest concentrations in the bed center: Increasing soil moisture levels (–20 kPa vs. –30 kPa) resulted in increased leaching and reduced NO3-N concentration throughout the bed. Foliage N concentration was not affected by N placement, but decreased seasonally. Total N uptake by the above-ground portion of the plants was not affected by fertilizer placement or soil moisture level.

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