scholarly journals Variations Regularity of Soil Nitrate Nitrogen in Hebei Piedmont Plain

2015 ◽  
Vol 9 (1) ◽  
pp. 98-102
Author(s):  
Huiyan Gao ◽  
Luhua Yang
Keyword(s):  
Soil Profile ◽  
Nitrate Nitrogen ◽  
Rotation Period ◽  
Growth Period ◽  
Utilization Efficiency ◽  
Nitrate Content ◽  
Soil Nitrate ◽  
Deep Soil ◽  
Piedmont Plain ◽  
Groundwater Environment

Field experiment was carried out to study on the spatial and temporal distribution of soil nitrate nitrogen at Ranzhuang water resources experiment station in Hebei piedmont plain from 2011 to 2012. The results show that nitrate nitrogen content varies in sinusoidal curve at shallow tilth soil and shows in “W” shape at deep soil profile during the wheat-maize rotation period. Nitrate nitrogen is mainly accumulated in 0~100cm soil and the maximum value occur at reviving stage in the wheat growth period. In the maize growth period, the distribution of nitrate nitrogen is double peak curve in 0∼500cm soil profile. The maximum peak emerges at 150∼260cm, the peak of soil nitrate content is between 36.7∼106.36mg/kg. In 0∼500cm soil layers, the cumulative amount of nitrate nitrogen is 1430.56∼5126.05 kg/hm2. The amount of nitrate nitrogen leaching is 1294.13kg/hm, which is 52.29% of the total amount of annual fertilization. It is scientific and technical groundwork to improve the utilization efficiency of nitrogen fertilizer and protect groundwater environment.

The Effect of Human Activity on the Distribution of Soil Nitrate Nitrogen in Unsaturated Zone

2013 ◽  
Vol 790 ◽  
pp. 202-205
Author(s):  
Hui Yan Gao ◽  
Lu Hua Yang ◽  
Tian Li ◽  
Zi Peng Guo
Keyword(s):  
Soil Moisture ◽  
Nitrogen Content ◽  
Human Activity ◽  
Soil Profile ◽  
Nitrate Nitrogen ◽  
Root Zone ◽  
Deep Layer ◽  
Soil Layer ◽  
Growth Period ◽  
Soil Nitrate

Soil moisture and nitrate nitrogen were measured respectively in planting area and non-planting area in RANZHUANG experiment station from 2011 to 2012. The effect of human activity on soil moisture and nitrate nitrogen was analyzed. The results show that soil moisture content varies from 8.61% to 30.09% within 0~250cm depth and is tended to be stable below 250cm deep layer in non-planting area. The distribution of soil nitrate nitrogen is a single peak curve, the peak moves downward at a speed of 0.81cm/d in percolation of rainfall. Soil moisture varies form 21.23% to 41.67% within 0~400cm depth and is tended to be stable below 400cm deep layer in planting area. Nitrate nitrogen is mainly accumulated at 0~100cm deep soil layer in the wheat growth period. In the maize growth period, the distribution of nitrate nitrogen is double peak curve in 0~500cm soil profile. The upper peak occurs at 40~100cm soil layer, the peak of nitrate nitrogen content is between 26.7~54.6mg/kg; the lower emerges at 150~260cm soil profile, the value is between 36.7~106.36mg/kg. Deep percolation of the nitrate nitrogen is obvious due to unreasonable irrigation and fertilization. The nitrate nitrogen content accounts for 52.3% of the total nitrate nitrogen below the root zone soil, which is a potential contamination source of groundwater.

scholarly journals Soil carbon sequestration by three perennial legume pastures is greater in deeper soil layers than in the surface soil

2016 ◽  
Vol 13 (2) ◽  
pp. 527-534 ◽  
Author(s):  
X.-K. Guan ◽  
N. C. Turner ◽  
L. Song ◽  
Y.-J. Gu ◽  
T.-C. Wang ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Soil Carbon ◽  
Soil Profile ◽  
Soil Depth ◽  
Arable Land ◽  
Growth Period ◽  
Bare Soil ◽  
Soil Carbon Sequestration ◽  
Deep Soil ◽  
Perennial Legume

Abstract. Soil organic carbon (SOC) plays a vital role as both a sink for and source of atmospheric carbon. Revegetation of degraded arable land in China is expected to increase soil carbon sequestration, but the role of perennial legumes on soil carbon stocks in semiarid areas has not been quantified. In this study, we assessed the effect of alfalfa (Medicago sativa L.) and two locally adapted forage legumes, bush clover (Lespedeza davurica S.) and milk vetch (Astragalus adsurgens Pall.) on the SOC concentration and SOC stock accumulated annually over a 2 m soil profile. The results showed that the concentration of SOC in the bare soil decreased slightly over the 7 years, while 7 years of legume growth substantially increased the concentration of SOC over the 0–2.0 m soil depth. Over the 7-year growth period the SOC stocks increased by 24.1, 19.9 and 14.6 Mg C ha−1 under the alfalfa, bush clover and milk vetch stands, respectively, and decreased by 4.2 Mg C ha−1 in the bare soil. The sequestration of SOC in the 1–2 m depth of the soil accounted for 79, 68 and 74 % of the SOC sequestered in the 2 m deep soil profile under alfalfa, bush clover and milk vetch, respectively. Conversion of arable land to perennial legume pasture resulted in a significant increase in SOC, particularly at soil depths below 1 m.

The impacts of CO2 enrichment on the plant resources utilization efficiency of Schima superba seedlings in subtropical China

2020 ◽  
Author(s):  
Jixin Cao ◽  
Hong Pan ◽  
Zhan Chen ◽  
He Shang
Keyword(s):  
Stomatal Conductance ◽  
Transpiration Rate ◽  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Utilization Efficiency ◽  
Total Biomass ◽  
Soil Nitrate ◽  
Schima Superba ◽  
Trade Offs

<p>The resources (light, nitrogen and water) utilization efficiency of plant is a key indicator reflecting the adaptive ability of plant to environment. CO<sub>2</sub> enrichment would increase photosynthesis substrate supply and nutrient absorption in plants，and may also change the utilization efficiencies of light (LUE), nitrogen (NUE) and water (WUE) and their trade-offs relationship. However, the knowledge regarding how the LUE, NUE and WUE of woody plant change in the context of CO<sub>2</sub> enrichment is still weak. In order to understand the impacts of CO<sub>2</sub> enrichment on the LUE, NUE and WUE of Schima superba and their trade-offs, one-year-old container seedlings of S. superba were grown with ambient air (AA treatment), 550 ppm of CO<sub>2</sub> concentration (E1-CO<sub>2</sub> treatment), 750 ppm of CO<sub>2</sub> concentration ( E2-CO<sub>2</sub> treatment) and 1000ppm of CO<sub>2</sub> concentration (E3-CO<sub>2</sub> treatment) using open top chambers. In the growing season, we regularly examined the net photosynthetic rate, stomatal conductance, transpiration rate, nitrogen concentration and photosynthetic pigment concentration of S. superba leaves. In addition, the different organ biomass, leaf area, soil nitrate and ammonium nitrogen concentrations were also simultaneously examined. The results demonstrate that three CO<sub>2</sub> enrichment treatments significantly increased the LUE and NUE of S. superba leaves at the end of June, while the leaf nitrogen concentration and soil nitrate nitrogen significantly decreased under both the E2-CO<sub>2</sub> and E3-CO<sub>2</sub> treatments compared with those under the AA treatment. In contrast, only the E1-CO<sub>2</sub> treatment significantly increased the LUE and NUE of S. superba leaves at the end of August. The NUE of S. superba leaves under both the E2-CO<sub>2 </sub>and E3-CO<sub>2</sub> treatments were significantly higher than that under the AA treatment at the end of October. With regard to the WUE of S. superba leaves, there were no significant differences between the four treatments. At the end of October, the total biomass of S. superba under the E1-CO<sub>2</sub> treatment was significantly higher than that under both the AA and E3-CO<sub>2</sub> treatments, while the total biomass of S. superba under the AA treatment was not significantly different from that under both the E2-CO<sub>2</sub> and E3-CO<sub>2</sub>treatments. During the experiment, the LUE, NUE, stomatal conductance, and transpiration rate of S. superba leaves were significantly and positively related to each other. The LUE also had a significantly positive correlation with specific leaf weight. Furthermore, the NUE was significantly and positively correlated with the total biomass and the ratio of underground and aboveground biomass. Meanwhile, the NUE was significantly and negatively correlated with the chlorophyll a concentration, chlorophyll b concentration, carotenoid concentration, leaf nitrogen concentration, soil ammonia nitrogen and nitrate nitrogen concentration. The WUE was significantly and negatively related to the stomatal conductance, transpiration rate and total biomass. CO<sub>2</sub> enrichment may enhance both the LUE and NUE of S. superba seedlings, whereas the impacts of CO<sub>2</sub> enrichment on the LUE and NUE of S. superba seedlings varied with time. S. superba seedlings would appear photosynthesis acclimation with the persistently high CO<sub>2</sub> enrichment.</p>

Fallow management, soil water, plant-available soil nitrogen and grain sorghum production in south west Queensland

1992 ◽  
Vol 32 (4) ◽  
pp. 473 ◽  
Author(s):  
G Gibson ◽  
BJ Radford ◽  
RGH Nielsen
Keyword(s):  
Soil Water ◽  
Nitrate Nitrogen ◽  
Soil Nitrate ◽  
Zero Tillage ◽  
Fallow Management ◽  
South West ◽  
Primary Tillage ◽  
Grain Nitrogen ◽  
Texture Contrast ◽  
Gypsum Application

The effects of tillage frequency (conventional, reduced and zero), primary tillage implement (disc, blade and chisel plough), stubble management (retention and removal), gypsum application, and paraplowing were examined with respect to soil water storage, soil nitrate accumulation, crop establishment, crop growth, grain yield and grain nitrogen content for 4 successive sorghum crops on a sodic, texture-contrast soil in south west Queensland. Retention of sorghum stubble (v. removal) produced an increase in mean yield of sorghum grain of 393 kg/ha, due to increased soil water extraction and increased water use efficiency by the following crop. The highest mean yield occurred after reduced blade tillage with stubble retained. Zero tillage with stubble removed gave the lowest mean grain yield. Zero tillage always had the lowest quantity of soil nitrate-nitrogen at sowing. In one fallow, increased aggressiveness of primary tillage (disc v. blade plough) increased the quantity of nitrate-nitrogen in the top 60 cm of soil at sowing. These effects on available soil nitrogen did not result in corresponding differences in grain nitrogen content. Results indicate that for optimum fallow management on this texture-contrast soil in south west Queensland, sorghum residues should be retained, tillage frequency should be reduced, but not to zero, blade ploughing should be preferred to discing, and gypsum application should not be practised.

Modelling uranium leaching from agricultural soils to groundwater as a criterion for comparison with complementary safety indicators

2006 ◽  
Vol 932 ◽  
Author(s):  
D. Jacques ◽  
J. Šimůnek ◽  
D. Mallants ◽  
M.Th. van Genuchten
Keyword(s):  
Soil Profile ◽  
Reactive Transport ◽  
Transport Model ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Water Flux ◽  
Fertilizer Application ◽  
Mineral Fertilizers ◽  
Deep Soil ◽  
Long Time

ABSTRACTNaturally occurring radionuclides can also end up in soils and groundwater due to human practices, such as application of certain fertilizers in agriculture. Many mineral fertilizers, particularly (super)phosphates, contain small amounts of 238U and 230Th which eventually may be leached from agricultural soils to underlying water resources. Field soils that receive P-fertilizers accumulate U and Th and their daughter nuclides, which eventually may leach to groundwater. Our objective was to numerically assess U migration in soils. Calculations were based on a new reactive transport model, HP1, which accounts for interactions between U and organic matter, phosphate, and carbonate. Solid phase interactions were simulated using a surface complexation module. Furthermore, all geochemical processes were coupled with a model accounting for dynamic changes in the soil water content and the water flux. The capabilities of the code in calculating natural U fluxes to groundwater were illustrated using a semi-synthetic 200-year long time series of climatological data for Belgium. Based on an average fertilizer application, the input of phosphate and uranium in the soil was defined. This paper discusses calculated U distributions in the soil profile as well as calculated U fluxes leached from a 100-cm deep soil profile. The calculated long-term leaching rates originating from fertilization are significantly higher after 200 years than estimated release rates from lowlevel nuclear waste repositories.

scholarly journals Nitrate-Nitrogen Leaching and Modeling in Intensive Agriculture Farmland in China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ligang Xu ◽  
Hailin Niu ◽  
Jin Xu ◽  
Xiaolong Wang
Keyword(s):  
Nitrate Leaching ◽  
Soil Profile ◽  
Nitrate Nitrogen ◽  
Initial Conditions ◽  
Simulated Data ◽  
Intensive Agriculture ◽  
Health Concern ◽  
N Leaching ◽  
And Migration ◽  
Leachm Model

Protecting water resources from nitrate-nitrogen (NO3-N) contamination is an important public health concern and a major national environmental issue in China. Loss of NO3-N in soils due to leaching is not only one of the most important problems in agriculture farming, but is also the main factor causing nitrogen pollution in aquatic environments. Three typical intensive agriculture farmlands in Jiangyin City in China are selected as a case study for NO3-N leaching and modeling in the soil profile. In this study, the transport and fate of NO3-N within the soil profile and nitrate leaching to drains were analyzed by comparing field data with the simulation results of the LEACHM model. Comparisons between measured and simulated data indicated that the NO3-N concentrations in the soil and nitrate leaching to drains are controlled by the fertilizer practice, the initial conditions and the rainfall depth and distribution. Moreover, the study reveals that the LEACHM model gives a fair description of the NO3-N dynamics in the soil and subsurface drainage at the field scale. It can also be concluded that the model after calibration is a useful tool to optimize as a function of the combination “climate-crop-soil-bottom boundary condition” the nitrogen application strategy resulting for the environment in an acceptable level of nitrate leaching. The findings in this paper help to demonstrate the distribution and migration of nitrogen in intensive agriculture farmlands, as well as to explore the mechanism of groundwater contamination resulting from agricultural activities.

MICROBES AND NITRATES IN SOILS FROM VIRGIN AND YOUNG-GROWTH FORESTS

1961 ◽  
Vol 7 (5) ◽  
pp. 785-792 ◽  
Author(s):  
W. B. Bollen ◽  
Ernest Wright
Keyword(s):  
Forest Soils ◽  
Ponderosa Pine ◽  
Nitrate Nitrogen ◽  
Nitrate Content ◽  
Soil Incubation ◽  
Red Alder ◽  
Coastal Soils ◽  
Water Holding ◽  
Penicillium Spp ◽  
Young Growth

Penicillium spp. predominated in samples of forest soils except occasionally at depths of more than three inches, when Mucor and Aspergillus spp. sometimes were more abundant. Incubation for 30 days at 28 °C and 50 per cent water-holding capacity frequently increased the percentage of Mucor spp. as well as Penicillium spp. Mucor spp. were consistently more prominent in soils associated with alder than for other coastal soils. Mucor and Aspergillus spp. also appeared often in soil from stands of ponderosa pine growing east of the Cascades.The greatest concentration of nitrogen as NO3− in unincubated soils was found in a young red alder stand. Samples of soil from stands of virgin coastal redwood showed no nitrate nitrogen. Soils from stands of virgin Sitka spruce, however, showed considerable nitrate content, which increased markedly with incubation.With few exceptions, bacteria and actinomycetes were most numerous in F layers of soil. Incubation greatly increased these populations in most soils.

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