scholarly journals N2O Fluxes and Related Processes of Denitrification in Acidified Soil

2020 ◽  
Author(s):  
Qian Zheng ◽  
Junjun Ding ◽  
Qiaozhen Li ◽  
Chunying Xu ◽  
Wei Lin ◽  
...  
Keyword(s):  
Soil Ph ◽  
Irrigation Water ◽  
Soil Acidification ◽  
N Fertilizer ◽  
Soil Conditions ◽  
Natural Soil ◽  
Large Contribution ◽  
Total N ◽  
Mapping Approach ◽  
The Impact

Abstract In North China, high levels of N fertilizer and irrigation water are used in fields, which cause considerable N2O fluxes via several pathways, especially anaerobic denitrification. Anaerobic denitrification is regarded as an important microbial process for N2O production in soils with a low O2 level and high N and labile C availability (the typical soil conditions caused by high levels of N fertilizer and irrigation water in the field). We conducted an anaerobic incubation experiment to determine the impact of soil acidification (with a series of soil pH levels, pH 6.2, pH 7.1, and pH 8.7) on N2O source partitioning with the addition of KNO3 and glucose. Natural abundance isotope techniques and gas inhibitor technique were applied to analyze the N2O flux derived from fungal denitrification and bacterial denitrification and its isotopocule characteristics emitted from soils after the addition of NO- 3 and glucose. A mapping approach was used to obtain further insight into the N2O production processes. Our findings confirmed that soil pH strongly controlled the N2O production and reduction rates of denitrification. Soil acidification significantly increased N2O emissions varied from 0.76 mg N kg-1 for natural soil (pH 8.7), to 1.88 mg N kg-1 for pH 7.1, and to 2.35 mg N kg-1 for pH 6.2, and had a blockage effect on the reduction of N2O to N2. The addition of carbon sources promoted complete denitrification. We assumed a higher contribution of fungal denitrification to N2O production compared to total N2O emission associated with acidified soil. A promotion of the contribution of fungal denitrification-derived N2O was indeed observed with decreasing pH, increasing from 0.28 mg N kg-1 for pH 8.7 to 0.94 mg N kg-1 for pH 6.2. The addition of glucose further increased the contribution of fungal denitrification to N2O production from 0.99 mg N kg-1 for pH 8.7 to 3.66 mg N kg-1 for pH 6.2. The mapping approach provided rational results for correcting N2O reduction compared with the acetylene inhibition method. The results calculated by both methods indicated a reasonably large contribution of fungal denitrification to total N2O production in acidified soils.

scholarly journals Nutrient Management Programs, Nitrogen Fertilizer Practices, and Groundwater Quality in Nebraska’s Central Platte Valley (U.S.), 1989–1998

2001 ◽  
Vol 1 ◽  
pp. 750-757 ◽  
Author(s):  
Stan Daberkow ◽  
Harold Taylor ◽  
Noel Gollehon ◽  
Milt Moravek
Keyword(s):  
Irrigation Water ◽  
Fertilizer Application ◽  
Management Program ◽  
N Fertilizer ◽  
N Availability ◽  
Modest Improvement ◽  
Total N ◽  
Drinking Water Standard ◽  
Irrigation Water Use ◽  
Farmer Behavior

Given the societal concern about groundwater pollution from agricultural sources, public programs have been proposed or implemented to change farmer behavior with respect to nutrient use and management. However, few of these programs designed to change farmer behavior have been evaluated due to the lack of detailed data over an appropriate time frame. The Central Platte Natural Resources District (CPNRD) in Nebraska has identified an intensively cultivated, irrigated area with average groundwater nitrate-nitrogen (N) levels about double the EPA’s safe drinking water standard. The CPNRD implemented a joint education and regulatory N management program in the mid-1980s to reduce groundwater N. This analysis reports N use and management, yield, and groundwater nitrate trends in the CPNRD for nearly 3000 continuous-corn fields from 1989 to 1998, where producers faced limits on the timing of N fertilizer application but no limits on amounts. Groundwater nitrate levels showed modest improvement over the 10 years of this analysis, falling from the 1989–1993 average of 18.9 to 18.1 mg/l during 1994–1998. The availability of N in excess of crop needs was clearly documented by the CPNRD data and was related to optimistic yield goals, irrigation water use above expected levels, and lack of adherence to commercial fertilizer application guidelines. Over the 10-year period of this analysis, producers reported harvesting an annual average of 9729 kg/ha, 1569 kg/ha (14%) below the average yield goal. During 1989�1998, producers reported annually applying an average of 162.5 kg/ha of commercial N fertilizer, 15.7 kg/ha (10%) above the guideline level. Including the N contribution from irrigation water, the potential N contribution to the environment (total N available less estimated crop use) was estimated at 71.7 kg/ha. This is an estimate of the nitrates available for denitrification, volatilization, runoff, future soil N, and leaching to groundwater. On average, between 1989–1993 and 1994–1998, producers more closely followed CPNRD N fertilizer recommendations and increased their use of postemerge N applications � an indication of improved synchrony between N availability and crop uptake.

Impact of cultivation year, nitrogen fertilization rate and irrigation water quality on soil salinity and soil nitrogen in saline-sodic paddy fields in Northeast China

2015 ◽  
Vol 154 (4) ◽  
pp. 632-646 ◽  
Author(s):  
L. H. HUANG ◽  
Z. W. LIANG ◽  
D. L. SUAREZ ◽  
Z.C. WANG ◽  
M. M. WANG ◽  
...  
Keyword(s):  
Soil Ph ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Northeast China ◽  
Paddy Fields ◽  
Inorganic N ◽  
N Application ◽  
Total N ◽  
Application Rates ◽  
Soil Inorganic N

SUMMARYSaline-sodic soils are widely distributed in the western Songnen Plain of Northeast China and planting rice has been found to be an effective and feasible approach for improving saline-sodic soil and increasing food production. Assessment of the effectiveness and sustainability of this method requires monitoring of the changes in soil salinity and nutrient content. The objective of the current study was to investigate the changes of soil salinity and nitrogen (N) contents over 1, 3, 6 and 9 years of cultivation, four application rates of N (N0: no N, N1: 100 kg N/ha, N2: 200 kg N/ha and N3: 300 kg N/ha) and two irrigation water types: ground water irrigation (GWI) and river water irrigation (RWI). Salinity and N contents of soil and water samples were analysed before planting and after harvest throughout the experiments. Soil pH and electrical conductivity (EC), especially in the surface layer of 0–40 cm depth, decreased with years of cultivation with both GWI and RWI, while soil inorganic N and total N contents increased. Moreover, with increasing N application rates, soil inorganic N and total N contents increased significantly in the 0–20 cm soil layer. Increasing N application had little effect on soil pH and EC. Reclaiming and planting rice promoted desalination of the surface and formation of a fertile tillage layer in saline-sodic paddy fields. In terms of irrigation and drainage in saline-sodic paddy fields, both soil salinity and N contents increased. Soil total salinity increased annually by 34 and 12·8 kg/ha, and inorganic N contents increased annually by 9 and 13·5 kg/ha with GWI and RWI, respectively. Therefore, comprehensive agricultural practices should be adopted for improving and cropping rice in saline-sodic paddy fields.

scholarly journals Effects of Soil pH and Fertilizers on Haskap (Lonicera caerulea L.) Vegetative Growth

Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 56
Author(s):  
Catherine Tremblay ◽  
Annie Deslauriers ◽  
Jean Lafond ◽  
Julie Lajeunesse ◽  
Maxime Paré
Keyword(s):  
Ammonium Nitrate ◽  
Soil Ph ◽  
Vegetative Growth ◽  
Root Biomass ◽  
Chicken Manure ◽  
Soil Conditions ◽  
Lonicera Caerulea ◽  
Baseline Knowledge ◽  
One Year ◽  
The Impact

Haskap (Lonicera caerulea L.) is a new northern latitude fruit crop that is increasing in popularity. This sudden enthusiasm for haskap increases the need for obtaining baseline knowledge related to establishing it as a crop, such as its optimal soil pH and fertilizer needs. In a greenhouse, one-year-old haskap plants (cultivar: Indigo Treat©) were grown in a local loamy sand. We assessed the impact of pH and fertilizer on haskap vegetative growth through an experiment involving four soil pH and five fertilization treatments of three N sources (ammonium, nitrate, and organic (chicken manure)). Leaf senescence as well as above-ground and root biomass were recorded after 19 weeks of vegetative growth. For cultivar Indigo Treat©, optimal vegetative growth was observed under slightly acidic soil conditions (pHCaCl2 5.5–6 or pHwater 5.9–6.5) without application of N. Phosphorus and K fertilizers did not influence vegetative growth. We here discuss the implications for establishing haskap orchards.

Value of Irrigation Water in the Middle Atlantic States: An Econometric Approach

1984 ◽  
Vol 16 (2) ◽  
pp. 91-98 ◽  
Author(s):  
Bruce Madariaga ◽  
Kenneth E. McConnell
Keyword(s):  
Irrigation Water ◽  
Economic Value ◽  
Simultaneous Equation ◽  
Soil Conditions ◽  
Middle Atlantic ◽  
Water Value ◽  
Product Function ◽  
Value Of Irrigation Water ◽  
Econometric Approach ◽  
The Impact

AbstractEstimation of the economic value of irrigation water is complicated by a lack of data on the price or marginal cost of water. Through econometric estimation of an aggregate total value product function, this paper obtains marginal irrigation water value estimates for the Middle Atlantic region. Additionally, the impact of temperature and soil conditions on aggregate production within the region is estimated. Ridge regression and covariance analysis are employed to deal with problems of multicollinearity and simultaneous equation bias, respectively. Estimates indicate a substantial and growing return to irrigation within the region.

scholarly journals Nitrogen Contents in Soil, Grains, and Straw of Hybrid Rice Differ When Applied with Different Organic Nitrogen Sources

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 386
Author(s):  
Amanullah ◽  
Hidayat Ullah ◽  
Mohamed Soliman Elshikh ◽  
Mona S. Alwahibi ◽  
Jawaher Alkahtani ◽  
...  
Keyword(s):  
Management Practices ◽  
Hybrid Rice ◽  
Inorganic Nitrogen ◽  
N Fertilizer ◽  
Organic Fertilizers ◽  
Plant Residues ◽  
Total N ◽  
Rice Plants ◽  
Animal Manures ◽  
The Impact

In the rice–wheat (R–W) system, inorganic nitrogen (N) fertilizer (urea, etc.) is the largest component of the N cycle, because the supply of N from organic fertilizers is insufficient. But the 4% Initiative aims to improve organic matter and stimulate carbon sequestration in soils using best agronomic practices (sustainable management practices) which are economically, environmentally, and socially friendly. This research project was, therefore, designed to assess the impact of various organic sources (OS, animal manure versus plant residues), inorganic N (urea), and their different combinations on the N concentrations in soils and plants (i.e., grains and straw) of hybrid rice plants. The experiments were conducted on farmers’ fields in Batkhela (Malakand), northwestern Pakistan, over 2 years (2011–2012 (Y1) and 2012–2013 (Y2)). The results revealed that N concentrations in soil as well as in rice plants ranked first when applied with urea-N, followed by the application of N in mixture (urea + OS), while the control plots (no N applied) ranked at the bottom. Among the six OS (three animal manures: poultry, sheep, and cattle; and three crop residues: onion, berseem, and wheat), application of N in the form of poultry manure was superior in terms of higher N concentrations in both soil and plants. Applying the required total N (120 kg N ha−1) in the form of 75% N from urea +25% N from OS resulted in higher N concentrations in soil and plants in Y1. The required total N (120 kg N ha−1) application in the form of 50% N from urea +50% N from OS produced higher N concentrations in soil and plants in Y2. It was concluded from the results, that combined application of N sources in the form of urea + OS can produce good performances in terms of higher N concentrations in soil as well as in rice plants under the R–W system. Integrated use of urea (N-fertilizer) with organic carbon sources (animal manures and crop residue) could sustain rice-based (exhaustive) cropping system.

scholarly journals Testing a thermometer of the past: abiotic and biotic drivers of the brGDGT-based temperature proxy along a subarctic elevation gradient.

2021 ◽  
Author(s):  
Cindy De Jonge ◽  
Robin Halffman ◽  
Jonas Lembrechts ◽  
Ivan Nijs
Keyword(s):  
Bacterial Community ◽  
Soil Temperature ◽  
Soil Ph ◽  
Altitudinal Gradient ◽  
Soil Conditions ◽  
Chemical Parameters ◽  
Total N ◽  
High Ph ◽  
Soil Chemical Parameters

<p>BrGDGTs are used in a variety of paleoclimate archives to reconstruct changes in temperature and pH. However, the temperature dependency, currently determined on a global scale, can be confounded on smaller spatial scales. To determine the unique effect of temperature on the brGDGT distribution in northern Scandinavia, 37 soils have been collected along a Swedish and Norwegian altitude gradient (14 to 1200 m asl). At this site, we measured in-situ soil temperature (1 year), as well as soil chemical parameters (pH, Ca, K, Mg, Mn, Fe, Mn, Al, total P, total N). Furthermore, we reconstructed the composition of the bacterial community in the same soils, using 16S rDNA, to allow direct comparison with the brGDGT lipid signatures.</p><p>Although we sampled over a limited range in pH values (3.3-5.4), large changes in brGDGT concentration are observed over the pH gradient. In low pH soils (>4.0), total brGDGT concentration (normalized per g soil) is increased, caused by an increase in the concentration of brGDGT Ia. This results in increased MBT’<sub>5ME</sub> values (0.53-0.7) in these soils. In high pH soils (pH>5.0) an increased concentration in 6-methyl brGDGTs is observed. These soils are characterized by a lower MBT’<sub>5ME</sub> values, driven by a decrease in the fractional abundance of brGDGT Ia. Along the altitudinal gradient, pH (and soil calcium) is the main driver of the MBT’<sub>5ME</sub> proxy (r= -0.60, p<0.01).</p><p>Along the Swedish and Norwegian altitudinal gradient, where a substantial change in temperature (-4.7 to 2.7 °C MAAT) was crossed, the MBT’<sub>5ME</sub> only shows a poor correlation with atmospheric MAAT values (r= 0.47, p<0.01). When comparing the MBT’5ME with in-situ measured soil temperatures (-2.5 to 4.3), that reflect the growth conditions of the soil bacteria better, the correlation is not improved (mean annual soil temperature: r= 0.32, p=0.05). A correlation with seasonal temperatures (Growing Degree Days [GDD]) results in a better dependency between the MBT’<sub>5ME</sub> and soil temperature (r= 0.44, p<0.01), which can reflect that brGDGT are generally produced in non-frozen soil conditions.</p><p>However, at the Swedish and Norwegian altitudinal gradient, there is a significant correlation observed between the temperature (GDD) and soil chemical parameters. In general, soil pH is increased at lower temperatures (r=-0.32, p=0.04, n=37). Considering all soil chemical parameters, the total concentration of K decreases closely with an increase in soil temperature (GDD: r= -0.63, p<0.01, n=37). The mechanism behind this is probably an interplay between local geology, and a temperature dependent extent of chemical and biological weathering. Because of this correlation, it is not clear whether MBT’<sub>5ME</sub> varies exclusively in response to soil chemistry, with an indirect response to temperature changes.</p><p>Although the environmental driver determining the brGDGT signal can not be determined unequivocally, the bacterial community composition is clearly determined by soil pH. In those high pH soils (pH> 4.9) where increased concentrations of 6-methyl brGDGTs are produced, several Acidobacterial OTUs (specifically Acidobacteria subgroup 6) are increased. This indicates that the mechanism behind the changed fractional abundances is a pH-modulated bacterial community shift.</p>

scholarly journals Base Neutralizing Capacity of Agricultural Soils in a Quaternary Landscape of North-East Germany and Its Relationship to Best Management Practices in Lime Requirement Determination

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 877
Author(s):  
Sebastian Vogel ◽  
Eric Bönecke ◽  
Charlotte Kling ◽  
Eckart Kramer ◽  
Katrin Lück ◽  
...  
Keyword(s):  
Soil Properties ◽  
Soil Ph ◽  
Soil Acidification ◽  
Titration Curve ◽  
Soil Acidity ◽  
Management Practices ◽  
Natural Soil ◽  
Natural Processes ◽  
North East ◽  
Neutralizing Capacity

Despite being a natural soil-forming process, soil acidification is a major agronomic challenge under humid climate conditions, as soil acidity influences several yield-relevant soil properties. It can be counterbalanced by the regular application of agricultural lime to maintain or re-establish soil fertility and to optimize plant growth and yield. To avoid underdose as well as overdose, lime rates need to be calculated carefully. The lime rate should be determined by the optimum soil pH (target pH) and the response of the soil to lime, which is described by the base neutralizing capacity (BNC). Several methods exist to determine the lime requirement (LR) to raise the soil pH to its optimum. They range from extremely time-consuming equilibration methods, which mimic the natural processes in the soil, to quick tests, which rely on some approximations and are designed to provide farmers with timely and cost-efficient data. Due to the higher analytical efforts, only limited information is available on the real BNC of particular soils. In the present paper, we report the BNC of 420 topsoil samples from Central Europe (north-east Germany), developed on sediments from the last ice age 10,000 years ago under Holocene conditions. These soils are predominantly sandy and low in humus, but they exhibit a huge spatial variability in soil properties on a small scale. The BNC was determined by adding various concentrations of Ca(OH)2 and fitting an exponential model to derive a titration curve for each sample. The coefficients of the BNC titration curve were well correlated with soil properties affecting soil acidity and pH buffer capacity, i.e., pH, soil texture and soil organic matter (SOM). From the BNC model, the LRs (LRBNC) were derived and compared with LRVDLUFA based on the standard protocol in Germany as established by the Association of German Agricultural Analytic and Research Institutes (VDLUFA). The LRBNC and LRVDLUFA correlated well but the LRVDLUFA were generally by approximately one order of magnitude higher. This is partly due to the VDLUFA concept to recommend a maintenance or conservation liming, even though the pH value is in the optimum range, to keep it there until the next lime application during the following rotation. Furthermore, the VDLUFA method was primarily developed from field experiments where natural soil acidification and management practices depressed the effect of lime treatment. The BNC method, on the other hand, is solely based on laboratory analysis with standardized soil samples. This indicates the demand for further research to develop a sound scientific algorithm that complements LRBNC with realistic values of annual Ca2+ removal and acidification by natural processes and N fertilization.

scholarly journals Plant, soil and faunal responses to a contrived pH gradient

2021 ◽  
Author(s):  
Sarah Duddigan ◽  
Tandra Fraser ◽  
Iain Green ◽  
Anita Diaz ◽  
Tom Sizmur ◽  
...  
Keyword(s):  
Soil Ph ◽  
Soil Chemistry ◽  
Plant Biomass ◽  
Ph Gradient ◽  
Soil Conditions ◽  
Ecological Group ◽  
Ph Change ◽  
Holistic Understanding ◽  
Abundance And Diversity ◽  
The Impact

Abstract Purpose To build a more holistic understanding of soil pH change we assessed the synchronised effects of a contrived soil pH change on soil chemistry, vegetation growth and nutrition, and soil faunal abundance and diversity. Methods We established a fifteen year old field experiment with a contrived pH gradient (pH 4.3 to 6.3) and measured the effect on soil chemistry, plant biomass and elemental composition and the impact of these changes on soil fauna (earthworms, nematodes, rotifers and tardigrades) and biological indices (based on ecological group structures of earthworms and nematodes). A single 20 × 20 × 20 cm soil block was excavated from each sample site to directly attribute biotic parameters in the block to the abiotic (soil) conditions. Results Acidification affected the extractable concentrations of Al, Ca, Mn and P and the C:N ratio of the soil and caused a reduction in plant Ca (rs for pH vs Ca = 0.804 p < 0.01), an increase in plant Mn (rs = −0.450 p = 0.019), along with significant decrease in root:shoot ratio (rs = 0.638, p < 0.01). There was a significant positive correlation between pH and earthworm index (rs = 0.606, p < 0.01), and a negative correlation between pH and nematode index (rs = −0.515, p < 0.01). Conclusion Soil pH influenced the mobility of Ca, Al, Mn and P, which in turn has impacted on plant tissue chemistry and plant biomass ratios. Linked changes in soil chemistry and vegetation had a corresponding effect on the abundance and diversity of nematodes and earthworms in the soil blocks.

N2 fixation by soybeans grown with different levels of mineral nitrogen, and the fertilizer replacement value for a following crop

2002 ◽  
Vol 82 (2) ◽  
pp. 139-145 ◽  
Author(s):  
M. J. Goss ◽  
A. de Varennes ◽  
P. S. Smith ◽  
J. A. Ferguson
Keyword(s):  
Response Curve ◽  
C:N Ratio ◽  
N Fertilizer ◽  
Fertilizer N ◽  
Mineral N ◽  
Total N ◽  
Fertilizer Recommendations ◽  
Second Year ◽  
The Impact ◽  
Different Levels

A field experiment was established to study the impact of added mineral N on the prediction of N2 fixation by soybean, and the consequences for the nature of any N credit that might be used to modify fertilizer recommendations to a following non-fixing crop. Nodulating and non-nodulating isolin es of soybean were grown with five rates of N fertilizer, and in a second year corn was grown in the same plots and its yield compared with a response curve. Yield, total N content, amount of N derived from soil, and fertilizer utilization of the nodulating isoline of soybean were not affected by fertilizer N. In contrast, mineral N inhibited nodulation and led to a decrease in the amount of N fixed. The balance of N in the soil was more negative for lower levels of applied N, but by the following spring the amount of mineral N in the soil was the same in all plots. The yield of corn was greater in the plots that had grown nodulating soybean than the non-nodulating isoline. The N fertilizer replacement value of 25 (8 kg N ha-1 resulted from a greater amount of root residues in the nodulating soybean, together with a C:N ratio that would favour faster mineralization than in the non-nodulating isoline. Key words: Corn, mineral N, N credit, fixation, soybean

scholarly journals Nitrification Inhibitor 3,4-dimethylpyrazole Phosphate Improves Nitrogen Recovery and Accumulation in Cotton Plants by Reducing NO3- Leaching Under 15N-urea Fertilization

2021 ◽  
Author(s):  
Ezio Nalin de Paulo ◽  
Fernando Shintate Galindo ◽  
Flávio Henrique Silveira Rabêlo ◽  
Joaquim José Frazão ◽  
Jose Lavres
Keyword(s):  
Nitrification Inhibitor ◽  
Tropical Soil ◽  
Soil Conditions ◽  
N Recovery ◽  
N Accumulation ◽  
Total N ◽  
Leaching Losses ◽  
Cotton Plants ◽  
Use Efficiency ◽  
The Impact

Abstract Purpose: The use of nitrification inhibitors could be an interesting alternative to enhance nitrogen (N) fertilizer use efficiency in annual crops such as cotton, under tropical soil conditions. Thus, our aim was to evaluate the efficiency of nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) in a typical tropical soil, evaluating the fate of nitrogen (N-NO3-, N-NH4+ and total N in soil and leached water), N-accumulation and N recovery by cotton plants and soil. Methods: Leaching columns with cotton plants were used to access N-NO3- and N-NH4+ losses in drainage water. Treatments consisted in three N levels applied in side-dressing (corresponding to 50, 100 and 150 kg N ha-1) as 15N-urea with and without DMPP application. An additional treatment (absence of N application in side-dressing) was used as control. Results: 3,4-dimethylpyrazole phosphate was efficient to improve N recovery from applied urea fertilizer in plants and in the soil by reducing NO3- leaching, leading to enhanced N acquisition from fertilizer and soil, augmenting plants N-accumulation, mainly when high N levels above 100 kg N ha-1 were applied. We found that total N recovery increased 31% when 150 kg N ha-1 was applied as urea + DMPP source compared to conventional urea. In addition, DMPP application reduced NO3- leaching losses (c.a. of 11 to 20%), although had no significant effect on shoot and root dry matter yield. Conclusion: The reduction of NO3- leaching losses highlights the potential of DMPP to mitigate the impact of increased urea input on leaching losses thereby improving N use efficiency and N uptake in cotton crop.

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