scholarly journals Carbon Availability and Nitrogen Mineralization Control Denitrification Rates and Product Stoichiometry during Initial Maize Litter Decomposition

2021 ◽  
Vol 11 (11) ◽  
pp. 5309
Author(s):  
Pauline Sophie Rummel ◽  
Reinhard Well ◽  
Johanna Pausch ◽  
Birgit Pfeiffer ◽  
Klaus Dittert

Returning crop residues to agricultural fields can accelerate nutrient turnover and increase N2O and NO emissions. Increased microbial respiration may lead to formation of local hotspots with anoxic or microoxic conditions promoting denitrification. To investigate the effect of litter quality on CO2, NO, N2O, and N2 emissions, we conducted a laboratory incubation study in a controlled atmosphere (He/O2, or pure He) with different maize litter types (Zea mays L., young leaves and roots, straw). We applied the N2O isotopocule mapping approach to distinguish between N2O emitting processes and partitioned the CO2 efflux into litter- and soil organic matter (SOM)-derived CO2 based on the natural 13C isotope abundances. Maize litter increased total and SOM derived CO2 emissions leading to a positive priming effect. Although C turnover was high, NO and N2O fluxes were low under oxic conditions as high O2 diffusivity limited denitrification. In the first week, nitrification contributed to NO emissions, which increased with increasing net N mineralization. Isotopocule mapping indicated that bacterial processes dominated N2O formation in litter-amended soil in the beginning of the incubation experiment with a subsequent shift towards fungal denitrification. With onset of anoxic incubation conditions after 47 days, N fluxes strongly increased, and heterotrophic bacterial denitrification became the main source of N2O. The N2O/(N2O+N2) ratio decreased with increasing litter C:N ratio and Corg:NO3− ratio in soil, confirming that the ratio of available C:N is a major control of denitrification product stoichiometry.

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 465 ◽  
Author(s):  
Kiwamu Ishikura ◽  
Untung Darung ◽  
Takashi Inoue ◽  
Ryusuke Hatano

This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.


1990 ◽  
Vol 70 (4) ◽  
pp. 555-564 ◽  
Author(s):  
SUZANNE BEAUCHEMIN ◽  
MARC R. LAVERDIÈRE ◽  
ADRIEN N'DAYEGAMIYE

Intensive potato cropping has been reported as a major cause of degradation of sandy soils. Wood residues from tree clipping applied to soils can substitute for crop residues to maintain adequate organic matter levels and crop productivity. However, this ligneous material presents a C:N ratio varying from 50 to 175 and, when applied in large quantities, may induce N immobilization at the expense of the crop. The objectives of this study were to quantify the importance of this N immobilization following addition of residues and its effect on yield and quality of potato crops. Fresh or humified residues (50 t ha−1) were applied to the soil and incorporated. The third treatment received no residue. Each treatment was subdivided into subtreatments which received either 0, 150, 200 or 250 kg N ha−1. P, K, Mg and S were applied at the same rate on all treatments. Following the application of wood residues in 1987, 46 kg N ha−1 were immobilized in amended plots. N recovery from fertilizer was 51%. To obtain comparable yields of similar quality to those measured on unamended plots, an additional 1.9 kg N t−1 residues added or 100 kg N ha−1 were required. In 1988, N immobilization was considerably reduced; yield and quality of potato tubers in plots that received wood residues the previous year were comparable to those of the unamended plots with appropriate fertilization. Water retention was significantly improved in plots that received wood residues. Partial decomposition of the residues for 1 yr prior to application on the soil did not significantly improve plant growth compared to fresh residues. Key words: Wood residues, tree clippings, potato yield, dry matter content, nitrogen immobilization, soil water content


1940 ◽  
Vol 18c (4) ◽  
pp. 136-141 ◽  
Author(s):  
R. Newton ◽  
R. S. Young

Proximate analyses of roots (to plow depth) and stubble in one-, three-, and five-year-old sods, considered in relation to sequence effects as judged by the nitrogen absorption of the first two wheat crops after each age of sod, indicated the nitrogen content of the hay crop residues to be the dominant influence. Alfalfa was much superior to the grasses, a result apparently of the higher quantity of nitrogen returned to the soil and of the narrower C:N ratio in its residues. Timothy led the grasses, contributing the highest quantity of nitrogen in residues with the lowest percentage of crude fibre and the narrowest ratio of crude fibre to nitrogen-free extract. Brome contributed more residual nitrogen than western rye, but was slightly inferior in sequence effects.


2018 ◽  
Vol 10 (1) ◽  
pp. 185-189
Author(s):  
Ashwini Ambadi ◽  
D. Krishnamurty ◽  
Sathyanaran Rao ◽  
B. K. Desai ◽  
M.V. Ravi ◽  
...  

A field experiment was conducted on vertisols (pH of 7.56 with organic carbon content of 0.55%) at Re- search Institute on Organic Farming, University of Agricultural Sciences, Raichur coming under northern Karnataka during rabi season of 2015-16 to study the Influence of varied crop residues and green biomass composts to rabi sorghum growing soils on uptake of major nutrients, organic carbon and soil fertility status. In general application of Cotton stalks, Redgram stalks, Glyricidia, combination of cotton and redgram stalks composts, FYM and combina- tion of organic and inorganic fertilizers helped to buildup soil nutrients with respect to organic carbon, available nitro- gen and phosphorus. Significantly higher nitrogen (227.3 kg ha-1), phosphorous (75.7 kg ha-1) and potassium (141.7 kg ha-1) uptake by rabi sorghum was recorded with combined application of recommended FYM (3 t ha-1) and NP fertilizers (50:25 kg N, P2O5 ha-1) (T14) followed by Cotton stalks +Redgram stalks + Glyricidia sp. with C:N ratio of 30:1 compost @ 50 kg N equivalent (T12: 222.0, 74.0 and 132.3 kg ha-1). The least uptake was recorded with abso- lute control (T15: 127.0, 42.0 and 71.7 kg ha-1). Similar trend was observed with organic carbon, available nitrogen and phosphorus. Combined application of recommended FYM (3 t ha-1) and NP fertilizers (50:25 kg N, P2O5 ha-1) followed by Cotton stalks +Redgram stalks + Glyricidia sp. with C:N ratio of 30:1 compost @ 50 kg N equivalent at the time of sowing recorded higher major nutrients uptake, microbial biomass and soil fertility status.


2017 ◽  
Vol 9 (2) ◽  
pp. 1123-1128
Author(s):  
Manpreet S. Mavi ◽  
B. S. Sekhon ◽  
Jagdeep Singh ◽  
O. P. Choudhary

An understanding of the mineralization process of organic amendments in soil is required to synchronize N release with crop demand and protect the environment from excess N accumulation. Therefore, we conducted a laboratory incubation experiment to assess nitrogen mineralization potential of crop residues (rice and wheat straw) and organic manures (poultry manure, farmyard manure, cowpea and sesbania) in two benchmark soils (Typic Haplustept and Typic Ustifluvents) of semi-arid region of Punjab, India, varying in textureat field capacity moisture level at a constant temperature of 331°C. Mineralization was faster during first 7 days of incubation in Typic Haplustept and upto 14 days in Typic Ustifluvents which subsequently declined over time. In both soils, net N mineralization continued to increase with increasing period of incubation (expect with crop residues) and was significantly higher in Typic Ustifluvents (54-231µg g-1) than Typic Haplustept (33-203 µg g-1). Compared to unamended soils, percent N mineralized was highest is sesbania (35-40 %) followed by cowpea (32-37 %) and least in wheat (10-11 %) after 42 days of incubation. Thus, sesbania and cowpea may preferably be used to meetthe large N demand during early period of plant growth. Further, mineralization rate constants (k) also indicated that availability of mineral N was significantly higher with application of organic amendments than unamended control treatments in both soils. Therefore, it may be concluded that considerable economy in the use of inorganic N fertilizer can be employed if N mineralization potential of organic inputs is taken into consideration.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1951
Author(s):  
Aleksandra Grzyb ◽  
Agnieszka Wolna-Maruwka ◽  
Alicja Niewiadomska

The aim of this article is to present the issues related to the significance of microorganisms in the mineralization of crop residues and the influence of environmental factors on the rate of this process. Crop residues play a very important role in agriculture because they can be used both as an environment-friendly waste management strategy and as a means of improving soil organic matter. The inclusion of crop residues in the soil requires appropriate management strategies that support crop production and protect the quality of surface water and groundwater. Crops need nutrients for high yields; however, they can only absorb ionic forms of elements. At this point, the microorganisms that convert organically bound nitrogen, phosphorus, and sulfur into soluble NH4+, NO3−, H2PO4−, HPO42−, and SO42− ions are helpful. Mineralization is the transformation of organic compounds into inorganic ones, which is a biological process that depends on temperature, rainfall, soil properties, the chemical composition of crop residues, the structure and composition of microbial communities, and the C:N ratio in soil after the application of plant matter. An adjustment of the values of these factors enables us to determine the rate and direction of the mineralization of crop residues in soil.


Author(s):  
P. Padmavathi ◽  
I. Y.L.N Murthy ◽  
M. Suresh

A field experiment was conducted to study the effect of nutrient management practices on the performance of soybean - safflower sequence in Vertisols. The safflower equivalent yield (2418 kg/ha-1); gross returns (Rs. 53196/ha-1); net returns (Rs 33734/ha-1) and B:C ratio (2.8) were significantly superior either with the application of NPK to the system + 5 t FYM/ha to safflower; or NPK to the system + soybean residues to safflower; or NPK to the system + both crop residues. Similar trend was also observed with respect to soil health indicators viz., soil respiration (108 mg C/g soil/10 days), microbial biomass C (284 mg C/g soil), microbial biomass N (41.9 mg N/g soil), mineral N (13.8 mg N/g soil) and net N mineralization (5.4 mg N/g soil/ 10 days). Significant improvement was observed in terms of PGPR and Trichoderma sp were found when NPK + crop residues were applied to the system.


2020 ◽  
Author(s):  
Felix Havermann ◽  
Klaus Butterbach-Bahl ◽  
Baldur Janz ◽  
Florian Engelsberger ◽  
Maria Ernfors ◽  
...  

<p>Crop residues are a significant source for soil N<sub>2</sub>O emissions and major component affecting the C storage in arable soils. The balance between C sequestration and N<sub>2</sub>O emissions is delicate and depends on the type of residues and its management. Thus, residue management might be a feasible option to reduce the GHG footprint of crop production. However, the mitigation potential of residue management is highly variable and strongly affected by the crop residue quality (C and N content, C:N ratio, concentrations of lignin, cellulose and solutes), field management (incorporation depth, amount applied) as well as soil physical and soil biogeochemical properties. In the frame of the EU-ERAGAS project RESIDUEGAS, we investigated the impact of different crop residue qualities on soil respiration and reactive N fluxes as well as soil ammonium (NH<sub>4</sub><sup>+</sup>) and nitrate (NO<sub>3</sub><sup>-</sup>) concentrations in order to test and possibly improve existing IPCC emission factors for GHG emissions from crop residue management.</p><p>In this study, we used sieved and homogenized soil columns of 8 cm height and 12 cm diameter filled with arable soil taken from a site near Gießen, Germany. Soil columns were incubated in the laboratory for 60 days at constant soil temperature (15°C) and water-filled pore space (60 %). Residues from nine different crops (oilseed rape, winter wheat, field pea, maize, potato, mustard, red clover, sugar beet, ryegrass) were re-wetted according to field moisture level and incorporated over approx. 0-4 cm topsoil layer one week after soil re-wetting and start of the measurements. The CO<sub>2</sub>, N<sub>2</sub>O (as well as NO and NH<sub>3</sub>) fluxes were measured automatically using a dynamic chamber approach. Soil samples were additionally analyzed for soil NH<sub>4</sub><sup>+</sup> and NO<sub>3</sub><sup>-</sup> concentrations at specific time steps during the experiment.</p><p>Re-wetting of the dry soil immediately resulted in a sharp increase of soil N<sub>2</sub>O and CO<sub>2</sub> emissions, which, however, was less pronounced than peak emissions following residue incorporation. Those were 4-5 times higher as compared to soil cores without residue amendment. Elevated emissions were short-lived and declined to background levels within 10 days for N<sub>2</sub>O and within 30 days for CO<sub>2</sub>. However, a small but significant period of higher than background N<sub>2</sub>O emissions was observed in the second half of the incubation period, which might be directly related to the decomposition of slower decomposable organic matter such as lignin and cellulose from crop residues. Generally, the emission magnitude was strongly affected by the crop residue quality, with highest N<sub>2</sub>O as well as CO<sub>2</sub> emissions being calculated for residues with a narrow C:N ratio. However, C:N ratio was not the single explaining factor. The range of calculated emission factors (fraction of cumulatively emitted N<sub>2</sub>O-N to crop residue N input) over a 60 day period was larger than the range given by IPCC in 2006.</p>


2011 ◽  
Vol 35 (3) ◽  
pp. 819-832 ◽  
Author(s):  
Ben-Hur Costa de Campos ◽  
Telmo Jorge Carneiro Amado ◽  
Carlos Gustavo Tornquist ◽  
Rodrigo da Silveira Nicoloso ◽  
Jackson Ernani Fiorin

Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0- monoculture system (soybean/wheat), (b) R1- winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat). The soil C-CO2 efflux was measured every 14 days for two years (48 measurements), by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO2 emissions, but in some individual evaluations, differences between tillage systems were noticed for C-CO2 evolution. Soil C-CO2 effluxes followed a bi-modal pattern, with peaks in October/November and February/March. The highest emission was recorded in the summer and the lowest in the winter. The C-CO2 effluxes were weakly correlated to air temperature and not correlated to soil moisture. Based on the soil C conservation indexes investigated, NT associated to intensive crop rotation was more C conserving than CT with monoculture.


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