N2O and CO2 emissions from a dryland wheat cropping system with long-term N fertilization and their relationships with soil C, N, and bacterial community

Agricultural management affects soil organic matter, which is important for sustainable crop production and as a greenhouse gas sink. Our objective was to determine how tillage, residue management and N fertilization affect organic C in unprotected, and physically, chemically and biochemically protected soil C pools. Samples from Breton, Alberta were fractionated and analysed for organic C content. As in previous reports, N fertilization had a positive effect, tillage had a minimal effect, and straw management had no effect on whole-soil organic C. Tillage and straw management did not alter organic C concentrations in the isolated C pools, while N fertilization increased C concentrations in all pools. Compared with a woodlot soil, the cultivated plots had lower total organic C, and the C was redistributed among isolated pools. The free light fraction and coarse particulate organic matter responded positively to C inputs, suggesting that much of the accumulated organic C occurred in an unprotected pool. The easily dispersed silt-sized fraction was the mineral-associated pool most responsive to changes in C inputs, whereas the microaggregate-derived silt-sized fraction best preserved C upon cultivation. These findings suggest that the silt-sized fraction is important for the long-term stabilization of organic matter through both physical occlusion in microaggregates and chemical protection by mineral association. Key words: Soil organic C, tillage, residue management, N fertilization, silt, clay

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Changes in Soil Microbial Activity, Bacterial Community Composition and Function in a Long-Term Continuous Soybean Cropping System After Corn Insertion and Fertilization

Frontiers in Microbiology ◽

10.3389/fmicb.2021.638326 ◽

2021 ◽

Vol 12 ◽

Author(s):

Demin Rao ◽

Fangang Meng ◽

Xiaoyan Yan ◽

Minghao Zhang ◽

Xingdong Yao ◽

...

Keyword(s):

Bacterial Community ◽

Microbial Activity ◽

High Throughput Sequencing ◽

Bacterial Community Composition ◽

Cropping System ◽

Soil Microbial Activity ◽

Functional Structure ◽

Soil Microbial ◽

Npk Fertilizer

Corn-soybean rotation and fertilization are common practices improving soil fertility and crop yield. Their effects on bacterial community have been extensively studied, yet, few comprehensive studies about the microbial activity, bacterial community and functional groups in a long-term continuous soybean cropping system after corn insertion and fertilization. The effects of corn insertions (Sm: no corn insertion, CS: 3 cycles of corn-soybean rotations and CCS: 2 cycles of corn-corn-soybean rotations) with two fertilization regimes (No fertilization and NPK) on bacterial community and microbial activity were investigated in a long-term field experiment. The bacterial communities among treatments were evaluated using high-throughput sequencing then bacterial functions were predicted based on the FaProTax database. Soil respiration and extracellular enzyme activities were used to assess soil microbial activity. Soil bacterial community structure was significantly altered by corn insertions (p < 0.01) and fertilization (p < 0.01), whereas bacterial functional structure was only affected by corn insertion (p < 0.01). The activities of four enzymes (invertase, β-glucosidase, β-xylosidase, and β-D-1,4-cellobiohydrolase) involved in soil C cycling were enhanced by NPK fertilizer, and were also enhanced by corn insertions except for the invertase and β-xylosidase under NPK fertilization. NPK fertilizer significantly improved soil microbial activity except for soil metabolic quotient (qCO2) and the microbial quotient under corn insertions. Corn insertions also significantly improved soil microbial activity except for the ratio of soil induced respiration (SIR) to basal respiration (BR) under fertilization and the qCO2 was decreased by corn insertions. These activity parameters were highly correlated with the soil functional capability of aromatic compound degradation, which was the main predictors of bacterial functional structure. In general, the combination of soil microbial activity, bacterial community and corresponding functional analysis provided comprehensive insights into compositional and functional adaptations to corn insertions and fertilization.

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Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832011000300017 ◽

2011 ◽

Vol 35 (3) ◽

pp. 819-832 ◽

Cited By ~ 10

Author(s):

Ben-Hur Costa de Campos ◽

Telmo Jorge Carneiro Amado ◽

Carlos Gustavo Tornquist ◽

Rodrigo da Silveira Nicoloso ◽

Jackson Ernani Fiorin

Keyword(s):

Co2 Emissions ◽

Crop Rotation ◽

Crop Residue ◽

Crop Residues ◽

Cropping Systems ◽

Co2 Efflux ◽

C Mineralization ◽

Tillage Systems ◽

Soil C

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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Effects of Long-Term Nitrogen Fertilization and Ground Water Level Changes on Soil CO2 Fluxes from Oil Palm Plantation on Tropical Peatland

Atmosphere ◽

10.3390/atmos12101340 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1340

Author(s):

Auldry Chaddy ◽

Lulie Melling ◽

Kiwamu Ishikura ◽

Kah Joo Goh ◽

Yo Toma ◽

...

Keyword(s):

Soil Respiration ◽

Co2 Emissions ◽

Oil Palm ◽

N Fertilization ◽

Root Activity ◽

Co2 Fluxes ◽

Soil Co2 ◽

Tropical Peatland ◽

Oil Palm Plantation

A long-term study on the effect of nitrogen (N) fertilization on soil carbon dioxide (CO2) fluxes in tropical peatland was conducted to (1) quantify the annual CO2 emissions from an oil palm plantation under different N application rates and (2) evaluate the temporal effects of groundwater level (GWL) and water-filled pore space (WFPS) on soil organic carbon (SOC) and CO2 fluxes. Monthly measurement of soil CO2 fluxes using a closed chamber method was carried out from January 2010 until December 2013 and from January 2016 to December 2017 in an oil palm plantation on tropical peat in Sarawak, Malaysia. Besides the control (T1, without N fertilization), there were three N treatments: low N (T2, 31.1 kg N ha−1 year−1), moderate N (T3, 62.2 kg N ha−1 year−1), and high N (T4, 124.3 kg N ha−1 year−1). The annual CO2 emissions ranged from 7.7 ± 1.2 (mean ± SE) to 16.6 ± 1.0 t C ha−1 year−1, 9.8 ± 0.5 to 14.8 ± 1.4 t C ha−1 year−1, 10.5 ± 1.8 to 16.8 ± 0.6 t C ha−1 year−1, and 10.4 ± 1.8 to 17.1 ± 3.9 t C ha−1 year−1 for T1, T2, T3, and T4, respectively. Application of N fertilizer had no significant effect on annual cumulative CO2 emissions in each year (p = 0.448), which was probably due to the formation of large quantities of inorganic N when GWL was temporarily lowered from January 2010 to June 2010 (−80.9 to −103.4 cm below the peat surface), and partly due to low soil organic matter (SOM) quality. A negative relationship between GWL and CO2 fluxes (p < 0.05) and a positive relationship between GWL and WFPS (p < 0.001) were found only when the oil palm was young (2010 and 2011) (p < 0.05), indicating that lowering of GWL increased CO2 fluxes and decreased WFPS when the oil palm was young. This was possibly due to the fact that parameters such as root activity might be more predominant than GWL in governing soil respiration in older oil palm plantations when GWL was maintained near or within the rooting zone (0–50 cm). This study highlights the importance of roots and WFPS over GWL in governing soil respiration in older oil palm plantations. A proper understanding of the interaction between the direct or indirect effect of root activity on CO2 fluxes and balancing its roles in nutrient and water management strategies is critical for sustainable use of tropical peatland.

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PENGARUH SISTEM OLAH TANAH DAN PEMUPUKAN NITROGEN JANGKA PANJANG TERHADAP RESPIRASI TANAH DI LAHAN POLITEKNIK NEGERI LAMPUNG TAHUN TANAM KE-27

Jurnal Agrotek Tropika ◽

10.23960/jat.v8i2.3898 ◽

2020 ◽

Vol 8 (2) ◽

pp. 247

Author(s):

Erdiana Damayanti ◽

Muhajir Utomo ◽

Ainin Niswati ◽

Henrie Buchari

Keyword(s):

Soil Respiration ◽

Co2 Emissions ◽

Nitrogen Fertilizer ◽

Nitrogen Fertilization ◽

Conservation Tillage ◽

N Fertilization ◽

No Tillage ◽

Tillage Systems ◽

Tillage System

Unsustainable cultivation techniques can cause carbon loss on farm. The cultivation technique that is often used by farmers today is intensive tillage. Intensive tillage can increase CO2. Steps to reduce CO2 gas emissions, while increasing carbon stored in the soil by implementing agricultural cultivation with conservation tillage system (Olah Tanah Konservasi). The conservation tillage system is able to reduce global warming through absorption of C in the soil, and reduce CO2 emissions. In addition, fertilization can also affect CO2 emissions. CO2 emissions in the soil come from soil respiration. The purpose of this study was to determine the effect of long-term tillage systems on soil respiration, determine the effect of long-term N fertilization on soil respiration, and determine the effect of interactions between tillage systems and long-term N fertilization on soil respiration. The study was arranged in a randomized block design (RBD) consisting of two factors, namely the tillage system and nitrogen fertilization factors. The first factor is the treatment of tillage system (T) namely T0 = no tillage, and T1 = intensive tillage, while the second factor is without nitrogen fertilizer (N0) and high nitrogen fertilizer (N1). The data obtained will be tested for homogeneity by Bartlett Test and additives tested by Tukey Test. Furthermore, the data were analyzed by analysis of variance and continued with a BNJ test of 5% level. Observation of soil respiration was done 4 times, namely -1, 1, 2, 3 days after tillage. The results showed that soil respiration one day before to three days after the soil was treated in intensive tillage (OTI) was the same as the no tillage system (TOT), soil respiration -1 days after tillage to 3 days after tillage on nitrogen fertilization (100 N kg ha-1 ) given in the previous planting season the same as without fertilization (0 kg N ha-1), and there is no interaction between the tillage system and nitrogen fertilization on soil respiration.

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Long-term effects of tillage and nitrogen fertilization on soil C and N fractions in a corn-soybean rotation

Canadian Journal of Soil Science ◽

10.1139/cjss-2021-0129 ◽

2021 ◽

Author(s):

Mervin St. Luce ◽

Noura Ziadi ◽

Martin H. Chantigny ◽

Justin Braun

Keyword(s):

Organic Matter ◽

N Fertilization ◽

Interactive Effects ◽

Long Term Effects ◽

Total N ◽

Soil C ◽

Glycine Max L ◽

C And N ◽

N Rates

Tillage and nitrogen (N) fertilization can influence soil organic matter (SOM) dynamics, but their interactive effects remain contradictory. A long-term (25 yr) corn (Zea mays L.)-soybean (Glycine max L. Merr.) rotation was used to investigate the effect of tillage [moldboard plow (MP) and no-till (NT)] and N rates (0, 80 and 160 kg N ha-1) on soil organic carbon (SOC), total N (STN), respiration, and SOM fractions [particulate organic matter (POMC, POMN), mineral-associated organic matter (MAOMC, MAOMN), and microbial biomass (MBC, MBN)]. Results indicate that NT had 27% higher SOC and 24% higher STN than MP in the 0-20 cm depth. Furthermore, SOC and STN stocks (0-20 cm) were 22% and 20% higher, respectively, under NT than MP. There was significant stratification under NT, with a rather uniform distribution under MP. The SOM fractions and soil respiration were 28-275% and 20-83% higher at the 0-5 and 5-10 cm depths, respectively, under NT than MP. Interestingly, N fertilizer rate or its interaction with tillage had no impact, except for respiration (tillage × N rate and N rate × depth). Hence, while N addition was required for adequate grain production and increased cumulative plant C and N inputs, our findings indicate that the vertical distribution of SOC, STN and SOM fractions were affected by tillage, thereby influencing resource accessibility and subsequent dynamics of SOM fractions. Taken together, our results support the adoption of NT and judicious use of N fertilizers for enhancing topsoil SOM storage and fertility under humid temperate conditions.

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Density and morphological characterization of bacteria in integrated and exclusive production systems

Scientific Electronic Archives ◽

10.36560/13920201194 ◽

2020 ◽

Vol 13 (11) ◽

pp. 1

Author(s):

A. R. B. Zanco ◽

A. Ferreira ◽

G. C. M. Berber ◽

E. N. Gonzaga ◽

D. C. C. Sabino

Keyword(s):

Bacterial Community ◽

Rainy Season ◽

Production Systems ◽

Cropping System ◽

Morphological Characterization ◽

Native Forest ◽

Exclusive Production ◽

Colony Forming Units

The different integrated production systems can directly interfere with its bacterial community. The present study aimed to assess density, bacterial diversity and the influence of dry and rainy season in different integrated and an exclusive production system. The fallow and a native forest area was assessed to. Samples were collected in 2012 March and September. The isolation were carried out into Petri dishes containing DYGS medium. The number of colony forming units (CFU) was counted after 48 hours and. The bacterial density ranged between 106 and 107 CFU g-1 soil. The crop system affected the dynamics of the bacterial community only in the rainy season. The rainy season showed greater density of total bacteria when compared to the dry period regardless of the cropping system. The dendrograms with 80 % similarity showed thirteen and fourteen groups in the rainy and dry seasons. Isolates with the capacity to solubilize phosphate in vitro were obtained from all areas in the two seasons, but this feature has been prevalent in bacteria isolated during the rainy season

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