Effects of straw incorporation on the stratification of the soil organic C, total N and C:N ratio in a semiarid region of China

We simulated soil organic carbon (C) dynamics across Australia with the Rothamsted carbon model ({\sc Roth C}) by connecting new spatially-explicit soil measurements and data with the model. This helped us to bridge the disconnection that exists between datasets used to inform the model and the processes that it depicts. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated {\sc Roth C} and run simulations to estimate the baseline soil organic C stocks and composition in the 0--0.3~m layer at 4,043 sites in cropping, modified grazing, native grazing, and natural environments across Australia. We used data on the C fractions, the particulate, mineral associated, and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the {\sc Roth C} model's structure.&#160; The model explained 97--98\% of the variation in measured total organic C in soils under cropping and grazing, and 65\% in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant and chainging climate in a 100-year simulation. Soils under native grazing were the most potentially vulnerable to C decomposition and loss, while soils under natural environments were the least vulnerable. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio, and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, contributing to the development of sustainable soil management under global change.&#160;

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Simulation of soil carbon dynamics in Australia under a framework that better connects spatially explicit data with Rᴏᴛʜ C

10.5194/bg-2020-150 ◽

2020 ◽

Author(s):

Juhwan Lee ◽

Raphael A. Viscarra Rossel ◽

Zhongkui Luo ◽

Ying Ping Wang

Keyword(s):

C:N Ratio ◽

Clay Content ◽

Spatially Explicit ◽

Natural Environments ◽

Soil Organic C ◽

Total N ◽

Organic C ◽

Soil C ◽

Continental Scale ◽

C Stocks

Abstract. We simulated soil organic carbon (C) dynamics across Australia with the Rothamsted carbon model (Rᴏᴛʜ C) under a framework that connects new spatially-explicit soil measurements and data with the model. Doing so helped to bridge the disconnection that exists between datasets used to inform the model and the processes that it depicts. Under this framework, we compiled continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Rᴏᴛʜ C and run simulations to predict the baseline soil organic C stocks and composition in the 0–0.3 m layer at 4,043 sites in cropping, modified grazing, native grazing, and natural environments across Australia. The Rᴏᴛʜ C model uses measured C fractions, the particulate, humus, and resistant organic C (POC, HOC and ROC, respectively) to represent the three main C pools in its structure. The model explained 97–98 % of the variation in measured total organic C in soils under cropping and grazing, and 65 % in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to predict the potential for C accumulation in a 100-year simulation. With an annual increase of 1 Mg C ha−1 in C inputs, the model predicted a potential soil C increase of 13.58 (interquartile range 12.19–15.80), 14.21 (12.38–16.03), and 15.57 (12.07–17.82) Mg C ha−1 under cropping, modified grazing and native grazing, and 3.52 (3.15–4.09) Mg C ha−1 under natural environments. Soils under native grazing were the most potentially vulnerable to C decomposition and loss, while soils under natural environments were the least vulnerable. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio, and cropping were the most important controls on POC change. Clay content and climate were dominant controls on HOC change. Consistent and explicit soil organic C simulations improve confidence in the model's predictions, contributing to the development of sustainable soil management under global change.

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Soil Chemistry and Cucumber (Cucumis sativus L.) Yield as Influenced by 16 Years of Composted Poultry Litter Addition

Journal of Agricultural Science ◽

10.5539/jas.v10n1p325 ◽

2017 ◽

Vol 10 (1) ◽

pp. 325

Author(s):

Hebert D. A. Abobi ◽

Armand W. Koné ◽

Bernard Y. Koffi ◽

Saint Salomon F. Diahuissié ◽

Stanislas K. Loukou ◽

...

Keyword(s):

Soil Fertility ◽

Growth Parameters ◽

Block Design ◽

C:N Ratio ◽

Poultry Litter ◽

Growth And Yield ◽

Soil Parameters ◽

Total N ◽

Organic C ◽

Litter Addition

Poultry litter is increasingly used as organic amendment in market gardening in Côte d’Ivoire. To know about the sustainability of this practice, its impacts on soil quality should be known. This study aimed at assessing the effect on soil fertility of composted poultry litter addition for 16 years following two distinct ways, and identifying soil parameters driving cucumber yield. Trials were laid out in a Fisher randomized block design with 3 treatments replicated 5 times each: Control (C), Surface-applied compost (SAC) and Buried compost (BC). Soil (0-20 cm) chemical characteristics and cucumber growth and yield parameters were measured. Values of all parameters were higher with compost addition compared to the control, except for the C:N ratio. SAC and BC showed similar values of organic C, total N, CEC, pH and available phosphorus. However, Ca2+, Mg2+, K+ and base saturation were higher in SAC than in BC. Relative to values in the control, the greatest changes in soil parameters were observed with exchangeable cations, followed by soil organic matter. Soil organic C and total N concentrations have doubled in SAC while Ca2+, Mg2+, and K+ increased at greater rate (702.4, 400.9 and 186.67% respectively). Also, cucumber growth parameters were the highest with compost addition compared to the control. Significant effect of the compost application way on cucumber was also observed: collar diameter, leaf area and fresh fruit yield in SAC (0.72±0.02 cm, 258.9±12.3 cm2, 11.1±1.3 t ha-1, respectively) were higher than in BC (0.56±0.01 cm, 230.2±2.5 cm2, 5.4±0.5 t ha-1 respectively). Fruit yields in SAC and BC were four times and twice higher than in the control (2.6±0.3 t ha-1), respectively. Cucumber growth parameters were determined by soil concentration in Mg2+ while yield was determined by Ca2+. Composted poultry litter should be promoted for a sustainable soil fertility management in vegetable farming systems.

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Douglas-fir soil C and N properties a decade after termination of urea fertilization

Canadian Journal of Forest Research ◽

10.1139/x01-162 ◽

2001 ◽

Vol 31 (12) ◽

pp. 2225-2236 ◽

Cited By ~ 23

Author(s):

Peter S Homann ◽

Bruce A Caldwell ◽

H N Chappell ◽

Phillip Sollins ◽

Chris W Swanston

Keyword(s):

Mineral Soil ◽

Cellulase Activity ◽

Douglas Fir ◽

Soil Organic C ◽

Total N ◽

Organic C ◽

Soil C ◽

Second Growth ◽

Heavy Fractions ◽

Urea Fertilization

Chemical and microbial soil properties were assessed in paired unfertilized and urea fertilized (>89 g N·m2) plots in 13 second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands distributed throughout western Washington and Oregon. A decade following the termination of fertilization, fertilized plots averaged 28% higher total N in the O layer than unfertilized plots, 24% higher total N in surface (05 cm) mineral soil, and up to four times the amount of extractable ammonium and nitrate. Decreased pH (0.2 pH units) caused by fertilization may have been due to nitrification or enhanced cation uptake. In some soil layers, fertilization decreased cellulase activity and soil respiration but increased wood decomposition. There was no effect of fertilization on concentrations of light and heavy fractions, labile carbohydrates, and phosphatase and xylanase activities. No increase in soil organic C was detected, although variability precluded observing an increase of less than ~15%. Lack of a regionwide fertilization influence on soil organic C contrasts with several site-specific forest and agricultural studies that have shown C increases resulting from fertilization. Overall, the results indicate a substantial residual influence on soil N a decade after urea fertilization but much more limited influence on soil C processes and pools.

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Stratification of soil organic C, N and the C:N ratio as affected by different plastic film mulching modes in a semiarid region of China

Soil Research ◽

10.1071/sr18256 ◽

2019 ◽

Vol 57 (4) ◽

pp. 408 ◽

Cited By ~ 2

Author(s):

Peng Zhang ◽

Ting Wei ◽

Zhikuan Jia ◽

Xiaolong Ren

Keyword(s):

Crop Yields ◽

C:N Ratio ◽

Semiarid Region ◽

Plastic Film ◽

Organic C ◽

Soil C ◽

North West ◽

Plastic Film Mulching ◽

Film Mulching ◽

The Mean

The soil degradation caused by plastic film mulching tillage in rain-fed areas of north-west China is known to affect sustainable and stable crop yields because of major losses of soil organic carbon (SOC) and nutrients. To evaluate the effects of different plastic film mulching modes on SOC and total nitrogen (STN) sequestration capacity in loessic soil, we investigated the effects of different plastic film mulching on SOC, STN, and the soil C:N ratio in semiarid areas of southern Ningxia for a 4-year period (2013–2016). Five treatments were tested: (i) the control, conventional flat planting without mulching (CK); (ii) alternating mulching and bare rows without ridges and planting in mulched rows (P); (iii) furrow planting of maize, separated by consecutive plastic film-mulched ridges (S); (iv) furrow planting of maize, separated by alternating large and small plastic film-mulched ridges (D); and (v) furrow-flat planting of maize with a large plastic film-mulched ridge alternating with a flat plastic film-mulched space (R). In the final experimental year (2016), the results showed that the mean soil bulk density at 0–60 cm depth had decreased with film mulching treatments by 2.82%, 5.90% (P < 0.05), 7.29% (P < 0.05), and 9.46% (P < 0.05) respectively, compared with CK. Film mulching increased the concentration of SOC and STN, which were ranked in order S > R/D > P > CK; however, there was no significant increase with the storage of SOC and STN. The mean soil C:N ratio was higher with mulching treatment, i.e. 2.91% (P > 0.05) higher than CK in 0–60 cm depth. Mulching treatments significantly (P < 0.05) increased the stratification ratio (SR) of SOC and soil C: N ratio from the surface (0–20 cm) to all depths compared with CK, i.e. the SR of SOC at the 0–20:20–40 cm depth significantly (P < 0.05) increased with D, R, S, and P by 14.81%, 9.47%, 14.18%, and 9.51% respectively, compared with CK.

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Identification of organic acids produced during rice straw decomposition and their role in rock phosphate solubilization

Plant Soil and Environment ◽

10.17221/2783-pse ◽

2008 ◽

Vol 54 (No. 2) ◽

pp. 72-77 ◽

Cited By ~ 20

Author(s):

A. Kumari ◽

K.K. Kapoor ◽

B.S. Kundu ◽

R. Kumari Mehta

Keyword(s):

Organic Acids ◽

Rice Straw ◽

Rock Phosphate ◽

C:N Ratio ◽

Straw Decomposition ◽

Total N ◽

Organic C ◽

P Solubilization ◽

Rock Phosphate Solubilization ◽

Oxalic Acids

The production of organic acids and changes during decomposition of rice straw amended with tricalcium phosphate (TCP) and Udaipur rock phosphate (URP) were studied under laboratory conditions. The organic C content of rice straw decreased and total N increased with time, resulting in a decrease in C:N ratio as the decomposition progressed. The pH decreased to acidic range in all the treatments on day 15, but became alkaline again later on. Soluble P increased at 15 days after incubation, declined later during decomposition, and was highest in the treatments containing TCP and Aspergillus awamori inoculation. Citric, oxalic, formic and maleic acids were detected during decomposition of rice straw and maximum amounts were present on day 15. Citric and oxalic acids were responsible mainly for P solubilization from TCP and URP; generally, citric acid was the most effective in P solubilization.

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Management of sugarcane harvest residues: consequences for soil carbon and nitrogen

Soil Research ◽

10.1071/sr06080 ◽

2007 ◽

Vol 45 (1) ◽

pp. 13 ◽

Cited By ~ 83

Author(s):

Fiona A. Robertson ◽

Peter J. Thorburn

Keyword(s):

Microbial Biomass ◽

Soil Fertility ◽

Microbial Activity ◽

Soil N ◽

Soil Organic C ◽

Total N ◽

Organic C ◽

Soil Microbial ◽

C And N

The Australian sugar industry is moving away from the practice of burning the crop before harvest to a system of green cane trash blanketing (GCTB). Since the residues that would have been lost in the fire are returned to the soil, nutrients and organic matter may be accumulating under trash blanketing. There is a need to know if this is the case, to better manage fertiliser inputs and maintain soil fertility. The objective of this work was to determine whether conversion from a burning to a GCTB trash management system is likely to affect soil fertility in terms of C and N. Indicators of short- and long-term soil C and N cycling were measured in 5 field experiments in contrasting climatic conditions. The effects of GCTB varied among experiments. Experiments that had been running for 1–2 years (Harwood) showed no significant trash management effects. In experiments that had been running for 3–6 years (Mackay and Tully), soil organic C and total N were up to 21% greater under trash blanketing than under burning, to 0.10 or 0.25 m depth (most of this effect being in the top 50 mm). Soil microbial activity (CO2 production) and soil microbial biomass also increased under GCTB, presumably as a consequence of the improved C availability. Most of the trash C was respired by the microbial biomass and lost from the system as CO2. The stimulation of microbial activity in these relatively short-term GCTB systems was not accompanied by increased net mineralisation of soil N, probably because of the greatly increased net immobilisation of N. It was calculated that, with standard fertiliser applications, the entire trash blanket could be decomposed without compromising the supply of N to the crop. Calculations of possible long-term effects of converting from a burnt to a GCTB production system suggested that, at the sites studied, soil organic C could increase by 8–15%, total soil N could increase by 9–24%, and inorganic soil N could increase by 37 kg/ha.year, and that it would take 20–30 years for the soils to approach this new equilibrium. The results suggest that fertiliser N application should not be reduced in the first 6 years after adoption of GCTB, but small reductions may be possible in the longer term (>15 years).

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Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework

Biogeosciences ◽

10.5194/bg-18-5185-2021 ◽

2021 ◽

Vol 18 (18) ◽

pp. 5185-5202

Author(s):

Juhwan Lee ◽

Raphael A. Viscarra Rossel ◽

Mingxi Zhang ◽

Zhongkui Luo ◽

Ying-Ping Wang

Keyword(s):

Global Change ◽

Future Climate Change ◽

Natural Environments ◽

Soil Organic C ◽

Total N ◽

Organic C ◽

Soil C ◽

Continental Scale ◽

Modelling Framework ◽

C Stocks

Abstract. Land use and management practices affect the response of soil organic carbon (C) to global change. Process-based models of soil C are useful tools to simulate C dynamics, but it is important to bridge any disconnect that exists between the data used to inform the models and the processes that they depict. To minimise that disconnect, we developed a consistent modelling framework that integrates new spatially explicit soil measurements and data with the Rothamsted carbon model (Roth C) and simulates the response of soil organic C to future climate change across Australia. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Roth C and ran simulations to estimate the baseline soil organic C stocks and composition in the 0–0.3 m layer at 4043 sites in cropping, modified grazing, native grazing and natural environments across Australia. We used data on the C fractions, the particulate, mineral-associated and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the Roth C model's structure. The model explained 97 %–98 % of the variation in measured total organic C in soils under cropping and grazing and 65 % in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant climate in a 100-year simulation. With an annual increase of 1 Mg C ha−1 in C inputs, the model simulated a potential soil C increase of 13.58 (interquartile range 12.19–15.80), 14.21 (12.38–16.03) and 15.57 (12.07–17.82) Mg C ha−1 under cropping, modified grazing and native grazing and 3.52 (3.15–4.09) Mg C ha−1 under natural environments. With projected future changes in climate (+1.5, 2 and 5.0 ∘C) over 100 years, the simulations showed that soils under natural environments lost the most C, between 3.1 and 4.5 Mg C ha−1, while soils under native grazing lost the least, between 0.4 and 0.7 Mg C ha−1. Soil under cropping lost between 1 and 2.7 Mg C ha−1, while those under modified grazing showed a slight increase with temperature increases of 1.5 ∘C, but with further increases of 2 and 5 ∘C the median loss of TOC was 0.28 and 3.4 Mg C ha−1, respectively. For the different land uses, the changes in the C fractions varied with changes in climate. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C : N ratio and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, facilitating the development of sustainable soil management under global change.

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Soil properties following long-term application of stockpiled feedlot manure containing straw or wood-chip bedding under barley silage production

Canadian Journal of Soil Science ◽

10.4141/cjss2013-087 ◽

2014 ◽

Vol 94 (3) ◽

pp. 389-402 ◽

Cited By ~ 6

Author(s):

J. J. Miller ◽

B. W. Beasley ◽

C. F. Drury ◽

X. Hao ◽

F. J. Larney

Keyword(s):

Soil Properties ◽

C:N Ratio ◽

Wood Chip ◽

Water Soluble ◽

Bedding Material ◽

Total N ◽

Organic C ◽

Silage Production ◽

Total Organic C

Miller, J. J., Beasley, B. W., Drury, C. F., Hao, X. and Larney, F. J. 2014. Soil properties following long-term application of stockpiled feedlot manure containing straw or wood-chip bedding under barley silage production. Can. J. Soil Sci. 94: 389–402. The influence of long-term land application of stockpiled feedlot manure (SM) containing either wood-chip (SM-WD) or straw (SM-ST) bedding on soil properties during the barley (Hordeum vulgare L.) silage growing season is unknown. The main objective of our study was determine the effect of bedding material in stockpiled manure (i.e., SM-WD vs. SM-ST) on certain soil properties. A secondary objective was to determine if organic amendments affected certain soil properties compared with unamended soil. Stockpiled feedlot manure with SM-WD or SM-ST bedding at 77 Mg (dry wt) ha−1 yr−1 was annually applied for 13 to 14 yr to a clay loam soil in a replicated field experiment in southern Alberta. There was also an unamended control. Soil properties were measured every 2 wk during the 2011 and 2012 growing season. Properties included water-filled pore space (WFPS), total organic C and total N, NH4-N and NO3-N, water-soluble non-purgeable organic C (NPOC), water-soluble total N (WSTN), denitrification (acetylene inhibition method), and CO2 flux. The most consistent and significant (P≤0.05) bedding effects on soil properties in both years occurred for total organic C, C:N ratio, and WSTN. Total organic C and C:N ratio were generally greater for SM-WD than SM-ST, and the reverse trend occurred for WSTN. Bedding effects on other soil properties (WFPS, NH4-N, NO3-N, NPOC) occurred in 2012, but not in 2011. Total N, daily denitrification, and daily CO2 flux were generally unaffected by bedding material. Mean daily denitrification fluxes ranged from 0.9 to 1078 g N2O-N ha−1 d−1 for SM-ST, 0.8 to 326 g N2O-N ha−1 d−1 for SM-WD, and 0.6 to 250 g N2O-N ha−1 d−1 for the CON. Mean daily CO2 fluxes ranged from 5.3 to 43.4 kg CO2-C ha−1 d−1 for SM-WD, 5.5 to 26.0 kg CO2-C ha−1 d−1 for SM-ST, and from 0.5 to 6.8 kg CO2-C ha−1 d−1 for the CON. The findings from our study suggest that bedding material in feedlot manure may be a possible method to manage certain soil properties.

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