Impact of Tillage and Residue Management Practices on Soil Aggregates and Soil Organic Carbon

Despite considerable research, predicting how soil organic carbon (SOC) in grain production systems will respond to conservation management practices, such as reduced tillage, residue retention and alternative rotations, remains difficult because of the slowness of change and apparent site specificity of the effects. We compared SOC stocks (equivalent soil mass to ~0–0.3 m depth) under various tillage, residue management and rotation treatments in three long-term (12-, 28- and 94-year-old) field experiments in two contrasting environments (Mallee and Wimmera regions). Our hypotheses were that SOC stocks are increased by: (1) minimum tillage rather than traditional tillage; (2) continuous cropping, rather than crop–fallow rotations; and (3) phases of crop or pasture legumes in rotations, relative to continuous cropping with cereals. We found that zero tillage and stubble retention increased SOC in some circumstances (by up to 1.5 Mg C ha–1, or 8%) but not in others. Inclusion of bare fallow in rotations reduced SOC (by 1.4–2.4 Mg C ha–1, or 8–12%) compared with continuous cropping. Including a pulse crop (field pea, where the grain was harvested) in rotations also increased SOC in some instances (by ~6–8 Mg C ha–1, or 29–35%) but not in others. Similarly, leguminous pasture (medic or lucerne) phases in rotations either increased SOC (by 3.5 Mg C ha–1, or 21%) or had no significant effect compared with continuous wheat. Inclusion of a vetch green manure or unfertilised oat pasture in the rotation did not significantly increase SOC compared with continuous wheat. The responses in SOC to these management treatments were likely to be due, in part, to differences in nitrogen and water availability (and their effects on carbon inputs and decomposition) and, in part, to other, unidentified, interactions. We conclude that the management practices examined in the present study may not reliably increase SOC on their own, but that significant increases in SOC are possible under some circumstances through the long-term use of multiple practices, such as stubble retention + zero tillage + legume N input + elimination of fallow. The circumstances under which increases in SOC can be achieved require further investigation.

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Changes in soil organic carbon and nitrogen after 47 years with different tillage, stubble and fertiliser management in a Vertisol of north-eastern Australia

Soil Research ◽

10.1071/sr19314 ◽

2020 ◽

Vol 58 (4) ◽

pp. 346

Author(s):

K. L. Page ◽

R. C. Dalal ◽

S. H. Reeves ◽

W. J. Wang ◽

Somasundaram Jayaraman ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Crop Residues ◽

Residue Management ◽

Eastern Australia ◽

North Eastern ◽

Over Time

No-till (NT) farming has been widely adopted to assist in reducing erosion, lowering fuel costs, conserving soil moisture and improving soil physical, chemical and biological characteristics. Improvements in soil characteristics are often driven by the greater soil organic matter accumulation (as measured by soil organic carbon (SOC)) in NT compared to conventional tillage (CT) farming systems. However, to fully understand the effect of NT it is important to understand temporal changes in SOC by monitoring over an extended period. We investigated the long-term effect of NT and stubble retention (SR) on changes in SOC and total soil nitrogen (STN) using results from an experiment that has been running for 50 years in a semi-arid subtropical region of north-eastern Australia. In this experiment, the effects of tillage (CT vs NT), residue management (stubble burning (SB) vs SR), and nitrogen (N) fertiliser (0 and 90 kg-N ha–1) were measured in a balanced factorial experiment on a Vertisol (Ustic Pellusert). The use of NT, SR and N fertiliser generally improved SOC (by up to 12.8%) and STN stocks (by up to 31.7%) in the 0–0.1 m layer relative to CT, SB and no N fertiliser, with the greatest stocks observed where all three treatments were used in combination. However, declines in SOC (up to 20%) and STN (up to 25%) occurred in all treatments over the course of the experiment, indicating that changes in management practices were unable to prevent a loss of soil organic matter over time in this farming system. However, the NT and SR treatments did lose less SOC than CT and SB treatments, and SR also reduced STN loss. The δ13C analysis of samples collected in 2008 and 2015 highlighted that crop residues have significantly contributed to SOC stocks at the site and that their contribution is increasing over time.

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Soil organic carbon dynamics from agricultural management practices under climate change

Earth System Dynamics ◽

10.5194/esd-12-1037-2021 ◽

2021 ◽

Vol 12 (4) ◽

pp. 1037-1055

Author(s):

Tobias Herzfeld ◽

Jens Heinke ◽

Susanne Rolinski ◽

Christoph Müller

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Management Practices ◽

Residue Management ◽

Biophysical Model ◽

Management Systems ◽

Climate Change Scenarios ◽

Warm Temperate ◽

Soc Stocks

Abstract. Sequestration of soil organic carbon (SOC) on cropland has been proposed as a climate change mitigation strategy to reduce global greenhouse gas (GHG) concentrations in the atmosphere, which in particular is needed to achieve the targets proposed in the Paris Agreement to limit the increase in atmospheric temperature to well below 2 ∘C. We analyze the historical evolution and future development of cropland SOC using the global process-based biophysical model LPJmL, which was recently extended by a detailed representation of tillage practices and residue management (version 5.0-tillage2). We find that model results for historical global estimates for SOC stocks are at the upper end of available literature, with ∼2650 Pg C of SOC stored globally in the year 2018, ∼170 Pg C of which is stored in cropland soils. In future projections, assuming no further changes in current cropland patterns and under four different management assumptions with two different climate forcings, RCP2.6 and RCP8.5, results suggest that agricultural SOC stocks decline in all scenarios, as the decomposition of SOC outweighs the increase in carbon inputs into the soil from altered management practices. Different climate change scenarios, as well as assumptions on tillage management, play a minor role in explaining differences in SOC stocks. The choice of tillage practice explains between 0.2 % and 1.3 % of total cropland SOC stock change in the year 2100. Future dynamics in cropland SOC are most strongly controlled by residue management: whether residues are left on the field or harvested. We find that on current cropland, global cropland SOC stocks decline until the end of the century by only 1.0 % to 1.4 % if residue retention management systems are generally applied and by 26.7 % to 27.3 % in the case of residue harvest. For different climatic regions, increases in cropland SOC can only be found for tropical dry, warm temperate moist, and warm temperate dry regions in management systems that retain residues.

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The Contribution of Some Soil and Crop Management Practice on Soil Organic Carbon Reserves: Review

JOURNAL OF ADVANCES IN AGRICULTURE ◽

10.24297/jaa.v3i3.4293 ◽

2015 ◽

Vol 3 (3) ◽

pp. 267-274

Author(s):

Agegnehu Shibabaw ◽

Melkamu Alemeyehu

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Crop Rotation ◽

Management Practices ◽

Management Practice ◽

Crop Management ◽

Residue Management ◽

Agricultural Sustainability ◽

Important Indicator

Soil organic carbon is the most important attribute and chosen as the most important indicator of soil and environment quality and agricultural sustainability. Maintaining of soil carbon stocks and other nutrient proved as the most important challenge of arable lands. It depends on soil type, surrounding climate and long term land use. Studies of various research reports indicates that agricultural management practice; crop rotation, residue management, reduced tillage, green manuring and organic matter amendment has identified for its contribution to the improvement of soil organic matter stocks and some other nutrients.Implementing of reduced or no tillage operation has underlined in increasing organic carbon stock of the soil through delaying of organic matter decomposition and N mineralization.Long term adoption of legume based crop rotation notably increases soil organic carbon and N contents, helped with natural gift of atmospheric nitrogen fixation. Organic sources of fertilizer are reservoirs of plant nutrients and organic carbon, and hence amendment with adequate and quality manure ultimately enhances the soil nutrients and SOC stocks of the soil. In general, soil and crop management practices allow the soil to sequester more atmospheric carbon in to the soil.The circumstances ultimately contribute to agricultural sustainability, environmental and soil quality and mitigation of climate change at large.

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Soil Organic Carbon in Sandy Paddy Fields of Northeast Thailand: A Review

Agronomy ◽

10.3390/agronomy10081061 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1061 ◽

Cited By ~ 2

Author(s):

Noppol Arunrat ◽

Praeploy Kongsurakan ◽

Sukanya Sereenonchai ◽

Ryusuke Hatano

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Sandy Soil ◽

Management Practices ◽

Ghg Emissions ◽

Cropping System ◽

Tropical Soils ◽

Paddy Fields ◽

Residue Management ◽

Rice Soil

Soil organic carbon (SOC) improvement has become a sustainable strategy for enhancing soil resilience and reducing greenhouse gas (GHG) emissions in the rice cropping system. For tropical soils, the SOC accumulation was limited by the unfavorable environment, likely the sandy soil area in Northeast (NE) Thailand. This review aims to quantify and understand SOC in sandy paddy fields of NE Thailand. The existing research gap for alternative management practices is also highlighted to increase ecological and agronomic values. We review previous studies to determine the factors affecting SOC dynamics in sandy paddy fields, in order to enhance SOC and sustain rice yields. High sand content, up to 50% sand, was found in 70.7% of the observations. SOC content has ranged from 0.34 to 31.2 g kg−1 for the past four decades in paddy rice soil of NE Thailand. The conventional and alternative practice managements were chosen based on either increasing rice crop yield or improving soil fertility. The lack of irrigation water during the mild dry season would physically affect carbon sequestration as the soil erosion accelerates. Meanwhile, soil chemical and microbial activity, which directly affect SOC accumulation, would be influenced by nutrient and crop residue management, including chemical fertilizer, manure and green manure, unburned rice straw, and biochar application. Increasing SOC content by 1 g kg−1 can increase rice yield by 302 kg ha−1. The predicted carbon saturation varied tremendously, from 4.1% to 140.6% (52% in average), indicating that the sandy soil in this region has the potential for greater SOC sequestration. Our review also suggests that broadening the research of rice production influenced by sandy soil is still required to implement adaptive management for sustainable agriculture and future food security.

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Dynamics of Soil Organic Carbon and Labile Carbon Fractions in Soil Aggregates Affected by Different Tillage Managements

Sustainability ◽

10.3390/su13031541 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1541

Author(s):

Xiaolin Shen ◽

Lili Wang ◽

Qichen Yang ◽

Weiming Xiu ◽

Gang Li ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Aggregates ◽

Aggregate Stability ◽

Soil Aggregate ◽

No Tillage ◽

Labile Carbon ◽

Carbon Fractions ◽

Soil Aggregate Stability ◽

Positive Effects

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.

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Three-year-period nitrogen additions did not alter soil organic carbon content and lability in soil aggregates in a tropical forest

Environmental Science and Pollution Research ◽

10.1007/s11356-021-13466-9 ◽

2021 ◽

Author(s):

Hui Wei ◽

Xiaomei Chen ◽

Mimi Kong ◽

Jinhong He ◽

Weijun Shen

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Tropical Forest ◽

Carbon Content ◽

Soil Aggregates ◽

Organic Carbon Content ◽

Soil Organic Carbon Content ◽

Nitrogen Additions

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Effects of Management and Hillside Position on Soil Organic Carbon Stratification in Mediterranean Centenary Olive Grove

Agronomy ◽

10.3390/agronomy11040650 ◽

2021 ◽

Vol 11 (4) ◽

pp. 650

Author(s):

Jesús Aguilera-Huertas ◽

Beatriz Lozano-García ◽

Manuel González-Rosado ◽

Luis Parras-Alcántara

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Quality ◽

Management Practices ◽

Soil Management ◽

Olive Grove ◽

No Tillage ◽

Short Term ◽

Degradation Degree

The short- and medium—long-term effects of management and hillside position on soil organic carbon (SOC) changes were studied in a centenary Mediterranean rainfed olive grove. One way to measure these changes is to analyze the soil quality, as it assesses soil degradation degree and attempts to identify management practices for sustainable soil use. In this context, the SOC stratification index (SR-COS) is one of the best indicators of soil quality to assess the degradation degree from SOC content without analyzing other soil properties. The SR-SOC was calculated in soil profiles (horizon-by-horizon) to identify the best soil management practices for sustainable use. The following time periods and soil management combinations were tested: (i) in the medium‒long-term (17 years) from conventional tillage (CT) to no-tillage (NT), (ii) in the short-term (2 years) from CT to no-tillage with cover crops (NT-CC), and (iii) the effect in the short-term (from CT to NT-CC) of different topographic positions along a hillside. The results indicate that the SR-SOC increased with depth for all management practices. The SR-SOC ranged from 1.21 to 1.73 in CT0, from 1.48 to 3.01 in CT1, from 1.15 to 2.48 in CT2, from 1.22 to 2.39 in NT-CC and from 0.98 to 4.16 in NT; therefore, the soil quality from the SR-SOC index was not directly linked to the increase or loss of SOC along the soil profile. This demonstrates the time-variability of SR-SOC and that NT improves soil quality in the long-term.

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