Targeting changes in soil porosity through modification of compost size and application rate

Soil Research ◽  
2020 ◽  
Vol 58 (3) ◽  
pp. 268
Author(s):  
Dirk Wallace ◽  
Peter Almond ◽  
Sam Carrick ◽  
Steve Thomas
Keyword(s):  
Particle Size ◽  
Agricultural Soils ◽  
Pore Space ◽  
Total Porosity ◽  
Fibre Production ◽  
Application Rate ◽  
Climatic Conditions ◽  
Available Water ◽  
Municipal Compost ◽  
Increase Food Production

The global demand to increase food production from underperforming, water and nutrient limited soils is increasing, which has resulted in an increased dependency on water for irrigation. As fresh water is a finite resource, the increase in irrigation use has resulted in competition between water used for municipal purposes and that used for food and fibre production for an increasing global population. An opportunity exists to improve the efficiency of both urban and agricultural systems by taking green waste compost generated in urban centres and incorporating it into agricultural soils with poor water retention, thereby increasing the ability of these soils to efficiently retain irrigation water for plant use and also to capture a greater volume of water from rainfall. Addition of amendments to soil changes the pore space. The magnitude and cause for this change depends on amendment type, application rate, soil type and climatic conditions. The aim of this research was to determine if the incorporation of municipal compost (MC) can increase the quantity (total volume) and concentration (total volume per unit volume) of soil pores that hold readily available water (defined as macro-mesopores of 30–3 μm diameter) and plant available water (defined as mesopores of 30–0.3 μm diameter). We hypothesised that increases in total porosity would be positively correlated with MC application rate and increases in water holding porosity (macro-mesoporosity and mesoporosity) would be positively correlated with decreasing MC particle size due to the creation of inter-particle pore spaces < 30 μm in diameter. The MC was screened to three different maximum particle sizes – MC4 (<4 mm), MC2 (<2 mm) and MC0.25 (<0.25 mm) – and incorporated into repacked soil cores at five different rates: 0, 5, 25, 50 and 80% wt/wt. Incorporation of MC0.25 increased the concentration and quantity of macro-mesopores and mesopores at significantly lower application rates than MC4 and MC2. The finding that modification of MC particle size can produce targeted changes in inter-particle porosity suggests that this practice has potential to remediate hydraulic limitations of soils.

scholarly journals N<sub>2</sub>O and N<sub>2</sub> losses from simulated injection of biogas digestate depend mainly on soil texture, moisture and temperature

2017 ◽  
Author(s):  
Sebastian Rainer Fiedler ◽  
Jürgen Augustin ◽  
Nicole Wrage-Mönnig ◽  
Gerald Jurasinski ◽  
Bertram Gusovius ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Pore Space ◽  
Inhibitory Effect ◽  
Application Rate ◽  
Organic Fertiliser ◽  
Potential Capacity ◽  
Clayey Silt ◽  
Biogas Digestate ◽  
Silty Soils

Abstract. Biogas digestate (BD) is increasingly used as organic fertiliser, but has a high potential for NH3 losses. Its proposed injection into soils as a counter-measure has been suggested to promote the generation of N2O, leading to a potential trade-off. Furthermore, the effect on N2 losses after injection of BD into soil has not yet been evaluated. We performed a simulated BD injection experiment in a helium-oxygen atmosphere to examine the influence of soil substrate (loamy sand, clayey silt), water-filled pore space (WFPS; 35, 55, 75 %), temperature (2° C, 15° C) and application rate (0, 160, 320 kg N ha−1) as a proxy for row spacing of injection on the emissions of N2O, N2, and CO2. To determine the potential capacity for these gaseous losses, we incubated under anaerobic conditions by purging with helium for the last 24 h of incubation. N2O and N2 emissions as well as the N2 / (N2O + N2) ratio depended on soil type and increased with WFPS and temperature, indicating a crucial role of soil gas diffusivity for the formation of these gases in agricultural soils. However, the emissions did not increase with the application rate of BD, i.e. a broader spacing of injection slits, probably due to an inhibitory effect of the high NH4+ content of BD. Our results suggest that the risk of N2O and N2 losses even after injection of relatively large amounts of BD seems to be small for dry to wet sandy soils and acceptable when regarding simultaneously reduced NH3 emissions for dry silty soils.

Effect of biochar and biochar particle size on plant-available water of sand, silt loam, and clay soil

2021 ◽  
pp. 104992
Author(s):  
Jun Zhang ◽  
James E. Amonette ◽  
Markus Flury
Keyword(s):  
Particle Size ◽  
Clay Soil ◽  
Silt Loam ◽  
Available Water ◽  
Plant Available Water

Nitrous oxide and carbon dioxide emissions from monoculture and rotational cropping of corn, soybean and winter wheat

2008 ◽  
Vol 88 (2) ◽  
pp. 163-174 ◽  
Author(s):  
C F Drury ◽  
X M Yang ◽  
W D Reynolds ◽  
N B McLaughlin
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Winter Wheat ◽  
Carbon Dioxide Emissions ◽  
Crop Residue ◽  
Agricultural Land ◽  
Application Rate ◽  
Climatic Conditions ◽  
Growing Seasons ◽  
Previous Crop

It is well established that nitrous oxide (N2O) and carbon dioxide (CO2) emissions from agricultural land are influenced by the type of crop grown, the form and amount of nitrogen (N) applied, and the soil and climatic conditions under which the crop is grown. Crop rotation adds another dimension that is often overlooked, however, as the crop residue being decomposed and supplying soluble carbon to soil biota is usually from a different crop than the crop that is currently growing. Hence, the objective of this study was to compare the influence of both the crop grown and the residues from the preceding crop on N2O and CO2 emissions from soil. In particular, N2O and CO2 emissions from monoculture cropping of corn, soybean and winter wheat were compared with 2 -yr and 3-yr crop rotations (corn-soybean or corn-soybean-winter wheat). Each phase of the rotation was measured each year. Averaged over three growing seasons (from April to October), annual N2O emissions were about 3.1 to 5.1 times greater in monoculture corn (2.62 kg N ha-1) compared with either monoculture soybean (0.84 kg N ha-1) or monoculture winter wheat (0.51 kg N ha-1). This was due in part to the higher inorganic N levels in the soil resulting from the higher N application rate with corn (170 kg N ha-1) than winter wheat (83 kg N ha-1) or soybean (no N applied). Further, the previous crop also influenced the extent of N2O emissions in the current crop year. When corn followed corn, the average N2O emissions (2.62 kg N ha-1) were about twice as high as when corn followed soybean (1.34 kg N ha-1) and about 60% greater than when corn followed winter wheat (1.64 kg N ha-1). Monoculture winter wheat had about 45% greater CO2 emissions than monoculture corn or 51% greater emissions than monoculture soybean. In the corn phase, CO2 emissions were greater when the previous crop was winter wheat (5.03 t C ha-1) than when it was soybean (4.20 t C ha-1) or corn (3.91 t C ha-1). Hence, N2O and CO2 emissions from agricultural fields are influenced by both the current crop and the previous crop, and this should be accounted for in both estimates and forecasts of the emissions of these important greenhouse gases. Key words: Denitrification, soil respiration, rotation, crop residue

Laboratory and field measurements of HONO emissions from agricultural soils in Guangdong of China 

2021 ◽  
Author(s):  
Baobin Han ◽  
Peng Cheng ◽  
Yihang Yu ◽  
Wenda Yang ◽  
Zhilin Tian ◽  
...  
Keyword(s):  
Emission Rate ◽  
Agricultural Soils ◽  
Pore Space ◽  
Primary Source ◽  
Field Measurements ◽  
Laboratory Studies ◽  
Release Rates ◽  
Laboratory Results ◽  
Flux Measurements ◽  
Soil Flux

&lt;p&gt;Laboratory studies indicated that soil could produce considerable nitrous acid (HONO) emissions, which is the main primary source of hydroxyl radical (OH) in the troposphere. However, very few field observations of HONO emission from soil were reported. In order to relate laboratory results and field measurements, we measured HONO emissions from 7 representative agricultural soils (rice, vegetables, orchards, peanuts, potatoes, sugarcane and maize) in Guangdong under controlled laboratory conditions, and took flux measurements on 2 of them (rice and vegetables) by dynamic chambers in the field. Generally, release rates of HONO from the seven soils increased with temperature and varied with soil moisture, and the optimum release rates can be reached under specific values of water-filled pore space (WFPS), which is considered to be beneficial to nitrification. The seven soils' optimum release rates ranged from 1.24 to 43.19 ng kg&lt;sup&gt;-1&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;, and the Q&lt;sub&gt;10&lt;/sub&gt; (It is defined as the multiple of the increase of soil gas emission rate when the temperature increases by 10&amp;#8451;) ranged from 1.03 to 2.25. Formulas were deduced from the lab results to express HONO emissions for every soil. Flux measurements on two soils varied around -1 to 4 ng N m&lt;sup&gt;-2&lt;/sup&gt; s&lt;sup&gt;-1&lt;/sup&gt;, and both showed similar diurnal variations with peaks around noontime and very low even negative values during nighttime. There were good correlations between HONO fluxes and soil temperature (R&lt;sup&gt;2&lt;/sup&gt;=0.5). Furthermore, irrigation enhanced the HONO emission substantially. However, a large discrepancy existed between soil HONO emissions measured in lab and low HONO fluxes in field. More investigations are needed to explain the paradox.&lt;/p&gt;

scholarly journals MODELING OF SOIL LOAD-BEARING CAPACITY AS A FUNCTION OF SOIL MECHANICAL RESISTANCE TO PENETRATION

2015 ◽  
Vol 39 (4) ◽  
pp. 1036-1047 ◽  
Author(s):  
Cícero Ortigara ◽  
Moacir Tuzzin de Moraes ◽  
Henrique Debiasi ◽  
Vanderlei Rodrigues da Silva ◽  
Julio Cezar Franchini ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Agricultural Soils ◽  
Total Porosity ◽  
Soil Bulk Density ◽  
Mechanical Resistance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Preconsolidation Pressure ◽  
Soil Load ◽  
Resistance To Penetration

Estimation of soil load-bearing capacity from mathematical models that relate preconsolidation pressure (σp) to mechanical resistance to penetration (PR) and gravimetric soil water content (U) is important for defining strategies to prevent compaction of agricultural soils. Our objective was therefore to model the σp and compression index (CI) according to the PR (with an impact penetrometer in the field and a static penetrometer inserted at a constant rate in the laboratory) and U in a Rhodic Eutrudox. The experiment consisted of six treatments: no-tillage system (NT); NT with chiseling; and NT with additional compaction by combine traffic (passing 4, 8, 10, and 20 times). Soil bulk density, total porosity, PR (in field and laboratory measurements), U, σp, and CI values were determined in the 5.5-10.5 cm and 13.5-18.5 cm layers. Preconsolidation pressure (σp) and CI were modeled according to PR in different U. The σp increased and the CI decreased linearly with increases in the PR values. The correlations between σp and PR and PR and CI are influenced by U. From these correlations, the soil load-bearing capacity and compaction susceptibility can be estimated by PR readings evaluated in different U.

scholarly journals Resolving conflicts over trans-boundary rivers using bankruptcy methods

2013 ◽  
Vol 10 (11) ◽  
pp. 13855-13887 ◽  
Author(s):  
M. Zarezadeh ◽  
K. Madani ◽  
S. Morid
Keyword(s):  
Temporal Distribution ◽  
Stability Index ◽  
River System ◽  
Planning Horizon ◽  
Climatic Conditions ◽  
Index Method ◽  
Allocation Rules ◽  
Available Water ◽  
Time Sensitivity ◽  
Solution Methods

Abstract. A bankruptcy approach is proposed for resolving trans-boundary rivers conflicts in which the total water demand or claim of the riparian parties is more than the available water. Bankruptcy solution methods can allocate the available water to the conflicting parties with respect to their claims. Four bankruptcy rules are used here to allocate the available water to the riparian parties. Given the non-uniform spatial and temporal distribution of water across river basins, bankruptcy optimization models are proposed to allocate water based on these rules with respect to time sensitivity of water deliveries during the planning horizon. Once allocation solutions are developed, their acceptability and stability must be evaluated. Thus, a new stability index method is developed for evaluating the acceptability of bankruptcy solutions. To show how the bankruptcy framework can be helpful in practice, the suggested methods are applied to a real-world tarns-boundary river system with eight riparians under various hydrologic regimes. Stability analysis based on the proposed stability index method suggests that the acceptability of allocation rules is sensitive to hydrologic conditions and demand values. This finding has an important policy implication suggesting that fixed allocation rules and trans-boundary treaties may not be reliable for securing cooperation over trans-boundary water resources as they are vulnerable to changing socio-economic and climatic conditions as well as hydrologic non-stationarity.

Numerical analysis of soil microstructure reveals conditions for natural attenuation in aged tar oil contaminated soil

2021 ◽  
Author(s):  
Pavel Ivanov ◽  
Karin Eusterhues ◽  
Kai Uwe Totsche
Keyword(s):  
Soil Solution ◽  
Contaminated Soil ◽  
Natural Attenuation ◽  
Pore Space ◽  
Total Porosity ◽  
Control Soil ◽  
Soil Microstructure ◽  
Cell Counts ◽  
Good Protection ◽  
Tar Oil

&lt;p&gt;Understanding of ongoing biogeochemical processes (natural attenuation) within contaminated soils is crucial for the development of plausible remediation strategies. We studied a tar oil contaminated soil with weak grass vegetation at a former manufactured gas plant site in Germany. Despite of the apparent toxicity (the soil contained up to 120 g kg&lt;sup&gt;-1&lt;/sup&gt; petroleum hydrocarbons, 26 g kg&lt;sup&gt;-1&lt;/sup&gt; toxic metals, and 100 mg kg&lt;sup&gt;-1&lt;/sup&gt; polycyclic aromatic hydrocarbons), the contaminated layers have 3-5 times as much cell counts as an uncontaminated control soil nearby. To test, if the geometry of the pore space provides favourable living space for microorganisms, we applied scanning electron microscopy to the thin sections and calculated on sets of 15 images per layer three specific Minkowski functionals, connected to soil total porosity, interface, and hydraulic parameters.&lt;/p&gt;&lt;p&gt;Our investigation showed that the uncontaminated control soil has a relatively low porosity of 15-20 %, of which 50-70 % is comprised of small (&lt; 15 &amp;#181;m) pores. These pores are poorly connected and show high distances between them (mean distance to the next pore 10 &amp;#181;m). The dominating habitats in the control soil are therefore created by small pores. They provide good protection from predators and desiccation, but input of dissolved organic C and removal of metabolic products are diffusion limited. Coarser pores (&gt;15 &amp;#181;m) provide less space (&lt; 50 % of total porosity) and solid surface area (&lt; 20 %), are prone to desiccation and offer less protection from predators. However, they serve as preferential flow paths for the soil solution (input of nutrients) and are well aerated, therefore we expect the microbial activity in them to appear in &amp;#8220;hot moments&amp;#8221;, i.e. after rain events.&lt;/p&gt;&lt;p&gt;All layers of the contaminated profile have higher porosities (20-70 %) than the control. Coarse pores comprise 83-90 % of total pore area and create 34-52 % of total interface. Pores are also more connected and tortuous than in the control soil, which implies a better aeration and circulation of soil solution. The loops of pore channels may retain soil solution and be therefore preferably populated with microorganisms. The small (&lt; 15 &amp;#181;m) pores comprise less than 17 % of total porosity but represent a substantial proportion of the interface (48-66 % vs 82-91 % in control). In the uppermost layer of the contaminated profile, such pores occur in plant residues, are close to the largest pores (mean distance to the next pore 4 &amp;#181;m) and therefore, along with good protection, are supplied with air, water, and non-tar C. In the middle of the profile, the small pores, presumably constantly filled with water, are located within dense tar pieces remote from the neighbouring pores (mean distance to the next pore 22 &amp;#181;m), and therefore, with hindered aeration and no supply of non-tar C, may create anaerobic domains of tar attenuation.&lt;/p&gt;&lt;p&gt;Our results show that the contaminated soil offers more favourable conditions for microorganisms than the control soil, probably because the hydrocarbons provide suitable energy and nutrition sources and a beneficial pore space geometry.&lt;/p&gt;

scholarly journals Influence of Climate Conditions on the Temporal Development of Wheat Yields in a Long-Term Experiment in an Area with Pleistocene Loess

Climate ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 100 ◽  
Author(s):  
Kurt Heil ◽  
Anna Lehner ◽  
Urs Schmidhalter
Keyword(s):  
Field Experiments ◽  
Wheat Yield ◽  
Climatic Conditions ◽  
Climate Indices ◽  
Winter Period ◽  
Climate Conditions ◽  
Spring Frost ◽  
Available Water ◽  
Late Spring Frost

Field experiments were conducted to test different agronomic practices, such as soil cultivation, fertilization, and pest and weed management, in highly controlled plot cultivation. The inter-annual yields and the interpretation of such experiments is highly affected by the variability of climatic conditions and fertilization level. We examined the effect of different climate indices, such as winterkill, late spring frost, early autumn frost, different drought parameters, precipitation-free periods, and heat-related stress, on winter wheat yield. This experiment was conducted in an agricultural area with highly fertile conditions, characterized by a high available water capacity and considerable C and N contents in lower soil depths. Residuals were calculated from long-term yield trends with a validated method (time series autoregressive integrated moving average ARIMA) and these served as base values for the detection of climate-induced, short-term, and inter-annual variations. In a subsequent step, the real yield values were used for their derivations from climate factors. Residuals and real yields were correlated with climate variables in multiple regression of quantitative analyses of the yield sensitivity. The inter-annual variation of yields varied considerably within the observation period. However, the variation was less an effect of the climatic conditions during the main growing time periods, being more of an effect of the prevailing climate conditions in the winter period as well as of the transition periods from winter to the warmer season and vice versa. The high storage capacity of plant available water exerted a remarkable dampening effect on drought-induced effects during the main vegetation periods. Increasing fertilization led to increased susceptibility to drought stress. The results indicate a changed picture of the yield development in these fertile locations.

scholarly journals Variations in selected soil physical properties with landforms and slope within an inland valley ecosystem in Ashanti region of Ghana

2011 ◽  
Vol 6 (No. 2) ◽  
pp. 73-82 ◽  
Author(s):  
S.E. Obalum ◽  
J.C. Nwite ◽  
J. Oppong ◽  
C.A. Igwe ◽  
T. Wakatsuki
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Bulk Density ◽  
Site Selection ◽  
Total Porosity ◽  
Soil Physical Properties ◽  
Silt Fraction ◽  
Inland Valley

One peculiar feature of the inland valleys abundant in West Africa is their site-specific hydrology, underlain mainly by the prevailing landforms and topography. Development and management of these land resources under the increasingly popular sawah (a system of bunded, puddled and levelled rice field with facilities for irrigation and drainage) technology is a promising opportunity for enhancing rice (Oryza sativa L.) production in the region. Information on the variations in selected soil physical properties as influenced by the prevailing landforms may serve as a useful guide in site selection. This is of practical importance since majority of the inland valleys are potentially unsuitable for sawah development and most farmers in the region are of low technical level. Three landforms (river levee, elevated area and depressed area) were identified within a sawah field located in an inland valley at Ahafo Ano South District of Ghana. Each of these landforms was topsoil-sampled along on identified gradient (top, mid and bottom slope positions). Parameters determined included particle size distribution, bulk density, total porosity and field moisture content. The soil is predominantly clayey. There were no variations in the particle size distribution among the slope positions in the river levee. Overall, the river levee had lower silt content than the elevated and the depressed landforms. The bulk density, total porosity, and gravimetric moisture content indicated relative improvements only in the depressed area in the order, bottom &gt; mid &gt; top slope. Irrespective of slope position, the three landforms differed in these parameters in the order, depressed &gt; river levee &gt; elevated. The sand fraction impacted negatively on the silt fraction and bulk density of the soil, both of which controlled the soil moisture status. Despite the fairly low silt content of the soil, the silt fraction strongly influenced the gravimetric moisture content (R<sup>2</sup> = 0.80). So too did the soil bulk density on the gravimetric moisture content (R<sup>2</sup> = 0.90). It is concluded that: (1) since the landforms more prominently influenced the measured parameters than the slope positions, the former should take pre-eminence over the latter in soil suitability judgment; (2) with respect to moisture retention, variations in silt fraction and bulk density of this and other clayey inland-valley soils should be used as guide in site selection for sawah development.

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