Effect Of Soil Texture Research Articles

Evaluating soil water movement and soil water content uniformity under sprinkler irrigation with different soil texture and irrigation uniformity using numerical simulation

Water movement and its distribution uniformity in the soil are essential for the design of sprinkler irrigation systems. They are both crucial factors influencing nutrient migration and the productivity of crops. In this study, a new numerical simulation method was proposed to investigate the soil water movement in sprinkler irrigation under nonuniform infiltration boundary conditions using COMSOL software. Besides, two soil tank experiments were conducted to test the reliability of the simulation model. Finally, the model was applied to evaluate the effects of sprinkler irrigation uniformity, soil texture, and initial soil water content on soil wetting patterns and soil water content uniformity. The results showed that the COMSOL-2D predictions of the vertical wetting fronts were in good agreement with the experimental data. The soil texture and initial soil water content influenced the soil wetting pattern and the risks of surface runoff and deep percolation in sprinkler irrigation systems. When the water application rate was 11.35 mm h−1 with an irrigation duration of 10 h, it was easy to cause surface runoff in silty clay loam while deep percolation in loamy sand. Additionally, when the initial soil water content is high, it should be better to avoid irrigation or cut down the irrigation duration to prevent percolation. The water within the soil was more uniformly distributed than that applied through a sprinkler irrigation system. The uniformity coefficient of soil water content distribution (CUs) increased from 87.75 % to 95.56 %, as the uniformity coefficient of sprinkler irrigation (CU) increased from 40.74 % to 82.41 %. Although a higher initial soil water content brought a higher soil CUs value, it also led to a higher risk of percolation. The experimental and simulation results indicated that the COMSOL-2D model could be used to accurately simulate soil water movement in sprinkler irrigation and determine the suitable operation mode of low-pressure sprinklers.

Effects of fir-wood biochar on CH4 oxidation rates and methanotrophs in landfill cover soils packed at three different proctor compaction levels

Application of biochar to landfill cover soils can purportedly improve methane (CH4) oxidation rates, but understanding the combined effects of soil texture, compaction, and biochar on the activity and composition of the methanotrophs is limited. The amendment of wood biochar on two differently textured landfill cover soils at three compaction levels of the Proctor density was explored by analyzing changes in soil physical properties relevant to methane oxidation, the effects on CH4 oxidation rates, and the composition of the methanotrophic community. Loose soils with and without biochar were pre-incubated to equally elevate the CH4 oxidation rates. Hereafter, soils were compacted and re-incubated. Methane oxidation rates, gas diffusivity, water retention characteristics, and pore size distribution were analyzed on the compacted soils. The relative abundance of methanotrophic bacteria (MOB) was determined at the end of both the pre-incubation and incubation tests of the packed samples. Biochar significantly increased porosity at all compaction levels, enhancing diffusion coefficients. Also, a re-distribution in pore sizes was observed. Increased gas diffusivity from low compaction and amendment of biochar, though, did not reflect higher methane oxidation rates due to high diffusive oxygen fluxes over the limited height of the compacted soil specimens. All soils, with and without biochar, were strongly dominated by Type II methanotrophs. In the sandy soil, biochar amendment strongly increased MOB abundance, which could be attributed to a corresponding increase in the relative abundance of Methylocystis species, while no such response was observed in the clayey soil. Compaction did not change the community composition in either soil. Fir-wood biochar addition to landfill cover soils may not always enhance methanotrophic activity and hence reduce fugitive methane emissions, with the effect being soil-specific. However, especially in finer and more compacted soils, biochar amendment can maintain soil diffusivity above a critical level, preventing the collapse of methanotrophy.

Factors controlling available soil nitrogen in Japanese paddy fields

ABSTRACT Available soil nitrogen (Av-N) is an important indicator for understanding the soil fertility in paddy fields. Previous studies have reported a decline in Av-N resulting from paddy-upland rotation at a regional scale in Japan, while the factors influencing this phenomenon on a national scale are not well understood. This study aims to assess the effects of soil temperature, land use, soil type and soil texture on Av-N in paddy fields across Japan. Soil surveys were conducted in 13 prefectures in 2020 and 2021, involving the collection of soil samples from the plow layer in a total of 2,600 paddy fields. Our results revealed that soil temperature had the most significant influence on Av-N, followed by land use and soil type. Av-N exhibited a negative correlation with soil temperature, whereby the average Av-N in the thermic soil temperature regime (>15°C, Av-N: 107 ± 48 mg kg−1) significantly lower than that in the mesic soil temperature regime (≤15°C, Av-N: 166 ± 74 mg kg−1). Increased upland frequency in paddy fields led to a decrease in Av-N, particularly pronounced in the thermic soil temperature regime, while partially mitigated in the mesic soil temperature regime. In the thermic soil temperature regime, paddy fields with long-term upland usage (upland frequency of paddy fields was more than 50%) had an average Av-N of 50 mg kg−1, necessitating additional organic matter application. Furthermore, the results concerning soil type and soil texture indicated that Av-N was higher in wet soil compared to semi-wet soil, and fine-textured soil had higher Av-N than medium-course textured soil. These findings underscore the negative effect of accelerated drying in paddy fields due to the expanding practice of paddy-upland rotation, leading to decreased Av-N. In conclusion, our study proposes the importance of organic matter management practices, with a primary emphasis on soil temperature, further refined by considering land use and soil type, to ensure the maintenance of adequate Av-N levels in paddy fields in Japan.

Interactions among soil texture, pore structure, and labile carbon influence soil carbon gains

Perennial vegetation with high plant diversity, e.g., restored prairie, is known for stimulation of soil carbon (C) gains, due in part to enhanced formation of pore structure beneficial for long-term C storage. However, the prevalence of this phenomenon across soils of different types remains poorly understood. The aim of the study was to assess the associations between pore structure, soil C, and their differences in monoculture switchgrass and polyculture restored prairie vegetation across a wide range of soils dominating the Upper Midwest of the USA. Six experimental sites were sampled, representing three soil types with texture ranging from sandy to silt loams. The two vegetation systems studied at each site were (i) monoculture switchgrass (Panicum virgatum L.), and (ii) polyculture restored prairie, also containing switchgrass as one of its species. X-ray computed micro-tomography (µCT) was employed to analyze soil pore structure. Structural equation modeling and multiple path analyses were used to assess direct and indirect effects of soil texture and pore characteristics on microbial biomass C (MBC), particulate organic matter (POM), dissolved organic C (DOC), short-term respiration (CO2), and, ultimately, soil organic C (SOC). Across studied sites, prairie increased fractions of medium (50–150 µm Ø) pores by 11–45 %, SOC by 3–69 %, and MBC by 18–59 % (except for one site). The greater were the prairie-induced increases in the medium pore volumes, the greater were the prairie-induced SOC gains. Greater C losses via CO2 and DOC contributed to slower C accumulation in the prairie soil. We surmise that the interactive feedback loop relating medium pores and soil C acts across a wide range of soil textures and is an important mechanism through which perennial vegetation with high plant diversity, such as restored prairie, promotes rapid SOC gains.

Hydrological regime and forest development have indirect effects on soil fauna feeding activity in Central European hardwood floodplain forests

Soil fauna act as regulators of decomposition processes via their feeding activity, thereby playing an important role in regulating carbon cycling and sequestration. Hardwood floodplain forests are critically endangered habitats, but strongly contribute to carbon sequestration in Central Europe. In the present study, within a floodplain forest-development programme, we investigated the feeding activity of soil fauna via the Bait Lamina test in hardwood floodplain forests of the middle Elbe River in Germany in sites with different hydrological regimes and forest-development stages, with neighbouring grassland sites for comparison. While statistically significant differences in overall feeding activity between general hydrological regimes or forest development stages were not found, decreases in feeding activity with soil depth were strongly modulated by these factors, indicating more unfavourable conditions for soil fauna at increasing soil depth due to, e.g., anoxic conditions in floodplains of tributaries or low soil moisture content below the shallow rooting zone of grasslands. Registered effects of soil texture on soil fauna feeding activity were dependent on forest-tree density, and combined effects indicate that soil-fauna feeding activity varies with soil temperature during spring, but with soil moisture in early autumn. In conclusion, our results highlight the importance of the current abiotic conditions on soil-fauna feeding activities in floodplain forests, i.e. soil temperature, moisture and ground water level. Hydrological regime and forest development have a strong impact on the effect of these conditions, indirectly affecting soil fauna feeding activity and highlighting the multifactorial influence on soil fauna functional activity to be considered in floodplain-forest restoration programs.

Facile microplastic recovery in soil using temperature-driven phase transition of saturated fat: Optimization and evaluation

Extracting microplastics (MPs) from soil matrices is challenging due to their heterogeneous distribution and the lack of standardized recovery techniques. Addressing this, we introduce a cost-effective and eco-friendly method utilizing the temperature-driven phase transitions of saturated fats for efficient and accurate MP separation. Among the evaluated saturated fats - butter, lard, and coconut oil - coconut oil demonstrated a 100% recovery of five MP types (LDPE, PP, PS, PET, and PTFE) from soil across three consecutive cycles, owing to its solidification characteristics. The process was further examined by exploring the effects of agitation force and soil texture (sea sand and agricultural soil), where agitation force impacted efficiency, while soil texture remained insignificant. The technique utilizing coconut oil demonstrated high matrix retaining efficiencies for both soil matrices, signifying its ability to separate MPs without soil contamination. To ensure MPs' integrity, isopropanol was used for solidified coconut oil removal, which did not alter the MPs' pristine state, as validated by microscopy, FTIR spectroscopy, and Py-GC/MS. In comparison to prior methods, our approach significantly reduces both operating costs and environmental impact. Overall, our study paves the way for a sustainable and affordable solution to MP contamination in soils.

Assessing Soil Organic Carbon Pool for Potential Climate-Change Mitigation in Agricultural Soils—A Case Study Fayoum Depression, Egypt

It is essential to assess the soil organic carbon pool (SOCP) in dry environments to apply appropriate management techniques that address sustainable development. A significant opportunity for sustaining agricultural output and reducing climate change is the storage of soil organic carbon in agricultural soil. The goal of this study was to measure the spatial variability of SOCP content, and determine the effects of soil texture, changes in land use, and land cover on SOCP in surface soil samples. The study additionally investigated the relationships between SOCP and other characteristics, including the normalized vegetation index (NDVI) and land surface temperature (LST), as well as the effects of increasing soil organic carbon on the amount of greenhouse gases. To accomplish this goal, 45 soil surface samples were collected to a depth of 30 cm at the Fayoum depression in Egypt, and analyzed. The soil samples were representative of various soil textures and land uses. The average SOCP concentration in cultivated regions is 32.1 and in bare soils it is 6.5 Mg ha−1, with areas of 157,112.94 and 16,073.27 ha, respectively. According to variances in soil textures, sandy soils have the lowest SOCP (1.8 Mg ha−1) and clay loam soils have the highest concentrations (49 Mg ha−1). Additionally, fruit-growing regions have the greatest SOCP values and may therefore be better suited for carbon sequestration. The overall average SOCP showed 32.12 Mg C ha−1 for cultivated areas. A rise in arable land was accompanied by a 112,870.09 Mg C rise in SOCP. With an increase in soil organic carbon, stored carbon dioxide emissions (greenhouse gases) would be reduced by 414,233.24 Mg CO2. We should consider improving fertilization, irrigation methods, the use of the multiple cropping index, decreasing desertion rates, appropriate crop rotation, and crop variety selection. The research highlights the significance of expanding cultivated areas towards sustainable carbon sequestration and the climate-change-mitigation potential.

Relationships between weather and yield anomalies vary with crop type and latitude in Sweden

CONTEXTInformation on how crop yields are affected by weather variations and extreme weather is needed to develop climate adaptation measures for arable cropping systems. Here, we analysed the effects of weather anomalies and soil texture on crop yield anomalies across Sweden from 1965 to 2020. OBJECTIVEThe aims of this study were to (i) assess the effects of temperature and precipitation anomalies and extreme weather on crop yield anomalies for major field crops across Sweden, (ii) quantify how crop responses to weather anomalies vary along the north-south climate gradient across Sweden, and (iii) elucidate the impacts of soil texture on yield responses to weather anomalies. METHODSWe used daily mean air temperature, daily total precipitation, soil texture and crop yield data from public databases covering all 21 counties in Sweden. Yield data was detrended to account for the effects of agricultural intensification on crop productivity. To assess seasonal weather influences on crop yields, temporal trends of daily average temperature and daily total precipitation were detrended for each season containing a three-month period. We also used a water balance index and a heat wave index to evaluate the impact of extreme weather. RESULTS AND CONCLUSIONSOur analyses showed that years with extreme weather during summer (i.e. heat waves, drought or water excess) resulted in the largest negative yield anomalies. Spring-sown crops were more negatively affected by extreme weather compared to autumn-sown crops, which we associate with differences in the lengths of the growth period for autumn- and spring-sown crops. Effects of soil texture on yield anomalies were found for spring-sown cereals, where negative effects of drought were exacerbated with increasing sand content. Moreover, we showed that the effects of weather conditions on crop yield anomalies differed between different regions within the country. In northern Sweden, crop yields were more sensitive to excess water, while drought effects were more pronounced in southern Sweden. Similarly, increased summer temperatures favoured crop yields in northern Sweden but had a negative impact on crop yields in the southern part of the country. SIGNIFICANCEOur study demonstrates that weather impacts on yields vary between crops and locations, and that adaptation to future climate will require crop- and site-specific strategies.

Effect of Soil Texture on the Productivity of Two Shallot Varieties

The Lake Toba Catchment Area (LTCA) has long been known as a producer of shallots in North Sumatra. The Samosir variety is the mainstay local variety of the farmers. Due to the lack of quality seeds and disease attacks on the Samosir variety, farmers began to cultivate the Bima Brebes variety. This study aims to prove the difference in productivity of shallot varieties Samosir and Bima Brebes cultivated in the LTCA region by considering soil texture as a factor affecting productivity. This study was conducted in 6 shallot producing districts included in the LTCA. For analysis, 30 samples were selected based on the level of shallot productivity, with details of 10 low category production (< 4.5 tons/ha), 10 medium category production (4.5-7.5 tons/ha), and 10 high category production (> 7.5 tons/ha), along with the results of soil texture analysis. Correlation analysis was conducted to find the type of soil fraction that influenced productivity. ANCOVA to analyze the relationship between soil fraction and shallot productivity in each variety and analyze the difference in the productivity of Samosir and Bima Brebes shallots. The results showed that the sand fraction had an effect on shallot productivity in LTCA. The shallot cultivation land in LTCA has a sand fraction of 69-76% (sandy loam texture), where the greater the percentage of sand fraction, the higher the productivity of both shallot varieties. There was no difference in the productivity of Samosir and Bima Brebes shallots varieties. Bima Brebes variety can be a substitute seed for shallot cultivation in LTCA.

Interpretation of uniaxial, confined compression test data for agricultural topsoils

Traditionally, soil strength is estimated from uniaxial, confined compression tests by procedures adopted from classical soil mechanics. The heterogeneity of agricultural topsoil calls for an alternative approach. Undisturbed soil cores were collected in the plough layer of 14 soils in arable agriculture. Soil texture ranged from coarse sandy to silty loam soils with a maximum of 20% clay. The samples were drained to either of six matric potentials in the range from − 30 to − 300 hPa. Uniaxial, confined compression was applied to ∼800 kPa with strain-controlled stress application (1 mm min−1). Measured strain was fitted to stress by the Morgan-Mercer-Flodin (MMF) model. The model fitted data remarkably well for all samples. Three fitting parameters of the model reflected physical characteristics of soil reaction to stress. The estimates of soil compressibility calculated from the model at 10 kPa (C10) correlated closely and linearly to the Cs index considered to reflect elastic deformation in classical studies of soil compression tests. Soil bulk density and content of soil organic matter decreased C10 as well as compressibility at 100 (C100) and 400 kPa (C400). A complex pattern in the effects of soil texture and soil moisture on compressibility was revealed. The pattern in strain-stress data is interpreted as a reflection of a gradual transition from elastic to plastic deformation of the mixture of structural units. The MMF model is suggested for interpretation of strain-stress data from uniaxial, confined compression tests. This implies use of stress in a linear scale.

The inverse texture effect of soil on vegetation in temperate grasslands of China: Benchmarking soil texture effect

The inverse texture effect of soil on vegetation has been reported in a few arid regions, but no information is available on the vast Chinese temperate grassland. In addition, no consistent criteria and approaches have been used to classify soil texture groups, determine the precipitation threshold (Pθ) below which the inverse texture effect occurs, and quantify the effect size (Z), which has limited the generalization of the rules of the soil texture effect in different ecosystems. We analyzed the soil texture effect on vegetation using the remotely sensed vegetation data (MODIS/NDVI) and the Chinese soil profile texture data at 6851 sites in temperate grasslands of China. We found, first, a strong inverse texture effect, i.e., a higher NDVI on coarse- (>50 % sand) than fine-textured soil in low precipitation areas, and Pθ was variable with annual precipitation and averaged 260 mm in the region. Second, we proposed a novel method to use the loam soil as a benchmark against which to quantify the effect of various textured soils, and determine Pθ as the point on precipitation gradient where the soil texture effect shift from positive to negative or vice versa. As such, Pθ decreased with soil coarseness, and increased with precipitation; and the texture effect decreased from positive to negative for sandy soils, whereas it increased from negative to positive for silt or clay soils, on the gradient of precipitation increase. Our results provide new insights into the relations of vegetation pattern and dynamics with precipitation and soil texture, and a method for quantifying and comparing soil texture effect across ecosystem types.

Soil organic carbon stock change following perennialization: a meta-analysis

Perennial crops replacing annual crops are drawing global attention because they harbor potential for sustainable biomass production and climate change mitigation through soil carbon sequestration. At present, it remains unclear how long perennial crops can sequester carbon in the soil and how soil carbon stock dynamics are influenced by climate, soil, and plant properties across the globe. This study presents a meta-analysis synthesizing 51 publications (351 observations at 77 sites) distributed over different pedo-climatic conditions to scrutinize the effect of perennialization on organic carbon accumulation in soil compared with two annual benchmark systems (i.e., monoculture and crop rotation). Results showed that perennial crops significantly increased soil organic carbon stock by 16.6% and 23.1% at 0–30 cm depth compared with monoculture and crop rotation, respectively. Shortly after establishment (< 5 years), perennial crops revealed a negative impact on soil organic carbon stock; however, long duration (> 10 years) of perennialization had a significant positive effect on soil organic carbon stock by 30% and 36.4% at 0–30 cm depth compared with monoculture and crop rotation, respectively. Compared with both annual systems, perennial crops significantly increased soil organic carbon stock regardless of their functional photosynthetic types (C3, C4, or C3-C4 intermediates) and vegetation type (woody or herbaceous). Among other factors, pH had a significant impact on soil organic carbon; however, the effect of soil textures showed no significant impact, possibly due to a lack of observations from each textural class and mixed pedoclimatic effects. Results also showed that time effect of perennialization revealed a sigmoidal increase of soil organic carbon stock until about 20 years; thereafter, the soil carbon stocks advanced towards a steady-state level. In conclusion, perennial crops increased soil organic carbon stock compared with annual systems; however, the time since conversion from annual to perennial system decisively impacted soil organic carbon stock changes.

Impact of soil structure and texture on occurrence of microplastics in agricultural soils of karst areas

The impact of microplastics (MPs) on soil ecosystems has attracted widespread attention; however, the effects of soil structure and texture on the occurrence of MPs are not fully understood. In this study, we investigated the effects of soil structure and texture on the abundance of MPs and their potential mechanisms in agricultural soils of karst areas in Guizhou, China. The results showed the average abundance of MPs was 2948 items/kg. The soil texture in the study area can be categorized into seven types such as powdered-light clay, the range of total soil porosity was 39.05–69.22 % and the range of soil bulk density was 0.66–1.51 g/cm3. Soils with a powdered-light clay, low soil porosity, and low soil bulk density showed higher MPs pollution. The percentage of pellet MPs in agricultural soils with a powdered-light clay was 84 %, which was higher than that of the other soil textures. The direct effects of soil texture, soil porosity, and soil bulk density on MPs abundance were much lower than the indirect effects, with soil texture having the highest effect on MPs abundance. We speculated that karst geology may affect the accumulation and distribution of MPs in soil by affecting soil texture and structure, which, in turn, affects the fragmentation and migration of MPs. These findings will help to better understand the mechanisms of soil MPs pollution and provide a scientific basis for the development of relevant control strategies.

Variation in soil infiltration properties under different land use/cover in the black soil region of Northeast China

Soil infiltration properties (SIPs) of infiltration rate and saturated hydraulic conductivity significantly affect hydrological and erosion processes, thus, knowledge of SIPs under different land use/cover are vital for land use management to control soil erosion for realizing the sustainable development of the small agricultural watershed. Nevertheless, few studies have been carried out to investigate the differences in SIPs and their dominant influencing factors between different land use/cover in the black soil region of Northeast China. Therefore, eight typical land use/cover were selected to clarify the variations in SIPs between different land use/cover and further identify their dominant influencing factors. SIPs of initial infiltration rate (IIR), steady infiltration rate (SIR), and saturated hydraulic conductivity (Ks) were determined under eight typical land use/cover (forestland, shrub land, grassland, longitudinal shelterbelt, transverse shelterbelt, agricultural road, and cropland of Zea mays L. and Glycine max (Linn.) Merr) using a tension disc infiltrometer with three pressure heads of −3, −1.5, and 0 cm. The results of one-way ANOVA analysis showed that SIPs varied greatly between different land use/cover. Shelterbelt plant with Populus L. had the maximum IIR, SIR, and Ks, and then followed by shrub land, agricultural road, cropland, grassland, and forestland. Spearman correlation analysis indicated that SIPs were significantly correlated with soil and vegetation properties. Redundancy analysis revealed that differences in SIPs between different land use/cover were dominantly attributed to the differences in soil texture, field capacity, and plant root mass density, which explained 79.36% of the total variation in SIPs. Among these dominant influencing factors, the results of structural equation model indicated that the indirect effects of plant root and soil texture played the most important role in variations of SIPs via affecting soil texture and pore characteristics. These results have significant implications for the precise prediction of watershed hydrological and erosion processes, also provide a scientific basis for guiding the distribution pattern of land use in the cultivated watershed.

Field-scale assessment of direct and indirect effects of soil texture on organic matter mineralization during a dry summer

Soil texture plays a crucial role in organic matter (OM) mineralization through both direct interactions with minerals and indirect effects on soil moisture. Separating these effects could enhance the modelling of soil organic carbon (SOC) dynamics under climate change scenarios. However, the attempts have been limited small-scale experiments. Here, we studied the effects of soil texture on added OM mineralization in loamy sand, loam and silt loam soils in nine agricultural fields in Flanders, Belgium. Soil moisture, temperature, groundwater table depth and the mineralization of 13C-labeled ryegrass were monitored in buried mesocosms for approximately three months during a dry summer. Ryegrass-C mineralization was lowest in the loamy sand (39 ± 7 %) followed by silt loam (48 ± 7 %) and loam (63 ± 5 %) soils, challenging the current clay%-based moderation of C-mineralization rates in soil models. Soil temperature was not influenced by soil texture, whereas soil moisture was indeed dependent on soil texture. It appears that capillarity sustained upward water supply from groundwater to the topsoil in loam and silt loam soils but not in loamy sand soil, although this difference in capillary rise could not fully explain the higher moisture content in loam than that in silt loam soils. Additionally, soil texture only impacted remnant added ryegrass pieces (>500 μm) but not the finer ryegrass-derived SOC (<500 μm), which might point at the important indirect control of texture on OM mineralization during prolonged summer drought. However, these effects are only manifested during drought when no other factors (e.g., groundwater depth or subsurface water flows) exert an overriding impact on the soil water balance. Overall, our findings highlight the need to properly incorporate the indirect effects of soil texture on OM mineralization into soil carbon models to accurately predict soil C stocks under future climate change scenarios.

Effect of Soil Texture on Water and Salt Transport in Freeze—Thaw Soil in the Shallow Groundwater Area

Research on the variation in soil water, heat, and salt in unsaturated zones during the freeze–thaw process has great significance in efficiently utilizing water resources and preventing soil salinization. The freeze–thaw field experiment was carried out with the lysimeter as the test equipment to analyze characteristics of the soil freeze–thaw process, profile water content, main ion content, and salt content of three textured soils with the groundwater table depth of 0.5 m. The results showed that the soil temperature gradient and freezing depth were greater as the average soil particle size increased. The increment of water content at the depth of 0 to 30 cm in sandy loam and loamy sand decreased by 40.20~93.10% and 28.14~65.52% compared with that in sandy soil, and the average increment of salt content at the depth of 0 to 30 cm decreased as the average soil particle size increased during the freeze–thaw period. The average content of Ca2+, Na+, Cl−, and SO42− in loamy sand and sandy soil decreased by 4.37~45.50% and 22.60~70.42% compared with that in sandy loam at the end of the freeze–thaw period, and the correlation between soil salt content and water content decreased with the increase in the average soil particle size. The research results can provide a theoretical basis for soil salinization prevention and crop production in shallow groundwater areas.

Microbial carbon functional responses to compaction and moisture stresses in two contrasting Australian soils

Soil compaction combined with water deficit may cause a significant decrease in microbial functions. Two texture-contrast sugarcane soils were exposed to the combined stresses of compaction and drought, and microbial responses were investigated going into stress (phase I) as well as their response coming out of stress (phase II). We artificially applied a gradient of bulk densities (0.9–1.5 g cm−3) and water-filled pore space (WFPS, 21–100%) to simulate compaction and drought conditions. PCA results clearly demonstrated the separation of impacts of soil types and the moisture treatments. Additionally, it is evidenced that soil texture can strongly regulate soil microbial response to compaction, as finer texture provides a better local environment for soil microbial community growth, supported by two folds higher microbial biomass carbon content and significantly higher CO2 respiration in Nitisol (clayey soil) than Planosol (sandy soil). The Structural Equation Modelling (SEM) analysis showed a strongly direct negative effect (path coefficient= −0.59 to −0.61, p < 0.01) of WFPS on the labile C at Phase I and Phase II in both Nitisol than Planosol. Further, soil moisture would govern microbial respiration cross soil types, particularly after removal of compactions which supported by the SEM result (path coefficient= −0.36 to −0.47, p < 0.05). Results from this study have implied the importance in considering the combined effects of soil texture and moisture in assessing compaction impacts and developing associated management regimes.

Using the Soil Texture Triangle to Evaluate the Effect of Soil Texture on Water Flow: A Review

Abstract: Water flow through soil is a critical process that affects many aspects of soil health and environmental sustainability. Soil texture, which is the relative proportion of sand, silt, and clay particles in soil, plays a significant role in regulating water flow through soils. The soil texture triangle is a widely used tool for classifying soil texture based on the proportions of sand, silt, and clay particles. This review paper aims to evaluate the effect of soil texture on water flow through soils using the soil texture triangle. The paper presents an overview of the soil texture triangle and its applications in soil texture classification, followed by a discussion of the relationship between soil texture and water flow. The paper reviews existing literature on the impact of soil texture on water flow and summarizes the key findings. The review highlights the importance of soil texture in regulating water flow through soils and discusses the implications for soil management and environmental sustainability. The paper concludes by identifying areas for future research to improve our understanding of the relationship between soil texture and water flow.

A new process-based and scale-aware desert dust emission scheme for global climate models – Part I: Description and evaluation against inverse modeling emissions

Abstract. Desert dust accounts for most of the atmosphere's aerosol burden by mass and produces numerous important impacts on the Earth system. However, current global climate models (GCMs) and land-surface models (LSMs) struggle to accurately represent key dust emission processes, in part because of inadequate representations of soil particle sizes that affect the dust emission threshold, surface roughness elements that absorb wind momentum, and boundary-layer characteristics that control wind fluctuations. Furthermore, because dust emission is driven by small-scale (∼ 1 km or smaller) processes, simulating the global cycle of desert dust in GCMs with coarse horizontal resolutions (∼ 100 km) presents a fundamental challenge. This representation problem is exacerbated by dust emission fluxes scaling nonlinearly with wind speed above a threshold wind speed that is sensitive to land-surface characteristics. Here, we address these fundamental problems underlying the simulation of dust emissions in GCMs and LSMs by developing improved descriptions of (1) the effect of soil texture on the dust emission threshold, (2) the effects of nonerodible roughness elements (both rocks and green vegetation) on the surface wind stress, and (3) the effects of boundary-layer turbulence on driving intermittent dust emissions. We then use the resulting revised dust emission parameterization to simulate global dust emissions in a standalone model forced by reanalysis meteorology and land-surface fields. We further propose (4) a simple methodology to rescale lower-resolution dust emission simulations to match the spatial variability of higher-resolution emission simulations in GCMs. The resulting dust emission simulation shows substantially improved agreement against regional dust emissions observationally constrained by inverse modeling. We thus find that our revised dust emission parameterization can substantially improve dust emission simulations in GCMs and LSMs.

Nitrogen release from different polymer‐coated urea fertilizers in soil is affected by soil properties

AbstractThe use of urea as nitrogen (N) fertilizer in agriculture needs to consider environmental, economic and resource conservation aspects because of low N‐use efficiency (NUE). Polymer‐coated urea (PCU) offers an effective way to improve the NUE of urea and to reduce its environmental trade‐offs. However, we lack information on the impact of climate and soil properties on N release from PCU. Therefore, this study was performed to quantify the effects of soil texture, moisture and temperature on the release kinetics of N from PCU. We designed a test system for soil incubation experiments and investigated three fertilizers with different release patterns, five topsoils, three moisture levels and two temperatures over 48 days. We analysed the concentrations of inorganic N ( and ) in the soil and estimated N release rates using the unified Richards model. Soil texture did not change the N release patterns, but release rates varied significantly among the investigated soils. Changes in soil moisture for a given soil had no effect on N release from PCU and urea when fertilizers were incorporated into the soil at conditions supportive of crop growth. Lowering soil temperatures, however, decreased N release rates from PCU by 16%–49% but only in silt loam and not in sandy loam. We conclude that PCU improves the N residence time in soil, but predictions on N release from PCU must be adapted to the prevailing environmental conditions and cannot be generalized across differently textured soils.