Soil Hydro-physical Properties Research Articles

Soil surface greenhouse gas emissions and hydro-physical properties as impacted by prairie cordgrass intercropped with kura clover

Prairie cordgrass (PCG) is a perennial crop which has the potential for biofuel production under marginal lands. The intercropping of a perennial legume, kura clover (KC) with PCG can reduce the use of chemical fertilizer while maintaining the soil hydro-physical conditions. The objective of this study was to compare the soil hydro-physical properties and greenhouse gas (GHG) fluxes under PCG intercropped with KC (PCG–KC), and PCG fertilized with graded levels of N (0, 75, 150, and 225 N kg ha−1). During the summer of 2021, soil samples (0–10 cm) were collected. Additionally, gas samples were collected weekly from April through September of the same year. Soil water retention, saturated hydraulic conductivity ( Ksat), thermal conductivity (λ), soil organic carbon (SOC), and total N (TN) concentrations were measured. Soil pore characteristics were measured using X-ray computed tomography. The PCG–KC had 1.42 g kg−1 TN and 24 g kg−1 SOC at 0–10 cm, non-significant to PCG-75, 150, and 225 N. Nonetheless, TN significantly increased in both PCG–KC and other fertilized treatments compared to the control. Intercropping boosted macroporosity (0.024 cm3 cm−3), Ksat (+50%), and lowered λ (−1%), compared to the N fertilized treatments. Soil cumulative CO2 under PCG–KC (1012.67 kg C ha−1) was similar to PCG-75, 150 N, but lower than PCG-225 N (1418.66 kg C ha−1). Overall, this study showed that PCG–KC can be a sustainable option over the use of N fertilizers since they had similar levels of hydro-physical characteristics and had a comparable ability to mitigate GHG emissions.

Effect of super absorbent hydrogel on hydro-physical properties of soil under deficit irrigation

Due to water scarcity challenges, efficient management of irrigation water is becoming crucial. Water use efficiency (WUE) involves increasing crop productivity without increasing water consumption. This study was carried out to study the effect of hydrogel, deficit irrigation and soil type on WUE, soil hydro-physical properties and lettuce productivity. For this purpose, four irrigation treatments (100%, 85%, 70% and 60% of full irrigation requirements), four hydrogel concentrations (0, 0.1, 0.2 and 0.3% w/w) and three soil textural classes (clay, loamy sand, and sandy-clay soil) were conducted in pot experiment at open field during two consecutive seasons. The results revealed that crop growth parameters and soil hydro-physical properties were significantly affected by hydrogel application rates. Hydrogel addition significantly enhanced head fresh and dry weights, chlorophyll content, number of leaves and WUE. Application of hydrogel at 0.3% and 85% of irrigation requirements achieved the highest WUE without significant yield reductions. Changes in the studied hydro-physical properties of soil were more dependent on soil texture and hydrogel application rate than on the amount of irrigation water. The significant decrease in soil saturated hydraulic conductivity and bulk density confirms that super absorbent hydrogels could be recommended to improve soil water retention and enhance water use efficiency under deficit irrigation conditions.

Crop-livestock integration influenced soil profile organic carbon and hydro-physical properties in converted grasslands to row crops

Integrated crop-livestock systems (ICLS) can mitigate the impacts of cropping intensification by improving soil organic carbon (SOC) and associated hydro-physical properties. This study was conducted on three on-farm long-term (≥30 years) sites (Site 1, 2, and 3) and one short-term (4 years) experimental site (Site 4) to compare the SOC and hydro-physical properties to a depth of 40 cm for an intensive-cropland (CL), a native-grassland (NG) and cropland managed with ICLS. Data showed higher SOC, soil water retention (SWR), macroporosity, available water capacity (AWC), and saturated hydraulic conductivity (Ksat) for the NG than the CL indicating the degradation of soil physical quality because of intensive agriculture. However, for sites 1 and 2, the ICLS had 27% and 46% more SOC than the CL in the 0–10 cm depth. In addition, the ICLS decreased bulk density (ρb) (sites 1 and 3) and increased the Ksat (sites 1, 2, and 3) at 0–10 cm depth as compared to the CL. No differences in SOC or hydro-physical properties were observed for the short-term ICLS (site 4) when compared to the CL. The impacts of ICLS were most prominent at the surface soil (0–10 cm) and no difference was observed for the deeper soil. The AWC showed a linear increase with the increase in SOC, however, soils under ICLS and CL showed a higher increase in AWC with an increase in SOC as compared to the NG. This study highlighted the negative impacts of grassland to cropland conversion and suggested the implementation of ICLS to improve organic carbon and other associated hydro-physical properties of soils.

Significance of pyrolytic temperature, application rate and incubation period of biochar in improving hydro-physical properties of calcareous sandy loam soil

Biochar is increasingly recognized for its ability to enhance hydro-physical properties of soil, offering promising solutions for improving soil structure, water retention, and overall agricultural productivity. In this study, sandy loam soil was amended at different rates (0, 15, 30, and 60 t ha−1) of biochar produced from olive pomace (Jift) at different pyrolysis temperatures (300, 400, 500, and 600 °C), and incubated for 30, 60, and 90 days. The biochar-amended soils were collected for analysis after each incubation period for infiltration rate, aggregate stability, soil water retention, water repellency, and penetration resistance. At 300 °C, aggregate stability increased with biochar amendments; the highest value (65%) was after 60 days of incubation. At other pyrolysis temperatures, aggregate stability decreased, or no effect of temperature was observed. Also, at 300 °C, the infiltration rate was decreased with biochar application and the lowest value of (0.14 ml/min) was at 90 days of incubation. At other pyrolysis temperatures, the infiltration rate was increased with increased biochar application rate. Water retention was increased with biochar application at 300 °C; however, biochar application did not affect water retention at other pyrolysis temperatures. These results strongly suggest the improvement of soil physical and hydraulic properties following the addition of biochar amendment. Overall, biochar had positive effects on hydro-physical properties. The biochar produced at 300 °C pyrolysis temperature was the most beneficial to agriculturally relevant hydraulic conditions. However, field assessments are necessary to evaluate the long-term effects of biochar on hydro-physical properties.

Effects of rainfall seasonality and land use change on soil hydrophysical properties of high-Andean dry páramo grasslands

High-Andean páramos deliver essential ecosystem hydrological services from a combination of soil, vegetation, and climate characteristics, particularly in their natural state. However, agricultural activities considerably affect the páramo's ability to store, regulate, and supply water. Although there is information on the effect of potato crops (Solanum tuberosum) on páramo soils' properties, the effect of spring onion (Allium fistulosum) crops has been studied less. In addition, dry páramos are underrepresented in existent páramoś research. This study assessed the effect of rainfall seasonality (RS) and land-use change (transformation from páramo vegetation to crops) on soil hydrophysical properties associated with hydrological services (streamflow buffering) in a dry páramo in the Eastern range in Colombia. Six dominant land uses were studied: natural páramo vegetation (low slope, steep slope, and dense shrublands) and anthropic use (onion crops, potato crops, and fallow). An in-depth random stratified discrete design (0–5, 10–15, and 20–25 cm) was used to collect samples for analysis of soil organic matter (SOM), bulk density (BD), pH, and electrical conductivity (EC). Hydrophysical properties were measured at the soil surface: water retention capacity (WRC), structural stability (SS), and infiltration capacity (IC). Soils under anthropic uses showed more remarkable changes in soil properties with RS than soils under natural páramo. On the other hand, land-use change from natural vegetation to potato and onion crops followed by fallow leads to a reduction in SOM (9.8 %) and an increase in BD (0.19 gcm−3), especially at the surface level. In addition, this leads to a loss of WRC (20 % at field capacity), an increase in unstable aggregates (13 %), water erosion, and a loss of IC (44 mmh−1). This paper demonstrates the impact of land use on soil hydrophysical properties that compromise the maintenance of hydrological services and contributes to a better understanding of the complexity of Andean páramos.

X-ray computed tomography – Measured pore characteristics and hydro-physical properties of soil profile as influenced by long-term tillage and rotation systems

Soil hydro-physical properties and pore characteristics are crucial for crop production as they determine water, air, and nutrients transfer. Long-term tillage and crop rotation studies provide valuable insights into the effects of management practices on various soil properties. Because of the inherent differences between the surface and sub-surface soils, the impact of management systems can be pronounced differently at different soil depths. Though many studies have reported the tillage and rotation effects on soil hydro-physical properties, their vertical impacts to a depth of 40 cm were less explored. This study aims to assess the impact of long-term tillage and crop rotations on soil hydro-physical properties and pore characteristics to a depth of 40 cm utilizing the X-ray Computed Tomography (XCT) technique. Intact soil cores of 7.6 cm height × 7.6 cm ∅ were collected from tillage [no-till (NT); reduced-till (RT); conventional-till (CT)] and crop rotation [continuous corn (CC) – Zea mays L. and corn-soybean (CS) – Glycine max [Merr.] L.] plots of 0–40 cm depth (each sample for 10 cm increment). The XCT scanning allowed us to investigate the soil pore size distribution, porosity, number of branches, and average branch length. Measured hydro-physical properties in the study include bulk density (ρb), plant available water content (PAW), saturated hydraulic conductivity (Ksat), and water retention. XCT image analysis revealed that NT with CC/CS rotation increased the number of macropores at surface and sub-surface depths. However, the number of mesopores was higher with NT × CS. In addition, NT lowered the ρb by 9.6 % and increased the PAW by 28 % compared to the CT. Ksat was higher under NT × CS at 0–10 cm and had a strong positive correlation with the XCT-measured number of macropores. Therefore, we conclude that NT with CS rotation can potentially improve soil pore characteristics and hydro-physical properties, leading to enhanced soil function.

Effect of Tillage Practices on Hydro-Physical Properties of Soils in a Rice-Grown Environment in North Central Nigeria

Effect of Tillage Practices on Hydro-Physical Properties of Soils in a Rice-Grown Environment in North Central Nigeria

Zoning of infiltration areas using Schosinsky’s Soil Water Balance in La Balsa River Basin, Costa Rica

In Central America there is little information of water infiltration at the basin level, despite its importance for the design of appropriate conservation and restoration strategies. Thus, the aim of this study is to develop an example for how to use Schosinsky?s Soil Water Balance (SSWB) model-along with other variables-as a more viable way to determine water infiltration zones at the basin level. Zones, in La Balsa River Basin (LBRB), were determined by overlaying information of basin slopes, existing land use, land cover and spatial distributed rainfall. Hydrophysical soil properties in each zone were obtained through field tests measurements and laboratory analyses of soil samples. Once the values of each zone were determined, SSWB model was applied to obtain a map of infiltration zones. Results indicate that rainfall is the most influential component in calculating SSWB, and its distribution and deposition on the ground as effective rainfall is related to soil exposure and land use characteristics. Soil properties control the behavior of water that enters the soil and replenishes groundwater. Infiltration values, obtained using the model are highly correlated to rainfall dynamics. It is concluded that SSWB model is an important tool for obtaining water infiltration estimates at the basin level, useful in those basins for which little information is available.

English

Lack of water is the main problem facing agriculture and crop production in arid and semi-arid regions. Deficit irrigation is widely used to optimize water application efficiency under drought conditions in arid areas. The purpose of the work is to estimate the efficiency of SALTMAD model for simulating soil moisture dynamics, water application efficiency, and seed yield under three Deficit Irrigation Strategies (DIS) [DIS1 (100% Full Irrigation (FI)), DIS2 (80% FI), and DIS3 (60% FI)] with six treatments of Integrated Nitrogen-Fertilization (INF) including [INF1 (100% MN + 0% ON), INF2 (80% MN + 20% ON), INF3 (60% MN + 40% ON), INF4 (40% MN+ 60% ON), INF5 (20% MN + 80% ON) and INF6 (0% MN + 100% ON)]. Moreover, the best strategy of deficit irrigation with the best treatment of integrated nitrogen fertilizer will be selected for improving soil hydro-physical properties, water productivity, and seed yield in semi-arid soil regions without any water stress. Field experiment was conducted during 2020/2021 and 2021/2022 at the Research Farm of National Research Center (NRC) at Nubaryia Region, Al Buhayrah Governorate, Egypt. Soil hydro-physical properties including infiltration rate (IR), and soil moisture dynamics were measured in the field. In addition, soil moisture dynamics, water application efficiency, seed yield, and water productivity of bean were simulated using the SALTMAD model and compared with thatmeasured in the field under the above conditions. The results observed that the best treatment that led to increased water application efficiency and seed yield was at DIS2 (80% FI) with INF4 (40% MN+ 60% ON) compared to DIS1 (100% FI), and DIS3 (60% FI). In this strategy, seed yield productivity increased by 43.4% in the first season, and 34.7% in the second season as well as saving irrigation water by up to 20% for cultivated faba bean in sandy soil without any water stress. The usage of balance a combination of mineral and organic fertilizers can be used to compensate for deficit irrigation by improving infiltration rate, water holding capacity, water application efficiency, and seed yield. The SALTMAD model can be used to simulate soil moisture dynamics, water application efficiency, seed yield, and water productivity with little calculation error under different deficit irrigation strategies and integrated nitrogen fertilization in arid and semi-arid areas with sandy soil.

Temporal and spatial distribution of soil water repellency in grassland soils and its relation to soil moisture, hydrophobic matter, and particle size

In grassland soils, soil water repellency (SWR) may be one of the triggers of soil erosion and degradation as it can reduce water infiltration and penetration into the soil. Few studies were focusing on the evaluation of soil hydro-physical properties, such as hydrophobicity, and their relation to soil moisture, hydrophobic matter, and particle size in grassland soils. In this study, 800 soil samples were collected from the Xilingol grassland in Inner Mongolia, China, using the water droplet penetration time (WDPT) test to evaluate water repellency and we aimed to investigate the temporal and spatial distribution of SWR in grassland soils using the Kriging and Inverse Distance Weighting (IDW) interpolation methods and determine the physical-chemical properties that trigger the SWR. The results showed that the grassland soils in the studied area were slightly water-repellent and a few portions of the area exhibited strong water-repellency. In April, areas of soils with a depth of 0–5 cm and slight to strong SWR accounted for 80 % of the total studied area, of which 5 % had strong water repellency. Moreover, in August, 90 % of the studied area consisted of soils with slight to strong SWR, of which 60 % accounted for soils with strong SWR. With a soil water content of 10.95 %, the SWR reached its peak, with an average value of 60.32 s. The SWR was positively correlated with total N, available N, and soil organic matter (SOM) contents, and therein the hydrophobic acid matter and the hydrophobic basic matter content had a positive contribution to SWR, and the hydrophilic basic matter and the hydrophilic acidic matter had a negative contribution on SWR. In addition, SWR was found to be negatively related to the soil particle size (r = −0.672). A slight SWR was also observed in the majority of the studied area, particularly in the topsoil and fine soils, especially during the monsoon period; hence, SWR must be also considered to reduce the risk of occurrence of soil erosion and degradation in grasslands.

Impact of Nanoparticles from Ball-Milled Date Palm Biochar on the Hydro-Physical Characteristics of Sandy Soils

Water management in sandy soils (Typic Torripsamments) is crucial in sustaining agricultural production. The main goal of this research was to assess the impact of date palm biochar on the physical properties of sandy soil with different particle sizes of biochar (macro and nano). For nano-biochar preparation, stick chips were established into a tubular furnace with nitrogen air and heated to 400–450 °C, which was accompanied by a holding period of 4 h. The ball-milled biochar was inclined via ball grinding in a model number PQN2.110 planetary mill and within jars (500 mL), and the biochar-to-sphere mass ratio was 1:100. The sphere-milling apparatus was processed at a speed of 300 rpm for 13 h. Laboratory experiments were carried out at one rate—biochar 5%—and three depths (0.0–5, 5–10, and 10–15 cm). Applying macro-biochar reduced cumulative evaporation compared to the control by 4%, 24%, and 14% for the macro-biochar particles at soil depths. In contrast, biochar reduced cumulative evaporation compared to the control by 8%, 12%, and 4% for the nano-biochar particles at the soil depths tested. Adding biochar significantly raised the amount of retained water, with the highest level recorded at the 5–10 cm depth, while the variations were significantly lower between the macro and nano-biochar when in the direction of the soil surface (0–5 cm), indicating the significance of mixing biochar with the top 10 cm of the soil to increase its ability to reduce evaporation and increase the amount of water retained in the soils. It could be concluded that applying at the top of the coarse soil can positively impact soil hydro-physical properties and increase soil water availability to plants.

Effectiveness of Biochar, Organic Matter and Mycorrhiza to Improve Soil Hydrophysical Properties and Water Relations of Soybean under Arid Soil Conditions

Effectiveness of Biochar, Organic Matter and Mycorrhiza to Improve Soil Hydrophysical Properties and Water Relations of Soybean under Arid Soil Conditions

Short-Term Effects of Soil Management Strategies on the Hydro-Physical Properties of Soil and Wheat Yield in an Arid Region in Southwestern Iran

Short-Term Effects of Soil Management Strategies on the Hydro-Physical Properties of Soil and Wheat Yield in an Arid Region in Southwestern Iran

Can application of biochar improve the soil water characteristics of silty loam soil?

PurposeThis study investigates if a biochar application in 2014 and its reapplication in 2018 had affected the selected physical and hydrophysical soil properties of silty loam Haplic Luvisol at Dolná Malanta experimental site (Nitra, Slovakia) during the studied period of 2018–2020.Materials and methodsBiochar was produced from cereal husks and paper fiber sludge by pyrolysis at temperature of 550 °C for 30 min and was applied to the soil in doses of 0, 10, and 20 t ha−1. The biochar treatments were combined with three levels of N fertilization (N0, N1, and N2).ResultsBiochar significantly decreased the bulk density up to − 12% and increased the soil porosity up to + 22% even 4–6 years after the biochar application. We also observed an increase in saturated hydraulic conductivity, which was reflected in better precipitation retention and a higher average soil water content by 12–15% depending on the fertilization level. Depending on the level of N fertilization, the interval of plant available water enlarged by 8–51% (10 t ha−1 of biochar), 18–21% (20 t ha−1 of biochar) after single biochar application, and by 18–34% (10 t ha−1 of biochar) and 19–31% (20 t ha−1 of biochar) after reapplication of biochar, which has positive implications regarding providing soil water to plants.ConclusionsThe results indicate that biochar amendments have the potential to substantially improve the soil water characteristics, and therefore, the quality status of silty loam agricultural soils.

Spatial Variability and Mapping of Selected Soil Physical Properties under Continuous Cultivation

Assessments of Soil physical properties and estimation of their associated variability are essential for making site-specific decisions on soil and crop management This study examined the spatial variability of soil hydro-physical properties and variance structure at Sector F1 of the Jibia Irrigation project Katsina State, Nigeria. Grid sampling technique was used to obtain one hundred and forty-four (144) soil samples from 206 ha of land using Google earth. The grids were drawn using Google earth software at intervals of 150 m x 150 m. Surface soil samples (0 - 20 cm) were collected at grid intersection points. The collected soil samples were air-dried and passed through a 2mm sieve, and analyzed using standard laboratory procedures for physical parameters. The ArcGIS software package 10.3 was used to model the variance structure of Sand, Silt, Clay, Bulk density, Particle density, Percent total porosity and Organic Matter (OM). Results obtained revealed that the coefficient of variation (CV) ranged from 5.724% in particle density to 109% in clay. The Semivariogram showed that the range of spatial dependence varied from 0.342m for (Dry mean weight diameter) to 9.3m (Organic matter) for all measured soil properties. High Spatial dependency ratios were observed for Bulk density, Sand, Silt and clay contents. Particle density exhibited moderate spatial dependency (Nugget to sill ratio 0.25 – 0.75%). Wet Mean weight diameter and organic matter content have a weak spatial dependency. The results indicated that sandy textured soils dominated the greater part of the study area with low to moderate organic matter content. The soils being sandy-dominated has a high infiltration rate and low ability to retain moisture and nutrients were observed as the major characteristics of the soil of the study area.

Influence of long-term tillage and diversified cropping systems on hydro-physical properties in a sandy loam soil of North-Western India

A study was conducted to determine the combined effects of three tillage practices and four maize (Zea mays L.)-based cropping systems on physical, saturated, and near-saturated hydraulic properties in a sandy loam soil of North-Western India. Split-plot experimental design was adopted with tillage [conventional tillage (CT), zero tillage (ZT), and permanent raised bed (PB)] as the main plot treatments and intensified crop rotations [Maize (Zea mays L.)-Wheat (Triticum aestivum)-Greengram (Vigna radiata L.) (MWGg), Maize-Chickpea (Cicer arietinum L.)-Sesbania (Sesbania aculeata) (MCpSb), Maize-Mustard (Brassica juncea) -Greengram (MMuGg) and Maize-Maize-Sesbania (MMSb)] as subplot treatments. The saturated and near-saturated soil hydraulic conductivity were derived from steady-state infiltration rates measured using a hood infiltrometer on the surface soil at 0, − 1, and − 3 cm pressure heads. The long-term (10 years) study revealed that the bulk density (BD) of the soil under conservation agriculture (CA) practices (PB and ZT) was significantly (P ≤ 0.05) lower than that in CT practices. The soil BD in the MCpSb cropping system was measured to be the lowest (1.24 g cm−3) among all the cropping systems. The soil aggregate mean weight diameter (MWD) under PB and ZT was determined to be 31% and 27% higher than in the CT treatments. In tillage × cropping systems interactions, the highest MWD was observed in the PB×MWGg. The saturated and near-saturated hydraulic conductivity (K(h)) were estimated to have higher values in CA practices (PB and ZT) than in the CT treatments. In the case of cropping systems, the soil's mean field saturated hydraulic conductivity was estimated to be significantly (P < 0.05) higher under the MWGg, MCpSb, and MMuGg than the MMSb. The present study indicates that conservation agriculture-based crop management with diversified maize-based rotation (MCpSb, MWGg, and MMuGg) could be promising alternatives to conventional tillage practices (CT). Among the cropping system choices, MWGg was more effective in improving the soil's hydro-physical properties in the study area.

THE IMPACT OF REFORESTATION ON PHYSICAL AND HYDROPHYSICAL PROPERTIES OF SOILS OF THE FALLOW LANDS (SKOLIVSKI BESKYDY, THE UKRAINIAN CARPATHIANS)

The article tackles the impacts of anthropogenic load on the physical and hydrophysical soil properties. In order to better comprehend the processes of spontaneous sylvatisation in a mountain region (the Pohartsi boundary, Koziova village, the Skolivski Beskydy physiographic region) four study plots were selected representing the successional sequence: forest → pasture → hay meadow → arable lands. Land patches that were affected the least by anthropogenic load restored faster to their natural baseline conditions. Tilling appeared to retardate restoration processes, however those anyway took place. Proper functioning of arable land patches may be facilitated by continuous land care actions (i.e. ploughing or mowing).We found that soil bulking density in arable lands increased in upper soil horizons compared to forest ecosystems. Such an increase is caused by mechanical turning upper soil horizons up down and vice versa, for lower horizons. In pasture lands, upper soil horizons are trampled down by livestock. This leads to lower water permeability of soils: increase in soil bulk density from 0.79 to 1.15 g•cm-3 resulted in a decrease of water permeability by 75 %. In forested lands, values of water permeability similar to those in arable lands (0.55 mm•min⁻¹) are usually observed along the walking trails and in wood trilling plots. On the land patches with scarce herbaceous cover erosion processes are emerging. The latter is especially dangerous for arable land patches causing extra leak of soil nutrients and thus soil depletion. In order to further exploitation soils in such patches need additional fertilizing. As agricultural load diminishes soil upper horizons restore. Restoration occurs through prolonged freezing and thawing cycles during the cold (autumn-winter-spring) season. Another path for soil physical properties restoration is associated with penetration of plant fine roots that loosen the soil. Increase of total sparing indices is observed, as well. For upper horizons of restored soil it is assessed as “intermediate” (62,00 ‒ 65,35 %) whilst for arable land patches it is significantly lower (54,90 %). Soil bulk density gradually decreased along soil profiles and study plots. In forested patches it reached minimum (2,28 g•cm⁻³) and in arable land patches – maximum (2.55 g•cm⁻³) values, which did not change upon termination of anthropogenic load. Significant changes were observed for the field humidity indices. These varied both spatially, along soil profiles, and temporarily, by seasons. Lack of herbaceous vegetation caused over-drying in upper soil horizons. At the same time in lower horizons field humidity increased. Upper soil horizons in forested patches undergo the least changes due to the presence of thick forest floor. We conclude that major indicators of agricultural load within a soil profile are soil bulk density, water permeability and total sparing. Such indicators as the solid phase density and field humidity are of additional value. Key words: reforestation; soil bulk density; water permeability; soil profile; arable lands; pastures; Skolivski Beskydy.

Impact of land use reformation on soil hydraulic properties and recovery potential of conservation tillage in India's North-West Himalayan region

Degradation of soil hydro-physical properties resulted from inappropriate land management, require a resilient management system to check further degradation. Hence, understanding soil hydraulic properties (SHPs) of various land-use regimes may aid in the long-term management of ecologically sensitive and vulnerable agroecosystems. The study looked at influence of land-use conversion from native forest land to subsequent agricultural practices on SHPs in India's N-W Himalayan area, one of the world's most susceptible agroecosystems. Moreover, the water-conducting porosity at different pressure heads and the contribution of macro and mesopores to saturation flow were quantified. For this purpose, the infiltration rate and soil hydraulic conductivity of surface soil were investigated for sal forest, conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT) using the hood infiltrometer at three pressure heads. The forest land use showed the highest value followed by ZT, RT, and CT respectively for soil hydraulic conductivity, tension and residual flux potential, flow-weighted mean pore radius, and hydraulically active porosity. Additionally, the macropores contributed 61.99–73.44 % of total water flow, while the meso-micropores contributed 26.56-38.01 % of total flow across the land uses. In the water-conducting process in all land use systems, macropore's contribution was relatively higher, which comprised only small space of total soil volume, signifies its importance. Further, scatter plot matrix depicted that, mean weighted diameter (MWD), and soil organic carbon (SOC) are dominating factors controlling hydraulic conductivity. The findings strongly suggest that, while conversion of native forest land to conventional agriculture degrades soil hydraulic characteristics, SHPs may be progressively recovered in the Himalayan region by adopting conservation agriculture strategies.

The Soil Environment of Abandoned Charcoal Kiln Platforms in a Low-Altitude Central European Forest

This study examines the soil environment of eight charcoal kiln platforms and the neighboring soil in Czech and Bohemian low-altitude forest stands. Both mixed and undisturbed soil samples were used to assess the hydrophysical soil properties, nutrient content, cation exchange capacity, enzyme activity, and soil active carbon content, while soil color, stoniness, root density, and horizon thickness were estimated in the field. Charcoal-rich horizons had high total organic carbon concentrations and total nitrogen content (about 150% and 40% higher than in the organomineral horizons of the control plot, respectively), with total carbon stocks being higher than those in neighboring forest soils. Fine root density was highest in the charcoal-rich horizons, encouraged by high soil porosity, aeration, and favorable chemical properties. Enzyme group activity differed between individual soil horizons and kiln and control plots, with depolymerization enzyme activity highest in charcoal-rich horizons and humification enzyme activity highest in mineral horizons. Phosphatase, chitinase, and phenoloxidase activity were highest in charcoal-rich horizons, while β-glucosidase activity remained similar across horizons. After long-term abandonment, kiln sites shift from inhospitable sites to localized hotspots for plant and microbial growth, having more favorable physical, enzymatic, and chemical soil properties than the surrounding areas. This study confirmed that kiln production platforms act as microhabitat hotspots, also providing information on a wide spectrum of soil properties linked with soil microorganisms and root growth.

Effect of biodegradable poly-3-hydroxybutyrate amendment on the soil biochemical properties and fertility under varying sand loads

BackgroundPoly-3-hydroxybutyrate (P3HB) is a bacterial intracellular carbon and energy storage polymer, used as a thermoplastic polyester in a wide array of industrial and agricultural applications. However, how the soil microbiome and fertility are altered by exogenously applied P3HB has been relatively unexplored. This study aimed to assess the effects of P3HB addition to nutrient restricted soil: its biological properties and lettuce (Lactuca sativa L. var. capitata L.) biomass production. The experiment was designed to evaluate impacts of spatial arrangement of the relatively organic-rich (soil organic matter, P3HB particles) versus poor fractions of the matrix with confounding factors such as variable microbial biomass, inherent nutrient/energy status, different water relations (due to variable hydrophysical properties of soil augmented by sand at different ratios).ResultsThe results revealed that P3HB in soils induced inconsistent to contradictory changes in the microbial abundance as well as in most enzymatic activities. The differences were conditioned by the sand content both under P3HB presence or absence. On the other hand, dehydrogenase, urease activities, basal and substrate-induced soil respirations were mostly enhanced by P3HB addition, directly with increasing sand content (several respiration types). Nevertheless, P3HB significantly inhibited lettuce biomass production.ConclusionsP3HB introduction to soil boosts the microbial activity owing to the preferential utilization of P3HB as C source, which depletes soil N and strongly inhibits the plant growth. Enhanced microbial activity in P3HB-amended soils with high sand content (60–80%) suggested that in nutrient-impoverished soil P3HB can temporarily replace SOM as a C source for microbial communities due to the shift of their structure to preferentially P3HB-degrading microbiome.Graphical