Effects of Straw and Biochar Returned to the Soil on Soil Physical Properties and pH Value in Cold Rice Region

[Objectives]In order to explore the feasibility of using straw and biochar returned to the soil to improve soil physical properties and pH value in cold rice regions of China.[Methods]the effects of straw directly returned to the soil and charred straw(biochar)returned to the soil on soil bulk density,porosity,temperature and pH value of cold paddy soil were studied in this paper.[Results]The results showed that compared with conventional production,straw(6 t/ha),a small amount of biochar(2 t/ha)and a large amount of biochar(40 t/ha)returned to the soil reduced paddy soil bulk density at different growth stages by 6.02%-11.86%,2.69%-6.67%and 8.58%-11.32%,respectively,increased total porosity by 7.41%-14.93%,3.19%-8.38%and 9.81%-14.27%,respectively,and increased aeration porosity by 22.28%-192.11%,17.80%-92.11%and 52.44%-157.11%,respectively.Straw and a small amount of biochar returned to the soil had no significant effect on soil temperature and pH value of paddy field,but a large amount of biochar returned to the soil could significantly increase soil temperature by 5.13%-8.79%and pH value by 3.15%-5.96%in the later stage of rice growth.[Conclusions]The straw and biochar returned to the soil could reduce soil bulk density,increase total porosity and aeration porosity,and only a large amount of biochar returned to the soil could significantly increase soil temperature and pH value.

Effects of restoration modes on the spatial distribution of soil physical properties after land consolidation: a multifractal analysis

Soil physical properties(SPP)are considered to be important indices that reflect soil structure,hydrological conditions and soil quality.It is of substantial interest to study the spatial distribution of SPP owing to the high spatial variability caused by land consolidation under various land restoration modes in excavated farmland in the loess hilly area of China.In our study,three land restoration modes were selected including natural restoration land(NR),alfalfa land(AL)and maize land(ML).Soil texture composition,including the contents of clay,silt and sand,field capacity(FC),saturated conductivity(Ks)and bulk density(BD)were determined using a multifractal analysis.SPP were found to possess variable characteristics,although land consolidation destroyed the soil structure and decreased the spatial autocorrelation.Furthermore,SPP varied with land restoration and could be illustrated by the multifractal parameters of D1,ΔD,ΔαandΔf in different modes of land restoration.Owing to multiple compaction from large machinery in the surface soil,soil particles were fine-grained and increased the spatial variability in soil texture composition under all the land restoration modes.Plough numbers and vegetative root characteristics had the most significant impacts on the improvement in SPP,which resulted in the best spatial distribution characteristics of SPP found in ML compared with those in AL and NR.In addition,compared with ML,Δαvalues of NR and AL were 4.9-and 3.0-fold that of FC,respectively,andΔαvalues of NR and AL were 2.3-and 1.5-fold higher than those of Ks,respectively.These results indicate that SPP can be rapidly improved by increasing plough numbers and planting vegetation types after land consolidation.Thus,we conclude that ML is an optimal land restoration mode that results in favorable conditions to rapidly improve SPP.

Digital mapping of soil physical and mechanical properties using machine learning at the watershed scale

Knowledge about the spatial distribution of the soil physical and mechanical properties is crucial for soil management,water yield,and sustainability at the watershed scale;however,the lack of soil data hinders the application of this tool,thus urging the need to estimate soil properties and consequently,to perform the spatial distribution.This research attempted to examine the proficiency of three machine learning methods(RF:Random Forest;Cubist:Regression Tree;and SVM:Support Vector Machine)to predict soil physical and mechanical properties,saturated hydraulic conductivity(Ks),Cohesion measured by fall-cone at the saturated(Psat)and dry(Pdry)states,hardness index(HI)and dry shear strength(SS)by integrating environmental variables and soil features in the Zayandeh-Rood dam watershed,central Iran.To determine the best combination of input variables,three scenarios were examined as follows:scenarioⅠ,terrain attributes derivative from a digital elevation model(DEM)+remotely sensed data;scenarioⅡ,covariates of scenarioⅠ+selected climatic data and some thematic maps;scenarioⅢ,covariates in scenarioⅡ+intrinsic soil properties(Clay,Silt,Sand,bulk density(BD),soil organic matter(SOM),calcium carbonate equivalent(CCE),mean weight diameter(MWD)and geometric weight diameter(GWD)).The results showed that for Ks,Psat Pdry and SS,the best performance was found by the RF model in the third scenario,with R2=0.53,0.32,0.31 and 0.41,respectively,while for soil hardness index(HI),Cubist model in the third scenario with R2=0.25 showed the highest performance.For predicting Ks and Psat,soil characteristics(i.e.clay and soil SOM and BD),and land use were the most important variables.For predicting Pdry,HI,and SS,some topographical characteristics(Valley depth,catchment area,mltiresolution of ridge top flatness index),and some soil characteristics(i.e.clay,SOM and MWD)were the most important input variables.The results of this research present moderate accuracy,however,the methodology employed provides quick and costeffective information serving as the scientific basis for decision-making goals.

GIS-Based Assessment of Soil Chemical and Physical Properties as a Basis for Land Reclamation in Toshka Area, Aswan, EGYPT

The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the chemical and fertility index for assisting land reclamation in Toshka area. The Toshka area is located between latitudes 31°32'N and 31°36'N and longitudes 32°40'E and 32°60'E. GIS was used to select 16 sites. The results revealed the soil has undesirable characteristics. The soil pH ranged from slightly alkaline to moderately alkaline. Furthermore, it was characterized as saline (with a ECe of 4.65 - 11.45 dS⋅m−1) and moderately calcareous soil (with CaCO3 at 11.85% - 17.20%). The soil had a low soil organic matter content which did not exceed 0.18%. The soil was dominated by a sandy loam texture (62.50%) followed by a sandy clay loam texture (18.75%). The bulk density, total soil porosity and saturated hydraulic conductivity values varied with 1.38 - 1.55 Mg⋅cm−3, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h−1, respectively. The chemical index ranged from low to moderate quality. The correlations between the parameters osculated between negative and positive. Therefore, the soil may be reclaimed if the soil properties are improved and crop selection is optimized for this soil.

Effects of irrigation water salinity on soil salt content distribution,soil physical properties and water use efficiency of maize for seed production in arid Northwest China

In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four different water salinity levels that were arranged in a split plot design.These four water salinity levels were s0,s3,s6 and s9(0.71,3,6 and 9 g/L,respectively).The soil salt content,soil bulk density,soil porosity,saturated hydraulic conductivity,plant height,leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution,soil physical properties and water use efficiency.It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation.Compared to initial values,the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0,s3,s6 and s9 was 0.189 mg/cm3,0.654 mg/cm3,0.717 mg/cm3 and 1.135 mg/cm3,respectively.Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density,but poorer soil porosity and less saturated hydraulic conductivity.The saturated hydraulic conductivity decreased with increase in soil bulk density,but increased with improvement in soil porosity.It was noted that the maize height,leaf area index and maize yield gradually decreased with increase in water salinity.The maize yield decreased over 25%and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels.However,maize yield following saline water irrigation with 3 g/L decreased less than 20%and the decline in water use efficiency was not significant during the three-year experiment period.The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable,while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing.

Experimental research on physical properties of saline soil subgrade filler in Chaerhan region

In order to improve the engineering stability of saline soil of high chloride content in the Chaerhan salt lake region, six typical characteristics saline soil samples were selected, and tests on their primary physical properties （total salt content, specific gravity of soil, liquid limit, plastic limit, maximum dry density, and optimal water content） were conducted. The relationships among them were analyzed, a series of variation laws between salt content and these basic physical parameters were determined, and regression equations were derived. This research can improve future engineering design and construction in saline soils and can also help prevent subgrade filler from undermining subgrade stability and producing disease.

Shear resistance characteristics and influencing factors of root-soil composite on an alpine metal mine dump slope with different recovery periods

Artificial vegetation restoration is the main measure for vegetation restoration and soil and water conservation in alpine mine dumps on the Qinghai-Tibet Plateau,China.However,there are few reports on the dynamic changes and the influencing factors of the soil reinforcement effect of plant species after artificial vegetation restoration under different recovery periods.We selected dump areas of the Delni Copper Mine in Qinghai Province,China to study the relationship between the shear strength and the peak displacement of the root-soil composite on the slope during the recovery period,and the influence of the root traits and soil physical properties on the shear resistance characteristics of the root-soil composite via in situ direct shear tests.The results indicate that the shear strength and peak displacement of the rooted soil initially decreased and then increased with the increase of the recovery period.The shear strength of the rooted soil and the recovery period exhibited a quadratic function relationship.There is no significant function relationship between the peak displacement and the recovery period.Significant positive correlations(P<0.05)exists between the shear strength of the root-soil composite and the root biomass density,root volume density,and root area ratio,and they show significant linear correlations(P<0.05).There are no significant correlations(P>0.05)between the shear strength of the root-soil composite and the root length density,and the root volume ratio of the coarse roots to the fine roots.A significant negative linear correlation(P<0.05)exists between the peak displacement of the rooted soil and the coarse-grain content,but no significant correlations(P>0.05)with the root traits,other soil physical property indices(the moisture content and dry density of the soil),and slope gradient.The coarse-grain content is the main factor controlling the peak displacement of the rooted soil.

Effects of soil physical properties on soil loss due to manual yam harvesting under a sandy loam environment

Soil degradation is a growing problem worldwide because it reduces the fertile top layer of the soil available for food production and one such degradative action is soil erosion due to the harvesting of crops.Soil loss due to crop harvesting with particular reference to yam tubers has not been quantified globally despite the fact that yam is a major staple food consumed worldwide and it is prevalent in many parts of Nigeria.Harvesting yams in our environment is usually done with the soil attached to the yams due to the fact that farmers do not want additional work of removing soil attached to the yams.This study investigates the soil physical properties that influence soil loss due to yam harvesting in Abeokuta,South-Western Nigeria and to assess the quantity of soil loss due to yam harvesting.Based on representative sampling area per location,yam tubers were harvested manually within the entire yam farmland from October to December 2012.Gross weight,net weight and the amount of soil adhering to the yams were measured.Effects of soil physical properties such as soil moisture content,heap bulk density,inter-heap bulk density and soil texture were investigated with respect to soil losses.The results showed that moisture content ranged from 4%to 15%,heap bulk density ranged from 0.93 to 1.29 g cm^(-3) and inter-heap bulk density ranged from 1.03 to 1.50 g cm^(-3).They all had a positive correlation with soil loss.Soil particle size analysis for Federal University of Agricultural,Abeokuta(FUNAAB)and Alabata revealed that sand content was(86.78%and 88.32%),clay content(10.69%and 7.6%)and silt content,(2.53%and 4.08%)respectively.Study also revealed that clay content of the soil positively influenced the total soil loss during the yam harvesting.The mean soil losses in Federal University of Agriculture,Abeokuta(FUNAAB)and Alabata village yam farms were 4303 and 2125 kg/ha/harvest respectively.The study also revealed that soil moisture content at harvesting time and clay content are the key factors affecting soil loss due to yam harvesting.Consequently,soil loss due to crop harvesting should be considered in soil erosion control strategies,sediment budget and for better post harvest procedures.

Effects of Long-Term Winter Planted Green Manure on Physical Properties of Reddish Paddy Soil Under a Double-Rice Cropping System

Soil physical properties are important indicators of the potential for agricultural production.Our objective was to evaluate the effects of long-term inputs of green manures on physical properties of a reddish paddy soil（Fe-Typic Hapli-Stagnic Anthrosols） under a double cropping system.The common cropping pattern before the study was early-late rice-fallow（winter）.The field treatments included rice-rice-fallow（R-R-WF）,rice-rice-rape（R-R-RP）,rice-rice-Chinese milk vetch（RR-MV）,and rice-rice-ryegrass（R-R-RG）.The rape,Chinese milk vetch and ryegrass were all incorporated as green manures 15 d before early rice transplanting during the following year.The soil bulk density in all green manure treatments was significantly reduced compared with the winter fallow treatment.Soil porosity with green manure applications was significantly higher than that under the winter fallow.The green manure treatments had higher 0.25-5 mm water stable aggregates and aggregates stabilities in the plow layer（0-15 cm depth） compared with the fallow treatment.The mean weight diameter（MWD） and normalized mean weight diameter（NMWD） of aggregates in the green manure treatment were larger than that with the winter fallow.Soil given green manure retained both a higher water holding capacity in the plow layer soil,and a larger volume of moisture at all matric potentials（-10,-33 and-100 kPa）.We conclude that the management of double-rice fields in southern central China should be encouraged to use green manures along with chemical fertilizers to increase SOC content,improve soil physical properties and soil fertility.

Effect of fire severity on physical and biochemical soil properties in Zagros oak(Quercus brantii Lindl.)forests in Iran

Fire affects the physical and chemical properties and soil biological activity of natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, where we sampled soils in areas that were classified by fire severity： low （LS）, high （HS） and medium severity （MS）, and unburned （UB）, which served as the control. In each severity class, 25 transect points were randomly selected for measurement. Around each transect plot center, 3 soil samples were selected randomly and soils collected from the 0 to 20 cm depth were combined into a composite sample that was used in laboratory analysis to represent conditions at that point. Plots in the UB and LS fire classes had similar soil conditions and had higher values of factors such as saturated moisture, organic carbon, carbon dioxide, and silt and clay content. In contrast, plots in the HS and MS fire severity classes were clustered in the positive direction along the first axis that represented gradients in soil acidity, electrical conductivity, cation exchange capacity, accessible phosphorus, accessible potassium, bulk density, and sand. Soil attributes were similar in areas of HS and MS fire severity classes, whereas soil conditions in the LS class and UB controls were most similar. Fire in the LS areas either did not significantly alter the physicalchemical soil properties and microbial basal respiration, or soils were able to recover quickly after being burned.

Robinia pseudoacacia leaves improve soil physical and chemical properties

The role of the leaves of Robinia pseudoacacia L., which is widely distributed in the arid lands, on improving soil physical and chemical properties was analyzed at various incubation periods. The incubated soils added with 0, 25, 50 and 75 g Robinia pseudoacacia leaves were tested after consecutive incubation intervals of 6, 8 and 10 months and the different soil parameters were measured. The results showed the increases in organic matter (OM), extractable K, cation exchange capacity (CEC), aggregate stability and water holding capacity, but the decreases in pH value and bulk density after 6 months’ incubation. The gradual decrease in change rates of soil properties indicated less microbial population and organic residual mineralization under acidic conditions, which were resulted from fast decomposition of leaves after the first 6 months incubation. The increases in soil organic matter content, extractable K, CEC, aggregate stability and water holding capacity and the decreases in soil pH and bulk density provide favorable conditions for crop’s growth.

Key Physical Factors Affecting Spatial-temporal Variation of Labile Organic Carbon Fractions by Biochar Driven in Mollisols Region of Northeast China

Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between physical properties and LOC fractions. A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions. Maize stalk biochar treatments included C1(1.5 kg·hm^(-2)), C2(3 kg·hm^(-2)), C3(15 kg·hm^(-2)), C4(30 kg·hm^(-2)), and CK(0). The results showed that maize stalk biochar increased soil water contents(SWC) and soil porosity(SP), but reduced bulk density(BD). Maize stalk biochar reduced dissolved organic carbon(DOC) contents in the 0-20 cm soil layer, ranging from 0.25 g·kg^(-1) to 0.31 g·kg^(-1) in harvest period, while increased in the 20-40 cm soil layer. In addition, the application of biochar had a significant impact on the spatial distribution and temporal change of SWC, BD, SP, DOC, hot-water extractable carbon(HWC), acid hydrolyzed organic carbon(AHC Ⅰ, Ⅱ), and readily oxidized organic carbon(ROC). High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC, HWC, AHC Ⅰ, AHC Ⅱ, and ROC. In addition, SWC and SP were the key physical factors to affect LOC fractions. In conclusions, maize stalk biochar could improve physical properties, and then influence LOC fractions, and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition.

Review and prospect of the effects of freeze-thaw on soil geotechnical properties

Freeze-thaw hazard is one of the main problems in cold regions engineering and artificial ground freezing engineering.To mitigate freeze-thaw hazards,it is essential to investigate the effects of freeze-thaw on soils engineering properties.This paper summarizes the effects of freeze-thaw on the physical and mechanical properties of soils reported in recent studies.The differences of freeze-thaw conditions between freezing shaft sinking and cold regions engineering are discussed.Based on the technological characteristics of freezing shaft sinking in deep alluvium,we further attempt to identify key research needs regarding the freeze-thaw effects on the engineering properties of deep soils.

Soil Loss by Wind Erosion for Three Different Textured Soils Treated with Polyacrylamide and Crude Oil, Iraq

The study is conducted to estimate the resistance of three soils (EL Hartha clay loam, Barjisiya sandy loam and the soil near the sand dunes in Sheikh sa'ad area sandy soil) to wind erosion, it is also aimed at getting full acquaintance of the relationship between the soil loss and the physical and chemical features of soil. In addition to the experiment of some soil stabilizers, polyacrylamide (PAM) concentration of 0.2 % and crude oil in concentration of 1 % in order to reduce or prevent wind erosion. The study shows that the amendment increased the dry soil aggregate >1 mm, mean weight diameter and soil moisture. It is clear that polyacrylamide had greater effect than that of crude oil, besides the great effectiveness of these amendments in decreasing bulk density and relations of soil loss.

Ecological effect of the plantation of Sabina vulgaris in the Mu Us Sandy Land,China

Vegetation restoration through artificial plantation is an effective method to combat desertification,especially in arid and semi-arid areas.This study aimed to explore the ecological effect of the plantation of Sabina vulgaris on soil physical and chemical properties on the southeastern fringe of the Mu Us Sandy Land,China.We collected soil samples from five depth layers(0-20,20-40,40-60,60-80,and 80-100 cm)in the S.vulgaris plantation plots across four plantation ages(4,7,10,and 16 years)in November 2019,and assessed soil physical(soil bulk density,soil porosity,and soil particle size)and chemical(soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN),available phosphorus(AP),available potassium(AK),cation-exchange capacity(CEC),salinity,p H,and C/N ratio)properties.The results indicated that the soil predominantly consisted of sand particles(94.27%-99.67%),with the remainder being silt and clay.As plantation age increased,silt and very fine sand contents progressively rose.After 16 years of planting,there was a marked reduction in the mean soil particle size.The initial soil fertility was low and declined from 4 to 10 years of planting before witnessing an improvement.Significant positive correlations were observed for the clay,silt,and very fine sand(mean diameter of 0.000-0.100 mm)with SOC,AK,and p H.In contrast,fine sand and medium sand(mean diameter of 0.100-0.500 mm)showed significant negative correlations with these indicators.Our findings ascertain that the plantation of S.vulgaris requires 10 years to effectively act as a windbreak and contribute to sand fixation,and needs 16 years to improve soil physical and chemical properties.Importantly,these improvements were found to be highly beneficial for vegetation restoration in arid and semi-arid areas.This research can offer valuable insights for the protection and restoration of the vegetation ecosystem in the sandy lands in China.

Adsorption-Desorption Characteristics of Chlorimuron-Ethyl in Soils

The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values （Kads-f） of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# （Jiangxi clay） and 3# （Jiangxi sand loam） soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients （H） of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values （Kads-f） increased with the OM （%） and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.

Effect of chemical and organic fertilization on soil carbon and nitrogen accumulation in a newly cultivated farmland

Increased food demand from the rapidly growing human population has caused intensive land transition from desert to farmland in arid regions of northwest China. In this developing ecosystem, the optimized fertilization strategies are becoming an urgent need for sustainable crop productivity, efficient resources use, together with the delivery of ecosystems services including soil carbon（C） and nitrogen（N） accumulation. Through a 7-year field experiment with 9 fertilization treatments in a newly cultivated farmland, we tested whether different fertilizations had significant influences on soil C and N accumulation in this developing ecosystem, and also investigated possible mechanisms for this influence. The results showed that applying organic manure in cultivated farmland significantly increased the soil C and N accumulation rates; this influence was greater when it was combined with chemical fertilizer, accumulating 2.01 t C and 0.11 t N ha^（–1） yr^（–1） in the most successful fertilization treatment. These high rates of C and N accumulation were found associated with increased input of C and N, although the relationship between the N accumulation rate and N input was not significant. The improved soil physical properties was observed under only organic manure and integrated fertilization treatments, and the significant relationship between soil C or N and soil physical properties were also found in this study. The results suggest that in newly cultivated farmland, long term organic manure and integrated fertilization can yield significant benefits for soil C and N accumulation, and deliver additional influence on physical properties.

Biochar applications influence soil physical and chemical properties,microbial diversity,and crop productivity:a meta-analysis

Biochar is a widely known soil amendment.Here we synthesize the available information on influence of biochar application on different soil properties and crop productivity using meta-analysis.Global data on influence of biochar applications on different soil physical,chemical,microbial properties,and crop productivity were extracted from literature and statistically analyzed.Based on selection criteria,59 studies from the literature published between 2012 and 2021 were selected for the meta-analysis.Correlations were developed between effect size of biochar application on different soil properties and crop productivity.Application of biochar increased soil pH,cation exchange capacity,and organic carbon by 46%,20%,and 27%,respectively,with greater effects in coarse and fine-textured soils.Effects on chemical properties were variable among biochar prepared from different feedstocks.Among physical properties,biochar application reduced bulk densities by 29%and increased porosity by 59%.Biochar prepared at higher pyrolytic temperatures(>500℃)improved bulk density and porosity to greater extents(31%and 66%,respectively).Biochar prepared at lower pyrolytic temperatures(<500℃)had a greater effect on microbial diversity(both bacterial and fungal),with more diverse bacterial populations in medium and coarse textured soils,while fungal diversity increased in fine textured soils.Biochar applications increased crop productivity only in fine and coarse textured soil.The effect size of biochar application on crop productivity was correlated with responses to physical properties of soils.The meta-analysis highlighted the need to conduct long-term field experiments to provide better explanations for changes in biochar properties as it undergoes aging,its longer-term effects on soil properties,and timing of re-application of different biochars.

LINKING CROP WATER PRODUCTIVITY TO SOIL PHYSICAL,CHEMICAL AND MICROBIAL PROPERTIES

Agriculture uses a large proportion of global and regional water resources.Due to the rapid increase of population in the world,the increasing competition for water resources has led to an urgent need in increasing crop water productivity for agricultural sustainability.As the medium for crop growth,soils and their properties are important in affecting crop water productivity.This review examines the effects of soil physical,chemical,and microbial properties on crop water productivity and the quantitative relationships between them.A comprehensive view of these relationships may provide important insights for soil and water management in arable land for agriculture in the future.

Response of soil macrofauna to urban park reconstruction

This study is based on a park in an industrial city in Ukraine.In 2019,a 2.8 ha area of the park was reconstructed.The park’s reconstruction aimed to create a comfortable environment for visitors and to improve the efficiency of ecosystem services,and thereby enhance the quality of life of citizens.The reconstruction of the park was found to cause changes in the physical properties of soils and the structure of the soil macrofauna community.The increases of soil compaction in the layers at depth 5-20 cm and the soil electrical conductivity were a consequence of technological operations during reconstruction.The park reconstruction activities can also explain 29% of the variation in the soil macrofauna community.Extracting the variation induced by the park reconstruction from the community variation induced by other causes was a major challenge.The specific changes in the community of soil macrofauna following the reconstruction of the park were revealed.The abundance of soil animal species A.rosea,A.trapezoides,H.affinis,H.rufipes,B.affinis was found to increase after the reconstruction.The earthworm A.trapezoides decreased in abundance due to the park reconstruction.