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Physical and mechanical properties and microstructures of submarine soils in the Yellow Sea 被引量:1
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作者 Zhuangcai Tian Yihua Chang +6 位作者 Sichao Chen Gengchen Wang Yanhong Hu Chuan Guo Lei Jia Lei Song Jianhua Yue 《Deep Underground Science and Engineering》 2024年第2期197-206,共10页
In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical propertie... In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical properties of silt and sand from the Yellow Sea were measured using a direct shear apparatus and their microstructures were observed using a scanning electron microscope.The test results suggest that the shear strength of silt and sand increases linearly with the increase of normal stress.Based on the direct shear test,the scanning electron microscope was used to observe the section surface of sand.It is observed that the section surface becomes rough,with many“V”‐shaped cracks.Many particles appear on the surface of the silt structure and tend to be disintegrated.The X‐ray diffraction experiment reveals that the sand and silt have different compositions.The shear strength of sand is slightly greater than that of silt under high stress,which is related to the shape of soil particles and the mineral composition.These results can be a reference for further study of other soils in the Yellow Sea;meanwhile,they can serve as soil parameters for the stability and durability analyses of offshore infrastructure construction. 展开更多
关键词 direct shear test MICROSCOPE physical properties submarine soil Yellow Sea
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Responses of microbial activities and soil physical-chemical properties to the successional process of biological soil crusts in the Gurbantunggut Desert,Xinjiang 被引量:28
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作者 BingChang ZHANG XiaoBing ZHOU YuanMing ZHANG 《Journal of Arid Land》 SCIE CSCD 2015年第1期101-109,共9页
Biological soil crusts (BSCs) are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformat... Biological soil crusts (BSCs) are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformation in BSCs. However, little is known about microbial activities and physical-chemical properties of BSCs in the Gurbantunggut Desert, Xinjiang, China. In the present research, a sampling line with 1-m wide and 20-m long was set up in each of five typical interdune areas selected randomly in the Gurbantunggut Desert. Within each sampling line, samples of bare sand sheet, algal crusts, lichen crusts and moss crusts were randomly collected at the depth of 0-2 cm. Varia- tions of microalgal biomass, microbial biomass, enzyme activities and soil physical-chemical properties in different succession of BSCs were analyzed. The relationships between microalgal biomass, microbial biomass, enzymatic activities and soil physical-chemical properties were explored by stepwise regression. Our results indicate that micro- algal biomass, microbial biomass and most of enzyme activities increased as the BSCs developed and their highest values occurred in lichen or moss crusts. Except for total K, the contents of most soil nutrients (organic C, total N, total P, available N, available P and available K) were the lowest in the bare sand sheet and significantly increased with the BSCs development, reaching their highest values in moss crusts. However, pH values significantly decreased as the BSCs developed. Significant and positive correlations were observed between chlorophyll a and microbial biomass C. Total P and N were positively associated with chlorophyll a and microbial biomass C, whereas there was a significant and negative correlation between microbial biomass and available P. The growth of cyanobacteria and microorganism contributed C and N in the soil, which offered substrates for enzyme activities thus increasing enzyme activities. Probably, improvement in enzyme activities increased soil fertility and promoted the growth of cyanobacteria, eukary- otic algae and heterotrophic microorganism, with the accelerating succession of BSCs. The present research found that microalgal-microbial biomass and enzyme activities played important roles on the contents of nutrients in the successional stages of BSCs and helped us to understand developmental mechanism in the succession of BSCs. 展开更多
关键词 chlorophyll a microbial biomass C soil enzyme physical-chemical properties biological soil crusts
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Digital mapping of soil physical and mechanical properties using machine learning at the watershed scale
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作者 Mohammad Sajjad GHAVAMI Shamsollah AYOUBI +1 位作者 Mohammad Reza MOSADDEGHI Salman Naimi 《Journal of Mountain Science》 SCIE CSCD 2023年第10期2975-2992,共18页
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 ap... 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. 展开更多
关键词 Machine learning soil physical property soilmechanical property Saturatedhydraulic conductivity soil cohesion soil shear strength.
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GIS-Based Assessment of Soil Chemical and Physical Properties as a Basis for Land Reclamation in Toshka Area, Aswan, EGYPT
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作者 Ahmed A. M. Awad Mostafa M. A. Al-Soghir 《Open Journal of Geology》 2023年第7期697-719,共23页
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... 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<sup>−1</sup>) and moderately calcareous soil (with CaCO<sub>3</sub> 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<sup>−3</sup>, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h<sup>−1</sup>, 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. 展开更多
关键词 Land Reclamation soil Chemical and physical properties Chemical Quality Index Fertility Quality Index
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Effects of land uses on soil physic-chemical properties and erodibility in collapsing-gully alluvial fan of Anxi County,China 被引量:17
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作者 DENG Yu-song XIA Dong +1 位作者 CAI Chong-fa DING Shu-wen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第8期1863-1873,共11页
the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2011BAD31B00)
关键词 land use soil physic-chemical properties soil erodibility collapsing gully alluvial fan Anxi
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Soil Physical and Chemical Properties of Five Subtropical Forests in Lingao of Hainan
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作者 薛杨 宿少锋 +1 位作者 王小燕 林之盼 《Agricultural Science & Technology》 CAS 2017年第8期1459-1464,共6页
With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that: the soil total porosi... With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that: the soil total porosity was the highest in the Casuarina equisetifolia forest (46.168%), but the lowest in the Encalyptus robusta forest (39.46%). The soil capillary porosity was the highest in the Acacia mangium forest (22.57%), but the lowest in the secondary forest (18.95%). The soil water content was the highest in the C. equisetifolia forest, with a mean value of 27.85%, but the lowest in the secondary forest, with a mean value of 4.34%. The soil pH values were in the range of 4.81-6.59, the soils in the A. mangium forest, C. equisetifolia forest and E. robusta forest were strongly acidic (pH 4.5-5.5), and the soils in the secondary forest and C. nucifera forest were weakly acidic. The soils had organic matter contents in the range of 0.34-28.68 g/kg, and showed an order of A. mangium forest〉C. equisetifolia forest〉E. robusta forest〉secondary forest〉C. nucifera forest, with a decreasing trend with the soil depth increasing. The soil total N contents were in the range of 0.10-1.63 g/kg, the A. mangium forest showed the highest soil total N contents, while the C. nucifera forest exhibited the lowest soil total N contents; the soil total P contents were in the range of 0.21-1.74 g/kg, and the E. robusta forest had the highest soil total P contents; and the soil total K contents were in the range of 0.16-2.15 g/kg, and the A. mangium forest exhibited the highest soil total K contents. The soil available P contents were in the range of 0.98-132.46 mg/kg; and the secondary forests had the highest soil available P contents; and the soil rapidly available K contents were in the range of 3.03-27.35 mg/kg, and the C. nucifera forest exhibited the highest soil rapidly available K contents. The soil ammonium N contents were in the range of 1.38-5.15 mg/kg, and the nitrate N contents were in the range were in the range of 0.56 -3.51 mg/kg. The A. mangium forest showed the highest soil nitrate N contents (with a mean value of 2.29 mg/kg) and ammonium N contents (with a mean value of 3.93 mg/kg). For the same forest type, with the increase of soil depth, the nitrate nitrogen and ammonium nitrogen content also showed a decreasing trend. 展开更多
关键词 Lingao County Coastal platform Different forest types soil physical and chemical properties COMPARISON
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Impact of Seasons on Soil Physico-Chemical Properties and Tea Yields Based on Enriched Sheep Manure Used in Kericho, Kenya
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作者 Rhoda Ruto Syphline Kebeney +1 位作者 John K. Bore David Chemei 《Journal of Agricultural Chemistry and Environment》 2019年第3期184-199,共16页
Tea (Camellia sinensis (L) O. Kuntze) is a perennial crop grown for beverage consumption. Its production is the leading foreign exchange earner in Kenya contributing about 26% foreign exchange and 4% GDP. Nitrogen (N)... Tea (Camellia sinensis (L) O. Kuntze) is a perennial crop grown for beverage consumption. Its production is the leading foreign exchange earner in Kenya contributing about 26% foreign exchange and 4% GDP. Nitrogen (N), Phosphorus (P) and potassium (K) are the recommended nutrients for tea production. However, their continuous use has been reported to have negative effect on soil physico-chemical properties and health. Sheep manure has been recommended in tea production for its soil pH buffering effect and increased tea yields. However, effects of sheep manure enriched with inorganic fertilizer on tea soils and yield have not been conclusively investigated. This study was established at KALRO—Tea Research Institute Kericho in Timbilil estate to determine the impact of seasonal variation on soil pysico-chemical properties and yields on enriched sheep manure used. Randomized complete block design (RCBD) experimental design was adopted with 14 treatments replicated thrice. The treatments were: control with no fertilizer use, NPK at 180 Kgs N/ha/yr, sheep manure only and two enriched sheep manure ratios of 4:1 and 8:1 which translates to a mixture of (4:1) 4 parts of sheep manure and 1 part of D.A.P inorganic fertilizer. Same applied to 8:1 ratio, respectively at rates of 60, 120, 180 and 240 Kgs N/ha once per year. Data were subjected to ANOVA in GenStat statistical package and means separated by Duncan’s multiple range tests at P ≤ 0.05 significance level. Results obtained showed that soil physico-chemical properties and tea yields were influenced significantly (P ≤ 0.05) by treatments applied. Soil available water and organic matter were higher on enriched sheep manure 4:1 at 240 rate used while soil porosity and bulk density were not significantly affected. Total N and P, increased with enriched sheep manure ratio of 4:1 at 240 rate while K+, Ca2+, Mg2+, Mn and pH increased with sole application of sheep manure at rate 180 and enriched sheep manure 8:1 at 180 rate. Tea yields increased with enriched sheep manure 4:1 ratios at the rates of 240. The findings recommend enriched sheep manure 4:1 ratio at 240 rates to be adopted by tea farmers within Kericho region. Further studies involving different geographical locations are proposed. 展开更多
关键词 SEASONS soil physic-chemical properties Enriched SHEEP MANURE TEA YIELDS
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Effects of Green Manure Mixed Cropping Patterns on Physical and Chemical Properties of Soil and Economic Characters of Flue-cured Tobacco 被引量:4
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作者 陈治锋 邓小华 +2 位作者 周米良 田峰 张明发 《Agricultural Science & Technology》 CAS 2015年第8期1723-1727,共5页
[Objective] The aim was to clear the suitable green manure cropping pat- terns in Xiangxi tobacco-planting areas. [Method] 8 treatments were set to study the effects of the monoculture and mixed cropping of common vet... [Objective] The aim was to clear the suitable green manure cropping pat- terns in Xiangxi tobacco-planting areas. [Method] 8 treatments were set to study the effects of the monoculture and mixed cropping of common vetch (Vicia gigantea Bge.), perennial ryegrass (Lofium) and rapeseed (Brassica campestris L.) on physi- cal and chemical properties of soil and economic characters of flue-cured tobacco. [Result] (1) Green manure turnover can reduce soil bulk density by 1.08%-8.62%, and the effect of green manure mixed cropping pattern was the best. (2) Green manure turnover also can increase the soil nutrient, soil organic matter, total nitro- gen (N), total phosphorus (P), total potassium (K), alkali-hydrolyzale N, rapidly available P and rapidly available K by 1.44%-6.10%, 0.01-0.12 g/kg, 1.89%- 11.32%, 0.12%-3.56%, 1.06%-11.76%, 0.04%-18.93% and 0.98%-23.12%, respec- tively, and the effect of the monoculture of common vetch was the best.(3) The overall change of soil pH was not obvious.(4)Green manure turnover can increase the yield and output of flue-cured tobacco, and the effect of the monoculture of common vetch was the best. [Conclusion] The monoculture of common vetch can be generalized in the dry land of Xiangxi tobacco-planting areas. 展开更多
关键词 Green manure Mixed cropping soil physical and chemical properties Economic characters of flue-cured tobacco
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Effects of Long-Term Winter Planted Green Manure on Physical Properties of Reddish Paddy Soil Under a Double-Rice Cropping System 被引量:41
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作者 YANG Zeng-ping XU Ming-gang +4 位作者 ZHENG Sheng-xian NIE Jun GAO Ju-sheng LIAO Yu-lin XIE Jian 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第4期655-664,共10页
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 s... 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. 展开更多
关键词 long-term experiment soil physical property green manure reddish paddy soil
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Soil physical properties and maize root growth under different tillage systems in the North China Plain 被引量:12
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作者 Baizhao Ren Xia Li +3 位作者 Shuting Dong Peng Liu Bin Zhao Jiwang Zhang 《The Crop Journal》 SCIE CAS CSCD 2018年第6期669-676,共8页
The standard cultivation system in the North China Plain is double cropping of winter wheat and summer maize. The main effects of this cultivation system on root development and yield are decreases in soil nutrient co... The standard cultivation system in the North China Plain is double cropping of winter wheat and summer maize. The main effects of this cultivation system on root development and yield are decreases in soil nutrient content and depth of the plow layer under either long-term no-tillage or rotary tillage before winter wheat sowing and no tillage before summer maize sowing. In this study, we investigated the combined effects of tillage practices before winter wheat and summer maize sowing on soil properties and root growth and distribution in summer maize. Zhengdan 958(ZD958) was used as experimental material, with three tillage treatments: rotary tillage before winter wheat sowing and no tillage before summer maize sowing(RTW + NTM), moldboard plowing before winter wheat sowing and no tillage before summer maize sowing(MPW + NTM), and moldboard plowing before winter wheat sowing and rotary tillage before summer maize sowing(MPW + RTM).Tillage practice showed a significant(P < 0.05) effect on grain yield of summer maize. Grain yields under MPW + RTM and MPW + NTM were 30.6% and 24.0% higher, respectively, than that under RTW + NTM. Soil bulk density and soil penetration resistance decreased among tillage systems in the order RTW + NTM > MPW + NTM > MPW + RTM. Soil bulk densities were 3.3% and 515% lower in MPW + NTM and MPW + RTM, respectively, than that in RTW + NTM, and soil penetration resistances were respectively 17.8% and 20.4% lower,across growth stages and soil depths. Root dry matter and root length density were highest under MPW + RTM, with the resulting increased root activity leading to a yield increase of summer maize. Thus the marked effects of moldboard plowing before winter-wheat sowing on root length density, soil penetration resistance, and soil bulk density may contribute to higher yield. 展开更多
关键词 TILLAGE system SUMMER MAIZE soil physical properties ROOT
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Effect of fire severity on physical and biochemical soil properties in Zagros oak(Quercus brantii Lindl.)forests in Iran 被引量:15
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作者 M.Heydari A.Rostamy +1 位作者 F.Najafi D.C.Dey 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期95-104,共10页
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, ... 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. 展开更多
关键词 Fire severity OAK soil respiration physical and chemical soil properties
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Effects of Crude Oil Contamination on Soil Physical and Chemical Properties in Momoge Wetland of China 被引量:12
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作者 WANG Ying FENG Jiang +3 位作者 LIN Qianxin LYU Xianguo WANG Xiaoyu WANG Guoping 《Chinese Geographical Science》 SCIE CSCD 2013年第6期708-715,共8页
Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,th... Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province,China.The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh.Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area,especially in fall.Crude oil contamination significantly increases the soil pH up to8.0,and reduces available phosphorus concentrations in the soil.The concentrations of total organic carbon are significantly different among sampling sites.Therefore,crude oil contamination could potentially alkalinize marsh soils,adversely affect soil fertility and physical properties,and cause deterioration of the marshes in the Momoge National Nature Reserve.Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands.Crude oil contamination affects the soil physical and chemical properties,so developing an effective restoration program in the Momoge wetland is neccesary. 展开更多
关键词 crude oil contamination marsh soil oilfield in marshes soil physical and chemical properties WETLAND Momoge National Nature Reserve
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Experimental research on physical properties of saline soil subgrade filler in Chaerhan region 被引量:2
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作者 Yu Zhang JianHong Fang +1 位作者 JianKun Liu AnHua Xu 《Research in Cold and Arid Regions》 CSCD 2015年第3期212-215,共4页
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 physica... 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. 展开更多
关键词 saline soil salt content soil physical properties
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Effects of Different Nitrogen Applications on Soil Physical, Chemical Properties and Yield in Maize (<i>Zea mays</i>L.) 被引量:3
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作者 Heng Zhong Qiao Wang +8 位作者 Xinhua Zhao Qi Du Yue Zhao Xiaoguang Wang Chunji Jiang Shuli Zhao Minjian Cao Haiqiu Yu Dawei Wang 《Agricultural Sciences》 2014年第14期1440-1447,共8页
Application of nitrogen (N) fertilizer is one of the most important approaches on improving maize grain yield. However, as is known to all, overuse N fertilizer not only leads to decline of N use efficiency and maize ... Application of nitrogen (N) fertilizer is one of the most important approaches on improving maize grain yield. However, as is known to all, overuse N fertilizer not only leads to decline of N use efficiency and maize yield, but also leads to potential risk to environment pollution. This experiment was conducted to determine the effects of N fertilizer applications with nine different treatments on soil physical-chemical characters and maize grain yield using hybrid variety Zhengdan 958 in 2011 and 2012. Results indicated that the soil bulk densities of T2 (CK) and T1 were the lowest compared to other treatments in 2011 and 2012, respectively, whereas the soil bulk density of T5 in 2011 and T3 in 2012 were higher than other treatments. The soil porosity and field capacity of T5 in 2011 and T3 in 2012 were lower than other treatments, but those of CK in 2011 and T1 in 2012 were higher than other treatments. The pH values of T3 to T7 were lower than other treatments. These results indicated that the soil bulk densities were increased, whereas the soil porosity, field capacity and values pH were decreased by N application at different stages. N application could increase the N contents of leaf and stem, whereas less or excess N application should not significant improve maize yield. Although the soil organic matter and total N contents of T3 were the highest in both 2011 and 2012, the yield of T4 is the highest in both 2011 and 2012. The application amount, period and times of N fertilizer were important to maize yield. 展开更多
关键词 MAIZE N Fertilizer Application YIELD soil physical and Chemical properties N Content
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Influences of Soil Physical Properties on Water-Supplying Capacity 被引量:1
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作者 ZHAOBINGZI XUFUAN 《Pedosphere》 SCIE CAS CSCD 1997年第4期367-374,共8页
The water-supplying capacity of two agricultural soils, red soil in Jiangxi Province and meadow soil in Henan Province, was assessed mainly using physical investigations. The reticulated mottting horizon in the red so... The water-supplying capacity of two agricultural soils, red soil in Jiangxi Province and meadow soil in Henan Province, was assessed mainly using physical investigations. The reticulated mottting horizon in the red soil was a horizon limiting roots distribution due to its high density and hardness in structure and low pH (pH 5.05). The resistance of the red soil to drought hazard was poor because of its low water-supply capacity and poor hydraulic conductivity. The meadow soil had superior profile infiltration to that of the red soil and great available water-storage capacity) which resulted in low run-off loss, especially in the wheat-growth season. It was difficult for water stored in the deep layers of the meadow soil to reach the surface due to the low unsaturated hydraulic conductivity of its clay-rich horizon in subsoil. However, water stored in deep layers was still available because the roots could extend to the deep layers due to the relatively low density in soil structure. 展开更多
关键词 meadow soil red soil soil physical properties water-supplying capacity
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Robinia pseudoacacia leaves improve soil physical and chemical properties 被引量:1
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作者 Babar KHAN Abdukadir Ablimit +1 位作者 Rashed MAHMOOD Muhammad QASIM 《Journal of Arid Land》 SCIE 2010年第4期266-271,共6页
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 adde... 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. 展开更多
关键词 soil physical and chemical properties Robinia pseudoacacia Gilgit-Baltistan
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Physical and Biochemical Properties of Apple Orchard Soils of Different Productivities 被引量:1
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作者 Takamitsu Kai Masaki Mukai +2 位作者 Kiwako S. Araki Dinesh Adhikari Motoki Kubo 《Open Journal of Soil Science》 2015年第7期149-156,共8页
Physical and biochemical properties of apple orchard soils of different productivities (orchard A: 30 t&#183ha&#451;orchard B: 20 t&#183ha&#451) were analyzed. Most of the physical properties were simi... Physical and biochemical properties of apple orchard soils of different productivities (orchard A: 30 t&#183ha&#451;orchard B: 20 t&#183ha&#451) were analyzed. Most of the physical properties were similar in both orchards. In orchard A, the horizontal saturated hydraulic conductivity at 10-cm depth was 16.42 cm&#183day&#451, and was about four times higher than that in orchard B (4.41 cm&#183day&#451). Total carbon, total nitrogen, and total phosphorus were about two times higher in orchard B soil, whereas total potassium, bacterial biomass, nitrification, and phosphorus mineralization activities were similar in both orchards. Excess nutrients accumulated on the top 15 cm layer of orchard B soil because the topographical and physical conditions were associated with reduced apple productivity. Appropriate management of fallen leaves and reduction of chemical fertilizer seem necessary for a high level of apple productivity. 展开更多
关键词 APPLE ORCHARD soil physical properties BIOCHEMICAL properties FRUIT Yield
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Tillage and Rice-Wheat Cropping Sequence Influences on Some Soil Physical Properties and Wheat Yield under Water Deficit Conditions 被引量:1
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作者 Sandeep Kumar Pradeep K. Sharma +1 位作者 Stephen H. Anderson Kapil Saroch 《Open Journal of Soil Science》 2012年第2期71-81,共11页
Adopting a better tillage system not only improves the soil health and crop productivity but also improves the environment. A field experiment was conducted to investigate the effects of tillage and irrigation managem... Adopting a better tillage system not only improves the soil health and crop productivity but also improves the environment. A field experiment was conducted to investigate the effects of tillage and irrigation management on wheat (Triticum aestivum L.) production in a post-rice (Oryza sativa L.) management system on silty clay loam soil (acidic Alfisol) for 2003-2006. Four irrigation levels (RF: rainfed;I1: irrigation at crown root initiation (CRI);I2: irrigation at CRI + flowering;I3: irrigation at CRI + tillering + flowering), and two tillage systems (ZT: zero tillage and CT: conventional tillage) were tested. Zero tillage compared to CT, resulted in higher bulk density (1.34 vs 1.23 Mg –3), lower total porosity (48.7 vs 52.9%), higher penetration resistance (1.51 vs 1.37 MPa), lower saturated hydraulic conductivity (1.60 vs 92.0 mm h–1), lower infiltration rate (9.40 vs 36.6 mm h–1) and higher volumetric available water capacity (7.9 vs 7.5%) in the surface 0.15 m soil layer. Irrigation levels significantly affected crop water use, wheat yield, and water use efficiency (WUE). Average total water use was 461, 491, 534 and 580 mm under RF, I1, I2 and I3 treatments, respectively. Grain and straw yield of wheat were statistically the same under ZT and CT during 2003-2004;the values, averaged over four irrigation levels were 2.10 and 2.38 Mg a–1 for grain, and 3.46 and 3.67 Mg a–1 for straw, respectively. Grain yield declined by 22%, 11% and 8% of I3 (2.32 Mg ha–1) with RF, I1 and I2 treatments, respectively, under ZT;and by 13%, 8% and 5% of I3 (2.61 Mg ha–1) with RF, I1 and I2 treatments under CT. Average values of WUE were 4.33 kg ha–1 m–1 and 2.35 m3–1 grain for the ZT and CT treatments. Wheat yield increased with increased irrigation levels for all the cropping seasons. Results from this study concluded that ZT system was better compared to the CT system even with lower yields due to lower input costs for this treatment. 展开更多
关键词 Conventional TILLAGE soil physical properties INFILTRATION WATER RETENTION WATER Use Efficiency Zero TILLAGE
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Effects of Straw and Biochar Returned to the Soil on Soil Physical Properties and pH Value in Cold Rice Region 被引量:1
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作者 Yuefeng CUI Hongru SHI +5 位作者 Aonan GUO Guocai SUN Guiyan WANG Jian WANG Wenjia HUANG Tiegang LU 《Asian Agricultural Research》 2021年第2期27-32,共6页
[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 ret... [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. 展开更多
关键词 STRAW BIOCHAR Cold rice region soil physical properties soil pH value
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Acoustic-Physical Properties of Calcareous Seafloor Soils and Their Significance in Engineering Geology 被引量:5
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作者 卢博 李赶先 黄韶健 《China Ocean Engineering》 SCIE EI 2000年第3期361-370,共10页
The basic features and acoustic-physical properties of calcareous seafloor soils in the tropic sea area are obviously different from those of sediments mainly composed of terrigenous materials in the South China Sea. ... The basic features and acoustic-physical properties of calcareous seafloor soils in the tropic sea area are obviously different from those of sediments mainly composed of terrigenous materials in the South China Sea. Generally calcareous soils, composed of carbonate particles of marine organism remains. have the characteristics of high water content, high porosity, low wet density, high sound velocity and greatly varied comprehensive strength. Recognizing the differences between calcareous soils and terrigenous sediments and engineering geologic significance of calcareous soils is crucial for seafloor geologic research and geotechnical survey for pile-jacket platform foundation design. 展开更多
关键词 South China Sea calcareous soil acoustic-physical properties engineering geology
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