scholarly journals Effects of Afforestation on Soil Bulk Density and pH in the Loess Plateau, China

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1710 ◽  
Author(s):  
Xiaofang Zhang ◽  
Jan Adamowski ◽  
Ravinesh Deo ◽  
Xueyun Xu ◽  
Guofeng Zhu ◽  
...  
Keyword(s):  
Bulk Density ◽  
Soil Quality ◽  
Loess Plateau ◽  
Soil Ph ◽  
Soil Depth ◽  
Soil Bulk Density ◽  
Stand Age ◽  
Clear Understanding ◽  
Sustainable Land Management ◽  
The Loess Plateau

Sustainable land management requires a clear understanding of the changes in soil quality. In exploring whether afforestation has the potential to improve the soil quality in China’s Loess Plateau, soil bulk density ( ρ s ) and pH were compared under five treatments: three forested treatments (16-and 40-year-old apricot stands, and 40-year-old poplar stands), and individual abandoned and cultivated treatments, serving as the controls. Bulk density across the 0–1.0 m soil profile under the 16-year-old apricot treatment (1.12 Mg m−3) and 40-year-old poplar treatment (1.16 Mg m−3) were significantly smaller than their counterparts under the cultivated (1.20 Mg m−3) and abandoned treatments (1.23 Mg m−3). Soil pH of the cultivated treatment (8.46) was significantly lower than that of the abandoned treatment (8.51) or than that of any forested treatment. The ρ s and pH were both affected by stand age, with the ρ s and pH of the 40-year-old apricot treatment being 0.10 Mg m−3 and 0.05 units greater, respectively, than those of the 16-year-old apricot treatment. Treatment and soil depth appeared to interact to influence the ρ s , but this same interaction did not influence the soil pH. This study suggested that afforestation species and stand age should be taken into consideration to harvest maximum benefits from the afforestation efforts.

scholarly journals Temporal changes of an alfalfa succession and related soil physical properties on the Loess Plateau, China

2009 ◽  
Vol 44 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Dong Li She ◽  
Ming An Shao ◽  
Luis Carlos Timm ◽  
Klaus Reichardt
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Soil Water ◽  
Loess Plateau ◽  
Water Storage ◽  
Soil Bulk Density ◽  
Soil Physical Properties ◽  
Natural Vegetation ◽  
Soil Water Storage ◽  
The Loess Plateau

The objective of this work was to investigate the relationship between changes in the plant community and changes in soil physical properties and water availability, during a succession from alfalfa (Medicago sativa L.) to natural vegetation on the Loess Plateau, China. Data from a succession sere spanning 32 years were collated, and vegetative indexes were compared to changes related to soil bulk density and soil water storage. The alfalfa yield increased for approximately 7 years, then it declined and the alfalfa was replaced by a natural community dominated by Stipa bungeana that began to thrive about 10 years after alfalfa seeding. Soil bulk density increased over time, but the deterioration of the alfalfa was mainly ascribed to a severe reduction in soil water storage, which was lowest around the time when degradation commenced. The results indicated that water consumption by alfalfa could be reduced by reducing plant density. The analysis of the data also suggested that soil water recharge could be facilitated by rotating the alfalfa with other crops, natural vegetation, or bare soil.

scholarly journals The Performance of the DES Sensor for Estimating Soil Bulk Density under the Effect of Different Agronomic Practices

Geosciences ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 117 ◽  
Author(s):  
Ahmed Abed Gatea Alshammary ◽  
Abbas Z. Kouzani ◽  
Akif Kaynak ◽  
Sui Yang Khoo ◽  
Michael Norton ◽  
...  
Keyword(s):  
Bulk Density ◽  
Soil Depth ◽  
Specific Energy Consumption ◽  
Strong Relationship ◽  
Soil Bulk Density ◽  
Electromechanical System ◽  
Soil Tillage ◽  
Tillage Systems ◽  
Agronomic Practices ◽  
Lack Of Information

The estimation of soil wet bulk density (ρn) and dry bulk density (ρb) using the novel digital electromechanical system (DES) has provided information about important parameters for the assessment of soil quality and health with a direct application for agronomists. The evaluation of the DES performance is particularly appropriate for different tillage methods, mulching systems, and fertilizers used to increase soil fertility and productivity, but currently, there is a lack of information, particularly in the arid areas in underdeveloped countries. Therefore, the main aim of this study was the application of a novel digital electromechanical system (DES) to evaluate bulk density, wet (ρn) and dry (ρb), under different soil treatments according to the variations in thermal efficiencies (ηth), microwave penetration depths (MDP), and specific energy consumption (Qcon) in an experimental area close to Baghdad (Iraq). The experimental design consisted of 72 plots, each 4 m2. The agronomic practices included two different tillage systems (disc plough followed by a spring disk and mouldboard plough followed by a spring disk) and twelve treatments involving mulching plastic sheeting combined with fertilizers, to determine their effect on the measured soil ρn and ρb and the DES performance in different soils. The results indicated that soil ρn and ρb varied significantly with both the tillage systems and the mulching systems. As expected, the soil ρn and ρb, MDP, and Qcon increased with an increase in the soil depth. Moreover, the tillage, soil mulching, and soil depth value significantly affected ηth and Qcon. A strong relationship was identified between the soil tillage and MDP for different soil treatments, leading to the changes in soil ρb and the soil dielectric constant (ε’).

scholarly journals Earthworm Burrowing Activity and Its Effects on Soil Hydraulic Properties under Different Soil Moisture Conditions from the Loess Plateau, China

2020 ◽  
Vol 12 (21) ◽  
pp. 9303
Author(s):  
Shuhai Wen ◽  
Ming’an Shao ◽  
Jiao Wang
Keyword(s):  
Soil Moisture ◽  
Loess Plateau ◽  
Hydraulic Properties ◽  
Soil Depth ◽  
Soil Aggregates ◽  
Field Capacity ◽  
Soil Hydraulic Properties ◽  
The Loess Plateau ◽  
Burrowing Activity ◽  
Soil Hydraulic

Earthworm activity has become more important in the Loess Plateau, where hydrological processes are crucial for ecosystem sustainability. In this study, we conducted a laboratory microcosm experiment to determine the various burrowing activities of Eisenia fetida and their impact on the soil hydraulic properties in response to different levels of soil moisture (50%, 70%, 90% of field capacity) in two common soil types (loessial and Lou soil) obtained from the Loess Plateau. Burrowing activity of E. fetida increased with higher soil moisture and was greater in loessial than in Lou soil. Most burrowing activities occurred within the top 5 cm and decreased with increasing soil depth. Macropores and burrow branching, which are highly related to the earthworm burrowing, were more prevalent in wetter soil. Earthworms significantly altered the formation of large soil aggregates (AGL, diameter >2 mm) under different soil moistures and depths. Distinct earthworm burrowing activities, controlled by soil moisture, altered soil hydraulic properties. However, soil saturated hydraulic conductivity (Ks) showed little differences between different treatments due to the horizontal and high–branched burrows of E. fetida, although higher burrowing activities were found in wetter soil. Soil field capacity was highest in drier soil due to the less macropores and burrowing activities.

Culturable autotrophic ammonia-oxidizing bacteria population and nitrification potential in a sheep grazing intensity gradient in a grassland on the Loess Plateau of Northwest China

2011 ◽  
Vol 91 (6) ◽  
pp. 925-934 ◽  
Author(s):  
Tianzeng Liu ◽  
Zhibiao Nan ◽  
Fujiang Hou
Keyword(s):  
Loess Plateau ◽  
Soil Depth ◽  
Grazing Intensity ◽  
Northwest China ◽  
Ammonia Oxidizing Bacteria ◽  
Stocking Rate ◽  
The Loess Plateau ◽  
Soil Microbial ◽  
Nitrification Potential ◽  
Dry Soil

Liu, T., Nan, Z. and Hou, F. 2011. Culturable autotrophic ammonia-oxidizing bacteria population and nitrification potential in a sheep grazing intensity gradient in a grassland on the Loess Plateau of Northwest China. Can. J. Soil Sci. 91: 925–934. Grazing is known to enhance the activity of soil microbial communities in many types of grasslands; however, the potential impacts of rotational grazing activity on soil microbial functional groups remain poorly understood. We investigated the effects of 9 yr of rotational grazing by livestock on culturable autotrophic ammonia-oxidizing bacteria (AOB) population size, nitrification potential and soil properties in a semi-arid grassland of the Loess Plateau in Northwest China. Three stocking rate treatments of 2.7, 5.3 and 8.7 wether lambs ha−1were evaluated in geographically separated paddocks. Grazing increased nitrification potential and culturable AOB populations compared with ungrazed treatments. Ammonia-oxidizing bacteria populations increased from 155 bacteria g−1dry soil with 0 sheep ha−1to 16 218 bacteria g−1dry soil with 8.7 sheep ha−1. Grazing led to an increase in population of AOB at 0–10 cm soil depth, but had no effect on AOB at 10–20 cm soil depth. Nitrification potential increased from 1.21 mg NO3-N kg−1soil d−1in ungrazed treatments to 2.86 mg NO3-N kg−1soil d−1at the highest stocking rate. Soil ammonium and nitrate concentrations increased; however, total soil nitrogen and soil moisture content decreased with increased stocking rate for both sampling depths (0–10 cm and 10–20 cm). Soil organic matter was not affected by grazing treatments. Soil nitrification potential and the size of culturable AOB populations were dependent on grazing intensity, soil depth and season. This information is potentially important for the optimal selection of stocking rate for grazed ecosystems.

scholarly journals Hydrologic feasibility of artificial forestation in the semi-arid Loess Plateau of China

2011 ◽  
Vol 15 (8) ◽  
pp. 2519-2530 ◽  
Author(s):  
T. T. Jin ◽  
B. J. Fu ◽  
G. H. Liu ◽  
Z. Wang
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Regional Scale ◽  
Negative Relationship ◽  
Northern Region ◽  
Shaanxi Province ◽  
Stand Age ◽  
Mean Annual Precipitation ◽  
The Loess Plateau ◽  
Semi Arid

Abstract. Hydrologic viability, in terms of moisture availability, is fundamental to ecosystem sustainability in arid and semi-arid regions. In this study, we examine the spatial distribution and after-planting variations of soil moisture content (SMC) in black locust tree (Robinia pseudoacacia L.) plantings in the Loess Plateau of China at a regional scale. Thirty sites (5 to 45 yr old) were selected, spanning an area of 300 km by 190 km in the northern region of the Shaanxi Province. The SMC was measured to a depth of 100 cm at intervals of 10 cm. Geographical, topographic and vegetation information was recorded, and soil organic matter was evaluated. The results show that, at the regional scale, SMC spatial variability was most highly correlated with rainfall. The negative relationship between the SMC at a depth of 20–50 cm and the stand age was stronger than at other depths, although this relationship was not significant at a 5 % level. Watershed analysis shows that the after-planting SMC variation differed depending upon precipitation. The SMC of plantings in areas receiving sufficient precipitation (e.g., mean annual precipitation (MAP) of 617 mm) may increase with stand age due to improvements in soil water-holding capacity and water-retention abilities after planting. For areas experiencing water shortages (e.g., MAP = 509 mm), evapotranspiration may cause planting soils to dry within the first 20 yr of growth. It is expected that, as arid and semi-arid plantings age, evapotranspiration will decrease, and the soil profile may gradually recover. In extremely dry areas (e.g., MAP = 352 mm), the variation in after-planting SMC with stand age was found to be negligible. The MAP can be used as an index to divide the study area into different ecological regions. Afforestation may sequentially exert positive, negative and negligible effects on SMCs with a decrease in the MAP. Therefore, future restoration measures should correspond to the local climate conditions, and the MAP should be a major consideration for the Loess Plateau. Large-scale and long-term research on the effects of restoration projects on SMCs is needed to support more effective restoration policies. The interaction between afforestation and local environmental conditions, particularly water availability to plants, should be taken into account in afforestation campaigns in arid and semi-arid areas.

scholarly journals Evaluating the soil quality of newly created farmland in the hilly and gully region on the Loess Plateau, China

2019 ◽  
Vol 29 (5) ◽  
pp. 791-802 ◽  
Author(s):  
Yiping Chen ◽  
Junhua Wu ◽  
Hong Wang ◽  
Jifu Ma ◽  
Cuicui Su ◽  
...  
Keyword(s):  
Soil Quality ◽  
Loess Plateau ◽  
The Loess Plateau

Laboratory and field evaluation of five soil water sensors

2004 ◽  
Vol 84 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Q. Huang ◽  
O. O. Akinremi ◽  
R. Sri Rajan ◽  
P. Bullock
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Depth ◽  
Field Evaluation ◽  
Soil Bulk Density ◽  
Laboratory Evaluation ◽  
Engineering Sciences ◽  
Probe Calibration

Accurate in situ determination of soil water content is important in many fields of agricultural, environmental, hydrological, and engineering sciences. As numerous soil water content sensors are available on the market today, the knowledge of their performance will aid users in the selection of appropriate sensors. The objectives of this study were to evaluate five soil water sensors in the laboratory and to determine if laboratory calibration is appropriate for the field. In this study, the performances of five sensors, including the Profile Probe™ (PP), ThetaProbe™ , Watermark™, Aqua-Tel™, and Aquaterr™ were compared in the laboratory. The PP and ThetaProbe™ were more accurate than the other soil water sensors, reproducing soil water content using factory recommended parameters. However, when PP was installed on a loamy sand in the field, the same soil that was used for the laboratory evaluation, it overestimated field soil water, especially at depth. Another laboratory experiment showed that soil water content readings from the PP were strongly influenced by soil bulk density. The higher the soil bulk density, the greater was the overestimation of soil water content. Two regression parameters, a0 and a1, which are used to convert the apparent dielectric constant to volumetric water content, were found to increase linearly with the soil bulk density in the range of 1.2 to 1.6 Mg m-3. Finally, the PP was calibrated in the field and a good calibration function was obtained with an r2 of 0.87 and RMSE of 2.7%. The values of a0 and a1 obtained in the field were different from factory recommended parameters (a0 = 2.4 versus 1.6 while a1 = 12.5 versus 8.4) and were independent of soil depth, bulk density, and texture. As such, individual field calibration will be necessary to obtain precise and accurate measurement of soil water content with this instrument. Key words: Soil water content, Profile Probe, calibration, soil water content sensor

Large-scale spatial interpolation of soil pH across the Loess Plateau, China

2012 ◽  
Vol 69 (8) ◽  
pp. 2731-2741 ◽  
Author(s):  
Zhi Peng Liu ◽  
Ming An Shao ◽  
Yun Qiang Wang
Keyword(s):  
Loess Plateau ◽  
Soil Ph ◽  
Spatial Interpolation ◽  
Large Scale ◽  
The Loess Plateau
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