scholarly journals Effects of revegetation on soil moisture under different precipitation gradients in the Loess Plateau, China

2016 ◽  
Vol 48 (5) ◽  
pp. 1378-1390 ◽  
Author(s):  
Fei Tian ◽  
Xiaoming Feng ◽  
Lu Zhang ◽  
Bojie Fu ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Large Scale ◽  
Tree Planting ◽  
Mean Annual Precipitation ◽  
Soil Water Deficit ◽  
The Loess Plateau ◽  
Soil Desiccation

Revegetation can alter catchment water balance and result in soil desiccation. Large-scale revegetation took place in the Loess Plateau of China to control soil erosion and improve environmental conditions. However, the dynamic nature of soil moisture in response to revegetation under different climatic conditions is still unclear mainly due to lack of long-term in situ observations. To overcome this challenge, a biophysically based ecohydrological model (WAVES) was used to examine the effects of revegetation on soil moisture. Results showed that trees consume more water (100% of precipitation) than shrub (97.6%) and grass (98.3%), and therefore are more likely to result in soil desiccation. No runoff occurred under the tree scenario, while for shrub and grass, runoff accounted for 2.4% and 1.7% of precipitation, respectively. In areas with mean annual precipitation (MAP) less than 400 mm, tree planting resulted in soil water deficit, while in areas with MAP exceeding 600 mm, no soil water deficit occurred. Within this MAP range (400 < MAP < 600 mm), this could lead to soil water deficit during dry years. Extending this analysis to the entire Loess Plateau, 40% of the region will face reduced soil moisture when converting cropland to trees.

Deep soil water deficit and recovery in alfalfa fields of the Loess Plateau of China

2021 ◽  
Vol 260 ◽  
pp. 107990
Author(s):  
Gulnazar Ali ◽  
Zikui Wang ◽  
Xinrong Li ◽  
Naixuan Jin ◽  
Huiying Chu ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Soil Water Deficit ◽  
The Loess Plateau ◽  
Deep Soil

Impact assessment of climate change and later-maturing cultivars on winter wheat growth and soil water deficit on the Loess Plateau of China

2016 ◽  
Vol 138 (1-2) ◽  
pp. 157-171 ◽  
Author(s):  
Dianyuan Ding ◽  
Hao Feng ◽  
Ying Zhao ◽  
Wenzhao Liu ◽  
Haixin Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Winter Wheat ◽  
Impact Assessment ◽  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Soil Water Deficit ◽  
The Loess Plateau ◽  
Wheat Growth

scholarly journals Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China

2015 ◽  
Vol 7 (4) ◽  
pp. 3199-3222
Author(s):  
H. C. Li ◽  
X. D. Gao ◽  
X. N. Zhao ◽  
P. T. Wu ◽  
L. S. Li ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Water Conservation ◽  
Flat Surface ◽  
Soil Evaporation ◽  
Fish Scale ◽  
Soil Water Deficit ◽  
The Loess Plateau ◽  
The Cost

Abstract. Conserving more soil water is of great importance to the success of arid and semiarid orchards. On the hilly areas of the Loess Plateau of China, mini catchments, named fish-scale pits, are widely used in orchards for collecting surface runoff to infiltrate more soil water. However, the flat surface inside fish-scale pits would increase soil evaporation during non-rainfall periods. Therefore, we integrated fish-scale pits with mulching, a popular meaning to reduce soil evaporation, to test whether this integration could improve soil water conservation. The results showed that soil water deficit was observed for all treatments. However, soil water deficit was further intensified in the dry month. An index was used to represent the soil water supply from rainfall infiltration denoted WS. For the fish-scale pit with branch mulching treatment in the entire soil profile, the compensation degree of SWS were greater than 0. However, the CK treatment showed negative values in the 40–180 cm. In conclusion, integrating fish-scale pits with mulching could conserve significantly more soil water by increasing infiltration and decreasing evaporation compared to fish-scale pits alone. Since the mulching branches were trimmed jujube branches, the integration of fish-scale pit with branch mulching is recommended in jujube orchards in order to both preserve more soil water and reduce the cost of mulching materials.

scholarly journals Assessment of the SMAP-Derived Soil Water Deficit Index (SWDI-SMAP) as an Agricultural Drought Index in China

2018 ◽  
Vol 10 (8) ◽  
pp. 1302 ◽  
Author(s):  
Jueying Bai ◽  
Qian Cui ◽  
Deqing Chen ◽  
Haiwei Yu ◽  
Xudong Mao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Deficit ◽  
Microwave Remote Sensing ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
In Situ Observation ◽  
Soil Water Deficit ◽  
The South ◽  
The North

China is frequently subjected to local and regional drought disasters, and thus, drought monitoring is vital. Drought assessments based on available surface soil moisture (SM) can account for soil water deficit directly. Microwave remote sensing techniques enable the estimation of global SM with a high temporal resolution. At present, the evaluation of Soil Moisture Active Passive (SMAP) SM products is inadequate, and L-band microwave data have not been applied to agricultural drought monitoring throughout China. In this study, first, we provide a pivotal evaluation of the SMAP L3 radiometer-derived SM product using in situ observation data throughout China, to assist in subsequent drought assessment, and then the SMAP-Derived Soil Water Deficit Index (SWDI-SMAP) is compared with the atmospheric water deficit (AWD) and vegetation health index (VHI). It is found that the SMAP can obtain SM with relatively high accuracy and the SWDI-SMAP has a good overall performance on drought monitoring. Relatively good performance of SWDI-SMAP is shown, except in some mountain regions; the SWDI-SMAP generally performs better in the north than in the south for less dry bias, although better performance of SMAP SM based on the R is shown in the south than in the north; differences between the SWDI-SMAP and VHI are mainly shown in areas without vegetation or those containing drought-resistant plants. In summary, the SWDI-SMAP shows great application potential in drought monitoring.

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.

Soybean Irrigation Initiation in Mississippi: Yield, Soil Moisture, and Economic Response

2019 ◽  
Vol 35 (1) ◽  
pp. 39-50
Author(s):  
H. C. Pringle, III ◽  
L. L. Falconer ◽  
D. K. Fisher ◽  
L. J. Krutz
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Mississippi Delta ◽  
Soil Water Potential ◽  
Irrigation Scheduling ◽  
Silty Clay ◽  
Soil Water Deficit ◽  
Soybean Yield

Abstract. Irrigated acreage is expanding and groundwater supplies are decreasing in the Mississippi Delta. Efficient irrigation scheduling of soybean [ (L.) Merr] will aid in conservation efforts to sustain groundwater resources. The objective of this study was to develop irrigation initiation recommendations for soybean grown on Mississippi Delta soils. Field studies were conducted on a deep silty clay (SiC) in 2012, 2013, 2014, and 2015 and on a deep silty clay loam (SiCL) and deep silt loam (SiL) or loam (L) soil in 2013, 2014, and 2015. Irrigation was initiated multiple times during the growing season and soybean yield and net return were determined to evaluate the effectiveness of each initiation timing. Growth stage, soil water potential (SWP), and soil water deficit (SWD) were compared at these initiation timings to determine which parameter or combination of parameters consistently predicted the resulting greatest yields and net returns. Stress conditions that reduce yield can occur at any time from late vegetative stages to full seed on these deep soils. The wide range of trigger values found for SWP and SWD to increase yields in different years emphasizes the complexity of irrigation scheduling. Monitoring soil moisture by itself or use of a single trigger value is not sufficient to optimize irrigation scheduling to maximize soybean yield with the least amount of water every year on these soils. Monitoring one or more parameters (e.g., leaf water potential, canopy temperature, air temperature, humidity, solar radiation, and wind) is needed in conjunction with soil moisture to directly or indirectly quantify the abiotic stresses on the plant to better define when a yield reducing stress is occurring. Keywords: Irrigation initiation, Irrigation scheduling, Soil water deficit, Soil water potential, Soybean, Water conservation.

scholarly journals Satellite Soil Moisture for Agricultural Drought Monitoring: Assessment of SMAP-Derived Soil Water Deficit Index in Xiang River Basin, China

2019 ◽  
Vol 11 (3) ◽  
pp. 362 ◽  
Author(s):  
Qian Zhu ◽  
Yulin Luo ◽  
Yue-Ping Xu ◽  
Ye Tian ◽  
Tiantian Yang
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Deficit ◽  
River Basin ◽  
Probability Of Detection ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
Soil Water Deficit ◽  
R Value ◽  
Xiang River

Agricultural drought can have long-lasting and harmful impacts on both the ecosystem and economy. Therefore, it is important to monitor and predict agricultural drought accurately. Soil moisture is the key variable to define the agricultural drought index. However, in situ soil moisture observations are inaccessible in many areas of the world. Remote sensing techniques enrich the surface soil moisture observations at different tempo-spatial resolutions. In this study, the Level 2 L-band radiometer soil moisture dataset was used to estimate the Soil Water Deficit Index (SWDI). The Soil Moisture Active Passive (SMAP) dataset was evaluated with the soil moisture dataset obtained from the China Land Soil Moisture Data Assimilation System (CLSMDAS). The SMAP-derived SWDI (SMAP_SWDI) was compared with the atmospheric water deficit (AWD) calculated with precipitation and evapotranspiration from meteorological stations. Drought monitoring and comparison were accomplished at a weekly scale for the growing season (April to November) from 2015 to 2017. The results were as follows: (1) in terms of Pearson correlation coefficients (R-value) between SMAP and CLSMDAS, around 70% performed well and only 10% performed poorly at the grid scale, and the R-value was 0.62 for the whole basin; (2) severe droughts mainly occurred from mid-June to the end of September from 2015 to 2017; (3) severe droughts were detected in the southern and northeastern Xiang River Basin in mid-May of 2015, and in the northern basin in early August of 2016 and end of November 2017; (4) the values of percentage of drought weeks gradually decreased from 2015 to 2017, and increased from the northeast to the southwest of the basin in 2015 and 2016; and (5) the average value of R and probability of detection between SMAP_SWDI and AWD were 0.6 and 0.79, respectively. These results show SMAP has acceptable accuracy and good performance for drought monitoring in the Xiang River Basin.

Effects of large-scale re-vegetation on soil desiccation in the Loess Plateau: problems and perspectives

2019 ◽  
Vol 39 (20) ◽  
Author(s):  
杨磊 YANG Lei ◽  
张子豪 ZHANG Zihao ◽  
李宗善 LI Zongshan
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
The Loess Plateau ◽  
Soil Desiccation

Aggravated water deficit in the Loess Plateau of China as indicated by the soil available water content

2020 ◽  
Author(s):  
Xiao Zhang ◽  
Wenwu Zhao ◽  
Paulo Pereira
Keyword(s):  
Land Cover ◽  
Water Content ◽  
Soil Water ◽  
Water Deficit ◽  
Loess Plateau ◽  
Characteristic Curve ◽  
The Loess Plateau ◽  
Land Cover Types ◽  
Soil Water Characteristic Curve ◽  
Available Water Content

<p>The soil available water content (AWC) has a strong ability to indicate the soil water conditions under different land cover types. Although the AWC has long been calculated, soil water characteristic curve estimation models and the distribution of AWC, as well as the impact factors, have rarely been evaluated in the Loess Plateau of China. In this study, four typical land cover types were selected: introduced shrubland, introduced grassland, natural restored shrubland and natural restored grassland. Four widely used models were compared with the van Genuchten (VG) model, including the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Tyler and Wheatcraft (TW) model, and linear fitting (LF) model to estimate the wilting point. The distribution of AWC and the relationships with environmental factors were measured and analyzed. The results showed the following: (1) the MV model was the most suitable model to estimate the soil water characteristic curve in the Loess Plateau; (2) the factors impacting the AWC varied under different precipitation gradients, and the area with a mean annual precipitation of 440-510 mm was the most sensitive zone to environmental and vegetation factors; and (3) the soil water deficit was more severe when considering AWC than when considering soil water content (SWC), and the water deficits were different under introduced grassland and introduced shrubland. Consequently, the construction of vegetation restoration should be more cautious and consider the trade-off between soil conservation and water conservation. During restoration, policy makers should focus on the AWC in addition to the SWC to better assess the soil moisture status.</p>

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