scholarly journals Effect of Drought and Topographic Position on Depth of Soil Water Extraction of Pinus sylvestris L. var. mongolica Litv. Trees in a Semiarid Sandy Region, Northeast China

Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 370 ◽  
Author(s):  
Lining Song ◽  
Jiaojun Zhu ◽  
Jinxin Zhang ◽  
Ting Zhang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Northeast China ◽  
Water Sources ◽  
Dry Period ◽  
Growth And Survival ◽  
Topographic Position ◽  
Pine Trees ◽  
Use Efficiency ◽  
Soil Water Extraction

Drought and topographic position are the most important factors influencing tree growth and survival in semiarid sandy regions of Northeast China. However, little is known about how trees respond to drought in combination with topographic position by modifying the depth of soil water extraction. Therefore, we identified water sources for 33-year-old Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) trees growing at the top and bottom of sand dunes by comparing stable isotopes δ2H and δ18O in twig xylem water, soil water at various depths and groundwater during dry and wet periods. Needle carbon isotope composition (δ13C) was simultaneously measured to assess water use efficiency. Results showed that when soil moisture was low during the dry period, trees at the top used 40–300 cm soil water while trees at the bottom utilized both 40–300 cm soil water and possibly groundwater. Nevertheless, when soil moisture at 0–100 cm depth was higher during the wet period, it was the dominant water sources for trees at both the top and bottom. Moreover, needle δ13C in the dry period were significantly higher than those in the wet period. These findings suggested that trees at both the top and bottom adjust water uptake towards deeper water sources and improve their water use efficiency under drought condition. Additionally, during the dry period, trees at the top used shallower water sources compared with trees at the bottom, in combination with significantly higher needle δ13C, indicating that trees at the bottom applied a relatively more prodigal use of water by taking up deeper water (possibly groundwater) during drought conditions. Therefore, Mongolian pine trees at the top were more susceptible to suffer dieback under extreme dry years because of shallower soil water uptake and increased water restrictions. Nevertheless, a sharp decline in the groundwater level under extreme dry years had a strong negative impact on the growth and survival of Mongolian pine trees at the bottom due to their utilization of deeper water sources (possibly groundwater).

scholarly journals Monitoring Spatio-Temporal Changes of Terrestrial Ecosystem Soil Water Use Efficiency in Northeast China Using Time Series Remote Sensing Data

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1481 ◽  
Author(s):  
Hang Qi ◽  
Fang Huang ◽  
Huan Zhai
Keyword(s):  
Time Series ◽  
Soil Moisture ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Northeast China ◽  
Regional Scale ◽  
Positive Effects ◽  
Use Efficiency ◽  
Spatio Temporal

Soil water use efficiency (SWUE) was proposed as an effective proxy of ecosystem water use efficiency (WUE), which reflects the coupling of the carbon–water cycle and function of terrestrial ecosystems. The changes of ecosystem SWUE at the regional scale and their relationships with the environmental and biotic factors are yet to be adequately understood. Here, we aim to estimate SWUE over northeast China using time-series Moderate Resolution Imaging Spectroradiometer (MODIS) gross primary productivity data and European Space Agency climate change initiative (ESA CCI) soil moisture product during 2007–2015. The spatio-temporal variations in SWUE and their linkages to multiple factors, especially the phenological metrics, were investigated using trend and correlation analysis. The results showed that the spatial heterogeneity of ecosystem SWUE in northeast China was obvious. SWUE distribution varied among vegetation types, soil types, and elevation. Forests might produce higher photosynthetic productivity by utilizing unit soil moisture. The seasonal variations of SWUE were consistent with the vegetation growth cycle. Changes in normalized difference vegetation index (NDVI), land surface temperature, and precipitation exerted positive effects on SWUE variations. The earlier start (SOS) and later end (EOS) of the growing season would contribute to the increase in SWUE. Our results help complement the knowledge of SWUE variations and their driving forces.

Effect of Soil pH, Soil Water, Light Intensity, and Temperature on Perennial Sowthistle (Sonchus arvensisL.)

Weed Science ◽  
1991 ◽  
Vol 39 (3) ◽  
pp. 376-384 ◽  
Author(s):  
Richard K. Zollinger ◽  
James J. Kells
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Soil Ph ◽  
Dry Weight ◽  
Photon Flux ◽  
Use Efficiency ◽  
Total Dry Weight

Growth of perennial sowthistle was examined under different levels of soil pH, soil moisture content, light intensity, and temperature. Soil pH ranging from 5.2 to 7.2 had little effect on the number of leaves, rosette diameter, plant height, and number of capitula. However, total dry weight was 30% less in plants grown in soil of pH 5.2 compared to those grown at higher soil pH levels. Perennial sowthistle demonstrated a consistent positive growth response to increasing soil water including saturation. Severe reduction in vegetative and reproductive growth occurred in plants grown in soil below field capacity. Plants grown under full light (1015 μE m−2s−1photosynthetic photon flux density) developed a fourfold increase in the number of capitula per plant and a 50% increase in total dry weight compared to plants grown at 285 μE m−2s−1. Initiation of reproduction was delayed 4 weeks for plants grown at 580 μE m−2s−1and 285 μE m−2s−1. Plants grown under less than full light developed fewer but larger leaves. Plants grown under a day/night temperature of 20/15 C grew more rapidly than those under 30/25 C or 10/5 C. Plants at 30/25 C began to senesce 7 to 8 weeks after planting. Net carbon assimilation, leaf conductance, transpiration, and water use efficiency decreased as soil moisture and light intensity decreased. Plants at 30/25 C had the highest rate of transpiration and the lowest water use efficiency. The observed optimum for perennial sowthistle growth occurred at a soil pH of 6.2 or 7.2, water-saturated soil, high light intensity, and a temperature of 20/15 C, day/night.

Effects of Re-Used Plastic Film Mulching on Soil Moisture and Water Use Efficiency in Hetao Area, China

2012 ◽  
Vol 622-623 ◽  
pp. 1725-1729
Author(s):  
Jian Guo Shi ◽  
Jing Hui Liu ◽  
Li Xin Jia ◽  
Bao Ping Zhao ◽  
Li Jun Li ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Field Experiments ◽  
Plastic Film ◽  
Plastic Film Mulching ◽  
Percentage Points ◽  
Use Efficiency ◽  
Film Mulching

Aiming at reducing agricultural pollution caused by plastic film and increasing soil moisture and water use efficiency (WUE), the field experiments were conducted to investigate the effects of re-used plastic film mulching on soil moisture, sunflower’s yield and water use efficiency by compared with new plastic film mulching and bare field in Hetao area, China. The results showed that, soil water of re-used film mulching increased at different degree. Compared with bare field and new film mulching, soi1 moisture of re-used film were higher significantly 1.5 percentage points in 0-100 cm, and especially 1.9 or 2.6 percentage points in 0-10 cm during sunflower’s growth stage. Soil water of re-used film was more than that of bare field 24.8 mm (in 2010) and 33.0 mm (in 2011) before seeding, and 21.6mm (in 2010) and 24.5mm (in 2011) at harvest when soil water was replenished to same level for each treatment before sowing. Meanwhile, the grain yield of re-used film was higher significantly than that of bare field 11.4% (in 2010) and 16.8% (in 2011), and WUE of re-used film was higher significantly 15.7% (in 2010) and 22.7% (in 2011) respectively, no significant with new film. So it was worth to apply re-used film to agriculture production for improving the soil moisture, enhancing water use efficiency and increasing the yield of sunflower. We suggest that the application of re-used film mulching is a suitable soil management practice for increase water and WUE in Hetao area or other areas with similar conditions.

Grain yield and water-use efficiency of summer maize in response to mulching with different plastic films in the North China Plain

2021 ◽  
pp. 1-12
Author(s):  
Rui Zong ◽  
Huifang Han ◽  
Quanqi Li
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Soil Water ◽  
Water Use ◽  
North China Plain ◽  
Soil Water Storage ◽  
Summer Maize ◽  
The North ◽  
Use Efficiency ◽  
Film Mulching

Summary Plastic film (PF) mulching is widely applied in agriculture to improve water-use efficiency (WUE) and crop production. However, without efficient recovery, the residual plastic fragments in arable land threaten soil health and food security. Degradable films are generally considered as alternatives to conventional PF to mitigate PF pollution. A 2-year field experiment was conducted in 2016 and 2017 to evaluate the effects of various film mulching treatments (conventional PF mulching, transparent degradable film (TDF) mulching, and black degradable film (BDF) mulching, and no mulching) on soil water availability and summer maize yield in the North China Plain (NCP). Soil moisture, soil water storage, water use, and grain yield were recorded. Below 20 cm depth, soil moisture and soil water storage were higher in film mulching than in no mulching. Conventional PF mulching yielded the best water conservation, especially from sowing to jointing. TDF and BDF were similar in their regulation of soil moisture. Comparing to no mulching, conventional PF and degradable transparent film significantly reduced maize grain yield by 15.4 and 8.0% (average over 2 years), and reduced WUE by 9.4 and 7.8% (average 2 years), respectively. The observed reduction of grain yield in transparent film mulching might be caused by excessive soil temperature, especially at vegetative stages, which potentially accelerates crop senescence. Black film mulching reduced the soil cumulative temperature and prevent crops from being overheated. As consequence, grain yield and WUE of summer maize under BDF covering were significantly increased by 11.1 and 15.6%, respectively, over the 2 years. Therefore, we suggest that BDF can be used to replace conventional plastics to improve crop yield and control environmental pollution in the NCP.

An electromagnetic induction method for monitoring variation in soil moisture in agroforestry systems

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 63 ◽  
Author(s):  
N. I. Huth ◽  
P. L. Poulton
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Seasonal Variations ◽  
Electromagnetic Induction ◽  
Agroforestry Systems ◽  
Water Extraction ◽  
Spatial And Temporal Patterns ◽  
Induction Method ◽  
Vertical Distributions ◽  
Soil Water Extraction

An understanding of the spatial and temporal patterns of soil water extraction by trees in agroforestry systems has long been seen as an important step towards understanding their functioning. Traditional methods of soil moisture monitoring have been employed with some success but limitations in utilising them efficiently across both time and space have led to restrictions in their use. An electromagnetic induction (EMI) technique has been evaluated and used to study the patterns of soil water extraction from a Grey Vertosol in fallow or cropped fields alongside a Eucalyptus argophloia windbreak near Warra, Qld (26.93°S, 150.93°E). This technique provides methods for minimising error caused by seasonal variations in temperature and the vertical distributions of both soil water and temperature. The calibration developed in this study was successful in describing the observed variations in total soil moisture in the surface 0.9 m of the soil profile (R2 = 0.93, s.e. = 15.3 mm). We conclude that EMI techniques can provide a quick and efficient means for monitoring soil moisture patterns in agroforestry systems when employed under suitable conditions. This paper describes the techniques developed and where they may be employed, the type of information available from the approach, and the likely methods for employing EMI approaches in a wider range of situations.

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