Responses of runoff, sedimentation, and induced nutrient loss to vegetation change in the Tengger Desert, northern China

Soil Research ◽  
2013 ◽  
Vol 51 (2) ◽  
pp. 124 ◽  
Author(s):  
Xiaojun Li ◽  
Jinggang Zheng ◽  
Xinrong Li ◽  
Huijuan Tan ◽  
Yanxia Pan ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Vegetation Change ◽  
Biological Soil Crust ◽  
Nutrient Loss ◽  
Water Infiltration ◽  
Tengger Desert ◽  
Total N ◽  
Organic C ◽  
Weighted Values ◽  
The Tengger Desert

Runoff and nutrient loss in drylands are closely related to vegetation cover. Simulated rainfall experiments with an intensity of 80 mm/h were conducted in sandy grassland and shrubland in the Tengger Desert, China, to investigate the responses of runoff and associated carbon (C) and nitrogen (N) losses to the replacement of grassland by shrubland. Times to ponding and to generate runoff, and the amount of rainfall for runoff commencement in bare, inter-shrub plots were significantly smaller than in shrub (ST) and grassland (GT) plots; no statistical differences were found for these parameters between ST and GT. Overall, this indicated a higher soil water infiltration rate in grassland than in shrubland. The volume-weighted concentrations of organic C (OC) and total N (TN) in runoff from shrubland (0.083 and 0.011 g/L, respectively) were lower than those from grassland (0.103 and 0.012 g/L, respectively). The cover-weighted runoff coefficients, and sediment, OC, and TN losses from shrubland (34.46%, and 44.95 1.72, and 0.23 g/m2, respectively) were greater than from grassland (15.22%, and 15.91, 0.94, and 0.11 g/m2). Vegetation degradation was accompanied by reduced nutrient retention capacity; both soil OC and TN of grassland (8.97 and 0.62 g/kg, respectively) were greater than those weighted values for shrubland (4.18 and 0.26 g/kg). Understanding of these processes suggests that decline or loss of vegetation cover, with the appearance of biological soil crust patches, inevitably leads to increases in runoff and induced soil loss, further accelerating desertification.

Minimising off-site movement of contaminants in furrow irrigation using polyacrylamide (PAM). II. Phosphorus, nitrogen, carbon, and sediment

Soil Research ◽  
2006 ◽  
Vol 44 (6) ◽  
pp. 561 ◽  
Author(s):  
Danielle P. Oliver ◽  
Rai S. Kookana
Keyword(s):  
Irrigation Water ◽  
Surface Runoff ◽  
Management Strategies ◽  
Water Infiltration ◽  
Sediment Surface ◽  
Irrigated Agriculture ◽  
Runoff Water ◽  
Total N ◽  
Organic C ◽  
Mode Of Application

Off-site movement of nutrients and sediment from furrow-irrigated agriculture has been a concern in the Ord River Irrigation Area, Western Australia. After consultation with growers, a range of management strategies were tested to assess the effectiveness of various practices to minimise off-site movement of nutrients during irrigation. This paper reports on the effectiveness of the additions of high molecular weight, anionic, polyacrylamide (PAM) to irrigation water to minimise off-site movement of phosphorus, nitrogen, carbon, and sediment. Surface runoff water quantity and quality from 4 separate irrigation bays, which contained 25 furrows per irrigation bay, was monitored over time for a single irrigation 35 days after sowing. Addition of PAM as a puck (cylindrical disc 55 mm diameter by 23 mm height) to the head of each irrigation furrow significantly (P < 0.001) decreased the average volume of surface runoff water leaving the irrigation bays by 54%, from 599 kL for the control irrigation bays to 277 kL for the PAM-treated irrigation bays. The addition of PAM also significantly (P < 0.001) decreased the average total suspended sediment load for the duration of the irrigation from 94.9 kg/ha for the control bays to 13.4 kg/ha for the PAM-treated irrigation bays. The concentrations of the different forms of N, P, and C measured in the runoff water were not significantly different between the 2 treatments. The amounts (g) of particulate (>0.45 µm) P and dissolved organic C were significantly (P < 0.01) less from the PAM-treated bays than from the control bays. There was a consistent trend for the addition of PAM to decrease the cumulative mass loss of all nutrients (N, P, and C) measured. However, significant decreases were only seen for particulate (>0.45 µm) P (by 94%), unfiltered (or total) N (by 56%), and unfiltered (or total) C (by 60%). This experiment demonstrated that the addition of PAM to irrigation waters has the potential to decrease the off-site movement of nutrients bound to colloidal material. However, in this study off-site movement of contaminants present in the ‘soluble’ (<0.45 µm) fraction is unlikely to be mitigated by the addition of PAM to irrigation water. The mode of application of PAM, however, may affect water infiltration and hence vertical movement of ‘soluble’ contaminants and requires further investigation to ensure that while off-site surface transport is being minimised, contamination of groundwater is not being increased. Other strategies to minimise off-site movement for contaminants in the dissolved phase also need investigation.

Response of biological soil crust coverage to wind-blown sand burial during the succession of artificial sand-fixing vegetation in the Tengger Desert, Northern China

2017 ◽  
Vol 37 (18) ◽  
Author(s):  
赵芸 ZHAO Yun ◽  
贾荣亮 JIA Rongliang ◽  
滕嘉玲 TENG Jialing ◽  
贾文雄 JIA Wenxiong ◽  
高艳红 GAO Yan
Keyword(s):  
Biological Soil Crust ◽  
Northern China ◽  
Soil Crust ◽  
Tengger Desert ◽  
Sand Burial ◽  
The Tengger Desert

scholarly journals Quantifying the Effects of Vegetation Restorations on the Soil Erosion Export and Nutrient Loss on the Loess Plateau

2020 ◽  
Vol 11 ◽  
Author(s):  
Jun Zhao ◽  
Xiaoming Feng ◽  
Lei Deng ◽  
Yanzheng Yang ◽  
Zhong Zhao ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Vegetation Cover ◽  
Vegetation Change ◽  
Soil Nutrient ◽  
Vegetation Restoration ◽  
Nutrient Loss ◽  
The Loess Plateau ◽  
Erosion Processes ◽  
Grain For Green Project

The transport of eroded soil to rivers changes the nutrient cycles of river ecosystems and has significant impacts on the regional eco-environment and human health. The Loess Plateau, a leading vegetation restoration region in China and the world, has experienced severe soil erosion and nutrient loss, however, the extent to which vegetation restoration prevents soil erosion export (to rivers) and it caused nutrient loss is unknown. To evaluate the effects of the first stage of the Grain for Green Project (GFGP) on the Loess Plateau (started in 1999 and ended in 2013), we analyzed the vegetation change trends and quantified the effects of GFGP on soil erosion export (to rivers) and it caused nutrient loss by considering soil erosion processes. The results were as follows: (1) in the first half of study period (from 1982 to 1998), the vegetation cover changed little, but after the implementation of the first stage of the GFGP (from 1999 to 2013), the vegetation cover of 75.0% of the study area showed a significant increase; (2) The proportion of eroded areas decreased from 41.8 to 26.7% as a result of the GFGP, and the erosion intensity lessened in most regions; the implementation significantly reduce the soil nutrient loss; (3) at the county level, soil erosion export could be avoided significantly by the increasing of vegetation greenness in the study area (R = −0.49). These results illustrate the relationships among changes in vegetation cover, soil erosion and nutrient export, which could provide a reference for local government for making ecology-relative policies.

Temporal shifts in cyanobacterial diversity and their relationships to different types of biological soil crust in the southeastern Tengger Desert

Rhizosphere ◽  
2021 ◽  
Vol 17 ◽  
pp. 100322
Author(s):  
Xiao-Chong Zhang ◽  
Jing-Yu Li ◽  
Jian-Li Liu ◽  
Cun-Xia Yuan ◽  
Yan-Nan Li ◽  
...  
Keyword(s):  
Biological Soil Crust ◽  
Soil Crust ◽  
Tengger Desert ◽  
Different Types ◽  
Cyanobacterial Diversity ◽  
Temporal Shifts

scholarly journals Effects of green-manure and tillage management on soil microbial community composition, nutrients and tree growth in a walnut orchard

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ningguang Dong ◽  
Guanglong Hu ◽  
Yunqi Zhang ◽  
Jianxun Qi ◽  
Yonghao Chen ◽  
...  
Keyword(s):  
Microbial Community ◽  
Green Manure ◽  
Rhizosphere Soil ◽  
Green Manures ◽  
Hairy Vetch ◽  
Mineral N ◽  
Total N ◽  
Organic C ◽  
Nutrient Contents ◽  
Walnut Tree

AbstractThis study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China.

scholarly journals Effect of Soil Management on Erosion in Mountain Vineyards (N-W Italy)

2021 ◽  
Vol 13 (4) ◽  
pp. 1991
Author(s):  
Silvia Stanchi ◽  
Odoardo Zecca ◽  
Csilla Hudek ◽  
Emanuele Pintaldi ◽  
Davide Viglietti ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Management Practices ◽  
Soil Management ◽  
Buffer Strips ◽  
Total N ◽  
Organic C ◽  
Erosion Rates ◽  
Soil Ecosystem Services ◽  
Erosion Mitigation ◽  
Management Approaches

We studied the effects of three soil management approaches (permanent grassing, chemical weeding, and buffer strips), and the additional impact of tractor passage on soil erosion in a sloping vineyard located in the inner part of Aosta Valley (N-W Italian Alps). The vineyard rows were equipped with a sediment collection system with channels and barrel tanks. A total of 12 events with sediment production were observed across 6 years, and the collected sediments were weighted and analyzed. Average erosion rates ranged from negligible (mainly in grassed rows) to 1.1 t ha−1 per event (after weeding). The most erosive event occurred in July 2015, with a total rainfall of 32.2 mm, of which 20.1 were recorded in 1 h. Despite the limited number of erosive events observed, and the low measured erosion rates, permanent grassing reduced soil erosion considerably with respect to weeding; buffering had a comparable effect to grassing. The tractor passage, independent of the soil management approaches adopted, visibly accelerated the erosion process. The collected sediments were highly enriched in organic C, total N, and fine size fractions, indicating a potential loss of fertility over time. Despite the measured erosion rates being low over the experiment’s duration, more severe events are well documented in the recent past, and the number of intense storms is likely to increase due to climate change. Thus, the potential effects of erosion in the medium and long term need to be limited to a minimum rate of soil loss. Our experiment helped to compare soil losses by erosion under different soil management practices, including permanent grassing, i.e., a nature-based erosion mitigation measure. The results of the research can provide useful indications for planners and practitioners in similar regions, for sustainable, cross-sectoral soil management, and the enhancement of soil ecosystem services.

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