scholarly journals Artificial Macropores with Sandy Fillings Enhance Desalinization and Increase Plant Biomass in Two Contrasting Salt-Affected Soils

2021 ◽  
Vol 11 (7) ◽  
pp. 3037
Author(s):  
Yifu Zhang ◽  
Ruihong Zhang ◽  
Baofeng Zhang ◽  
Xiaobo Xi
Keyword(s):  
Arid Regions ◽  
Plant Biomass ◽  
Soil Column ◽  
Soil Layer ◽  
Northern China ◽  
Control Group ◽  
Rooting Zone ◽  
Salt Ions ◽  
Salt Affected Soils ◽  
Soil Desalinization

Salt accumulation in topsoil is a widespread restricting factor that limits agricultural production and threatens food security in arid and semi-arid regions. However, whether this upward enrichment was suppressed by macropores was less documented. Therefore, artificial macropores with sandy fillings (AMSF) method was proposed in this study. Soil column experiments showed a significant improvement of saturated hydraulic conductivity (Ks) by more than 260% under artificial macropore treatment. Freshwater irrigation was conducted to monitor the short-term water and salt movement. This research aimed at evaluating the potential benefit of AMSF method on soil desalinization in coastal farmland of northern China. The results demonstrated that downward movement of soil water was stimulated in AMSF method, accordingly, washing more salt ions out of top rooting zone. Particularly, 10 cm or more macropore depth treatments of AMSF method enhanced total desalinization by 52.1% to 176.6% in 0–30 cm soil layer, in comparison to the control group without macropore. Subsequent observations for alfalfa showed higher biomass by 20.8% under 15 cm macropore depth. The results here provided an exploration demonstration to pursue these studies with the ultimate goal of optimizing application strategies for amendment in coastal salt-affected lands of northern China.

Root exposure to apple replant disease soil triggers local defense response and rhizoplane microbiome dysbiosis

2021 ◽  
Author(s):  
Alicia Balbín-Suárez ◽  
Samuel Jacquiod ◽  
Annmarie-Deetja Rohr ◽  
Benye Liu ◽  
Henryk Flachowsky ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plant Defense ◽  
Defense Response ◽  
Soil Column ◽  
Soil Layer ◽  
Soil Microbiome ◽  
Control Soil ◽  
Apple Rootstocks ◽  
Apple Replant Disease ◽  
Replant Disease

Abstract A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD) causing agents to spread in soil. ‘M26’ apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of OTUs affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production, and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.

Aboveground Biomass of Reaumuria soongorica Shrub Effect on Soil Moisture and Nutrient Spatial Distribution in Arid and Semi-Arid Region

2013 ◽  
Vol 726-731 ◽  
pp. 3803-3806
Author(s):  
Bing Ru Liu ◽  
Jun Long Yang
Keyword(s):  
Spatial Distribution ◽  
Soil Moisture ◽  
Moisture Content ◽  
Aboveground Biomass ◽  
Soil Moisture Content ◽  
Plant Biomass ◽  
Soil Layer ◽  
Soil Nutrient ◽  
Desert Plant ◽  
Important Species

In order to revel aboveground biomass of R. soongorica shrub effect on soil moisture and nutrients spatial distribution, and explore mechanism of the changes of soil moisture and nutrients, soil moisture content, pH, soil organic carbon (SOC) and total nitrogen (TN) at three soil layers (0-10cm,10-20cm, and 20-40cm) along five plant biomass gradients of R. soongorica were investigated. The results showed that soil moisture content increased with depth under the same plant biomass, and increased with plant biomass. Soil nutrient properties were evidently influenced with plant biomass, while decreased with depth. SOC and TN were highest in the top soil layer (0-10 cm), but TN of 10-20cm layer has no significant differences (P < 0.05). Moreover, soil nutrient contents were accumulated very slowly. These suggests that the requirement to soil organic matter is not so high and could be adapted well to the desert and barren soil, and the desert plant R. soongorica could be acted as an important species to restore vegetation and ameliorate the eco-environment.

scholarly journals Divergent responses of biomass accumulation and its allocation to the altered precipitation regimes among different degraded grasslands in China

2021 ◽  
Author(s):  
Tianxue Yang ◽  
Junda Chen ◽  
Xiaoyue Zhong ◽  
Xuechen Yang ◽  
Gui Wang ◽  
...  
Keyword(s):  
Climate Models ◽  
Plant Biomass ◽  
Inorganic Nitrogen ◽  
Precipitation Amount ◽  
Soil Layer ◽  
Ecosystem Functions ◽  
Precipitation Frequency ◽  
Positive Effects ◽  
Altered Precipitation ◽  
Precipitation Regimes

Abstract Purpose Climate models predict shifts in precipitation patterns characterized by increased precipitation amount and decreased frequency for semi-arid grasslands in northeast China. However, under these novel climatic conditions, potential differences in plant biomass and its allocation among different degraded grasslands remain unclear.Methods We conducted a mesocosm experiment to test the effects of higher precipitation amount (increased by 50% from the long-term mean) and lower frequency (decreased by 50%) on plant biomass and allocation in the lightly degraded (LDG), moderately degraded (MDG), and severely degraded grasslands (SDG).Results Lower precipitation frequency promoted belowground biomass (BGB), while reducing aboveground biomass (AGB) allocation through enhancing soil water variability. Higher precipitation amount enhanced AGB in LDG and MDG, but not in SDG due to less soil inorganic nitrogen. Lower precipitation frequency weakened the positive effects of higher precipitation amount on biomass. Under altered precipitation, adjustment of AGB vs. BGB allocation was the primary biomass allocation strategy in LDG and SDG. However, to maintain water acquirement, plants in MDG preferred to adjust root vertical distribution, and allocated more roots to the deep soil layer where had a relatively stable water source. This strategy was driven by the changes in plant community composition of the dominant species in MDG.Conclusions The findings of this research emphasized the importance of considering the degradation level of grasslands when predicting the responses of the ecosystem functions to the projected changes in precipitation regime. These findings are critical for making feasible decisions for the sustainable management of degraded grasslands.

scholarly journals Evaluation of soil moisture in CMIP5 simulations over contiguous United States using in situ and satellite observations

2016 ◽  
Author(s):  
Shanshui Yuan ◽  
Steven M. Quiring
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Soil Column ◽  
Regional Analysis ◽  
Soil Layer ◽  
Model Performance ◽  
Coupled Model ◽  
Cmip5 Models ◽  
Near Surface

Abstract. This study provides a comprehensive evaluation of soil moisture simulations in the Coupled Model Intercomparison Project Phase 5 (CMIP5) extended historical experiment (2003 to 2012). Soil moisture from in situ and satellite sources are used to evaluate CMIP5 simulations in the contiguous United States (CONUS). Both near-surface (0–10 cm) and soil column (0–100 cm) simulations from more than 14 CMIP5 models are evaluated during the warm season (April–September). Multi-model ensemble means and the performance of individual models are assessed at a monthly time scale. Our results indicate that CMIP5 models can reproduce the seasonal variability in soil moisture over CONUS. However, the models tend to overestimate the magnitude of both near-surface and soil-column soil moisture in the western U.S. and underestimate it in the eastern U.S. There are large variations in model performance, especially in the near-surface. There are significant regional and inter-model variations in performance. Results of a regional analysis show that in deeper soil layer, the CMIP5 soil moisture simulations tend to be most skillful in the southern U.S. Based on both the satellite-derived and in situ soil moisture, CESM1, CCSM4 and GFDL-ESM2M perform best in the 0–10 cm soil layer and CESM1, CCSM4, GFDL-ESM2M and HadGEM2-ES perform best in the 0–100 cm soil layer.

Mechanisms regulating spatial changes in grassland productivity following nutrient addition in northern China

2019 ◽  
Vol 41 (1) ◽  
pp. 83
Author(s):  
Na Zhao ◽  
Xinqing Shao ◽  
Chao Chen ◽  
Jiangwen Fan ◽  
Kun Wang
Keyword(s):  
Functional Traits ◽  
Plant Biomass ◽  
Northern China ◽  
Functional Trait ◽  
Community Response ◽  
Nutrient Addition ◽  
Leymus Chinensis ◽  
Ecosystem Functions ◽  
Natural Grasslands ◽  
Key Species

Plant biomass is the most fundamental component of ecosystems. The spatial stability of plant biomass is important, and the mechanisms regulating plant biomass spatial variability in variable environments are a central focus of ecology. However, they have rarely been explored. We conducted an experiment to test how diversity and functional traits affected variation in biomass and community response to nutrient availability in three plant communities: natural; forb, legume, and bunchgrass; and rhizomatous grass. We found that biomass stability rarely changed with increasing taxonomic species richness and functional group richness but declined with increasing Shannon–Weiner indices (the combination of richness and evenness) and functional trait diversity. However, differences in plant species composition generated different responses in both the amount and spatial variation of biomass following nutrient addition. Because rhizomatous grasses are weakly competitive in nutrient-poor conditions, interaction between resource-acquisitive (grass) and stress-tolerant (forb) species in the natural community conferred the greatest overall stability. The rapid nutrient acquisition ability of the rhizomatous grass Leymus chinensis was stimulated in nutrient-abundant conditions. The functional traits of this dominant species overrode the diversity interaction effects of the natural and forb, legume, and bunchgrass communities. This ultimately resulted in the rhizomatous grass community being the most stable. Community stability was strongly determined by a few key species, particularly rhizomatous grasses, rather than by the average response of all species, thereby supporting the mass ratio hypothesis. Our results indicated that rhizomatous grasses could provide vegetative productivity to reduce soil loss and prevent degradation of L. chinensis-dominant grassland. Thus, protecting specific species is critical for maintaining rangeland ecosystem functions. Moreover, the conservation importance of grasses, non-leguminous forbs, legumes, or even rare species could not be ignored. Maintaining stability mechanisms in natural grasslands is complex, and therefore, further studies need to focus on finding a unified mechanism that can regulate appreciable biomass variation under shifting environmental conditions.

Impacts of different mulching patterns in rainfall-harvesting planting on soil water and spring corn growth development in semihumid regions of China

Soil Research ◽  
2017 ◽  
Vol 55 (3) ◽  
pp. 285 ◽  
Author(s):  
Xiaolong Ren ◽  
Peng Zhang ◽  
Xiaoli Liu ◽  
Shahzad Ali ◽  
Xiaoli Chen ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Plant Biomass ◽  
Soil Layer ◽  
Water Storage ◽  
Field Trials ◽  
Dry Matter Accumulation ◽  
The Loess Plateau ◽  
Dryland Farming ◽  
Growth Development ◽  
Average Plant

Rain-harvesting planting can improve crop biomass and enhance precipitation use efficiency in rainfed semiarid areas. In this study, field trials were conducted during summer 2007–2010 to determine the impacts of different mulching patterns in rainfall harvesting planting on spring corn growth and development in a typical semihumid dryland farming area of the Loess Plateau in China, which is characterised by spring droughts. Rain-harvesting ridges and planting furrows were mulched with 8% biodegradable film (RCSB), liquid film (RCSL), or not mulched (RCSN), and bare land drilling without mulching served as the control (CF). We found that the rain-harvesting effects of ridges and the evaporation-inhibiting and moisture-conserving effects of mulching materials during the spring corn growing season significantly increased water storage in the 0–100cm soil layer (P<0.05) compared with CF, where mulching was more beneficial than the non-mulching treatments. In the 100–200cm soil layers, there were no significant effects (P>0.05) of the treatments on water storage. During 2007–2010, the average plant height increased by 26.6%, 15.4%, and 11.1% under RCSB, RCSL, and RCSN relative to CF respectively, whereas the per plant biomass increased by 26.6%, 15.4%, and 11.1% under these treatments, and the grain yield increased by 32.3%, 17.5%, and 15.0%. Therefore, in the semihumid dryland farming areas of the Loess Plateau, rain-harvesting planting greatly increased the growth, development, and dry matter accumulation by spring corn, thereby enhancing its biomass yield, whereas the plastic-covered ridges and furrows mulched with biodegradable films substantially increased the yield-enhancing effects.

scholarly journals Aridity-driven shift in biodiversity–soil multifunctionality relationships

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weigang Hu ◽  
Jinzhi Ran ◽  
Longwei Dong ◽  
Qiajun Du ◽  
Mingfei Ji ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Arid Regions ◽  
Environmental Gradients ◽  
Positive Association ◽  
Biodiversity Loss ◽  
Northern China ◽  
Ecosystem Functions ◽  
Conservation Strategies ◽  
Soil Microbial Diversity ◽  
Ecosystem Multifunctionality

AbstractRelationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification.

An assessment of soil moisture in the MARINE flash flood model using in situ measurements, reanalysis and satellite derived estimates

2020 ◽  
Author(s):  
Judith Eeckman ◽  
Hélène Roux ◽  
Bertrand Bonan ◽  
Clément Albergel ◽  
Audrey Douniot
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Model Calibration ◽  
Flash Flood ◽  
Soil Column ◽  
Subsurface Flow ◽  
Soil Layer ◽  
Observation Network

&lt;p&gt;The representation of soil moisture is a key factor for the simulation of flash flood in the Mediterranean region. The MARINE hydrological model is a distributed model dedicaded to flash flood simulation. Recent developments of the MARINE model lead to an improvement of the subsurface flow representation : on the one hand, the transfers through the subsurface take place in a homogeneous soil column based on the volumic soil water content instead of the water height. On the other hand, the soil column is divided into two layers, which represent respectively the upper soil layer and the deep weathered rocks. The aim of this work is to assess the performances of these new representations of the subsurface flow with respect to the soil saturation dynamics during flash flood events. The performances of the model are estimated with respect to three soil moisture products: i) the gridded soil moisture product provided by the LDAS-Monde assimilation chain. LDAS-Monde is based on the ISBA-a-gs land surface model and integrates high resolution spatial remote sensing data from the Copernicus Global Land Service for vegetation through data assimilation; ii) the upper soil moisture measurements taken from the SMOSMANIA observation network&amp;#160;; iii) The satellite derived surface soil moisture data from Sentinel1. The case study is led over two french mediterranean catchments impacted by flash flood events over the 2017-2019 period and where one SMOSMANIA station is available. Additionnal tests for the initialisation of MARINE water content for the two soil layers are assessed. Results show first that the dynamic of the soil moisture both provided by LDAS-Monde and simulated for the upper soil layer in MARINE are locally consistent with the SMOSMANIA observations. Secondly, the use of soil water content instead of water height to describe lateral flows in MARINE is cleary more relevant with respect to both LDAS-Monde simulations and SMOSMANIA stations. The dynamic of the deep layer moisture content also appears to be consistent with the LDAS-Monde product for deeper layers. However, the bias on these values strongly rely on the calibration of the new two-layers model. The opportunity of improving the two-layers model calibration is then discussed. Finally, the impact of the soil water content initialisation is shown to be significant mainly during the flood rising, and also to be dependent on the model calibration. In conclusion, the new developments presented for the representation of subsurface flow in the MARINE model appear to enhance the soil moisture simulation during flash floods, with respect to both the LDAS-Monde product and the SMOSMANIA observation network.&lt;/p&gt;

Leaching of Indaziflam Compared with Residual Herbicides Commonly Used in Florida Citrus

2012 ◽  
Vol 26 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Amit J. Jhala ◽  
Megh Singh
Keyword(s):  
Weed Control ◽  
Broad Spectrum ◽  
Field Experiments ◽  
Plant Biomass ◽  
Soil Column ◽  
Annual Ryegrass ◽  
Soil Columns ◽  
Leaching Behavior ◽  
Natural Rainfall ◽  
Florida Citrus

Soil-applied herbicides are commonly used for broad-spectrum residual weed control in Florida citrus. Groundwater contamination from some soil-applied herbicides has been reported in citrus growing areas in Florida. Indaziflam is a new soil-applied herbicide recently registered for broad-spectrum weed control in Florida citrus. There is no information available on leaching behavior of indaziflam in sandy soil. Experiments were conducted to compare leaching of indaziflam with five commercially used residual herbicides in a Florida Candler soil under simulated rainfall of 5 or 15 cm ha−1. Herbicide movement down soil columns was measured by visually evaluating injury and harvesting aboveground biomass of the bioassay species annual ryegrass. Ryegrass was not injured and plant biomass was not affected beyond 30 cm when indaziflam at a recommended rate of 73 g ai ha−1was leached through the soil column. Leaching of indaziflam increased with increasing amounts of rainfall. For example, indaziflam leached up to 12.2 ± 0.8 cm (values are expressed ± SD) and 27.2 ± 2.6 cm at 5 and 15 cm ha−1rainfall, respectively. The herbicide ranking from high to low mobility at 15 cm ha−1of rainfall was bromacil = norflurazon > indaziflam > simazine = pendimethalin > diuron. Overall results suggested that indaziflam leaching was limited in Florida Candler soil in this study; however, field experiments are required to confirm the leaching of indaziflam under natural rainfall situation.

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