scholarly journals Negative plant–soil feedbacks may limit persistence of an invasive tree due to rapid accumulation of soil pathogens

2007 ◽  
Vol 274 (1625) ◽  
pp. 2621-2627 ◽  
Author(s):  
Somereet Nijjer ◽  
William E Rogers ◽  
Evan Siemann
Keyword(s):  
Soil Fungi ◽  
Field Experiments ◽  
Species Coexistence ◽  
Original Experiment ◽  
Soil Pathogens ◽  
Soil Community ◽  
Plant Soil ◽  
Counter Example ◽  
Introduced Range ◽  
Negative Feedbacks

Soil organisms influence plant species coexistence and invasion potential. Plant–soil feedbacks occur when plants change soil community composition such that interactions with that soil community in turn may positively or negatively affect the performance of conspecifics. Theories predict and studies show that invasions may be promoted by stronger negative soil feedbacks for native compared with exotic species. We present a counter-example of a successful invader with strong negative soil feedbacks apparently caused by host-specific, pathogenic soil fungi. Using a feedback experiment in pots, we investigated whether the relative strength of plant–soil feedbacks experienced by a non-native woody invader, Sapium sebiferum , differed from several native tree species by examining their performance in soils collected near conspecifics (‘home soils’) or heterospecifics (‘away soils’) in the introduced range. Sapium seedlings, but no native seedlings, had lower survival and biomass in its home soils compared with soils of other species (‘negative feedback’). To investigate biotic agents potentially responsible for the observed negative feedbacks, we conducted two additional experiments designed to eliminate different soil taxa (‘rescue experiments’). We found that soil sterilization (pot experiment) or soil fungicide applications (pot and field experiments) restored Sapium performance in home soil thereby eliminating the negative feedbacks we observed in the original experiment. Such negative feedbacks apparently mediated by soil fungi could have important effects on persistence of this invader by limiting Sapium seedling success in Sapium dominated forests (home soils) though their weak effects in heterospecific (away) soils suggest a weak role in limiting initial establishment.

Effects of crop rotations on microbial community in rhizosphere soil of cucumber seedlings and its feedback

2021 ◽  
Vol 52 (2) ◽  
pp. 239-250
Author(s):  
X.J. He ◽  
W.W. Zhu ◽  
F.Z. Wu
Keyword(s):  
Soil Fungi ◽  
Dry Weight ◽  
Crop Rotations ◽  
Kidney Bean ◽  
Absolute Abundance ◽  
Cucumber Seedlings ◽  
Soil Microbial ◽  
Plant Soil ◽  
Significant Difference ◽  
Soil Feedback

We studied the effects of 7-crop rotations and continuous - monocropping systems on soil microorganism and its feedback. The results showed that absolute abundance of soil bacteria (Pseudomonas and Bacillus) in tomato - celery - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than control (CK). Absolute abundance of soil fungi in tomato - celery - cucumber - cabbage, kidney bean - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage and cucumber - tomato - cucumber - cabbage rotation were significantly higher than CK. Dry weight of cucumber seedlings was significantly positively correlated with bacterial (Pseudomonas and Bacillus) abundance, and negatively correlated with fungal count. The results of inoculation with Fusarium oxysporum f.sp. cucumerinum showed that plant dry weight of cucumber seedlings in tomato - celery - cucumber - cabbage, cucumber - kidney bean - cucumber - cabbage, cucumber - tomato - cucumber - cabbage rotation soil was significantly higher than other treatments, and their disease index was significantly lower than other treatments. There was no significant difference in dry weight of cucumber seedlings in rotation and CK in the soil sterilization test. The results of plant - soil feedback experiment showed that soil microbial changes caused by different rotation patterns had a positive feedback effect on growth of cucumber seedlings.

scholarly journals Initial soil community drives heathland fungal community trajectory over multiple years through altered plant–soil interactions

2019 ◽  
Vol 225 (5) ◽  
pp. 2140-2151 ◽  
Author(s):  
Dajana Radujković ◽  
Rudy Diggelen ◽  
Roland Bobbink ◽  
Maaike Weijters ◽  
Jim Harris ◽  
...  
Keyword(s):  
Fungal Community ◽  
Soil Community ◽  
Plant Soil ◽  
Initial Soil ◽  
Plant Soil Interactions

scholarly journals The Use of Ciliates (Ciliophora) for Bioassay of the Toxicity of Insecticides

2016 ◽  
Vol 50 (5) ◽  
pp. 467-470
Author(s):  
V. F. Mamedova ◽  
I. Kh. Alekperov
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Physiological Parameters ◽  
Virgin Soil ◽  
Soil Community ◽  
Soil Ciliates ◽  
Experimental Plots

Abstract Field and laboratory experiments have been carried out to determine the degree of toxicity in the soil community of ciliates of two insecticides: “Confidor Extra” and “Decis Profi” at concentrations of 80 mg/l, 50mg/l and 25mg/l. Laboratory experiments were performed with the soil ciliates species Colpoda cucullus (Müller, 1773). Changes in phagocytosis and osmoregulation were used as indicators of the survival and physiological parameters. In addition to the laboratory experiments, we carried out field experiments on experimental plots (50 × 50 cm) of the virgin soil. Field experiments were carried out in 5 replications. The results showed that the modification of physiological parameters is thinner exponent toxicity than survival.

scholarly journals Irrigation and Nitrogen Management of Artichoke: Yield, Head Quality, and Phenolic Content

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Togo Shinohara ◽  
Shinsuke Agehara ◽  
Kil Sun Yoo ◽  
Daniel I. Leskovar
Keyword(s):  
Field Experiments ◽  
Bare Soil ◽  
Yield Reduction ◽  
Globe Artichoke ◽  
Marketable Yield ◽  
Soil System ◽  
Available N ◽  
Plant Soil ◽  
Yield Responses ◽  
N Rates

Globe artichoke [Cynara cardunculus L. var. scolymus (L.) Fiori] has been recently introduced as a specialty crop in southwest Texas. Marketable yield, yield components, quality, and phenolic compounds of artichoke heads were investigated in response to three irrigation [50%, 75%, and 100% crop evapotranspiration (ETc)] regimes and four nitrogen (0 to 10, 60, 120, and 180 kg·ha−1) rates under subsurface drip irrigation. Field experiments were conducted over three seasons (2005–2006, 2006–2007, and 2007–2008) at Uvalde, TX. Irrigation was more effective than nitrogen (N) rates to optimize crop yield and head quality. Marketable yields significantly increased at 100% ETc compared with 75% and 50% ETc, whereas a 20% to 35% yield reduction occurred at 50% ETc across seasons. This yield reduction was associated with a decrease in both number of marketable heads and head weight and with reductions in plant physiological responses as measured in the last season. The lack of yield responses to N rates was in part the result of high pre-plant soil NO3-N and NH4-N levels. Total phenolics and chlorogenic acid of artichoke heads increased as the harvesting season progressed and were highest at 50% ETc during mid- and late harvests in one season. Based on these results, we estimate that under these environmental conditions, ≈700 mm (for a bare soil system) of water inputs and 120 kg·ha−1 or less of N (rate depending on soil available N) appear sufficient to obtain high marketable yields, superior size, and nutritional head quality of artichokes.

scholarly journals Control of Rhizome Rot Disease of Ginger (Zingiber officinale Rose) by Chemicals, Soil Amendments and Soil Antagonis

2010 ◽  
pp. 57-61 ◽  
Author(s):  
A Ayub ◽  
N Sultana ◽  
MI Faruk ◽  
MM Rahman ◽  
ANM Mamun
Keyword(s):  
Seed Treatment ◽  
Field Experiments ◽  
Control Measure ◽  
Soil Amendments ◽  
Organic Amendments ◽  
Zingiber Officinale ◽  
Effective Control ◽  
Plant Soil ◽  
Rot Disease ◽  
Rhizome Rot

Two field experiments were conducted at domar and sadar upzilla of Nilphamari district to find out an effective control measure against rhizome rot (Pythium aphanidermatam) disease of ginger (Zingiber officinale Rose). Each experiment consisted of nine treatments, where three fungicides (Ridomil, Metataf and Secure), three organic amendments (poultry refuse, mustard oilcake and saw dust burning) and two bio control agents (Trichoderma harzianum and T. viride) were tested. Fungicides were used as seed treatment and soil drenching and organic materials and bio control agents were used as pre plant soil amendments. All the treatments significantly decreased the incidence and severity of the diseases and increased germination, tiller number and rhizome yield. The most effective treatment was seed treatment (0.2%) and soil drenching (0.2%) with Ridomil gold. Seed treatment and soil drenching with Secure (0.1%) and soil amendment with poultry refuse (10 t/ha) were also found to be effective to control the diseases and to increase rhizome yield.

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