Soil factors determined nematode community composition in a two year pot experiment

Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 889-897 ◽  
Author(s):  
Bryan Griffiths ◽  
Roy Neilson ◽  
A. Glyn Bengough

Abstract Two similar, sandy loam soils from the same geographical region but with distinct nematode communities were used to determine the extent to which water, soil and inoculum factors affected nematode community structure. Treatments were established in pots containing a middle layer of frozen defaunated soil, sandwiched between an inoculum that was either fresh soil from the same site ('self') or a mixture of soils to give a more diverse inoculum ('mixed'). During year 2, half the pots were watered at regular intervals while the other half received only rainfall. For individual nematode taxa, soil layer and watering regime were the main factors discriminating between treatments, while initial inoculum had a larger influence than soil type. Acrobeloides was most affected by the watering regime, being more abundant under variable water conditions, whereas Hoplolaimidae, Longidorus and Pratylenchus were more abundant in deeper soil layers in contrast to other taxa. For the community as a whole, when analysed by principal component analysis, soil factors clearly influenced composition and also indicated that the biological properties of the soils were important.

Nematology ◽  
2002 ◽  
Vol 4 (8) ◽  
pp. 943-952 ◽  
Author(s):  
A. Glyn Bengough ◽  
Roy Neilson ◽  
Bryan Griffiths ◽  
David Trudgill

AbstractFour similar, agricultural soils with distinct nematode communities were used to determine the extent to which soil and inoculum factors affected nematode community structure. The soils all had a sandy loam texture from the same geographical area and had been in pasture or arable rotation for the last 10 years. Treatments were established in pots containing a middle layer of frozen defaunated soil, sandwiched between an inoculum that was either fresh soil from the same site ('self') or a mixture of soils to give a more diverse inoculum ('mixed'). Principal component analysis indicated that a single soil type given different inocula developed different community structures (i.e., the community under 'self' differed from that under 'mixed') suggesting an inoculum effect. It was also true that different soil types under a single inoculum soil also developed different community structures (i.e., community under 'mixed' differed with soil type), suggesting a soil effect. It is likely that the nematode community structure is influenced by a combination of antecedent land use, soil factors, species introductions and inter-species competition, which should be considered in any interpretation of nematode communities as a biotic indicator.


2020 ◽  
Vol 12 (16) ◽  
pp. 6443
Author(s):  
Zhiwei Cao ◽  
Xi Fang ◽  
Wenhua Xiang ◽  
Pifeng Lei ◽  
Changhui Peng

The study was to investigate the change patterns of soil organic carbon (SOC), total nitrogen (TN), and soil C/N (C/N) in each soil sublayer along vegetation restoration in subtropical China. We collected soil samples in four typical plant communities along a restoration chronosequence. The soil physicochemical properties, fine root, and litter biomass were measured. Our results showed the proportion of SOC stocks (Cs) and TN stocks (Ns) in 20–30 and 30–40 cm soil layers increased, whereas that in 0–10 and 10–20 cm soil layers decreased. Different but well-constrained C/N was found among four restoration stages in each soil sublayer. The effect of soil factors was greater on the deep soil than the surface soil, while the effect of vegetation factors was just the opposite. Our study indicated that vegetation restoration promoted the uniform distribution of SOC and TN on the soil profile. The C/N was relatively stable along vegetation restoration in each soil layer. The accumulation of SOC and TN in the surface soil layer was controlled more by vegetation factors, while that in the lower layer was controlled by both vegetation factors and soil factors.


2021 ◽  
Author(s):  
Fengjuan Pan ◽  
Ruirui Yan ◽  
Jinling Zhao ◽  
Linghao Li ◽  
Yanfeng Hu ◽  
...  

Abstract Aims Grazing is a key driver of plant communities and soil functions in grassland ecosystems. Soil nematodes play a vital role in soil ecological functions. however, few studies have explored how grazing shapes soil nematode community in different soil layers.Methods we investigated the composition, abundance, diversity, metabolic footprint, and food web metrics of soil nematodes over a gradient of grazing in the 0-10 cm and 10-20 cm soil layers in a meadow steppe. The relationships between nematode community structure and biotic and abiotic factors were analyzed by principal component analysis (PCA) and structural equation model (SEM) analysis. Results Light grazing tended to increase the abundance of soil nematodes. Intensive grazing decreased the biomass carbon and metabolic footprints of plant parasites, fungivores, and total soil nematodes in 0-10 cm soils. There was no difference in the biomass carbon and metabolic footprints of soil nematodes among different grazing intensities in the 10-20 cm soil layer. Soil moisture, aboveground biomass, belowground biomass and Shannon diversity of grass contributed more to changes in soil nematode composition in both soil layers. In the 0-10 cm soil layer, grazing directly and indirectly affected soil nematode diversity via soil moisture and aboveground biomass, while grazing directly affected soil nematode diversity in 10-20 cm soil layer. Conclusions Our results indicate that soil depth can weaken the effect of grazing intensities on soil nematode fauna. Grazing affected the soil nematode community structure via different paths in different soil layers.


AGRICA ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 63-70
Author(s):  
Julio Correia

       Soils are the main media for the growth of crops, the low yield of crops is always related to soil physical, chemical and biological soil conditions. Cattle manure is an organic fertilizer known well before chemical fertilizer. Many types of research on the use of cattle manure to ameliorate physical, chemical and biological soil properties have been conducted, but the optimum rates of cattle manure especially on sandy soil have never been found. This fact may be caused by leaching of organic materials and nutrients to deeper soil layer unreachable by roots. An experiment was conducted in a plastic house using sandy soils from the district of Kubu, Karangasem regency, with the objectives of studying the effects of rates of cattle manure on physical, chemical and biological properties f soils and the effects of inundated and water field capacity of soils on leaching of nutrients in the soils. The experiment was conducted from June until August 2010. The design used was a split-plot design consisted of four rates of cattle manure (0, 10, 20 and 30 t ha-1) as main plots and two water status of soils (inundated and water capacity) as subplots, with three replications. The results of the experiment indicated that cattle manure is able to ameliorate some of the soil physical properties as bulk densities (g cm-3), soil water status (%), soil permeability (cm hour-1) and total soil pores (%), and increased soil pH, C-organic content (%), C/N ratio, NPK and biological properties of soils of low nutrients status of sandy loam brown regosol soils derived from Vulcan intermediary. The results of the experiment also indicated the occurrence of leaching of organic materials and NPK nutrients to 20-40 cm layer. Based on the experiment results it is to suggest to the farmers that the use of cattle manure should be combined with synthetic chemical fertilizer in several applications during growth periods, but this required further researches.


2019 ◽  
Vol 65 (No. 2) ◽  
pp. 71-77
Author(s):  
Liu Pingping ◽  
Ren Huarui ◽  
Zhang Yiling ◽  
Wu Tiantian ◽  
Zheng Chunli ◽  
...  

Soil phosphorus (P) fraction distribution and correlation at different soil depths along vegetation succession in wetland next to a lake in the Hongjiannao National Nature Reserve, China were studied using the Hedley fraction method. The overall trend for soil P content was calcium-bound P (Ca-P) > organic P (O-P) > aluminum/iron-bound P (Al/Fe-P) > labile-P (L-P). Ca-P and O-P were the predominant P forms in all the soil layers, representing on average 53.8‒84.9% and 12.9‒45.2% of the total P, respectively, whereas L-P (ranging from 0.5 to 1.5 mg/kg) was less than 1%. The soil in the Bassia dasyphylla and Carex duriuscula vegetation zones had the largest P contents. In these two vegetation zones, soil L-P was greatest in the surface soil layer; Al/Fe-P was most abundant in the deep layer; O-P was highest in the middle layer. Ca-P levels were generally similar across all soil layers. Regression analysis showed that distribution of P was highly correlated with organic carbon, total nitrogen and plant biomass. Results showed that the soils under Bassia dasyphylla and Carex duriuscula have considerable carbon input potentials, which would facilitate P mineralization as compared to other plants.


2019 ◽  
Vol 32 (4) ◽  
pp. 924-933
Author(s):  
VALDECI CALIXTO DA SILVA FILHO ◽  
ADERSON SOARES DE ANDRADE JÚNIOR ◽  
VALDENIR QUEIROZ RIBEIRO ◽  
FRANCISCO DE BRITO MELO ◽  
ALZENEIDE DA SILVA LOPES

ABSTRACT The objective of this study was to evaluate the distribution of NO3 - and K+ in the profile of soils cultivated with sugarcane crops, after application of different nitrogen (N) and potassium (K2O) rates via subsurface drip fertigation, in Teresina, PI, Brazil. The experiment was conducted at the experimental area of Embrapa Meio-Norte, using a randomized block design with four replications. The treatments were arranged in split plots, with N+K2O rates (60+120, 180+120, 120+60, 120+180, and 120+120 kg ha-1 of N + K2O, respectively) in the plots, and soil layers (0.0-0.2, 0.2-0.4, and 0.4-0.6 m), for quantification of NO3- and K+ concentrations in the soil, in the subplots. The soil of the experimental area was a Typic Hapludult of sandy-loam texture. The distribution of nitrate (NO3-) and potassium (K+) in the soil layers after the N+K2O applications were evaluated. The NO3- and K+ concentrations in soils under sugarcane crops in the plant crop cycle is higher at the beginning and at the end of the cycle, respectively. The NO3 - and K+ concentrations in the soil solution are dependent on the evaluation time, soil layer, and N and K2O rates applied via fertigation. The highest concentrations of NO3- (264 mg L-1) and K+ (377 ppm) were found in the 0.0-0.2 m soil layer. No leaching of NO3- or K+ to deepest soil layers (>0.4 m) was found.


2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.


Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1300
Author(s):  
Xiaogang Ding ◽  
Xiaochuan Li ◽  
Ye Qi ◽  
Zhengyong Zhao ◽  
Dongxiao Sun ◽  
...  

Stocks and stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in ultisols are not well documented for converted forests. In this study, Ultisols were sampled in 175 plots from one type of secondary forest and four plantations of Masson pine (Pinus massoniana Lamb.), Slash pine (Pinus elliottii Engelm.), Eucalypt (Eucalyptus obliqua L’Hér.), and Litchi (Litchi chinensis Sonn., 1782) in Yunfu, Guangdong province, South China. Five layers of soil were sampled with a distance of 20 cm between two adjacent layers up to a depth of 100 cm. We did not find interactive effects between forest type and soil layer depth on soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) concentrations and storages. Storage of SOC was not different between secondary forests and Eucalypt plantations, but SOC of these two forest types were lower than that in Litchi, Masson pine, and Slash pine plantations. Soil C:P was higher in Slash pine plantations than in secondary forests. Soil CNP showed a decreasing trend with the increase of soil depth. Soil TP did not show any significant difference among soil layers. Soil bulk density had a negative contribution to soil C and P stocks, and longitude and elevation were positive drivers for soil C, N, and P stocks. Overall, Litchi plantations are the only type of plantation that obtained enhanced C storage in 0–100 cm soils and diverse N concentrations among soil layers during the conversion from secondary forests to plantations over ultisols.


Author(s):  
Jinsheng Li ◽  
Jianying Shang ◽  
Ding Huang ◽  
Shiming Tang ◽  
Tianci Zhao ◽  
...  

The distribution of soil particle sizes is closely related to soil health condition. In this study, grasslands under different grazing intensities and different cultivation ages grasslands were selected to evaluate the dynamics of soil particle size redistribution in different soil layers. When the grazing intensity increased, the percentage of 2000~150-μm soil particles in the 0–10-cm soil layer decreased; 150~53-μm soil particles remained relatively stable among the grazing intensities—approximately 28.52%~35.39%. However, the percentage of less than 53-μm soil particles increased. In cultivated grasslands, the larger sizes (>53 μm) of soil particles increased and the smaller sizes (<53 μm) decreased significantly (p < 0.05) in the 0–10 cm-soil layer with increasing cultivation ages. The increase in small soil particles (<53 μm) in topsoil associated with grazing intensity increased the potential risk of further degradation by wind erosion. The increase in big soil particles (>53 μm) in topsoil associated with cultivation ages decreased the soil capacity of holding water and nutrient. Therefore, to maintain the sustainability of grassland uses, grazing grasslands need to avoid heavy grazing, and cultivated grasslands need to change current cultivation practices.


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