scholarly journals Fungal colonization patterns and enzymatic activities of peatland ericaceous plants following long-term nutrient addition

2020 ◽  
Vol 147 ◽  
pp. 107833
Author(s):  
Heikki Kiheri ◽  
Sannakajsa Velmala ◽  
Taina Pennanen ◽  
Sari Timonen ◽  
Outi-Maaria Sietiö ◽  
...  
2018 ◽  
Vol 69 (10) ◽  
pp. 2608-1612 ◽  
Author(s):  
Alina Dora Samuel ◽  
Simona Bungau ◽  
Delia Mirela Tit ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Lavinia Purza ◽  
...  

Long term productivity and conservation of soils is critical for sustaining agricultural ecosystems. The specific objective of the work reported was to determine the effects of long term application of organic and mineral fertilizers on soil enzyme activity as an index of soil biology and biochemistry. Three key soil enzymes involved in intracellular metabolism of microorganisms and two soil enzymes involved in phosphorus metabolism were selected. Actual and potential dehydrogenase, catalase, acid and alkaline phosphatase activities were determined in the 0-20 cm layer of an eroded soil submitted to a complex fertilization experiment. Results showed that addition of mineral fertilizers to organic (green manure and farmyard manure) fertilizers led to a significant increase in each activity because of increased plant biomass production which upon incorporation stimulates soil biological activity. The enzymatic indicators of soil quality calculated from the values of enzymatic activities depending on the kind of fertilizers showed that by the determination of enzymatic activities valuable information can be obtained regarding fertility status of soils. A weak positive correlation between enzymatic indicators of soil quality and maize yield was established. The yield data demonstrate the superiority of farmyard manure which provided greater stability in crop production. Substantial improvement in soil biological activity due to application of organic fertilizers with mineral fertilizers contribute in maintaining the productivity and soil health.


2018 ◽  
Vol 48 (4) ◽  
pp. 420-428
Author(s):  
Johana Juliet Caballero Vanegas ◽  
Karen Bibiana Mejía Zambrano ◽  
Lizeth Manuela Avellaneda-Torres

ABSTRACT Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.


2021 ◽  
Vol 9 (3) ◽  
pp. 501
Author(s):  
Zhimin Zhang ◽  
Qinghui Deng ◽  
Lingling Wan ◽  
Xiuyun Cao ◽  
Yiyong Zhou ◽  
...  

Aquaculture is among the most important and fastest growing agriculture sectors worldwide; however, it generates environmental impacts by introducing nutrient accumulations in ponds, which are possibly different and further result in complex biological processes in the sediments based on diverse farming practices. In this study, we investigated the effects of long-term farming practices of representative aquatic animals dominated by grass carp (GC, Ctenopharyngodon idella) or Chinese mitten crab (CMC, Eriocheir sinensis) on the bacterial community and enzyme activity of sediments from more than 15 years of aquaculture ponds, and the differences associated with sediment properties were explored in the two farming practices. Compared to CMC ponds, GC ponds had lower contents of TC, TN, and TP in sediments, and similar trends for sediment pH and moisture content. Sediment bacterial communities were significantly different between GC and CMC ponds, with higher bacterial richness and diversity in GC ponds. The bacterial communities among the pond sediments were closely associated with sediment pH, TC, and TN. Additionally, the results showed profoundly lower activities of β-1,4-glucosidase, leucine aminopeptidase, and phosphatase in the sediments of GC ponds than CMC ponds. Pearson’s correlation analysis further revealed strong positive correlations between the hydrolytic enzyme activities and nutrient concentrations among the aquaculture ponds, indicating microbial enzyme regulation response to sediment nutrient dynamics. Our study herein reveals that farming practices of fish and crab differently affect bacterial communities and enzymatic activities in pond sediments, suggesting nutrient-driven sediment biological processes in aquaculture ponds for different farming practices.


2021 ◽  
Author(s):  
William Rickard ◽  
Marcos Paradelo Perez ◽  
Aurelie Bacq-Labreuil ◽  
Andy Neal ◽  
Xiaoxian Zhang ◽  
...  

<p>Soil organic matter is associated with important biological and physical functions. There are many theories to interpret this association, as yet there is not a fully developed understanding linking soil properties to nutritional management in arable systems.</p><p>We used X-ray computed tomography to analyse soil structure at the core and aggregate scale on the Broadbalk long term experiment (Hertfordshire, England). Here we present results of the treatments that have been under continuous wheat for 175 years. Corresponding to treatments that the only difference between the treatments is the nutrient management regime, with the exception of the baseline, or ‘wilderness’ treatment in which the plot was left unmanaged and has returned to mature woodland since 1882. The other nutrient treatments correspond to inorganic fertiliser addition with and without phosphorus, farmyard manure, and no added nutrient.</p><p>At core scale (40 µm resolution) we capture macro pore structures that are responsible for convective flow, while the aggregate scale images (1.5 µm resolution) include structures responsible for retention of water by capillary forces.  Therefore, a comparison of images taken at the two resolutions 1.5 µm and 40 µm provides information on how soil partitions between drainage and storage of water, and therefore on the air water balance under different environmental contexts.</p><p>The results are presented as a state-space plot of simulated permeability vs. porosity for each treatment. We find that nutrient management resulted in two distinct states at aggregate scale corresponding to water storage potential. Inorganic nutrient management resulted in structures of lower porosity and lower simulated permeability. There was no significant difference between each treatment, or between these treatments and the treatment with no nutrient addition. By comparison, the wilderness and manure treatments had higher porosity and higher permeability, with no significant difference between them.</p><p>At core scale, the results are slightly different. Again, the inorganic nutrient management treatments had lower porosity and simulated permeability, with no significant difference between them, and between them and the treatment with no nutrient addition. However, the manure treatment had a significantly lower porosity and permeability than the wilderness treatment. We conclude that long-term cultivation with organic nutrient management results in a similar capacity for water storage and transport to roots than a wilderness control, but that long-term management using a purely inorganic nutrient regime results in a smaller capacity for water storage and a lower transport rate to roots. Organic inputs, roots and plant detritus ploughed into the soil after harvest had no significant impact. Infiltration potential is highest in the wilderness control, lower for the manure treatment, and lowest for the inorganic nutrient management treatment. Again, inputs of organic nutrients from plants had no significant impact. We interpret these findings in terms of a previously hypothesised self-organising feedback loop between microbial activity and soil structure.</p>


2018 ◽  
Vol 8 (10) ◽  
pp. 4958-4966 ◽  
Author(s):  
Rose M. Martin ◽  
Cathleen Wigand ◽  
Elizabeth Elmstrom ◽  
Javier Lloret ◽  
Ivan Valiela

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