Effects of the herbicides fluometuron and prometryn on Rhizoctonia solani in soil cultures

1977 ◽  
Vol 23 (5) ◽  
pp. 617-623 ◽  
Author(s):  
H. Wayne Beam ◽  
E. A. Curl ◽  
R. Rodriguez-Kabana

Responses of Rhizoctonia solani to herbicides in soil cultures were assessed by measuring soil enzyme activity and other growth-related factors. Both β-galactosidase (EC 3.2.1.23) and phosphatase (EC 3.1.3.1, 3.1.3.2) activities were highly correlated with amounts of mycelium in soil. Both enzyme activities were reduced significantly by either fluometuron or prometryn at 40 μg/g of soil; the pathogen was more distinctly suppressed by fluometuron and showed a stronger tendency to overcome the effects of prometryn with time. Inhibition was also reflected in reduced utilization of glucose and less CO2-C evolved. Except for an increase in β-galactosidase activity in the presence of 1 μg fluometuron, low levels of either herbicide had little effect on the pathogen.

2020 ◽  
Author(s):  
Ming Wang

<p>Hummock-hollow microtopography is a common feature in northern peatlands. It<br>creates microsites of variable hydrology, vegetation, and soil biogeochemistry, thus affect soil C<br>cycling in peatlands at the local scale. This study investigated effects of microtopography on soil<br>enzyme (β-1,4-glucosidase (βG), β-1,4-N-acetylglucosaminidase (NAG), acid phosphatase (AP)<br>and peroxidase (PER)) activities and environment variables as well as their relationships in a<br>typical sedge peatland in Changbai Mountain, northeast of China. Our results showed that the<br>enzyme activities in the sedge peatland significantly varied across seasons and microtopographical<br>positions. Soil enzyme activities in hummocks exhibited more obvious seasonal variation than<br>hollows, with the βG, AP and PER activities presented a distinct valley in summer and the<br>maximum values occurred in Spring or Autumn. Soil hydrolase (βG, NAG and AP) activities in<br>hummocks were significantly higher compared to hollows, while soil oxidase (PER enzyme)<br>activity in hollows was higher than hummocks. The NMDS analysis revealed that the influence<br>degree of microtopography on the enzyme activities was higher than that of seasonal variation.<br>Redundancy analysis (RDA) indicated that the variations of soil enzyme activities in the peatland<br>were related to environmental variables, especially to water table depth (WTD), soil temperature<br>(ST), SOC, N availability and P availability. Furthermore, correlation analysis showed that the<br>three hydrolase (BG, NAG and AP) activities were positively correlated with soil TN, SOC and<br>C/N, and negatively correlated with WTD and TP. On the contrast, the PER activities were<br>positively correlated with TP, and negatively correlated with ST, SOC and C/N. The present<br>study demonstrated that small scale topographic heterogeneity created by hummock cause habitat<br>heterogeneity and thus lead to significant difference of soil enzyme activity between hummock<br>and hollow in the sedge peatlands. This finding provides further evidence of the importance of<br>peatland microtopography to C cycling and has direct implications for scaling biogeochemical<br>processes to the ecosystem level.</p>


2012 ◽  
Vol 500 ◽  
pp. 238-242
Author(s):  
Yan Hong Li ◽  
Xin Zheng Chu

This paper selected wetland area in Ganjiahu as research area which impacts of human activity was evident and analyzed the soil enzyme activity of each five edge land-use types (reed wetland, salt meadow, Populus euphratica, Haloxylon ammodendro, farm land), results showed that: Under the effects of different land use types, the impact of the enzyme activity causes its surface layer soil to the catalase to be higher, and in the vertical direction, the soil enzyme activity assumes declining trend along with the depth change. It`s the biggest changing scope among each layer of the enzyme activity in the Populus euphratica. Secondly, each layer of the farmland and reed wetland enzyme activity has the sub-change scope. The average value of enzyme activity of urease exists a declining tendency from the soil surface to the bottom, in which the changing scope of the enzyme activity of each layer in the salt meadow is the biggest. Correespondingly, the each layer of farm land, Populus euphratica and reed wetland enzyme activity has the sub-change scope. The enzyme activity of sucrase exists a declining tendency from the soil surface to the bottom,Each changing scope of the soil enzyme activity in the Populus euphratica is the biggest, the salt meadow and reed wetland`s soil enzyme activity is relatively smaller, and each changing scope of sucrase activity in farm land is not obvious. soil is not obvious to the proteinase activity influence, which indicating that the proteinase is unable representative to reflect this area soil fertility condition . whereas four kinds of enzyme activities in the Haloxylon ammodendro are relatively low, and each change is not obvious, instructing that the disturbance by human are more lightly. Soil enzymes as part of the soil, it plays an important role in the transformation of nutrients, organic matter decomposition, degradation and restoration of pollutants [1].Soil enzyme is kind of substances which remains catalytic ability of decomposition in the soil, it is from microorganisms, plants, animals and there living secretion of debris [2]. In recent years, scholars have paid a lot of attention in the soil enzyme activities as indicators of soil quality research in biological activity [3], they think that the land use could affected significantly enzyme activity of soil, determination of soil enzyme activity and quality has become indispensable. But on the research of soil enzyme activities in the wetland soil of arid desert edge is lack. This paper study the soil enzyme in different land use in Xinjiang Ganjiahu Wetland edge, and discuss the human activities on wetland and ecosystem interference mechanism, in order to carry out construction projects of wetland degradation and restoration and provide evidence.


2012 ◽  
Vol 518-523 ◽  
pp. 39-43
Author(s):  
Xiao Guang Zhao ◽  
Yuan Yuan Guan ◽  
Wen Yu Huang

In this paper, simulated experiments were performed in pots by using soil materials in different conditions of film remnant. Based on the research on soil microorganism quantity trends of soil enzyme activities were analyzed systematically: soil without film remnant, soil with film remnant for 5, 10, 15 and 20 years. By analyzing crop progress, the relationship with soil material was studied, in order to provide scientific basis for the variation laws between different conditions of film remnant and the activity of soil enzyme.


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