scholarly journals Use of Fungal Laccases to Facilitate Biodethatching: A New Approach

HortScience ◽  
2012 ◽  
Vol 47 (10) ◽  
pp. 1536-1542 ◽  
Author(s):  
Sudeep S. Sidhu ◽  
Qingguo Huang ◽  
Robert N. Carrow ◽  
Paul L. Raymer

Accumulation of excessive organic matter as thatch restricts permeability of putting greens and is one of the most difficult problems in turfgrass management. A greenhouse experiment using potted bentgrass (Agrostis stolonifera L.) determined the efficacy of a ligninolytic enzyme, laccase, in reducing organic matter accumulation in the thatch-mat layer. Laccase was added biweekly at 0, 0.206, 2.06, and 20.6 units of activity/cm2 with and without guaiacol (2-methoxyphenol), a mediator of laccase, and sampling was performed after two and nine months. Parameters investigated included thickness of the organic layer, thatch layer and mat layer, organic matter content, saturated hydraulic conductivity, and lignin content. Organic matter and thatch layer increased between the two sampling dates in all treatments. Laccase was shown to be effective in slowing the rate of accumulation of organic matter and thatch layer. After two months, application of 20.6 units/cm2 of laccase reduced organic layer thickness by 8.7% and extractive-free total lignin content by 8.4% when compared with non-treated control. After nine months, laccase application rates of 2.06 units/cm2 reduced organic matter and thatch layer thickness by 15.6% and 45.0%, respectively, below levels observed in the non-treated control. Applications using 0.206 units/cm2 of laccase were ineffective. Laccase applications had no influence on turf quality. These positive responses suggest laccase treatments could be a non-disruptive option for thatch and/or mat control in bentgrass.

1998 ◽  
Vol 49 (5) ◽  
pp. 775 ◽  
Author(s):  
Ajit K. Sarmah ◽  
Rai S. Kookana ◽  
A. M. Alston

The sulfonylurea herbicides comprise a group of compounds designed to control broad-leaved weeds and some grasses in a variety of crops. The herbicides have become popular because of their low application rates (10-40 g/ha), low mammalian toxicity, and unprecedented herbicidal activity. We present a review of the fate and behaviour of these herbicides in soils with particular reference to alkaline soils of Australia. The review shows that the low application rates of sulfonylurea herbicides continue to present an analytical challenge, although in recent years a number of new methods capable of detecting them at very low concentrations have been developed. A range of analytical methods is available, including high performance liquid chromatography, gas chromatography, immunoassay, and bioassay. However, analytical sensitivity required to detect trace levels of these herbicides continues to pose problems in routine detection of herbicide residues in soils. The review reveals that there are no reports of studies of the behaviour of sulfonylureas in soils with pH >8·2. This is of particular significance to Australian conditions because a number of Australian soils are even more alkaline, and the pH(water) in subsoils can be as high as 10· 2. Sorption of sulfonylureas is pH-dependent and has a strong negative correlation with pH. At pH >8·0 sorption is very low. In acid soils, however, sorption of chlorsulfuron, metsulfuron-methyl, and triasulfuron is strongly influenced by the soil temperature, clay content, and, particularly, organic matter content. The principal modes of degradation of the herbicides are acid hydrolysis and microbial degradation with the latter being the only major pathway in alkaline soils. Hydrolysis of the sulfonylureas is more rapid under acidic conditions (pH 4{7), and the data suggest that hydrolysis is likely to be very slow in alkaline soils. Data from other countries suggest that the half-life of chlorsulfur on increases exponentially with pH, and that it is also influenced by variations in the temperature and water content of the soil. Being acidic in nature, the herbicide molecules become anionic at high pH and can move to a considerable depth in the soil profile by leaching. Movement of the sulfonylureas in soil is largely influenced by organic matter content and soil pH and the reviewed data show that sulfonylureas have substantial leaching potential in the sandy alkaline soils of Australia. This is likely to result in increased persistence in alkaline subsoils lacking in organic matter and biological activity. Computer models to predict the persistence and movement of the sulfonylureas are available; however, additional input parameters are required to predict accurately the behaviour of specific herbicides in alkaline soils under Australian conditions. Since new herbicides with chemistry similar to existing sulfonylureas are increasingly likely to be available for use, there is a need to develop comprehensive understanding of their fate, behaviour, and impact on Australian cropping and ecological systems.


1990 ◽  
Vol 70 (3) ◽  
pp. 767-775 ◽  
Author(s):  
ADRIEN N’DAYEGAMIYE

A long-term field experiment was initiated on a Neubois silty loam in 1978 in the county of Levis, Québec to study the changes in soil characteristics and silage corn yields following manure application. Solid beef cattle manure was incorporated without fertilizer every 2 yr in fall, at rates of 0, 20, 40, 60, 80 and 100 t ha−1. Even when significant differences were observed between treatments low corn yields were obtained from 1978 to 1984. These low yields were related to the low N, P and K recoveries from applied manure. For the 20 t ha−1 application rate, N. P and K recoveries from manure in the first year were 28, 7 and 1396, respectively. N, P and K recovery decreased with manure application rates. Corn yields increased progressively, but they achieved their maximum value (10–12 t ha−1 DM) only in 1985 and after three manure applications. This was due to the important residual effect of manure. Highly significant increases in N (7–64%), P (80–300%) and K (37–158%) as well as other nutrients were associated with manure applications. Manure application also significantly increased soil pH, CEC and organic matter. Average yearly increases of organic matter content were 0.06% and 0.16% for 20 to 40 t ha−1, respectively, and varied from 0.20 to 0.30% for the highest application rates (60–100 t ha−1). These improvements of soil properties constitute the "indirect effect" of manure. This study showed that percent recovery of N, P and K from solid cattle manure was generally low. Thus, manure should be mainly considered as an organic amendment.Key words: Solid cattle manure, corn silage, percent recovery, pH, mineral nutrients, cation exchange capacity, organic matter


1962 ◽  
Vol 42 (2) ◽  
pp. 276-288 ◽  
Author(s):  
H. Lueken ◽  
W. L. Hutcheon ◽  
E. A. Paul

Additions of mineral nitrogen accelerated the initial decomposition rate of incorporated wheat straw, alfalfa hay and glucose when added to two soils differing widely in organic matter content. However, in the more advanced stages of decomposition the reverse was true, and over the total incubation period larger amounts of carbon were maintained in soils supplemented with nitrogen.In contrast to all other residues used, nitrogen additions to cellulose effected a continuous and substantial increase in residue decomposition. This was the only residue for which the mineralization of soil organic matter did not supply nitrogen adequate for its decomposition within 120 days.The very slow rate of decomposition of sphagnum peat could be attributed to its high lignin content, rather than to the nitrogen levels.Sulphacetolysis analysis, which measures the non-humified carbon, indicated the feasibility of separating non-humified crop residues from the more complex soil organic matter. Addition of organic amendments thus resulted in a drop in the soil humification quotient. Nitrogen resulted in the retention of a significantly higher percentage of the added residue, without a drop in the humification quotient for the high organic matter Melfort soil.Residue applications to soils produced a significant improvement of structural development, especially in the low organic matter soil (Arborfield).


2013 ◽  
Vol 23 (3) ◽  
pp. 369-375 ◽  
Author(s):  
John M. Kauffman ◽  
John C. Sorochan ◽  
Dean A. Kopsell

Thatch-mat and organic matter (OM) accumulation near the putting green soil surface impacts soil physical properties and turf performance. Excessive thatch and OM can encumber infiltration of water and oxygen into the soil profile and slow drainage of excess water away from the putting surface. Proper sampling of thatch-mat depths and OM contents is vital for management of putting green turf; therefore, a study was performed in Knoxville, TN, to derive proper sampling procedures of these important parameters using ‘TifEagle’ and ‘Champion’ bermudagrass (Cynodon dactylon × C. transvaalensis), ‘SeaDwarf’ seashore paspalum (Paspalum vaginatum), and ‘Diamond’ zoysiagrass (Zoysia matrella). ‘TifEagle’ and ‘Champion’ accumulated thatch-mat to a greater depth than ‘SeaDwarf’ and ‘Diamond’. However, ‘SeaDwarf’ had a higher OM content than ‘Diamond’ and both had higher OM contents than ‘TifEagle’ and ‘Champion’. Data generated from sampling procedures indicate that previous studies often undersampled plots for thatch-mat depth; however, previous sampling procedures have not traditionally undersampled plots for OM. Data in this study provide a range of confidence and minimum detectable difference levels which may allow future researchers to more accurately sample ‘TifEagle’, ‘Champion’, ‘SeaDwarf’, and ‘Diamond’ putting green plots for thatch-mat depth and OM content.


2020 ◽  
Vol 46 (1) ◽  
pp. 303-318 ◽  
Author(s):  
A.R. Lopes ◽  
S.A. Prats ◽  
F.C. Silva ◽  
J.J. Keizer

Forest wildfires typically increase runoff and associated soil and organic matter losses. Both ploughing and mulching with forest residues have been applied in recently burnt areas in Portugal to mitigate these effects in soil erosion, but their effectiveness has never been compared directly. To this end, soil and organic matter losses by water after a wildfire were studied in two eucalypt plantations in central Portugal that had been affected by the same wildfire (August 2015). One of the sites was instrumented with six erosion plots (2 m by 8 m), divided over two blocks with one treatment per block: control (doing nothing) and ploughing to 0.2 m depth with a tracked excavator. The other site was instrumented with nine erosion plots, divided over three blocks with three treatments in each block: control (doing nothing) and mulching with forest logging residues at reduced (2.6 Mg ha-1) and standard application rates (8 Mg ha-1). Mulching was performed one month after the wildfire, whereas ploughing took place one year after the wildfire. For this study, soil and organic matter losses were monitored at 12 occasions from July 2016 to May 2017, roughly coinciding with the second post-fire year. Over this relatively dry period sediment losses at the control plots of both ploughed and mulched sites averaged 1.6 and 0.6 Mg ha-1 respectively. The corresponding losses of the ploughed plots were 19% lower, whereas those of the mulched plots were 67 and 93% lower at the reduced and standard mulch rates, respectively. The organic matter content of the eroded sediments was 22% in the unploughed plots, and ploughing reduced this figure in half, which could be explained by the inversion of the topsoil horizons by the excavator. Mulching at the standard application rate seemed to produce a clear enrichment in organic matter content compared to mulching at the reduced rate as well as doing nothing (25 vs. 16 and 14%). The two main findings of this research were that i) erosion rates exceeded the 1 Mg ha-1 tolerable soil loss during the second post-fire year, indicating that mitigation measures have to be implemented, ii) ploughing was clearly less suited for mitigating post-fire erosion than mulching with forest logging residues, even at application rates as low as that typically used in operational post-fire emergency stabilization with straw mulching.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Bernard Fei-Baffoe ◽  
Jeffery Amo-Asare ◽  
Alhassan Sulemana ◽  
Kodwo Miezah

The study focused on levels of selected heavy metals (Pb, Zn, and Cu) in sewage sludge, soil, and in lettuce and cabbage grown on sewage sludge amended soil. Also, the effect of sewage sludge on soil properties (pH, soil organic matter, and soil conductivity) was studied. Three treatments were used based on nitrogen application rates of the sewage sludge: 100, 150, and 200 kg N/ha for lettuce while 160, 210, and 260 kg N/ha for cabbage. A pot experiment was conducted with pots arranged in a completely randomized design and under local climatic conditions. The study revealed that soil organic matter content and conductivity increased significantly with increasing nitrogen application rates. Levels of heavy metals in the soil increased significantly with increasing application rates. The controls for both plants recorded the lowest heavy metal uptake. Cabbage had an uptake of 0.48 ± 0.13, 1.36 ± 0.23, and 2.60 ± 0.29 mg/kg for Pb, Zn, and Cu, respectively, while lettuce had 0.34 ± 0.19, 1.35 ± 0.31, and 2.30 ± 0.14 mg/kg uptake for Pb, Zn, and Cu, respectively. Highest metal uptake was recorded at the highest application rate in both plants (0.66 ± 0.17, 2.66 ± 0.09, and 4.33 ± 0.14 mg/kg for Pb, Zn, and Cu, respectively, for cabbage and 0.54 ± 0.01, 2.24 ± 0.17, and 3.88 ± 0.19 mg/kg of Pb, Zn, and Cu, respectively, for lettuce). The uptake of Zn and Cu was significant, while Pb uptake was insignificant for both plants. Yields increased significantly with increasing application rates. The study provides information on yield enhancement resulting from cultivating plants on soil amended with sewage sludge and the associated health risk implication.


2018 ◽  
Vol 28 (3) ◽  
pp. 62-66
Author(s):  
V. Yu. Yuhnovskyi ◽  
Yu. S. Urliuk ◽  
M. P. Holovetskyi ◽  
I. L. Sereda

The survival and growth of pine plantations, created at the clear cuttings, with the use of organic fertilizer "Dostatok" are analyzed. The research was conducted in 11 forest units of the State Enterprise "Vyshche-Dubechna Forestry" in the fresh poor and rich forest sites. The plantations were created according to the following schemes: 4 rows of Scotch pine and 1 row of red oak with placement of seedlings 1.5×0.5 m and 1.5×1.0 m by planting them in a furrow formed by a plow PKL-70. The total forest pine plantations with application of fertilizer amounted to 22.2 hectares. The agrochemical analysis revealed that 40.6 % of organic matter was concentrated in the fertilizer, whereas in the organic layer of fresh poor and rich pine sites, the content of humus was 22.2 % and 30.7 % respectively. At the same time, fertilizer is characterized by a neutral environment, while the organic soil of fresh poor and rich pine sites has a very high acidity of the pH of the salt extract, which fluctuates within 3.5–3.6. The double predominance of the organic matter content in the fertilizer promotes the survival and growth of pine plantations. It was established that the introduction of fertilizer "Dostavok" in the form of tablets on the root system of pine seedlings increases the survival of forest plantations, which on sandy and sandy loam soils, respectively, reaches 90 and 95 %. Values of pH salt extraction indicate that the soils are very acid (3.5 and 3.1), with an average level of humus (2.4 and 7.4 %), low levels of ammonia and nitrate nitrogen and mobile phosphorus. Soil of fresh poor pine site has an elevated level of mobile potassium (139.87 mg·kg-1), while the fresh rich pine site is characterized by a low level of potassium, which is 46.39 mg·kg-1. Granulometric analysis of the soil showed that the poor sites are represented by sandy soils and rich sites – rough-dust sandy loam soils. Almost double the predominance of the organic matter content in the fertilizer "Dostatok" contributes to the survival and growth of pine plantations. The annual increment of pine seedlings on 4–7 cm was more than at the control. The use of bio-fertilizer also reduces the number of manual care and accelerates the closure in the rows, which in turn allows the transfer of forest crops to covered forest area a year earlier.


Author(s):  
O. A. Lipatnikova

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.


Author(s):  
Amita M Watkar ◽  

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.


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