scholarly journals Effects of ploughing and mulching on soil and organic matter losses after a wildfire in Central Portugal

2020 ◽  
Vol 46 (1) ◽  
pp. 303-318 ◽  
Author(s):  
A.R. Lopes ◽  
S.A. Prats ◽  
F.C. Silva ◽  
J.J. Keizer
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Mitigation Measures ◽  
Forest Residues ◽  
Logging Residues ◽  
Application Rates ◽  
Forest Logging ◽  
Standard Application ◽  
Central Portugal

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.

Fate and behaviour of triasulfuron, metsulfuron-methyl, and chlorsulfuron in the Australian soil environment: a review

1998 ◽  
Vol 49 (5) ◽  
pp. 775 ◽  
Author(s):  
Ajit K. Sarmah ◽  
Rai S. Kookana ◽  
A. M. Alston
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Herbicidal Activity ◽  
Analytical Sensitivity ◽  
Sulfonylurea Herbicides ◽  
Alkaline Soils ◽  
Metsulfuron Methyl ◽  
Application Rates ◽  
Mammalian Toxicity

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.

EFFETS À LONG TERME D’APPORTS DE FUMIER SOLIDE DE BOVINS SUR L’ÉVOLUTION DES CARACTERISTIQUES CHIMIQUES DU SOL ET DE LA PRODUCTION DE MAIS-ENSILAGE

1990 ◽  
Vol 70 (3) ◽  
pp. 767-775 ◽  
Author(s):  
ADRIEN N’DAYEGAMIYE
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Residual Effect ◽  
Application Rate ◽  
Exchange Capacity ◽  
Matter Content ◽  
Cattle Manure ◽  
Manure Application ◽  
Application Rates ◽  
Percent Recovery

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

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
Keyword(s):  
Organic Matter ◽  
Layer Thickness ◽  
Lignin Content ◽  
Organic Matter Content ◽  
Ligninolytic Enzyme ◽  
Matter Content ◽  
Organic Layer ◽  
Putting Greens ◽  
Turf Quality ◽  
Application Rates

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.

scholarly journals Levels of Lead, Copper, and Zinc in Cabbage (Brassica oleracea sp.) and Lettuce (Lactuca sativa sp.) Grown on Soil Amended with Sewage Sludge

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Bernard Fei-Baffoe ◽  
Jeffery Amo-Asare ◽  
Alhassan Sulemana ◽  
Kodwo Miezah
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Sewage Sludge ◽  
Metal Uptake ◽  
Organic Matter Content ◽  
Matter Content ◽  
Yield Enhancement ◽  
Nitrogen Application ◽  
Application Rates

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.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

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.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

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.

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply

scholarly journals Effect of Clay, Soil Organic Matter, and Soil pH on Initial and Residual Weed Control with Flumioxazin

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1326
Author(s):  
Calvin F. Glaspie ◽  
Eric A. L. Jones ◽  
Donald Penner ◽  
John A. Pawlak ◽  
Wesley J. Everman
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Weed Control ◽  
Soil Ph ◽  
Organic Matter Content ◽  
Amaranthus Retroflexus ◽  
Matter Content ◽  
Weed Species ◽  
Soil Organic Matter Content ◽  
Field Soils

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.

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