scholarly journals Using Microwave Soil Heating to Inhibit Invasive Species Seed Germination

2017 ◽  
Vol 10 (3) ◽  
pp. 262-270 ◽  
Author(s):  
Mélissa De Wilde ◽  
Elise Buisson ◽  
Nicole Yavercovski ◽  
Loïc Willm ◽  
Livia Bieder ◽  
...  
Keyword(s):  
Invasive Species ◽  
Soil Moisture ◽  
Seed Germination ◽  
Invasive Plant ◽  
Organic Matter Content ◽  
Seed Viability ◽  
Germination Percentage ◽  
Matter Content ◽  
Burial Depth ◽  
Experimental Conditions

Successful invasive plant eradication is rare, because the methods used target the adult stage, not taking into account the development capacity of a large seedbank. Heating by microwave was considered, because it offers a means to quickly reach the temperature required for loss of seed viability and inhibition of germination. Previous results were not encouraging, because homogeneous and deep-wave penetration was not achieved, and the various parameters that can affect treatment effectiveness were incompletely addressed. This study aimed to determine, under experimental conditions, the best microwave treatment to inhibit invasive species seed germination in terms of power (2, 4, 6 kW) and duration (2, 4, 8 min) of treatments and depending on soil moisture (10%, 13%, 20%, 30%) and seed burial depth (2, 12 cm). Three invasive species were tested: Bohemian knotweed, giant goldenrod, and jimsonweed. The most effective treatments required relatively high power and duration (2kW8min, 4kW4min, 6kW2min, and 6kW4min; 4kW8min and 6kW8min were not tested for technical reasons), and their effectiveness diminished with increasing soil moisture with germination percentage between 0% and 2% for the lowest soil moisture, 0% and 56% for intermediate soil moisture, and 27% and 68% in control treatments. For the highest soil moisture, only 2kW8min and 4kW4min reduced germination percentage between 2% and 19%. Occasionally, germination of seeds located at the 12-cm depth was more strongly affected. Giant goldenrod seeds were the most sensitive, probably due to their small size. Results are promising and justify further experiments before developing a field microwave device to treat large volumes of soil infested by invasive seed efficiently and with reasonable energy requirements. Other types of soil, in terms of texture and organic matter content, should be tested in future experiments, because these factors influence soil water content and, consequently, microwave heating.

scholarly journals Effects of freeze-thaw on soil properties and water erosion

2021 ◽  
Author(s):  
Baoyang Sun ◽  
Feipeng Ren ◽  
Wenfeng Ding ◽  
Guanhua Zhang ◽  
Jinquan Huang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Erosion ◽  
Soil Properties ◽  
Field Experiments ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Water Erosion ◽  
Matter Content ◽  
Experimental Conditions ◽  
Freeze Thaw

Freeze-thaw erosion occurs primarily at high latitudes and altitudes. Temperature controlled freeze-thaw events dislodge soil particles and serve as a catalyst for erosion. This review paper provided an overview of the effects of freeze-thaw on soil properties and water erosion. The process of freeze-thaw cycles results in temporary and inconsistent changes in the soil moisture, and affects the soil’s mechanical, physical and chemical properties, such as the soil moisture content, porosity, bulk density, aggregates stability, shear strength and organic matter content and so on. The variation trend and range of the soil properties were related to the soil texture, water content and freeze-thaw degree. Furthermore, the soil erosion was affected by the freeze-thaw processes, as thawing and water erosion reinforce each other. However, research of different experimental conditions on indoor simulations have numerous limitations compared with field experiments. The use of indoor and field experiments to further reveal the freeze-thaw effect on the soil erosion would facilitate improved forecasting.

scholarly journals Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions

Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Poa Pratensis ◽  
Acid Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Moisture Level ◽  
Soil Conditions ◽  
Soil Moisture Level

scholarly journals Effect of Environmental Factors on the Germination and Emergence of Drunken Horse Grass (Achnatherum inebrians)

Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Yonghuan Yue ◽  
Guili Jin ◽  
Weihua Lu ◽  
Ke Gong ◽  
Wanqiang Han ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Germination Percentage ◽  
Western China ◽  
Burial Depth ◽  
Achnatherum Inebrians ◽  
Water Ph

Abstract Drunken horse grass [Achnatherum inebrians (Hance) Keng] is a perennial poisonous weed in western China. A comprehensive understanding of the ecological response of A. inebrians germination to environmental factors would facilitate the formulation of better management strategies for this weed. Experiments were conducted under laboratory conditions to assess the effects of various abiotic factors, including temperature, light, water, pH and burial depth, on the seed germination and seedling emergence of A. inebrians. The seeds germinated at constant temperatures of 15, 20, 25, 30, 35°C and in alternating-temperature regimes of 15/5, 20/10, 25/15, 30/20, 35/25, 40/30°C, and the seed germination percentages under constant and alternating temperatures ranged from 51% to 94% and 15% to 93%, respectively. Maximum germination occurred at a constant temperature of 25°C, and germination was prevented at 45/35°C. Light did not appear to affect seed germination. The germination percentage of seeds was more than 75% in the pH range of 5 to 10, with the highest germination percentage at pH 6. The seeds germinated at osmotic potentials of 0 MPa to -1.0 MPa, but decreasing osmotic potential inhibited germination, with no germination at -1.2MPa. After 21 d of low osmotic stress, the seeds that did not germinate after rehydration had not lost their vitality. The seedling emergence percentage was highest (90%) when seeds were buried at 1 cm but declined with increasing burial depth and no emergence at 9 cm. Deep tillage may be effective in limiting the seed germination and emergence of this species. The results of this study provide useful information on the conditions necessary for A. inebrians germination and provide a theoretical basis for science-based prediction, prevention and control of this species.

scholarly journals Organic matter and soil moisture content and double cropping with organic matter sourceplants

2005 ◽  
Vol 21 (1) ◽  
Author(s):  
John Bako Baon ◽  
Aris Wibawa
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Organic Matter Content ◽  
Matter Content ◽  
Farm Yard Manure ◽  
Soil Organic Matter Content ◽  
Matter Source ◽  
Robusta Coffee ◽  
Double Cropping ◽  
Organic Matter Source

Double cropping of coffee with organic matter source plants is thought to increase organic matter content of soil. This study examined the effect of double cropping of coffee and organic matter source plants on soil organic matter content and yield of coffee plants. Arabica coffee trees in Andungsari Experimental Station (Bondowoso district), 1400 m asl. and climate type C; and Robusta coffee trees in Sumberasin Experimental Station (Malang district), 550 m asl. and climate type C, were used as experimental sites of this study which lasted for five years. Organic matter source plants consisted of some species that can be routinedly pruned and surface applied to coffee soil, and other creeping species that not being pruned, however the organic matter source derived from their fallen leaves. Application of farm manure and control (neither organic matter source plants nor farm yard manure) were used as comparison treatments. Results indicate that Ramayana (Cassia spectabilis) had vigorus growth resulting in greater biomass production compared to lamtoro (Leucaena leucocephala), mogania (Moghania macrophylla) and even kaliandra (Calyandra calothyrsus) which produced greater biomass among organic matter source plants grown in Arabica coffee farming. Double cropping of coffee with organic matter source plants did not affect soil organic matter content of Arabica and Robusta coffee farmings, though farm yard manure application increased soil organic matter content and soil bulk density, especially of Robusta coffee farm. Soil moisture content examined in dry season was not affected by double cropping. In contrary, Robusta coffee farm applied with farm yard manure had higher soil moisture content. At Arabica coffee farm, double cropping did not influence green coffee yield, on the other hand Ramayana reduced green coffee yield of Robusta coffee while farm yard manure increased the yield.Keywords : Coffeea arabica, Coffeea canephora, organic matter, soil moisture, double cropping, biomass producing plants.

Field dissipation of S-metolachlor in organic and mineral soils used for sugarcane production in Florida

2019 ◽  
Vol 34 (3) ◽  
pp. 362-370
Author(s):  
Jose V. Fernandez ◽  
D. Calvin Odero ◽  
Gregory E. MacDonald ◽  
Jason A. Ferrell ◽  
Brent A. Sellers ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Linear Trend ◽  
Organic Matter Content ◽  
Field Studies ◽  
Matter Content ◽  
Organic Soils ◽  
Sugarcane Production ◽  
Mineral Soils ◽  
Moisture Conditions

AbstractDissipation of S-metolachlor, a soil-applied herbicide, on organic and mineral soils used for sugarcane production in Florida was evaluated using field studies in 2013 to 2016. S-metolachlor was applied PRE at 2,270 g ha−1 on organic and mineral soils with 75% and 1.6% organic matter, respectively. The rate of dissipation of S-metolachlor was rapid on mineral soils compared with organic soils. Dissipation of S-metolachlor on organic soils followed a negative linear trend resulting in half-lives (DT50) ranging from 50 to 126 d. S-metolachlor loss on organic soils was more rapid under high soil-moisture conditions than in corresponding low soil-moisture conditions. On mineral soils, dissipation of S-metolachlor followed an exponential decline. The DT50 of S-metolachlor on mineral soils ranged from 12 to 24 d. The short persistence of S-metolachlor on mineral soils was likely attributed to low organic matter content with limited adsorptive capability. The results indicate that organic matter content and soil moisture are important for persistence of S-metolachlor on organic and mineral soils used for sugarcane production in Florida.

Climate drives differences in the germination niche of a globally distributed invasive grass

2020 ◽  
Vol 13 (2) ◽  
pp. 195-203
Author(s):  
Rebecca A Fletcher ◽  
Kayla M Varnon ◽  
Jacob N Barney
Keyword(s):  
Invasive Species ◽  
Seed Germination ◽  
Invasive Plants ◽  
Water Availability ◽  
Invasive Plant ◽  
Invasive Grass ◽  
Climate Gradients ◽  
Exotic Invasive Species ◽  
Temperature And Precipitation ◽  
Wide Range

Abstract Aims Exotic invasive species are often exposed to strong selection pressures in their new ranges that can often lead to substantial intraspecific variation. Population differentiation in the timing of life history events in response to climate gradients is thought to be an important mechanism facilitating the range expansion of many invasive species. For seed producing plants, the timing of seed germination determines the first environmental conditions experienced by newly emerged germinates, and can have important implications for the successful colonization, establishment and spread of invasive plants—though the role of germination in the success of invasive plants remains poorly understood. Methods We assessed the variation in seed germination dynamics among 10 populations of the invasive plant Johnsongrass (Sorghum halepense) across its North American distribution, capturing both a temperature and precipitation gradient, and whether that variation is associated with home climate. Seeds were exposed to a wide range of temperatures (11–48°C) and two water availability treatments. Important Findings We found that Johnsongrass seeds germinated across a wide range of temperatures, but there was substantial variation among populations in the proportion of seeds that germinated in response to both temperature and water availability. Evidence indicates that as Johnsongrass expanded its range from warmer climates into cooler climates, there was a concurrent shift in the germination temperature niche to cooler temperatures. Our results suggest that the germination of Johnsongrass seeds has adapted to home climate allowing this invader to maximize germination throughout its range, and that this may be an important contributing factor to its invasion into new environments.

Mycofloral Succession and Viability Losses in Pigeon pea Seed in Puerto Rico

1969 ◽  
Vol 68 (1) ◽  
pp. 19-31
Author(s):  
P. R. Hepperly ◽  
R. Rodríguez
Keyword(s):  
Puerto Rico ◽  
Soil Moisture ◽  
Seed Germination ◽  
Seed Viability ◽  
Pigeon Pea ◽  
Fungal Colonization ◽  
Fusarium Spp ◽  
Storage Losses ◽  
Highly Correlated ◽  
Total Fungi

Using the cellulose pad and potato dextrose agar (PDA) assays, twenty three fungi were found on pigeonpea seed in Puerto Rico. In the PDA assay, Botryodiplodia theobromae was the most common (29%). On cellulose pads, the same fungus was not very common (7%). PDA assay favored increased detection of Alternaria tenuissima, Phomopsis sp., and total fungi compared with cellulose pads. Cellulose pads favored detection of Cladosporium sp. In both assays, incidences of B. theobromae, Fusarium spp., and total fungi were negatively correlated with seed germination. Measurements for seedlot germination were highly correlated (r = 0.77**) between the two assays. The influences of seed type and delayed harvest on pigeonpea seed viability were studied. Pigeonpeas "28-Bushy," with large tan seeds, showed reduced seed viability and higher incidence of B. theobromae and Fusarium spp. compared with segregants of the same cultivar with small flattened hard red seed. A 3-week delayed harvest drastically increased incidence of B. theobromae, Fusarium spp., and total fungi, and reduced germination in "Kaki" pigeonpeas from Santa Isabel. Pigeonpea seed viability and mycoflora were followed before and after farm storage. Incidences of Fusarium spp., Phomopsis sp., Cladosporium sp., and B. theobromae after storage were 15, 26, 30, and 38% of their respective prestorage values. Incidence of species of Penicillium, Rhizopus, and Aspergillus increased during storage. Although less than 3% Aspergillus spp. was detected in the cellulose pad assay at 27° C, 28 to 92% was detected when seed were incubated at 35° C using pigeonpea seed extract in 2% agar. With the Aspergillus selective assay, seed viability losses during storage were highly correlated with incidence of Aspergillus spp. (r = 0.96**). Aspergillus incidence in the cellulose pad assay was not associated with storage losses in seed germination (r = 0.18 NS). Emergence and fungal colonization of pigeonpea seed were dependent on soil moisture. Pigeonpea seed did not emerge at either 25 or 100% soil moisture holding capacity (SMHC). Optimum emergence was found at 50% SMHC. Pythiaceous fungi were predominent on seed at and above 75% SMHC, whereas Aspergillus spp. predominated at 50% SMHC or less. Mixed populations of the two were visible at 50 and 75% SMHC.

scholarly journals Sixty years of Dutch nitrogen fertiliser experiments, an overview of the effects of soil type, fertiliser input, management and of developments in time

1999 ◽  
pp. 215-241 ◽  
Author(s):  
T.V. Vellinga ◽  
G. Andre
Keyword(s):  
Soil Type ◽  
Peat Soil ◽  
N Uptake ◽  
Organic Matter Content ◽  
Matter Content ◽  
Experimental Conditions ◽  
N Application ◽  
Total N ◽  
Mixed Use ◽  
Cutting Frequency

Data of nitrogen fertilization experiments of 1934 - 1994 have been analysed, using models for N uptake and dry matter (DM) yield. Both models were affected by fertilizer level, soil type, soil organic matter content, grassland use, cutting frequency, grassland renovation, white clover content and the N content analysis (Crude Protein or total-N). Effects on Soil Nitrogen Supply (SNS), Apparent Nitrogen Recovery (ANR) and Nitrogen Use Efficiency (NUE) are discussed. Differences in SNS, ANR and NUE between sand and clay were small, SNS on poorly drained peat soil was 60 and 80 kg N per ha higher than on clay and sand, respectively, ANR on poorly drained peat soil was 7 and 10% lower. The NUE was similar on sand, clay and poorly drained peat. ANR was low at low N application levels, due to immobilization. ANR increased from 35% to 65% at application levels of 50 and 250 kg N per ha, respectively. At application levels of more than 250 kg N per ha, ANR decreased. NUE decreased from 45 to 29 kg DM per kg N with increasing N application levels of 0 and 550 kg per ha. It is suggested that for a good N utilization a minimum N application of 100 kg N per ha should be used. SNS increased by a mixed use of grazing and cutting with 27 and 40 kg N per ha for sand/clay and poorly drained peat respectively. ANR on sand decreased from 5 to 10% at applications of 200 and 500 kg N per ha and NUE decreased with 1-2 kg DM per kg N. The effect of grazing was stronger under pure grazing than with a mixed use of grazing and cutting. Increasing the cutting frequency from 3 to 8 cuts per year had no effect on SNS, increased ANR with 0-20% and decreased NUE with 4-7 kg DM per kg N. The positive effect of the higher ANR compensated the lower NUE at application levels of 400 kg N per ha. Changes in ANR over the last sixty years can be explained by changes in experimental conditions, experimental treatments and chemical analysis. Changes in NUE can be explained by a higher proportion of perennial ryegrass and genetic improvement.

scholarly journals The Effect of Sodium Hypochlorite (NaOCl) and Heat Treatments on Seed Germination of Rice: An Approach to Restore Seed Viability

2021 ◽  
pp. 49-53
Author(s):  
Monoj Sutradhar ◽  
Subhasis Samanta ◽  
Brijesh Kumar Singh ◽  
Md. Nasim Ali ◽  
Nirmal Mandal
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Sodium Hypochlorite ◽  
Seed Viability ◽  
Germination Percentage ◽  
Heat Treated ◽  
Mother Plants ◽  
Breaking Seed Dormancy ◽  
One Year

Dormancy in rice serves as a mechanism of survival by protecting the seed from germinating in the mother plants; however, it becomes a problem in germination during sowing in soil or under in vitro conditions. This study was conducted to determine the effect of heat treatment and sodium hypochlorite (NaOCl) treatment of seeds on dormancy alleviation. The seeds included both freshly harvested seeds and one-year-old stored seeds, which were tested for germination after different types of seed treatments. Both the treatments increased the germination percentage in seeds, however, it was lesser in the case of old seeds. The best results were obtained from 2% NaOCl treatment for 24 hrs in new seeds, i.e. 92.84±0.103 % germination percentage (GP). However, the higher GP in old seeds were obtained from 48 hrs of heat-treated seeds i.e. 82.9±0.509 % GP. The results of the experiment revealed that rice seeds start to lose viability within a year due to seed dormancy, but this can be reversed with proper measures. These methods of breaking seed dormancy can be considered effective to break seed dormancy and improve seed germination in rice.

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