Soil characteristics and water potential effects on plant-available clomazone in rice

Weed Science ◽  
2004 ◽  
Vol 52 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Do-Jin Lee ◽  
Scott A. Senseman ◽  
John H. O'Barr ◽  
James M. Chandler ◽  
L. Jason Krutz ◽  
...  
Keyword(s):  
Water Potential ◽  
Weed Control ◽  
Soil Solution ◽  
Potential Problem ◽  
Plant Root ◽  
Soil Characteristics ◽  
Accurate Estimate ◽  
Water Soluble ◽  
Biological Availability ◽  
Soil Environment

Clomazone has been successfully used for weed control in rice, but crop injury is a potential problem on light-textured soils. Experiments were conducted to determine the effect of soil characteristics and water potential on plant-available clomazone and rice injury. A centrifugal double-tube technique was used to determine plant-available concentration in soil solution (ACSS), total amount available in soil solution (TASS), and Kdvalues for clomazone on four soils at four water potentials. A rice bioassay was conducted parallel to the plant-available study to correlate biological availability to ACSS, TASS, and Kd. TASS was significantly different in all soils. The order of increasing TASS for the soils studied was Morey < Edna < Nada < Crowley, which correlated well with soil characteristics. The order of increasing TASS after equilibrium was − 90 < − 75 < − 33 < 0 kPa. TASS values at 0 kPa were greater than two times the TASS values at − 90 kPa. It appears that severe rice injury from clomazone on these soils could occur if TASS > 110 ng g−1and Kd< 1.1 ml g−1. We propose that the double-tube technique provides a more accurate estimate of available herbicide because the solution–soil ratios are < 0.33:1 and would be more representative of a plant root–herbicide relationship. This technique or some variation possibly could be further developed such that clomazone rates could be more clearly defined particularly on lighter-textured soils. TASS may be a better predictor of plant-available herbicide than ACSS when evaluating moderately to highly water-soluble herbicides in a nonsaturated soil environment.

Verbascoside from Verbena incompta is a plant root growth inhibitor

2021 ◽  
Author(s):  
Tomonori Date ◽  
Kanamu Shigeno ◽  
Megumi Hiroshima ◽  
Kohei Seo ◽  
Masashi Sato ◽  
...  
Keyword(s):  
Root Growth ◽  
Growth Inhibition ◽  
Weed Control ◽  
Plant Root ◽  
Lotus Japonicus ◽  
Growth Inhibitor ◽  
Control Agent ◽  
Water Soluble ◽  
Root Growth Inhibition ◽  
Phenolic Components

Abstract The use of biopesticides has expanded rapidly in recent years; however, their use in weed control is less advanced. Herein, we describe the development of a weed control agent by screening 208 plant extracts (104 species) for their plant growth-inhibition activities, which resulted in 142 active samples (from 89 plant species). Verbascoside, isolated from the shoots of Verbena incompta, was identified as a growth inhibitor against rice-root (EC50, 1.75 mM), and its root growth-inhibition activity was also confirmed in radish, tomato, and Lotus japonicus. Verbascoside is composed of hydroxytyrosol (EC50,12.51 mM) and caffeic acid (EC50, 4.08 mM), two poorly water-soluble phenolic components with weak growth-inhibition activities, and two sugars, which are more soluble but inactive. The plant apparently developed a more active and highly soluble compound by condensing these four components. We conclude that a biopesticide containing verbascoside may be useful for weed-control purposes.

scholarly journals Effect of Sulfate-Reducing Bacteria (SRB) on the Corrosion of Buried Pipe Steel in Acidic Soil Solution

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 625
Author(s):  
Lijuan Chen ◽  
Bo Wei ◽  
Xianghong Xu
Keyword(s):  
Soil Solution ◽  
Steel Surface ◽  
Pipeline Steel ◽  
Electrochemical Techniques ◽  
Sulfate Reducing Bacteria ◽  
Acidic Soil ◽  
Microbiologically Influenced Corrosion ◽  
Soil Environment ◽  
Sulfate Reducing ◽  
Reducing Bacteria

The influence of sulfate-reducing bacteria (SRB) on the corrosion behaviors of X80 pipeline steel was investigated in a soil environment by electrochemical techniques and surface analysis. It was found that SRB grew well in the acidic soil environment and further attached to the coupon surface, resulting in microbiologically influenced corrosion (MIC) of the steel. The corrosion process of X80 steel was significantly affected by the SRB biofilm on the steel surface. Steel corrosion was inhibited by the highly bioactive SRB biofilm at the early stage of the experiment, while SRB can accelerate the corrosion of steel at the later stage of the experiment. The steel surface suffered severe pitting corrosion in the SRB-containing soil solution.

scholarly journals ASSESSMENT OF THE INFLUENCE OF ABIOTIC FACTORS ON THE ENZYMATIVE ACTIVITY OF THE SOIL

ÈKOBIOTEH ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 128-134
Author(s):  
E.V. Tovstik ◽  
◽  
A.S. Olkova ◽  
Keyword(s):  
Enzymatic Activity ◽  
Soil Solution ◽  
Ph Value ◽  
Abiotic Factors ◽  
Inverse Correlation ◽  
Invertase Activity ◽  
Soil Environment ◽  
Factors Affecting ◽  
Activity Of Enzymes ◽  
Made In

Аn attempt is made in this work to establish correlations between the level of enzymatic activity of the soil and factors of an abiotic nature. It was found that the activity of invertase and urease in the soils of more southern territories is higher than that of northern ones. In soils with a pH value of the soil environment close to neutral reaction, the level of enzymatic activity is higher than in more acidic ones. The most sensitive to soil acidity among the studied urease enzymes. In relation to zinc, an inverse correlation was established between its content in the soil and the level of invertase activity. According to the degree of resistance to salinity, the enzymes are arranged in the following order: catalase> invertase> urease. An increase in the mineralization of the soil solution leads to an increase in the activity of urease. Of the studied enzymes, the most labile are representatives of the class of hydrolases (invertase and urease), less labile are oxidoreductases (catalase). Thus, when diagnosing the state of the soil by the level of enzymatic activity, it is necessary to take into account the main abiotic factors affecting the activity of enzymes: the average annual air temperature; pH and mineralization of the soil solution; the content of substances that inhibit microorganisms and block exozymes.

Advances in understanding plant root responses to root-feeding insects

2021 ◽  
pp. 231-266
Author(s):  
Scott N. Johnson ◽  
◽  
Ximena Cibils-Stewart ◽  
◽  
Keyword(s):  
Plant Root ◽  
Plant Roots ◽  
Insect Herbivores ◽  
Soil Environment ◽  
Knowledge Gaps ◽  
Root Herbivores ◽  
Mutualistic Fungi ◽  
Root Responses ◽  
Insect Attack ◽  
Root Feeding

This chapter presents an overview of the interactions between plant roots and root-feeding insect herbivores, focussing on changes in growth and physiology and crucially how roots are defended against insect attack. Several reviews have covered the ecology and management of insect root herbivores, together with their interactions with the abiotic and biotic soil environment. Therefore, the chapter focuses particularly on advances in our understanding of how plant mutualistic fungi may affect root-herbivores. This is an emerging area of research, with many attendant knowledge gaps, but we argue that this is an important component of how plants resist attack by belowground insect herbivores.

Solute Transport in the Soil near Root Surfaces

2000 ◽  
Author(s):  
Peter B. Tinker ◽  
Peter Nye
Keyword(s):  
Soil Solution ◽  
Dynamic Equilibrium ◽  
Pore Solution ◽  
Plant Root ◽  
Unit Length ◽  
Solution Concentration ◽  
Root Surface ◽  
Transport Processes ◽  
Soil Pores ◽  
Intact Root

We discussed in chapter 4 the movement of solute between small volumes of soil, and in chapter 5 some properties of plant roots and associated hairs, particularly the relation between the rate of uptake at the root surface and the concentration of solute in the ambient solution. In the chapters to follow, we consider the plant root in contact with the soil, and deal with their association in increasingly complex situations; first, when the root acts merely as a sink and, second, when it modifies its relations with the surrounding soil by changing its pH, excreting ions, stimulating microorganisms, or developing mycorrhizas. In this chapter, we take the simplest situation that can be studied in detail, namely, a single intact root alone in a volume of soil so large that it can be considered infinite. The essential transport processes occurring near the root surface are illustrated in figure 6.1. We have examined in chapter 3 the rapid dynamic equilibrium between solutes in the soil pore solution and those sorbed on the immediately adjacent solid surfaces. These sorbed solutes tend to buffer the soil solution against changes in concentration induced by root uptake. At the root surface, solutes are absorbed at a rate related to their concentration in the soil solution at the boundary (section 5.3.2); and the root demand coefficient, αa, is defined by the equation . . . I = 2παaCLa (6.1) . . . where I = inflow (rate of uptake per unit length), a = root radius, CLa = concentration in solution at the root surface. To calculate the inflow, we have to know CLa, and the main topic of this chapter is the relation between CLa, and the soil pore solution concentration CL. The root also absorbs water at its surface due to transpiration (chapter 2) so that the soil solution flows through the soil pores, thus carrying solutes to the root surface by mass flow (convection). Barber et al. (1962) calculated whether the nutrients in maize could be acquired solely by this process, by multiplying the composition of the soil solution by the amount of water the maize had transpired.

Biodegradation Rate of Chloroethylene in Soil Environment

1992 ◽  
Vol 25 (11) ◽  
pp. 419-424 ◽  
Author(s):  
O. Yagi ◽  
H. Uchiyama ◽  
K. Iwasaki
Keyword(s):  
Soil Solution ◽  
Substrate Concentration ◽  
Material Balance ◽  
Field Soil ◽  
Soil Environment ◽  
Biodegradation Rate ◽  
Vegetable Field ◽  
Degradation Rates ◽  
Field Soils ◽  
Degradation Time

Degradation rates of PCE and TCE were determined in lotus, rice and vegetable field soils. The lotus field soil had the highest ability to degrade tetrachloroethylene(PCE) and trichloroethylene(TCE). The values of T50(50% degradation time) in L-1 lotus soil were 8 and 15 days for PCE and TCE under the substrate concentration of 5 µg in 50ml of soil solution. PCE was biologically transformed to TCE in all soils. The material balance of PCE depletion and TCE production were determined. The degradation rates of PCE and TCE were significantly influenced by temperature and substrate concentration.

Increased Carrier Volume Improves Preemergence Control of Rigid Ryegrass (Lolium rigidum) in Zero-Tillage Seeding Systems

2013 ◽  
Vol 27 (4) ◽  
pp. 649-655 ◽  
Author(s):  
Catherine P. D. Borger ◽  
Glen P. Riethmuller ◽  
Michael Ashworth ◽  
David Minkey ◽  
Abul Hashem ◽  
...  
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Water Soluble ◽  
Zero Tillage ◽  
Tillage System ◽  
Quality Water ◽  
High Carrier ◽  
Rigid Ryegrass ◽  
Carrier Volume ◽  
The Impact

PRE herbicides are less effective in the zero-tillage system because of increased residual crop stubble and reduced soil incorporation. However, since weeds are not physically controlled in the zero-tillage system, reliance on efficacy of PRE herbicides is increased. This research investigated the impact of carrier volume and droplet size on the performance of PRE herbicides (in wheat crops at four sites in 2010) to improve herbicide efficacy in conditions of high stubble biomass in zero-tillage systems. Increasing carrier volume from 30 to 150 L ha−1increased spray coverage on water-sensitive paper from an average of 5 to 32%. Average control of rigid ryegrass by trifluralin (at Cunderdin and Merredin sites) and trifluralin or pyroxasulfone (at Wickepin and Esperance sites) improved from 53 to 78% with increasing carrier volume. Use of ASABE Medium droplet size improved spray coverage compared with ASABE Extremely Coarse droplet size, but did not affect herbicide performance. It is clear that increased carrier volume improves rigid ryegrass weed control for nonwater-soluble (trifluralin) and water-soluble (pyroxasulfone) PRE herbicides. Western Australian growers often use low carrier volumes to reduce time of spray application or because sufficient high-quality water is not available, but the advantages of improved weed control justifies the use of a high carrier volume in areas of high weed density.

INORGANIC SOIL PHOSPHORUS FRACTIONS OF SOME ONTARIO SOILS AS STUDIED USING ISOTOPIC EXCHANGE AND SOLUBILITY CRITERIA

1962 ◽  
Vol 42 (1) ◽  
pp. 150-156 ◽  
Author(s):  
A. F. MacKenzie
Keyword(s):  
Soil Solution ◽  
Isotopic Exchange ◽  
Soil Phosphorus ◽  
Low Ph ◽  
Water Soluble ◽  
Ph Values ◽  
Measurable Amount ◽  
P Fraction ◽  
Solubility Studies ◽  
Inorganic Phosphates

The water soluble and inorganic phosphates associated with aluminum (Al-P), iron (Fe-P) and calcium (Ca-P) were studied in eight Ontario soils. Isotopic exchange studies indicated that in most of the soils the Al-P fraction was in equilibrium with the water soluble phosphorus. Exceptions were thought to be a result of high or low pH values. Solubility studies in 0.01M CaCl2 indicated that the Al-P fraction supplied most of the phosphorus to the soil solution. In one soil the Fe-P fraction may have supplied a measurable amount of phosphorus to the soil solution also.

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