Soils properties affecting

The order of the mobilities of alachlor, butylate, and metolachlor in columns of various soils was metolachlor > alachlor > butylate. This correlates directly with the water solubilities and inversely to the adsorption coefficients and octanol/water partition coefficients of these compounds. Diffusion of these compounds in soil thin-layers was as follows butylate > alachlor > metolachlor, which correlates directly with the vapor pressures of these compounds. Significant soil properties affecting diffusion appeared to be bulk density and temperature. Soil moisture is also probably important, but its effect on the diffusion of these compounds was not determined. 

Information on how soil properties affect the photolysis is lacking. Also, the depth dependence of photolysis is not well understood. 

HARADA T. and TAMAI M. 1968. Factors affecting behaviour of boron in soil 1. Some soil properties affecting boron adsorption of soil. Soil Science and Plant Nutrition, 14, 215-224. 

The soil properties, affecting the pore-water movement in the partially saturated domain, are estimated from the pore-size measurement through the network model. The model can estimate the soil-water retention as well as hydraulic conductivity. No mathematical model exists that can compute both properties. In addition, no model exists indicating the hysteresis between wetting and drying. The network model also predicts the hysteresis in the water retention. 

Many factors affect the mechanisms and kinetics of sorption and transport processes. For instance, differences in the chemical stmcture and properties, ie, ionizahility, solubiUty in water, vapor pressure, and polarity, between pesticides affect their behavior in the environment through effects on sorption and transport processes. Differences in soil properties, ie, pH and percentage of organic carbon and clay contents, and soil conditions, ie, moisture content and landscape position climatic conditions, ie, temperature, precipitation, and radiation and cultural practices, ie, crop and tillage, can all modify the behavior of the pesticide in soils. Persistence of a pesticide in soil is a consequence of a complex interaction of processes. Because the persistence of a pesticide can govern its availabiUty and efficacy for pest control, as weU as its potential for adverse environmental impacts, knowledge of the basic processes is necessary if the benefits of the pesticide ate to be maximized. 

GCSAA - GCM July 2000 - Soil amendments affect turf... five days (9). To improve water-holding properties, another team recommended the use of diatomaceous earth as an amendment to sand (8). However, another report.., http //WWW. gcsaa. org/gcm/2000/july00/07soil. html... 

L. Badalucco, F. De Cesare, S. Grego, L. Landi, and P. Nannipieri, Do soil physical properties affect the chloroform efficiency in lysing microbial biomass Soil Biol. Biochem. 29 1135 (1997). 

In Table II, we use DBCP to illustrate how soil properties and conditions can affect diffusion half-lives. Increasing the... 

The objective of this chapter is to discuss how the soil production rate of GHG is affected by treatment type, soil properties, and cultivar. This review will also discuss which processes are involved in the production of CO2, N20, and CH4 when crops are grown under in vitro or greenhouse conditions, and will discuss how these processes work. 

In this study, the main aim was to investigate how maize fertilized with wastewater at 120 kg N ha-1 affected crop growth, soil properties and the production of carbon dioxide (C02), methane (CH4) and nitrous oxide (N20) compared with plants fertilized with urea [16]. 

The fate of trace organic compounds applied to soil is controlled by several processes volatilization, degradation, sorption, leaching and bioaccumulation. The significance of each process is affected by the physicochemical properties of the organic compound, sludge and soil properties, and environmental conditions. 

Because of rice s origins as a wetland plant, it is more sensitive to water deficiency than most other crops. But provided sufficient water is supplied to periodically inundate the land and the soil is able to retain the water, rice will thrive on almost any type of soil. The productivity of rice land therefore often depends more on position in the landscape and soil physical properties than on the finer attributes of the soil. Nonetheless, subtle differences in properties distinguish productive and problem soils and affect the behaviour of the soil in the environment. 

Fig. 8.31 Adsorption isotherms of terbuthylazine and atrazine at different depths along the soil profile, as affected by the vertical variability of soil properties. (Dror et al. 1999)...

Despite the differences in soil properties, /7-nitrophenol was recovered in all the soils studied, together with water-soluble diethyl-thiphosphate. This result proves that hydrolysis is the main degradation path, independent of the nature of the soil. However, both the type of clay and the presence of organic matter affect the amount of degraded parathion. This behavior is illustrated in Fig. 16.16. 

The conversion of parathion is affected by soil constituents in the order kaolinite > smectite > organic matter and is related inversely to the adsorption affinity of these materials for this contaminant (Mingelgrin and Saltzman 1977). Although the extent of hydrolysis differs among soils, it is apparent that soil-surface degradation of parathion is caused by hydrolysis of the phosphate ester bond. The presence of water in the soil-parathion system led to a decrease in the surface-induced degradation of the organic molecule and diminished the effect of natural soil properties on its persistence. 

An assessment of the rates and duration of phenolic acid production from a residue is an important first step. Laboratory and field studies for assessing the dynamics of phenolic acid production must include considerations of the nature of the residue, soil properties, nutrient status of the system, microbial biomass interrelationships, temperature, moisture, residue placement in or on the soil, and other factors that relate to the field. Soil properties in the field are especially important when organic residues are incorporated. When soils are wet, such as those with more than -0.02 MPa water potential, oxygen diffusion is impeded and anaerobic conditions prevail, especially in soils that are high in clay content. Under these circumstances, microbial byproducts change dramatically and one result, for example, is an increase in the production of phenolic acids. Phenolic acid production is also affected by temperature (22) and soil fertility status (23). While the C H ratio of an organic residue may influence the rate of its decomposition and, hence, the rate of phenolic acid production, the... 

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