Soil, environmental impacts organic matter

Although there is good correlation of the ELISA results with both the standard GLC methods and with the bioassay results conducted under controlled conditions, unpublished results with clomazone indicate that the correlation of any soil analytical results (ELISA or GLC) with actual crop injury that is observed in the field is poor. This poor correlation between observed soil levels of clomazone, and the actual occurance of carryover injury in the field, indicates that factors unrelated to the soil analytical methods used, have a large impact on the ability to use soil residual levels as a predictive tool for this herbicide. An example of the impact of other factors can be seen with corn, where unpublished results attribute the poor correlation between detected soil levels of clomazone and observed injury in the field to several factors, which include differences in corn sensitivity toward clomazone, the method of clomazone application, application rate, soil type/organic matter levels, soil pH, soil sampling methods, time of corn injury assessment, interactions with other pesticides and environmental factors. 

Another relevant general review summarizes the knowledge on the behavior of series radionuclides in soils and plants and is intended to provide a comprehensive source of information for environmental impact studies (Mitchell et al. 2013). The summary of the data on plant to soil concentration ratios that depends on the specific soil and type of plant and the distribution of uranium within the parts of the plant is especially important. The dependence of the sorption of dissolved uranium compounds on the type of soil (like the clay content) and the parameters mentioned earlier (pH, complex forming agents, anions, presence of iron, organic matter, etc.), based mainly on studies of the (distribution factor) of spiked soil samples, is discussed. It is noted that in general the uranium concentration in plants is several orders of magnitude lower than in soil, but some plants may efficiently absorb uranium and translocation within the plant is quite common (Mitchell et al. 2013). These features, and especially the soil-to-plant transfer factors, will be discussed in Section 3.4 that deals with the uranium content in plants and soil and the relation between them. 

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