An understanding of soil nutrient pools and their relationship to soil properties and to soil test values should underpin soil tests, but few studies of this type have been conducted for soil B. Boron was fractionated by sequential extraction in 13 soils collected from north (47°N) to south (20°N) in eastern China. The nonspecifically adsorbed B (NSA-B) and specifically adsorbed B (SPA-B) comprised＜1% of total B. By contrast, B occluded in Mn oxyhydroxide (MOH-B), in amorphous Fe and Al oxides (AMO-B) and in crystalline Fe and Al oxides (CRO-B) comprised from 0.01 to 7.6% of total B. The content of the NSA-B fraction significantly decreased with increasing mean annual rainfall of the site and increased with increasing soil pH and exchangeable Ca. The MOH-B fraction was positively correlated with soil pH and cation-exchange capacity (CEC), and negatively with rainfall and temperature. The AMO-B fraction was significantly related to amorphous Fe2O3 and rainfall. The CRO-B fraction was positively correlated with pH and exchangeable Ca, but not with crystalline Fe2O3. The SPA-B fraction was not correlated with any soil properties or climate factors. These results emphasize that the forms of B in Chinese soils were distinctly different from those in soils of southeast USA and Greece.

A laboratory incubation study was conducted to evaluate the effect of bensulfuron-methyl treatment on soil microbial biomass and N-mineralization of a loamy sand soil. The herbicide was applied at 0 (control), 0.01 (field rate), 0.1, and 1.0μg g-1, and soil microbial biomass carbon (Cmb), soil microbial biomass nitrogen (Nmb), and N-mineralization rate (k) were measured at different times after herbicide treatment. Compared to the untreated soil, Cmb and Nmb decreased significantly (p≤0.05) within the first 7 days after herbicide treatment at 0.1 and 1.0μg g-1, and the impact was greater for Nmb than for Cmb. Nitrogen mineralization was significantly suppressed during the first 5 days of incubation when the soil was treated with bensulfuron-methyl at 0.1 and 1.0μg g-1. The overall impact of bensulfuron-methyl to the soil microbial communities was closely related to the application rate in the range of 0.01-1.0μg g-1. This effect, however, was found to be transitory, and significant impact occurred only at high application rates.

Co-electroosmotic capillary zone electrophoresis (CZE) with direct UV detection was developed for simultaneous determination of inorganic anions, carboxylic and aromatic carboxylic acids. These solutes were separated using a 30mM phosphate buffer containing 1.0mM tetradecyltrimethylammonium bromide (TTAB) and 20% (v/v) acetonitrile at pH of 6.5 and directly detected by UV at 190nm. Calibration curves were linear in the range 0.01-2.0mM, depending of the solutes. The detection limits ranged from 1.0 to 8.0μM and the relative standards deviations (n=5) in range from 1.9 to 3.6% for the peak area. The proposed method was used to determine inorganic anions and carboxylic and aromatic acids in soil and plant tissue extracts.

Characteristics of fluoride emission from 12 soils at temperatures of 400-1100℃ related to the brick-making process were studied. The results obtained in this study indicate that fluoride emission as gaseous HF and SiF4 was related to the firing temperature, soil total fluoride content, soil composition and calcium compounds added to soils. Soils began to release fluoride at temperatures between 500 and 700℃. Marked increases of the average fluoride mission rate from 57.2% to 85.4% of soil total fluoride were noticed as the heating temperature was increased from 700 to 1100℃. It was found that the major proportion (over 50%) of the soil total fluoride was emitted from soils at approximate 800℃. The amount of fluoride released into the atmosphere when heated depended on the total fluoride contents in the soils. Correlation analysis showed that the soil composition, such as cation exchange capacity, exchangeable calcium and CaCO3, had some influence on fluoride emission below 900℃, but had no influence at temperatures above 900℃. Addition of four calcium compounds (CaO, CaCO3, Ca(OH)2, and CaSO4) at 1.5% by weight raised the temperature at which fluoride began to be released to 700℃. The greatest decrease in fluoride emission among the four calcium compound treatments was found with CaCO3.