Phosphorus Sorption Characteristics Of Soils Research Articles

Evaluation of phosphorus sorption characteristics of soils from the Bambouto sequence (West Cameroon)

The evaluation of phosphorus sorption characteristics of soils and their relation to soil properties from the Bambouto sequence of Baranka 1, Baranka 2, Femock 1 and Femock 2 has been studied. Phosphorus, an essential plant nutrient, is often not readily available to plants and this deficiency tends to limit plant growth. It is thus, necessary to investigate the quantity that is readily available to plants in order to avoid excesses and reduce water pollution by fertilizers. The Freundlich, Langmuir, Temkin, Van Huay and Linear adsorption isotherms were used to describe the P adsorption processes. Phosphorus adsorption capacity decreased in the order Femock 2 > Femock 1 > Baranka 2 > Baranka 1 with maximum adsorption values of 3464.21, 3112.17, 2866.00 and 2758.38 mg kg-1 respectively. Accuracy of fitness of data of the four soil series into the adsorption equations increased in the order Langmuir, Linear, Van Huay, Temkin and Freundlich isotherm. The capacity of each soil sample to adsorb phosphorus was significantly correlated with the clay content (r = 0.949*) of the soils. The use of organic materials and liming as a basis for phosphorus sorption reduction will be useful for crop production in the Bambouto sequence.© 2016 International Formulae Group. All rights reserved.Keywords: Phosphorus fixation, volcanic soil, free aluminium, clay, soil pH

Effects of animal effluents on the phosphorus sorption characteristics of soils

Two groups of soils were examined to determine the effects of dairy, pig, or sewage effluent and other materials containing phosphorus (P) on their P sorption characteristics, using the Langmuir equation to estimate values of both sorption capacity and sorption strength. There were 19 soils (0-15 cm) from 6 sites in the Williams River catchment and 3 soils (0-100 cm) from Bermagui, all from coastal New South Wales. Effluent usually decreased P sorption capacities of the Williams River soils, and in 3 soils the capacities were reduced to zero. Sorption strength was reduced substantially by effluent treatment in all soils except one, which had received effluent for only 3 years. Sorption strength, but not necessarily capacity, was also lower after treatment with poultry manure or chicken litter than after treatment with superphosphate only. Where effluent did not decrease sorption capacity there was a substantial increase in total carbon and iron, both of which could increase sorption capacities. After 3 years of effluent treatment of the Bermagui soil, sorption capacities had been reduced in the top 70 cm depth, the extent of the reduction varying from 17% at 0-7 · 5 cm depth to 38% at 40-70 cm depth. Sorption strength was reduced in the top 40 cm depth only. After 12 years of effluent treatment, sorption capacities and strength had also decreased at the deeper sampling depths (to 100 cm), and the average reduction in capacity was about 40%. These results suggest that P leaching will begin well before the total sorption capacity has been saturated. There was a direct and significant correlation between the sorption strength of the untreated soil and the percentage saturation reached before leaching began. Further saturation of the sorption complex appears to be slow after this degree of saturation has been reached, and it seems that P leaching exceeds adsorption during this phase. There was also a negative correlation between sorption strength and KCl-soluble P in all soils, suggesting that soil P solubility and potential saturation are both controlled by this characteristic.

X‐Ray Diffraction Line Profile Analysis Vs. Phosphorus Sorption by 11 Puerto Rican Soils

AbstractThe increase in the areas under goethite (110), gibbsite (002), and hematite (104) x‐ray diffraction lines, due solely to small crystallite effects, was plotted against phosphorus sorption for 11 Puerto Rican soils. This increase is shown to be proportional to the total surface area of each phase measured and is therefore referred to as the surface area index. The data showed a very high correlation (R2 = 0.95 for a straight line and R2 = 0.96 for a second‐order polynomial) between the surface area index of goethite and phosphorus sorption. In comparison, the correlation between the surface area index of gibbsite and phosphorus sorption was poor (perhaps because gibbsite was present in low concentrations relative to goethite) but judged to be significant (R2 = 0.56). The correlation between the surface area index of hematite and phosphorus sorption was not significant (R2 = 0.26) as compared to goethite and gibbsite. The sum of the surface area indices of goethite and gibbsite showed a near‐perfect correlation with phosphorus sorption (R2 = 0.98 for a second‐order polynomial). The study demonstrated that, in the case of goethite and to a lesser extent gibbsite, the mean crystallite size is more important than the abundances of the phases for explaining observed phosphorus sorption characteristics of soils.