Iron-impregnated filter paper (Fe-Pi) was evaluated as phosphorus (P) extractant in four soils of Ogun state, southwest Nigeria in a screenhouse experiment. The experiments lasted for 8 weeks. Soil P contents were extracted at 0, 4, and 8... more
Iron-impregnated filter paper (Fe-Pi) was evaluated as phosphorus (P) extractant in four soils of Ogun state, southwest Nigeria in a screenhouse experiment. The experiments lasted for 8 weeks. Soil P contents were extracted at 0, 4, and 8 weeks after the incorporation of amendments (cattle manure, poultry manure, and wood ash) using Fe-Pi, Bray-1, Bray-2, Mehlich-1, Hunter, and Olsen extractant. Agronomic variables were taken fortnightly from grown maize plants and later harvested at 8 weeks, residual effects of the treatments were also evaluated. Maize dry matter weight (DMW) and P uptake were also measured. Results indicated that a linear relationship existed among the extractants with significant coefficient at p ≤ .001. Fe-Pi established a strong relationship with the conventional extractants in the following order: Bray-1 (R 2 = 0.99) > Bray-2 (R 2 = 0.98) > Hunter (R 2 = 0.96) > Mehlich-1 (R 2 = 0.86) > Olsen (R 2 = 0.82). Fe-Pi had a significant relationship with P uptake and DMW. Phosphorus uptakes under the animal manure amendments were statistically higher than uptake in control and woodash amended soils. Therefore, the study concluded that Fe-Pi was a good predictor of plant available P and had significant relationship with Bray-1, thus it could be considered for the estimation of soil available P in soils of southwest Nigeria.
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The use of phosphorus saturation ratio (PSR) as the index for soil pollution potential in some animal waste dump sites of southwest Nigeria was evaluated. Surface and sub-surface soil samples were taken from 20 animal waste dump sites.... more
The use of phosphorus saturation ratio (PSR) as the index for soil pollution potential in some animal waste dump sites of
southwest Nigeria was evaluated. Surface and sub-surface soil samples were taken from 20 animal waste dump sites. Soil
chemical properties, phosphorus availability indices and PSR were determined and analyzed. Results indicated that the
unregulated dumping of manures in soils resulted in high phosphorus availability with a higher concentration in the top
20 cm of the soils. The PSR of the soils (0.42, topsoil and 0.32, subsoil) are more than the threshold values of 0.10-0.15,
indicating soil P pollution of the environment. Some P availability indices could be used as a proxy for estimating soil PSR
and hence soil P pollution potential. The soil P load is more than the amount that could be sorbed by the soil clay but has
a strong correlation with soil organic matter. It was concluded that there is potential pollution of surface and groundwater
in the vicinities of the dumpsites with possible attendant health hazards. Hence, the need to exploit alternative soluble P
management options like precipitating the soluble P in the manure by applying materials rich in Al, Fe and Ca.
southwest Nigeria was evaluated. Surface and sub-surface soil samples were taken from 20 animal waste dump sites. Soil
chemical properties, phosphorus availability indices and PSR were determined and analyzed. Results indicated that the
unregulated dumping of manures in soils resulted in high phosphorus availability with a higher concentration in the top
20 cm of the soils. The PSR of the soils (0.42, topsoil and 0.32, subsoil) are more than the threshold values of 0.10-0.15,
indicating soil P pollution of the environment. Some P availability indices could be used as a proxy for estimating soil PSR
and hence soil P pollution potential. The soil P load is more than the amount that could be sorbed by the soil clay but has
a strong correlation with soil organic matter. It was concluded that there is potential pollution of surface and groundwater
in the vicinities of the dumpsites with possible attendant health hazards. Hence, the need to exploit alternative soluble P
management options like precipitating the soluble P in the manure by applying materials rich in Al, Fe and Ca.