Dairy manure influences on phosphorus retention capacity of spodosols

• Published in: Journal of environmental quality 1998-05, Vol.27 (3), p.522-527
• Main Authors: Nair, V.D. (Univ. of Florida, Gainesville, FL.), Graetz, D.A, Reddy, K.R
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; DAIRY INDUSTRY; DECHET; DESECHOS; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; FOSFORO; Fundamental and applied biological sciences. Psychology; INDUSTRIA LECHERA; INDUSTRIE LAITIERE; PHOSPHORE; PHOSPHORUS; Pollution; Pollution, environment geology; Retention capacity; Soil and sediments pollution; Soil and water pollution; Soil science; SORCION; SORPTION; SPODOSOL; SPODOSOLES; SPODOSOLS; WASTES
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq1998.00472425002700030007x

Land areas used for dairy farming can result in accumulation of manure on soils that could produce nutrient-rich surface and subsurface runoff and cause accelerated lake eutrophication. This research was conducted on Spodosols that were differentially impacted by manure; the study included sites with different levels of total P (TP), from 2300 mg kg-1 in the soil highly impacted by intensive dairy farming to 18 mg kg-1 in an unimpacted area. The P retention characterictics of these soils were determined by using both single-point (1000 mg P kg-1 or 100 mg P L-1) and traditional Langmuir isotherms. Phosphorus sorption values using a single high P solution had approximately a 1:1 relationship with values obtained for the maximum retention capacity, S(max), obtained from Langmuir isotherms (r2 = 0.98). The surface A and E horizons of manure-impacted soils had essentially no sorbing capacity while the Bh (spodic) and Bw horizons had mean S(max) values 430 and 385 mg kg-1, respectively. The P sorbing capacity of the Bh and Bw horizons were attributed to high Al concentrations in these horizons. Higher P concentrations in the surface A horizon resulted in greater P concentrations in solutions equilibrated with the Bh- and Bw- horizon materials, which suggests a potential for vertical P movement through the soil profile. The spodic horizon of the less-impacted soils may not have been exposed to sufficiently high solution P concentrations to accumulate significant P in the soluble fraction