Comparability of anaerobic swine lagoon effluent to commercial fertilizer on soil nutrient dynamics
2002
Adeli, A. | Varco, J.J. | Mostafa, S.M. | Rowe, D.E. | Bala, M.F.
The effects of swine effluent relative to commercial fertilizer on nutrient dynamics in two soils were studied. Swine effluent and commercial fertilizer were applied to established bermudagrass [Cynodon dactylon (L.) Pers.] on a slightly acid Vaiden silty clay (very fine, montmorillonitic, thermic, Aquic Hapludalfs) and to johnsongrass [Sorghum halepense (L.) Pers.] on a slightly alkaline Okolona silty clay (fine, montmorillonitic, thermic, Typic Chromuderts) from 1994 to 1996. Treatments were multiple effluent irrigations resulting in 4 nitrogen (N) rates from 0 to 665 kg N ha -1 yr -1. Treatments were arranged as randomized complete blocks and replicated four times. Commercial fertilizer treatments were applied at equivalent nitrogen-phosphorus-potassium (N-P-K) rates. The extractable soil P, K, calcium (Ca), magnesium (Mg), copper (Cu), and zinc (Zn) at the top 5 cm of soil profile increased with increasing swine effluent application rates. For both soils, the high effluent and medium fertilizer treatments resulted in similar NO3-N concentrations when compared to lower application rates. Excessive soil NO3-N was observed with the high fertilizer treatments with concentrations of 50 mg kg -1 or more for some depths of both soils. No significant differences in extractable soil K and P were observed between swine effluent and commercial fertilizer at the low and medium rates. However, at the high rate, P and K contents were greater for swine effluent than for fertilizer. Swine effluent applied at a rate equivalent to approximately 448 kg N ha -1 y -1 minimized soil residual NO3(-)-N and salt content, and appears to be the optimal rate under the conditions of this study.
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