%0 Journal Article
%T Soil Test Phosphorus Recovery from Livestock Manures Compared with Inorganic Fertilizer in Soil Incubations
%A J. Craig Miller
%A T. Astatkie
%A Ali Madani
%J Applied and Environmental Soil Science
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/425613
%X This paper compared dairy and hen manure P recovery relative to fertilizer P recovery for two Nova Scotia soils with different antecedent soil test P (STP), incubated for 5, 15, 30, 60, and 110 days. Fertilizer equivalence of manure P was expressed as P recovery ratio in percentage points (%PRR). Repeated measures analysis with soil pH covariate revealed: (1) manure %PRR averaged 72% (low-STP soil) and 80% (medium-STP soil), (2) there were no significant differences in %PRR between dairy and hen manure, and (3) manure %PRR decreased with incubation time for the low-STP soil but not for the medium-STP soil. The soil pH covariate was significant for both low- and medium-STP soils, and the relationship with %PRR was positive for low- but not for the medium-STP soil. 1. Introduction The traditional approach of basing manure applications on N content leads to the buildup of soil P to levels that pose a pollution hazard. As a result, many jurisdictions have adopted P-based nutrient management planning regulations for intensive livestock operations. P-based nutrient management seeks to match P application to crop P requirements as indicated by soil testing. However, soil test P recommendations are based on crop response to inorganic fertilizer P and there is lack of agreement on the equivalence between manure P and fertilizer P. While some studies have found that livestock manures were equivalent to inorganic fertilizer in P availability [1¨C4], others [5¨C8] have reported results that indicate that manure P was generally less available than inorganic fertilizer P. Laboski and Lamb [9] found that availability of soil P from injected swine manure was greater than that from fertilizer P for incubation periods of 1 to 9 months, with the difference between the two P sources increasing over time. Some of the differences in results may be attributed to experimental conditions. Goss and Stewart [10] found that plants grown in superphosphate-amended soil removed a higher percentage of added P than in manure-amended soil, partly because of luxury consumption. On the other hand, Sikora and Enkiri [11] found no significant overall differences between poultry litter compost and triple superphosphate fertilizer in plant cumulative P uptake; however, the soil used was already high to excessive in STP. The choice of fertilizer used for comparison can have an effect on the estimated fertilizer equivalence of manure P [12, 13]. Reagents used for soil extraction also differ in the amounts and forms of P they recover [12, 14]. Environmental conditions also play a role. For
%U http://www.hindawi.com/journals/aess/2010/425613/