Phosphorus Extractability of Soils Amended with Stockpiled and Composted Cattle Manure

Abstract

Managing fertilizer applications to maintain soil P below environmentally unacceptable levels should consider the contribution of manure and synthetic fertilizer sources to soluble and extractable forms of P. Our objective was to evaluate soil and manure characteristics and application rates on P extractability in recently amended soils. Five soils of the U.S. southern High Plains were amended with beef cattle manures, composted beef manure, and inorganic fertilizers [Ca(H(2)PO(4))(2) or KH(2)PO(4)] at five rates and incubated under controlled conditions. Mehlich 3-, Olsen (NaHCO(3))-, Texas A&M extractant (TAM)-, and water-extractable P were determined for the soils after selected incubation periods. Except for TAM and some water extractions, P extractability as a function of total P applied was linear (P < 0.001) for a wide range of application rates. Mehlich-3, NaHCO(3), and water P extraction efficiencies of KH(2)PO(4)-amended soils averaged 22, 34, and 115% greater (P < or = 0.036), respectively, than efficiencies of soils amended with manures except for the Texline (calcareous) loam and Pullman clay loam soils. Phosphorus extraction efficiencies decreased with time for KH(2)PO(4)-amended soils (P < 0.05) but remained stable or increased for manure-amended soils during the 8-wk incubation period. Across all soils and manure sources, changes in water-extractable P per unit increase in Mehlich 3-, NaHCO(3)-, and TAM-extractable P averaged 100, 85, and 125% greater, respectively, for inorganic as compared with manure-amended soils. These source-dependent relationships limit the use of agronomic soil extractants to make correct inferences about water-extractable P and dissolved P in runoff.

Changes in Soil Properties and Enzymatic Activities Following Manure Applications to a Rangeland

“…Increases in extractable P (0-200 mm) as a fraction of the total P applied for 2 seasons were similar for manure (24.4%) and inorganic fertilizer (24.8%). Schwartz and Dao (2005) also found that Mehlich 3-P extractabilities in a Paleustoll amended with scraped cattle manure were similar to KH 2 PO 4 -amended soil applied at the same rate when incubated for 8 weeks under controlled wettingdrying conditions. However, the percentages of extractable P as a proportion of total P applied reported by Schwartz and Dao (2005) were considerably greater (68% and 79% for manure and KH 2 PO 4 , respectively) than in this study, even considering an estimated forage uptake of 0.5 kg P ha À1 yr…”

X-ray fluorescence spectrometry-based approach to precision management of bioavailable phosphorus in soil environments

“…A number of extraction procedures have been developed and calibrated to estimate this supplying capacity; they include generalized soil testing methods such as Mehlich 3, Olsen, Morgan, or Bray 1 methods (Kuo 1996;Schwartz and Dao 2005). Multi-element extraction solutions such as the Mehlich 3 extractant have been developed to obtain as much information on nutrient composition and availability in a single extract as possible.…”

Soil Test Phosphorus Recovery from Livestock Manures Compared with Inorganic Fertilizer in Soil Incubations

“…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].…”

“…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].…”