Phosphorus Availability in a Calcareous Soil After High Loading Rates of Animal Manure

Abstract

The fixing of phosphorus (P) added to calcareous soils is rapid but can be reduced by applying organic sources. The objectives of this study were to measure in the field the residual NaHCO3‐extractable P resulting from manure applications at high rates and to contrast the NaHCO3‐extractable P levels for manure vs. inorganic P fertilizers.When inorganic P was applied at 490 kg/ha for each of 2 years the NaHCO3‐extractable P was increased from 16 to 31 ppm at the 0‐ to 30‐cm depth. The application of 98 kg/ha of P as triple superphosphate each of 2 years applied just before planting lettuce (September‐October) was as effective for increasing NaHCO3‐extractable P during the lettuce‐growing season (November 1976) as applying 490 kg/ha of P in May or June each of 2 years.High rates of P (5,344 kg/ha) applied from manure sources (treatment 720E) resulted in high levels of NaHCO3‐extractable P up to 377 ppm. Total application of more than 360 metric tons/ha of manure (2,672 kg P/ha) resulted in movement of P to the 30‐ to 60‐cm depth. The increased level of NaHCO3‐extractable P from a manure application (treatment 360B) was still evident in the 0‐ to 30‐cm depth 6 years after manure application had ceased.The application of 392 kg P/ha as triple superphosphate for each of 2 years increased the NaHCO3‐extractable P over the check by 11 ppm (November 1976). In contrast, the application of 334 kg P/ha from applied manure (treatment 180B) each of 2 years increased the NaHCO3‐extractable P over the check (after harvest in 1972) by 100 ppm.

Effect of Organic and Inorganic Amendments on the Phytoavailability of Phosphorus to Corn (<i>Zea mays</i>)

“…McCoy et al [8] found that biosolids (treated City wastes) P was four to seven times less available than triple super phosphate P. In contrast, other studies have suggested that P in organic amendments may be equally or more available than fertilizer P [9,10]. Therefore, this study was conducted to investigate the effects of cow manure, city wastes, chicken manure and TSP on the growth of corn and phytoavailability of phosphorus in soils.…”

Phosphorus fractions in soil amended with organic and inorganic phosphorus sources

“…McCoy et al (1986) reported that biosolids P was four to seven times less available to plants compared to triple super phosphate. On the other hand, Tunney and Pommel (1987) reported that P in pig slurry was at least 90% as effective as fertilizer P because pig slurry contains 70 to 90% inorganic P. Other studies have suggested that manure P may be equally or more available than fertilizer P (Gale et al 2000;Meek et al 1979). A measure of the forms of P in soil amended with biosolids and manures, and how these forms change with time, can provide important information on how these amendments affect soil test P and plant available P.…”

Organic Phosphorus Source Effects on Calcareous Soil Phosphorus and Organic Carbon

“…Consequently, different measurement procedures and limits are required to define solubility, mobility, and plant availability of P (Olsen et al, 1954). Inorganic P fixation in calcareous soils is relatively rapid whereas the rate and extent of fixation may be much slower or less extensive when P is added with organic matter or in an organic form (Meek et al, 1979).…”

“…Utah calcareous soils that had received turkey and beef manures for two to four decades showed increased bicarbonate extractable ortho-and total-P (STP and STPt) concentrations to a depth of 2.1 m in most cases (James et al, 1996). A calcareous California soil that received 1336 kg P ha" with applied feedlot manure still contained 53 mg STP kg' in the surface 0.30 m after 6 yr (Meek et al, 1979). Higher manure rates increased surface soil STP concentrations to 237 mg kg-1 .…”