EXTRACTABLE PHOSPHORUS FOLLOWING SOIL AMENDMENT WITH MANURE FROM SWINE FED LOW-PHYTATE CORN
作者:
H. Gollany,
M. Schmitt,
P. Bloom,
G. Randall,
P. Carter,
期刊:
Soil Science
(OVID Available online 2003)
卷期:
Volume 168,
issue 9
页码: 606-616
ISSN:0038-075X
年代: 2003
出版商: OVID
关键词: Low-Phytate corn;swine manure;phosphorus availability index;total P;P mineralization
数据来源: OVID
摘要:
Manure application rate recommendations have been based almost exclusively on nitrogen (N) management considerations, which can result in over-application of phosphorus (P) and its accumulation in soil. Low-phytate (LP) corn (Zea maysL.) was introduced into swine (Sus scrofa domesticus) feed to reduce the amount of P in manure. Unlike ruminants, swine cannot utilize phytate, the major form of P in normal hybrid corn. The objectives of this study were to determine extractable P following swine manure application from different manure sources and compare the relative P availability of LP-manure to standard (S) manure. A laboratory incubation study was conducted using a Waukegan silt loam, a Verndale sandy loam soil, and five levels of total P (Pt) from three P sources (KH2PO4, S-manure, LP-manure). Extractable P from manures of swine fed low-phytate corn and standard corn diets were compared with a soluble P (KH2PO4) source. Slope ratio procedure was used to determine a phosphorus availability index (PAI). The effect of the P application rate on extractable Bray-1 P was linear (r2>0.97). Small but significant P mineralization was observed for the Verndale sandy loam soil. Mineralization of organic P was detected only at the highest LP-manure application rate for the Waukegan silt loam soil. Relative to KH2PO4, the LP-manure and S-manure had PAI of 0.55 and 0.61, respectively. Swine manure P availability was about 60% that of the KH2PO4source for both manure sources. The total P concentration for the LP-manure was 42% lower than that for the S-manure. The important factor in the difference between manure sources is the 42% lower total P content for the LPmanure, not a difference in availability. Further evaluation of available P from LP-manure is needed under field conditions.
点击下载:
PDF
(619KB)
返 回