Land Requirement for Manure from Hogs Fed Phytase-Amended Rations

Project: MLMMI 04-01-01

Objective

To determine if the longevity of a parcel of land utilized for manure spreading will be reduced or enhanced with the use of phytase in hog rations. More specifically:

  1. To determine the concentration and forms of phosphorus in swine manure from a phytase and non-phytase barns;
  2. To measure soil test P following the addition of manure from phytase and non-pyhtase barns; and
  3. To determine whether or not the longevity of a parcel of land utilized for manure spreading will be reduced or enhanced with the use of phytase in hog rations.

KEYWORDS: manure, phytase, land requirements, P concentrations, P forms in manure, soil P levels

Performer

L. Slevinsky,
Larry Slevinsky Consulting

Details

Status: Completed
Started: 2004-05-01
Completed: 2006-06-01

Funding Partners: who have contributed to MLMMI in support of this project:
MRAC - $34,860
Manitoba Pork Council and industry groups - $34,860

Amount Funded: $69,720.00
Performer Funded: $0.00
Total Cost: $69,720.00

Activity

First Progress Report received on October 29, 2004.
Second Progress Report due May 1, 2005.
Second Progress Report received on May 3, 2005.
Third Progress Report received on October 24, 2005.
Final Report due on May 1, 2006.
Final report received June 1, 2006.

Summary

The application of manure based on crop N requirements will lead to the accumulation of phosphorus in the soil. High soil phosphorus content increases the risk of soil loss to surface water. To address the problem of phosphorus accumulation in the soil, hog producers use phytase supplement in swine diet. While this has been shown to reduce the phosphorus content of manure, its impact on soil test P level and land requirement for manure application are unknown. Therefore the objectives of this study were: (1) To determine the concentration and forms of phosphorus in swine manure from a phytase and non-phytase barns; (2) to measure soil test P following the addition of manure from phytase and non-pyhtase barns; and (3) to determine whether or not the longevity of a parcel of land utilized for manure spreading will be reduced or enhanced with the use of phytase in hog rations.

To achieve these objectives we carried out a field study in 2004 and 2005 on a farmer cooperator's field on which the dominant soil types were the imperfectly drained Red River clay and the poorly drained Osborne Clay. Six experimental treatments were imposed on a strip of land with a total area of 91 by 122 m. The six treatments were: manure from the large cell of a phytase barn; manure from the small cell of a phytase barn; manure from the large cell of a non-phytase barn and manure from the small cell of a non-phytase barn; and two controls. These plots were seeded to barley in 2004 and canola in 2005. During manure application, samples of manure were taken for total P measurement and a detailed analysis of forms of P in the manure. In the spring and fall of each year, soil samples were taken from 20 random positions of each strip of land and were analyzed for various extractable phosphorus.

Our results show that the use of phytase resulted in a significantly smaller manure phosphorus compared to the barns that do not use phytase. On average, the phosphorus content of manure from the phytase barn was one-half of that from the non-phytase barn. Manures from the large cells had smaller phosphorus concentrations and higher N:P ratios compared to that from the small cells. The results from the two years of study confirmed that, not only is the P concentration of manure from barns that do not use phytase greater than those that use phytase, the manure from non-phytase barns are also more water soluble particularly those from the large cells of these barns. All manures had considerable amount of labile phosphorus, however, the highest was found in manure from the large cell of the non-phytase barn (88%) and the value of the labile P from the other manures was about 60%.

The soil test P was significantly greater for soil that received manure from the small cells compared to those that received manure from the large cells. Also, plots that received manure from the phytase barn had smaller soil test P compared to plots that received manure from non-phytase barn. The rate of increase in soil test P was similar among various manures. While soil test P increased by about 0.2 lb/acre for every lb/acre of added manure according to Mehlich-3 P, the corresponding value for Olsen was 0.1 lb/acre while the rate of increase in water P was 0.03 lb/acre for every lb/acre of manure P. Based on this, and using the P concentration in the manure we estimated that twice the amount of land will be needed for manure from a non-phytase barn compared to a phytase barn. Stated differently, if the same size of land were used to apply the manure from the phytase barn and the non-phytase barn, the land that received manure from the phytase barn will have twice the longevity of the land that is applied with manure from the non phytase barn.

This study, thus, show the importance of management practices, such as the use of large cell and small cell to separate manure and the use of phytase to reduce the phosphorus level of manure, in reducing soil test P values with an increase in the longevity of land receiving this manure and reduced risk of P loss from the soil to surface water.

Documents

Final Report

Manitoba Pork represents 613 Manitoba hog farms