6C1-C5 : ANNEXE 'C'

Recherche de Shippagan

PROCEEDINGS

SYMPOSIUM '87

Wetlands/Peatlands

Compiles by

C.D.A Rubec and R.P Overend

Edmonton Convention Centre

Edmonton, Alberta, Canada

August 23-27m 1987

173

SPHAGNUM PEAT: A TOOL FOR UQUID HOG MANURE MANAGEMENT

J. Y. Daigle, A. Arseneau and A. Robichaud

Peat Research and Development Centre Inc. Centre universitaire de Shippagan Shippagan, New Brunswick

ABSTRACT

Hog farmers have been plagued with problems in the management of liquid hog manure mainly because of the offensive odors emerging from the lagoons. This paper shows how sphagnum peat moss can be efficiently used to minimize these odors and at the same time. provide an odorless peat-manure mixture with very good agricultural potential.

RÉSUMÉ

Les éleveurs de porcs sont souvent la cible de nombeuses plaintes dues aux odeurs nauséabondes émanant des fosses à purin. La présente communication montre l'efficacité de la tourbe de sphaigne comme outil pour minimiser les mauvaises odeurs, tout en générant un méLange tourbe-purin pouvant servir en agriculture.

INTRODUCTION

In 1977, the hog production was estimated at 50000 in New Brunswick. This year, 90 farmers will bring to maturity more than 150000 hogs. In our immediate area, 5 hog farms generate annually 9 x 10 litres of.liquid hog manure.

In the North-Eastern part of New Brunswick, 12 hog farms are located at short distances from peat extraction sites; these farm operations generate more than 22,5 x 10 litres of manure annually.

We are very much aware of the inconvenience caused by the offensive odors evolving from hog manure lagoons and from manuring operations. Furthermore, one must not forget the potential pollution risks during hamdling operations.

Many compounds are involved in manure smells. Some such as NH3 and H2S are produced in easily detected quantities. Others, such as mercaptans and amines, are present in low concentrations; even at such levels, a number of these compounds can be perceived as offensive by the human nose.

The chemical composition of manures and the availability of nutrients will vary from one farm to another. Even on a given farm, it will vary according to the age of the animals, protein content of feed, intake of water and volume of water used in the flushing process.

Over 50% of the nitrogen in manure is in the ammonical form and amonia, being very volatile, tends to be lost rapidly in the air unless absorbed by some material or chemical reactions. In hog manure lagoons, the 1oss in nitrogen may range from 30 to 60%. When spread on land, it may 1oose another 20 to 30% nitrogen when applied during warm dry days; much less on cool days.

Manure nutrients are potential environment contaminants. The most direct contamination occurs when manure applied on sloping land is ashed directly to a watercourse. Addition of manure to water enhances algal and/or submerged plant growth because of the increase nutrients, creates a demand on the dissolved oxygen as organic matter decomposes and introduces potentially pathogenic bacteria to the water.

Over-application of manure over a long term may also result in nitrate contamination of ground water. Nitrates should be kept from entering groundwater or surface water because of its potential toxicity to animais and humans when consumed in the water supply.

Because of the offensive odors of manure, the farmer is often limited in the availability of agricultural land where he can dispose of large volumes of manure. Reducing the intensity of the odors would bring the cooperation of neighbouring land-owners in the use of manure as soil amendment .

Sphagnum peat moss has large absorption capacities for liquid and gases; it may absorb over 20 times its own weight in liquid and up to 6% its dry weight in gases, this should help to prevent the lost of nitrogen and at the same time retain other odorous compounds.

ln European countries, peat is used extensively as litter in farm operations and for example, more than 500 x 10 tonnes of "peat-manure" material are used annua11y as soil amendment in USSR for vegetable and fodder production.

OBJECTIVES

With large quantities of peat moss and hog manure available locally, the following objectives were identified:

1- To contro1 offensive odors emerging from hog manure lagoons;

2- To compost peat and liquid hog manure;

3- To use this peat-manure compost on agricultural land.

With these objectives in mind, it was hoped to find a solution to the social pressure on the farmer by the community and at the same time, increase the value of hog manure as a soil amendment.

Based on previous experience in the treatement of fish wastes, peat is used to minimize the dad odors evolving from hog manure lagoons and composting this mixture could diminish the pollution risks during the subsequent application to agricultural lands. In Nord-Eastern New Brunswick, there are over 600 ha of farmlands, in great need of organic matter, used for vegeteble production within relatively close distance from hog farms. The need for good quality organic soil amendent in the area is evident.

METHOD

The experimental site was located on a farm which has over 800 hogs. The manure produced is stored in two lagoons approximately 1 000 m and 250 m in size.

The larger lagoon was covered with a 30 cm layer of sphagnum peat (H2-H3) using a p.t.o. powered snow blower; normal flushing activities into this lagoon were carried out during the season. Most of the subsequently added manure would filter through the peat layer.

ln the smaller lagoon, 130 m of peat were

mechanically mixed to approxirmately 300 m of manure. Part of this "peat-manure" slurry was then transported to a remote site 2 km away where it was blended, in different proportions, to more peat for composting experiments.

At first, tub-shaped peat heaps were prepared in oder to receive the peat-manure slurry; they were subsequently mixed with a front end loader. All heaps were 3 m wide at the base, 1,5 m high and of different length. Some had plastic aeration pipes placed within the heaps; all heaps were sheltered from rain by a plastic sheeting.

RESULTS AND DISCUSSION

The first objective was met with both lagoons. Within 24 hours after covering the large lagoon with peat, a significant difference in the intensity of the odors was noticed. The neighbouring population estimated a 70 to 90 % reduction in intensity of ordors.

In two separate occasions, additional manure was flushed into the larger lagoon; in less than 48 hours, the odour level was reduced after the manure had seeped through the layer of peat. A similar effect was noticed around the smaller lagoon where peat and manure had been mixed into a slurry.

Another hog farm located one kilometer down the road from our experimental site was used as a control for odors. A short visit to this second site was very convincing for every sceptical noze. Needless to add, the number of complaints from the neigbouring community had greatly diminished.

The composting process seemed complete after 30 to 45 days and the material was tested for its physical and chemical properties. The resulting material was dark brown in colour and had no manure odor. Table 1 shows the analytical results for peat, peat-manure slurry and composted materials obtained. The total nitrogen content of these composts varied from 0,93 to 1,06'0' % total phosphorus 0,22 to 0,87% and total potassium 0,14 to 0.32' % with a pH in the range of 4,62 -5,94.

Since the hog manure used for these experiments had been in the lagoons for some 6 months. it had already lost a substantial amount of nitrogen which would explain why some composting mixtures did not produce thermophilic activities higher than 50 oC and an slower reaction rate.

Work on this project is well in progress. The same two hog-manure lagoons have received peat treatments for the past 12 months. Quantities of this peat-manure slurry and composted materials have been applied to specific sites where vegetables are grown this season. Preliminary results are positive.

CONCLUSIONS

These results confirm the possibility of reducing considerably the intensity of offensive odors emerging from hog manure lagoons and in the same effort, end up with a good quality organic soil amendment.

ACKNOWLEDGEMENTS

The authors wish to express their gratitude to the Department of Agriculture for their financial support in this research. The excellent cooperation of La Ferme Godin Ltée and specially Mr. Maurice Godin is greatly appreciated.

REFERENCES

Animal Manure Management Committee. Agriculture Canada. 1979. Canada Animal Manure Guide. Commit tee chaired by E.M. Barber. Publication No.1534. Ottawa, Ontario. 37 DD.

Belzile, M. Agricole des l'Agriculture, l'Alimentation, 227 pp.

Chiasson, G.. 1987. Horticultural Crops in North-Eastern New Brunswick. ln: Soils & Crops Improvemenç.Association Conference, Bathurst, N.B.

1984. Manuel de Gestion Fumiers. Ministère de des Pêcheries et de Gouvernement du Québec.

Gelfer, B.Y., Mankinen, G.W., 1985. USSR Experience in the Use of Peat in Agriculture and Horticulture. ln: a Technical and Scientific Conference on Peat and Peatlands, p. 239-263. Proceedings Symposium '85, Rivière-du-Loup, Québec.

Mathur, S.P., Daigle, J.Y., Levesque, M.P. and Dinel, H. 1985. Peat as a Medium for Composting Fish and Crab Wastes. In: A Technical and Scientific Conference O; Peat and Peatlands, p. 279-290. Proceedings Symposium '85, Rivière-du-Loup, Québec.

Meyer, D.j. 1980. Contro11ing Swine Manu Odors Using Artificia1 F1oating Scums. Ph.D. thesis. Univ. of Wisconsin.

Merkel, J.A. 1981. Composting. Managing Livestock Wastes, p. 306-324

Postnikov, A.V. 1980. Experience in Large-sca1e Peat Application as Organic Fertilizer in the USSR. In: 6th International Peat Congress, p. 441-443.

Duluth, Minnesota, USA.

Soniassy, R.N. 1974. Adsorption of Odours by Peat Moss. ln: Canadian Mining & Metallurgical Bulletin 67 (748) p. 95-98.