Environmental Impact of Animal Manure Management

P.J. Brandjes J. de Wit H.G. van der Meer H. Van Keulen International Agriculture Centre Wageningen, The Netherlands January, 1996

Study Sponsors

Commission of the European Union
Denmark
France (Ministère de la Coopération)
Germany (Deutsche Gesellschaft für Technische Zusammenarbeit - GTZ)
Netherlands
United Kingdom (Overseas Development Administration)
United States (Environmental Protection Agency)

Study Coordination by:

Food and Agriculture Organization of the United Nations
United States (U.S. Agency for International Development)
World Bank

Livestock, Environment and Development (LEAD) Initiative

This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

Table of Contents

Preface

Abbreviations

Summary

1 Introduction

2 Manure management and effects of manure on the environment

2.1 Manure management systems
2.2 Emissions before manure application
2.3 Effects on soil quality
2.4 Effects on ground water and surface water quality
2.5 Effects on air quality
2.6 Effects on crops
2.7 Parameters influencing effects of manure on the environment

2.7.1 Climate
2.7.2 Soil
2.7.3 Hydrological conditions

3 Environmental impact of manure

3.1 Balancing nutrient import and export
3.2 Manure production

3.2.1 Manure production per animal
3.2.2 Nutrient excretion per animal
3.2.3 Nutrient distribution between faeces and urine

3.3 Ammonia emission

3.3.1 Adjustment of feeding rations to reduce NH3 emission from manure
3.3.2 Emission from stables and storage
3.3.3 Emission after manure application to land
3.3.4 Emission from grazed pastures
3.3.5 Emission from flooded fields
3.3.6 Threshold value

3.4 Surface water pollution

3.4.1 Direct discharge
3.4.2 Run off
3.4.3 Threshold values

3.5 Nitrate leaching

3.5.1 Nitrification and denitrification
3.5.2 Factors affecting fate of "N not accounted for": leaching or denitrification
3.5.3 Threshold values

3.6 Phosphorus leaching

3.6.1 Phosphorus balance
3.6.2 Phosphorus balance in relation to other environmental problems of manure application
3.6.3 Adjustment of feeding rations to reduce P excretion
3.6.4 Threshold values

3.7 Agricultural value

3.7.1 Fertilizing value of nitrogen in manure
3.7.2 Fertilizing value of phosphorus in manure
3.7.3 Fertilizing value of potassium in manure
3.7.4 Contribution of manure to soil organic matter

4 Discussion and implications of manure management

4.1 Technical aspects
4.2 Economic aspects
4.3 Manure legislation
4.4 Assessment of the impact of manure

5 References

Annexes

Annex I - Assumptions and sources of nutrient excretion calculations
Annex II - Emission of NH3 from pig houses
Annex III - Slurry application techniques with limited NH3 emission
Annex IV - Average composition of animal manure
Annex V - Fossil energy requirements for the production of inorganic fertilizer