A survey of dairy effluent management in the South of Chile: an effective tool to determine farmers and research requirements.

A survey was carried out on 55 commercial dairy farms located in the South of Chile during 1995-97. A questionnaire was developed to obtain informed estimates of slurry management on those farms. Information was analysed on an annual basis using a computer spreadsheet linking all the parameters surveyed. In addition, slurry samples were taken for analysis of dry matter content (DM). Herd size varied between 50 and 800 cows per farm. A large proportion of the total volume of effluents produced came from rainfall (47%), dirty water accounted for 29% with only 24% from cow’s faeces and urine. The large volume of effluents produced resulted in a reduced storage capacity (on average of 2 months) or more frequent and higher application rates to the field. Only 36.5% of farmers knew the application rates of manure and there was a wide range in the quantity used per year (12 m ha to 300 m ha). Dairy effluents applied mainly on grass (71%) throughout the year round but, mostly concentrated in winter and spring time using only surface irrigation system.. The total solids contents of effluents was very low, with 62% of the samples being < 4% DM. This reflected the large volumes of clean water that the storage received. The information collected has identified problems in effluent management in Chilean dairy farms where research and technology transfer will be necessary to avoid pollution problems. INTRODUCTION Most of the cattle herd (56%) is concentrated in the 10 Region of Chile (Lake District). These cattle produce 65% of the country’s milk and 45% of its meat. In addition, 80% of the dairy farmers are located in this region which have 67% of the dairy agricultural land used nationally. Cattle production is one of the major resources for the regional economy representing an important proportion of the Gross Regional Product (ANRIQUE, 1999). In recent years the dairy production systems have been intensifying the use of purchased fertilisers, concentrates and silage. This has resulted in an increase in milk production but also in the generation of large quantities of farm effluents (e.g. slurries and dirty water). Nationally there was no information or estimation about dairy effluent production and the environmental impact of dairy production systems. Nevertheless, recent research has suggested that dairy farms could be related with pollution problems in surface waters. Farm waste surveys have been carried out widely by a number of authors in different countries using various approaches (e.g. BIRCHALL and KLENOW, 2000; SMITH et al., 2000). Surveys such as these represent a valuable source of information allowing focusing the research and extension programs. Information and advice based on research have been important aspects of dealing with the environmental problems associated with agriculture in most of the countries in Europe (THEVENET et al.., 1993). Farmers need to be educated about the issues and persuaded that change is desirable. Without this, as has been demonstrated particularly in France, neither regulation nor advisory approaches are likely to be effective (ARCHER and MARKS, 1997). This study attempt, as a first step, to evaluate farm waste management practices in slurry based systems in Southern Chile. With this information it will be possible to determine a basic knowledge of farm waste problems