There are three different areas of concern in suggesting guidelines for the disposal and/or utilization of poultry manure on the land. The primary concern deals with human and farm animal health or safety associated with land manure application. Ground and surface water levels of nitrates are of greatest interest because they present potential human and animal health problems. To avoid this primary problem the following guidelines are offered:
The second area of concern deals with ecological considerations and environmental alterations in public waters that may have undesirable effects on aquatic plant and animal populations. If pollution of streams and lakes with ammonia, phosphates and organic matter takes place, application of poultry manure may need to be further limited than is the case for the primary area of concern. Further attention to guidelines two, three and four may also be required to alleviate this second area of concern.
The third area of concern is agronomic. The interest is in the best utilization of poultry manure as a crop fertilizer and its incorporation into soils at levels to provide only the necessary levels of plant nutrients. The rate of manure application should be limited to that amount required for crop production and maintenance of a reasonable level of soil fertility. Generally this means that soil levels of phosphorous and/or potassium govern the amount of poultry manure that it is appropriate to use. In this case supplementary sources of nitrogen usually must be used to produce an appropriate nutrient balance. Phosphorus accumulation takes place in some soils as a result of over-fertilization. The amount of poultry manure used under these conditions depends on crop needs, soil fertility levels, physical characteristics of the soil and the potency of the manure. The actual amount of manure applied should be calculated for each crop production situation. These calculations will generally result in the lowest level of manure application. Even when manure is used to satisfy agronomic concerns at reduced application rates, guidelines two, three and four should be carefully observed.
The steps to follow in determining how much poultry manure can be utilized as a crop fertilizer are presented in Table 3.
Table 3 How much poultry manure can be utilized as a crop fertilizer?Steps to follow: