Food Processing Residuals, or FPRs, are by-products generated during the processing, packaging, and other operations of food industries, whose application to land benefit crop growth and soil productivity. FPRs fall into two main categories: vegetative waste and residuals waste. Vegetative wastes include such things as peels, hulls, stems, skins, and seeds left over from trimming, reject sorting, cleaning, pressing, cooking and other food processing operations. Residual wastes are solid materials removed during the physical, chemical, or biological treatment of wastewater in a food processing plant.

FPRs are considered “cake” or “liquid” materials based on the solids content. This classification determines how a material is transported and managed at the land application site, with each type of material requiring different transportation and application equipment.

FPRs are separate from sanitary input, and do not include process wastewater.

FPRs are land applied as either a soil conditioner or fertilizer based on the C:N ratio and N content of each material.

Residuals used as soil conditioners have high C:N ratios and low amounts of N. Soil conditioners contribute to organic matter content of the soil, soil structure and aggregation, and soil moisture retention.

Materials with a low C:N ratio and high N contents are mainly used as fertilizers, serving secondarily as a soil conditioner. Depending on the amount of nitrogen present in the FPR, it can be used solely or in conjunction with other fertilizer materials to supply the nitrogen requirements of a crop.

FPRs are beneficial in agriculture as fertilizers or soil conditioners. Chemical fertilizer application rates and irrigation needs can be reduced by the amounts provided through the application of FPRs. When used as a soil conditioner, FPRs increase the levels of organic matter in the soil, which can increase the soil’s water holding capacity and allow plant available nutrients to remain in the root zone for longer time periods.

Crops that are appropriate for the land application of FPRs are field crops such as corn, legumes, grasses, ornamental nursery stock and some vegetable and fruit crops. When incorporation of the FPRs is required, the timing of application and field availability need to be considered. Legume crops that produce nodules to supply N by fixation are recommended for soils where high C:N organic wastes are applied as soil conditioners. Winter cover crops are recommended when using FPRs as N fertilizers to minimize leaching of residual nitrate.

The food processing company generating the FPRs is responsible for permitting its materials and adhering to all requirements under the land application permit. The land application company is responsible for managing operations at the site, delivery of materials to the site, employing proper application practices, and determining application rates. The land application company and the land owner should work together to decide who will be responsible for developing and maintaining a conservation site plan, incorporating material into the soil if required, soil sampling and analysis, and nutrient management recordkeeping.

An RMS or Conservation plan is required to be filed with the local NRCS office and implemented prior to and during application for agricultural land application sites. The RMS should address all resource concerns of the farm, such as erosion control, pest management, crop rotation, pasture management, nutrient management, wildlife considerations, etc.

The parties responsible for the development, filing, and implementation of the plan and the practices required under the plan should be agreed upon between the site owner and land application company prior to and land application activity.

Potential problems with land application can be avoided with timely application and incorporation of materials. Problems can also be reduced it the wastes are processed by composting. Incorporation aids in waste degradation, odor reduction, and wind distribution of organic wastes applied. Mixing the waste into the soil reduces run-off of organic wastes and volatilization of ammonia from wastes used as N fertilizers.

Incorporation can negatively affect crop residue cover and thereby increase soil erosion; therefore, it is not required when there is 75% ground cover protection from residue.

Once an FPR is delivered to a farm for land application, it needs to be spread and possibly incorporated into the soil. Equipment necessary for the spreading and incorporation of FPRs varies depending on soil types, crops grown, and the type of waste being spread. Loading and applying cake FPRs requires tractor front end loaders and rear or side-delivery manure spreaders. Chisel plows, rototillers, moldboard plows or offset discs can be tailored to incorporate the specific form of waste used. Liquid FPRs can be injected directly into the soil using an injector such as an ag-gator.

The approval of an FPR for land application is determined based on its potential to benefit crop growth and soil productivity when applied to land. Analyses for nutrient content are required prior to and during land application operations to determine application rates and track nutrient loading.

FPRs are permitted by the state in which the food processing operations are located. The food processor, not the farmer, is responsible for obtaining all permitting for the land application of FPRs. A general permit is not required for each application site.

Considerations made when land applying FPRs include such parameters as the value of the material for beneficial use, the suitability of the site’s topography and soils, and crop nutrient requirements. Weather conditions and field availability during crop season help determine when and where materials are applied.

The land application of FPRs is governed by site requirements included in the materials permits. Fields that should be avoided for land application are those with slopes greater than 12%, near waterways, and with high water tables or bedrock within 24 inches of the soil surface. FPRs should not be applied to flooded, frozen, or snow-covered ground. Application of FPRS shall not exceed the annual nitrogen requirement of the crop to be established, or exceed the hydraulic loading rate capacity of the site’s soils. FPRs need to be incorporated within 48 hours unless the slope of the land is less than 5% or crop residue or vegetative land cover of at least 75% is present to prevent run-off of materials.

Land application of FPRs shall only proceed on a site if the agricultural conservation or soil erosion sediment control plan (RMS) is on file with the local NRCS office and implemented to manage site-related impacts from land application. Other restrictions, such as setbacks from surface water bodies or property boundaries, can be required by the FPR permit to manage potential impacts of applying the material.

Conditions which preclude a FP by-product from land application are excessive pollutant levels, pathogen contamination, and potential for nuisance conditions to occur when land applied. Permitting of materials excludes those that would not meet land application requirements. Nuisance conditions are prevented or minimized through setbacks, application methods (such as incorporation into the soil), and adherence to RMS guidelines.