by | Nov 14, 2022 | Ask The Experts

Introduction to Standard Operating Procedures

The goal of any producer in the agri-food industry is to efficiently produce a high-quality and safe food product. This is especially true in indoor farms, whose product is often of exceptional quality. An important document supporting this goal is the farm operations manual which includes standard operating procedures (SOPs) and sanitation standard operating procedures (SSOPs).

The SOPs in an operations manual covers everything from how to wash your hands to how to manage shipments. SOPs outline what to do, who needs to do it, how to do it, and when it needs to be done. They are an integral difference between farms which operate as businesses and hobby projects. Standardizing procedures allows for uniform, continuous workflow and allows for teams to seamlessly expand in numbers while maintaining the overall quality of work.

In the agri-food space, the goal is to produce or process food safely, and these procedures contribute to the overall food safety plan, from food production to processing.

Comparing Indoor Farming to Traditional Farming

Many indoor farm SOPs are more similar to those of food processing plants or laboratories, than traditional outdoor farms. As the environment in a Controlled Environment Agriculture (CEA) facility is closed, there is more emphasis on the movement of people and materials into the space, as it is a critical control point to maintain a clean farm space.

The requirements for an operations manual and food safety plan are often outlined by a food safety certification, which is given by a certifying body. Currently, there is a CEA Food Safety certification, but it is not recognized alone and must be accompanied by an accredited certification. It should be noted that many criteria of traditional food safety certifications are not applicable in indoor farm settings and result in the farmer having to weed through a large amount of information, while ruling much of it out.

Overall, the standard structure of an SOP for an indoor farm is largely unchanged from traditional templates, but specific considerations should be made regarding what to include and how to optimize the documents’ structure.

Top Nuances Discussed in an Indoor Farm’s SOPs

Procedures for Biosecurity

One of the top advantages of vertical farms is being a majorly sealed environment, especially the increased exclusion from pests. To maintain this advantage the utmost level of biosecurity must be adhered to. SOPs related uniquely to biosecurity are not enough, rather each SOP involving work in the farm should highlight the biosecurity actions required.

Biosecurity has many facets, including hygiene best practices, sanitation and diligent record keeping; all of which contribute to maintaining a pest-free and healthy farm. All SOPs should include sanitation steps in their protocols. It may seem obvious in many cases, but it is important to ensure no oversight of these steps. Hand washing and sanitizing SOPs are required to obtain food safety certifications, and although they may seem superfluous they speak to the thorough approach which must be taken and acknowledge that nothing should be taken for granted in terms of people’s knowledge of proper safety protocols.

Procedures for Record Keeping and Access to Data

Another important aspect related to biosecurity, crop health, and farm management is proper record keeping. Steps indicating what data to collect and when to do so should be included in SOPs, with a clear indication of where the information should be recorded. This is an important step to allow farmers to monitor their system and ensure they can have a retroactive picture of conditions if needed in the future. Regarding biosecurity, recording who and what has come into the farm allows the team to, in the event of a pest or disease outbreak, look back and try to determine potential causes. This knowledge allows current procedures to be updated and future risks mitigated.

Thorough record-keeping also allows for improved crop management. Thus, SOP steps should include what and when data measurements should be taken and recorded. As many hydroponic systems are recirculating, measurements from one location can give a general overview of the state of the whole system. Although shifts can occur locally in a hydroponic system, for example, a nutrient gradient along a long NFT gutter, overall it is easier to obtain an overview of crop environment for both foliage and root zone compared to conventional farm systems.

Proper record keeping includes all growers recording what inputs (nutrients, cleaning products, etc) are put into the system, and what the measured values were before and after making any additions. If there are shifts in crop health, these records can indicate what caused the shifts. Further, this same information can be used to note what steps lead to improvements in crop health and overall yields in the farm when examined correctly.

Dynamic Procedures

Fundamentally, a farm is an ecosystem relying on technology and human inputs. So, no matter how strictly an operations plan is implemented, technology does fail and people will make mistakes. This is why the structure of many SOPs for an indoor farm should not only be listed as linear steps. Rather, a well-designed flowchart SOP allows for each grower working in a farm to be confident in their decisions and ensure a more consistent response to abnormalities in the system. For example, nutrient management is now often largely controlled autonomously with instrumentation, but should still be monitored manually to ensure compliance. If a grower is following an SOP list procedure and measures a pH outside of the desired range, the following steps will be much less intuitive than following a flow chart.

The figure below shows an example of a portion of a flow chart procedure describing steps to follow when monitoring a hydroponic nutrient solution. Thorough procedures such as the one below are not necessary for all SOPs, but once developed for the most dynamic aspects of farm production they become invaluable resources for the growing team.

example of standard operating procedures workflow


In conclusion, SOPs play an indispensable role in both ensuring food safety and as a tool for the growing team. As farms scale up, the attempt to ensure homogeneity between the work of different employees allows for crop health and yield to be maintained more predictably. As an ecosystem relying on technology and humans acknowledging there will be issues and ingraining flexibility into these procedures sets the farm up for success.