June 28, 2022

How Farmers Are Making Lettuce Safer: Soil is Part of the Food Chain Too

Making sure lettuce and leafy greens are safely grown encompasses a lot of factors. Most people aren’t aware a program exists in California and Arizona to make sure specific food safety practices are being followed on farms producing over 90 percent of the lettuce consumed by Americans.

What might surprise people even more is to know that these food safety practices don’t just apply to how the product is grown and harvested, but that a whole set of requirements extend to the soil that nourishes leafy greens plants.

The food safety program for lettuce that operates under state food and agriculture departments in California and Arizona is somewhat oddly named the Leafy Greens Marketing Agreement or the LGMA.  The  sole function of this body is not to market and sell lettuce; but rather to establish mandatory food safety requirements and then verify the standards are being followed through government audits of leafy greens farms that occur several times per year.

The LGMA was created back in 2007, Since that time, the food safety practices farmers are required to follow have been updated numerous times.  In the beginning, when farmers were audited by government inspectors, they were required to pass nearly 300 food safety checkpoints. Today, the number has grown to over 500 checkpoints.

Recently, the LGMA has been focused on reviewing all of the mandatory practices it requires of farmers with an eye toward making lettuce even safer. A special committee of farmers and food safety experts recently completed an overhaul of the food safety requirements that involve soil. Several additions were recently made to the LGMA’s list of requirements that cover the use of what are called Soil Amendments and Crop Inputs.  In plain English, this means anything that is added to the soil to fertilize the crop or to help improve soil health. 

The food safety practices enforced by the LGMA encompass different kinds of lettuce farming including both conventional and organic methods and cover all leafy greens varieties included in the LGMA program.

Colby Pareira of Braga Family Farms who serves as the chair of a special committee charged with updating food safety requirements involving soil used to farm lettuce, explains how the LGMA focuses on safety and soil health.

Sales and availability of organic lettuce has increased in recent years and many, if not all, of the farmers who are members of the LGMA grow leafy greens using organic farming practices. This means that they are not allowed to use certain kinds of synthetic pesticides or fertilizers. When it comes to fertilizers, it’s very common practice for farmers – both conventional and organic — to use manure to fertilize their crops. This is an acceptable practice under the stringent food safety requirement of the LGMA – but only if the manure has been properly composted. 

Composting is a science unto itself and can actually be quite complicated and specific, but what’s important from a lettuce food safety standpoint is that pathogens must be absent from compost before it’s applied to the soil. Manure, of course, can be a carrier of E. coli and salmonella and when farming a product like lettuce, which can easily come into contact with the soil, it is absolutely imperative that measures be taken to ensure that anything applied to the soil is safe and free of pathogens.

To the LGMA, commercial suppliers of compost and other soil amendments are considered an integral part of the food supply chain and many suppliers treat themselves as if they’re manufacturing food, not fertilizer. In fact, under new requirements approved by the LGMA Board that’s exactly how suppliers of soil amendments used in farming leafy greens MUST act.  

Not only does the LGMA now have even more stringent requirements for how compost is made, but the requirements call for these companies to be able to trace their products back through their own manufacturing systems and to be able to recall their products if a problem is detected.

Mike Menes, Ph. D, of True Organic Products explains how fertilizer and soil amendment suppliers are part of the food chain.

Requirements such as this are just one of several changes recently approved by the LGMA’s Board to cover anything that is added to soil used to grow lettuce. Under the LGMA program, farmers are being audited to verify the new practices have been followed and farmers. The new updated audits begin July 1. With updated requirements, this means that farmers must pass all of the over 500 food safety checkpoints included in an LGMA government audit, which includes over 250 that are now in place to ensure the safe use of crop inputs and soil amendments.

These updates are just one of the many ways that lettuce farmers in California and Arizona are making to be sure lettuce is safe to eat. We encourage you to learn more about what else is being done to protect you and your family here.