Snails Occurrence In Soybean Fields In Kentucky During The Offseason In 2024

FELIPE C. BATISTA

PRINCETON, KENTUCKY

The main loss caused by snails and slugs in soybean fields is the reduction of plant stands by feeding on newly emerged seedlings. Thus, the initial number of snails present in the field by the beginning of the season might have a high impact on the plant population.  Consequently, if replanting is necessary or yield loss occurs at the end of the season, it may affect soybean productivity.

We have been monitoring post-harvest soybean fields to evaluate the survival and occurrence of snails and slugs in the fields during the offseason (Figure 1) and the impact on the soybean crops in the next season. We do not intend to identify isolated factors that lead to the prevalence of slugs and/or snails in the areas, since this is more a result of a set of conditions than it is any isolated factor. However, based on the history of the areas we have been monitoring over the past couple of years, we can identify some factors that can contribute to a better understanding and management of these pests in commercial fields.

We have monitored several fields with different characteristics and management. The higher numbers of snails were found in areas with a thick layer of organic matter in the lower part of the field, where higher moisture is found (Figure 2). We found an average of 1.9 vs 1.1 snails/sq ft in the lower and higher parts of these areas, respectively. In other fields in the same region, but with a thinner layer of organic matter, an average of 0.3 snails/ sq ft were found. It is important to mention that we found alive and active snails in these areas even after some days with temperatures below freezing during the second half of November.

We are conscious of the importance of organic matter to the conservation and improvement of the quality of the fields, and we do encourage the use of both cover crops and non-till practices. Our intent here is to alert growers about the possible issues with snails and slugs and draw attention to the importance of monitoring them in areas where such practices and environmental conditions exist.  Thus, enabling them to take the necessary measures to deal with these pests in case they happen.

Based on these monitoring trials, and on the recent historic presence of snails in these areas, we would like farmers to be aware of potential problems in areas with a thick layer of organic matter, high moisture, irrigated fields, and a lack of control of previously applied measures. We will keep monitoring the presence of slugs and snails in these fields throughout the offseason and testing known and new control measures in order to provide information and reduce the negative impacts of mollusks on soybean fields in the season 2025.   ∆

FELIPE C. BATISTA: University of Kentucky