How Soil Health Affects Bees
Soil health can influence the production of flowers, pollen, and nectar, and it plays a role in pollinator visitation patterns. Healthy soil should have balanced nutrients, a proper pH, sufficient water-holding capacity, strong and diverse microbial activity, and be free of toxins. There has been a decline in pollinators over the last few decades, and two of its major causes are changes in habitat use and agricultural practices. The use of chemicals such as pesticides and herbicides in the soil is detrimental to these relationships. On the other hand, many methods to enhance soil quality have been developed such as adding organic matter to the soil.
Compost
In one study, researchers examined how vermicompost affects the behavioral and biological responses of pollinators to flowers and floral resources using cucumbers, Cucumis sativus, as their model system. Vermicompost (VC) is the product of decomposition of worms and other organic material, and it improves soil quality by adding nutrients and micro-organisms, among other things. The study found that the quantity of flowers was not different between groups, but that VC plants flowered significantly earlier and had heavier flowers. In addition, pollinators (bumblebees, honey bees, and non-bumblebee natives) spent more time on VC flowers. The results of this study suggest that enhancing soil quality can be beneficial for bees.
Nitrogen Levels
Another study tested the impact of soil nitrogen (N) availability on pollinator visitation patterns. It wasn’t until the third growing season that the N addition’s efforts paid off. Nitrogen is essential to plants because it is a major component of chlorophyll which is used by plants for photosynthesis. It also contributes to a plant’s structure and metabolism. Without nitrogen, plants cannot grow taller or produce enough food. The N addition shrubs had more than double the number of flowers, received more than twice the number of insect pollinator visits, and had three to four times the amount of seed output.
Soil Fertilizer
Changes in the soil quality can also impact the chemical composition of nectar and pollen. One study found that soil fertilizer can alter the amino acid make-up in nectar. Bees, and all arthropods, need amino acids for development and reproduction, and sometimes it can be hard to find during their adult stages. They found that there was an increase in the amount of glutamine and a decrease in the amount of remaining amino acids. Bees need a certain percentage of all ten essential amino acids in their diet in order to digest all the protein they have eaten, and glutamine is not one of them. Another study’s results showed that there were less of the essential amino acids in the pollen of fertilized plants. They also found that nectar glucose and pollen fructose levels were lower in fertilized plants.
Pesticides
Pesticides are substances meant to prevent, destroy, repel, or mitigate any pest, and they promote efficiency on farms by allowing more food to be grown on less land. All farmers use pesticides, whether from synthetic or natural sources. Pesticides can degrade soil by damaging the living organisms inside it, which adversely impacts human and animal health. Researchers in one study found that A. mellifera and Halictus sp. bees visited melon plants less after pesticides were applied.
Soil Health Does Affect Bees!
Research has shown that soil health has some impact on pollinators. With the decline of honey bees, natibe bees, and other pollinators, it is important that we do what we can to promote their wellbeing–whether that be adding organic material to soil or reduce the use of pesticides.