Grown in the Fall or early Spring, Broadleaf Mustard is the best crop for managing soil pests. Known as a cool season cover crop it contains a chemical compound called glucosinolate, that allows it to decrease several common pests and diseases from the garden. Another benefit this cover crop has to offer is it can suppress nematode populations and soil fungi. Broadleaf mustard contains a significant amount of biomass that increases organic matter in the soil which is important for erosion control. Erosion control will prevent water runoff and reduce nutrient leaking in heavy rainfalls. Similar to other cover crops, mustard contains a taproot system that extends deep into bottom soil layers that help serve to loosen hard clay soils. When loosening these hard soils it improves aeration and soil drainage in the vegetable garden. Improving the aeration of the soil allows for air, water, and nutrients to reach the plant roots that grow in the soil and make the nutrients accessible to the plants. With proper aeration, this also helps soil drainage in the garden. With accurate soil drainage, this will decrease soil and nutrients from being lost to runoff and avoid soil erosion. Broadleaf mustard is our go-to crop when controlling soil pests and increasing our overall soil structure in the vegetable garden. Two other cover crops that help control soil pests are Brown Top Millet and Sorghum Sudangrass.
Controlling Soil Pests
On this week’s episode, Travis explains ways to control soil pests that are disturbing your vegetable garden. He recently planted Broadleaf mustard in his garden using the Hoss Garden Seeder. The garden seeder has adjustable planting depth and premade seed plates that allow you to easily plant a variety of vegetable plants. Leaving the mustard to grow a couple of months it ended up producing a great cover crop that covered the garden area nicely. In order to use this cover crop effectively for biofumigation, we have to cut up the mustard leaves and incorporate it back into the soil. When the leaves are cut or ground up that’s when they release the chemicals for bio-fumigation to control soil pests like nematode populations. The chemical compounds are glucosinolates that are converted into sulfur compounds known as thiocyanates. The thiocyanates will actually apply the biofumigation technique to the nematode populations in the vegetable garden. Many researchers have done studies that explain when incorporating the biofumigation technique into the soil the most effective way is when the soil is a little moist or wet in the garden. This technique should also be done before the mustard plant goes to seeds. Wait until the mustard produces a good amount of leaves to ensure you get an effective amount of biomass, but incorporate them back into the soil before they produce any seeds so you avoid weed problems in the vegetable garden. The broadleaf mustard is edible to harvest and eat but our main goal was to increase the biomass in the soil so we incorporated all of the mustard back into the soil instead of harvesting it. Along with the biofumigant properties, the broadleaf mustard has the ability to effectively suppress weeds and control erosion. When mustard is planted densely in the garden it will shade out any new weed development and protect the garden area from erosion problems. If you are looking for a crop that will help control soil pests like nematode populations, suppress weed germination, control soil erosion, and even incorporate a nice green organic matter back into the soil a cover crop such as Broadleaf mustard will work perfectly to ensure an efficient and effective vegetable garden for the next growing season.