Four Ways to Improve Your Vineyard's Soil
Certified organic vineyards depend on fertile soils. Optimal soil conditions prevent disease, improve grape flavor and quality, and mitigate drought and other problematic weather conditions. Whether your vineyard is decades old, generations-old or just starting out, here are a few ways you can improve your soil.
Over time, chemical fertilizers can damage soil and weaken its structure. Excess nitrogen can acidify soil. Over-fertilization can negatively impact the presence of healthy microbes. These microbes are essential for breaking down organic nutrients, releasing them slowly and making them consistently available to plants. By making fertilizing agents easy to access, plant roots lack diversity and depth. This puts plants at a disadvantage during times of drought, wind or flood.
You can improve soil nutrients by incorporating compost into sandy soils to nutrient leaching. Since sandy soils are often the desired soil for vineyards, these soils may have been overused. Vineyard equipment such as organic vineyard floor management systems are used to evenly distribute compost materials into porous soils.
Not all vineyards are located in the light soils of Northern California. Regions with high-density, clay soils suffer from flooded areas during the spring and winter. Clay soils do not drain away excess water, a scenario that can lead to root damage and poor vine growth. Orchard equipment such as a 3-tooth cultivator can loosen clay soil and allow for better drainage. Vineyard equipment design is especially suitable for this task because cultivation depth can be controlled, allowing for compost and other organic matter to be incorporated into heavy soils without disturbing delicate, underground growth.
Organic wines and grapes are often said to taste "cleaner" than conventionally-grown grapes. Studies have shown that healthy, organic soils have higher levels of bacteria. These bacteria have successfully reduced the number of heavy metal particulates, like copper and lead, in soil. Upon closer inspection, scientists found that produce grown in these soils also have lower levels of heavy metals. While the levels that are present in conventionally-grown grapes are considered safe, our tastebuds might be able to appreciate the subtleties found in grapes that are grown in microbe-rich soils.
Plant a Cover Crop
Experienced growers know first hand how deeply vine roots penetrate soils. When it comes time to replace a vine, specialized vineyard equipment augers are used so that surrounding vines are not disturbed. This is important because root systems access the minerals, nutrients and deep earth that are responsible for each vineyard's unique terroir. Damage the roots and you might just damage the flavor. That said, the fewer disturbances to deep earth, the better your vines' health. Planting cover crops using specialized orchard equipment will help protect topsoil and shelter root systems. Covercrops' slow-release nutrients will become essential soil elements. Since covercrops can be rotated seasonally, you have the ability to control and vary the nutrients your crops receive.
Of course, there are many variables that contribute to soil quality and texture. One major variable is topography. Before planting a vineyard, consider the effects that slopes have on soil quality. Tops of slopes might leach nutrients while the bottom might be nutrient-saturated. The amount of water that collects also creates varying soil composition. Good soil maintenance can mitigate these factors and improve your vineyard's soil conditions.