Have you ever noticed how farmers rotate their crops? Well, probably not if you’re a city goat. But if you’ve ever driven across our great country through the plains states (it’ll take you about a week if you stop and smell the roses), you’d see different rows of vegetables next to each other or different crops on the same parcel every couple of months. Even with cow pastures, you’ll see fences where the cattle are grazing on different types of grasses, different times of year. This is done because different vegetables remove different elements from the soil but leave behind others. For example, carrots are high in Vitamin A that they pull from the soil and leave behind nitrates. Other plants might put Vitamin A into the soil but take something else.
Rocky soils are bad for growing produce, simply because the rocks take up some of the space that plants need, but they leach help micro nutrients into the soil. Thus, alluvial soils that you find in valleys between rocky hills are some of the best soils for grapes as well as Citrus and Avocado trees because of their minerality. However, they tend to be more nutrient rich, which retains more water. This will give you more fruit, but less intensity in flavor profile of the fruit. Whereas on rocky terrain, the fruit will be less (from less water retention) but more intense. A great vineyard has both valleys and hillsides.
All fruiting plants need 17 Essential Plant Elements which include nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum, and nickel. The non-mineral essential plant elements include hydrogen, oxygen, and carbon. These are absorbed in water. There are 4 elements that are beneficial to promote plant growth but are not considered to be necessary for completion of the plant life cycle. They are silicon, sodium, cobalt, and selenium.
I have met so many people who get excited about planting a small vineyard in their backyard because they have the space or they do the numbers and they realize that it’s the same cost to plant a small vineyard as it would be to plant any other landscaping. Grapes usually require less water. But folks fail to realize, that grape vines, because they are fruiting plants, need the soil to be balanced before planting. This can take 6 months. It’s different than Europe, because in Europe, they have been growing the grape vines for thousands of years. The vines have adapted. But with a new plant, they need to be handled like a newborn. Think about human gestation. A baby is absorbing everything it needs to grow in utero. Before, you plant a grape vine, you need to make sure the soil has everything it needs to grow.
Chicken manure contains Calcium, Magnesium, Sulfur, Copper, Zinc, Chlorine, Boron, Iron and Molybdenum. 75% rapid release of Nitrogen source in one year. For the first three years of the plant’s life, chicken manure may be spread every dormant season (right after harvest season). This will help establish the root systems. You can’t spread after spring, because there are new roots and too much of a good thing can burn the new roots. The manure needs six months to decay. Composting contains Nitrogen and Carbon. Worm Castings increases organic matter giving the soil a boost for natural bacteria and improves water retention. Organic matter should comprise 5% or more for healthy soil. Bat guano has high content of Nitrogen, Phosphate, and Potassium. Lava Rock improves drainage in soil and capabilities of roots. During the day it retains moisture, releasing it slowly. At night, it retains heat keeping roots warm and is an erosion blocker.
No two places (even in a one mile radius) will have identical soil. Take into account hills, drainage, fires, floods, landslides. Different soils might range in composition on each acre.
In SoCal, there have been a lot of wildfires. With each wildfire, phosphorous from the ash increases the pH of the soil. Trace amount of Phosphorous are ideal. But too much Phosphorous impedes the plant from taking in the other essential elements. High Phosphorous and high pH in the water also prevent all of the other essential elements from being absorbed.
Choosing a site for a vineyard, you have to bear in mind how much work the land needs. There are agricultural places where you can send soil samples to find out what the soil is missing and how best to amend. They will also tell you what the soils have and what will grow best in that soil.
Some vines need diurnal temperature ranges. This can be found in proximity to oceans, sun traps, valleys, shadow effects from hills.
When I think of a grape such as Sangiovese, I look at latitude and longitude. The Chianti region is about 43 degrees North Latitude and the land I want sits at 34 degrees North Latitude…so they are similar. Similar latitudes will account for about 14 hours of daylight in the summer. The elevation of the hilltops sits at about 2400 feet, whereas the land I want sits at 700 feet. This gives an idea of drainage and soil types. Both are between 15-20 miles from the ocean. Miles from the ocean equates to how much nighttime fog passes over the land. In SoCal we have something called June Gloom. When the sun sets, the fog rolls in and the temperature drops at least 10 degrees. The fog lingers in the morning until about noon. This cools the grapes and increases the acidity. The soil types also add acidity. The medium plus acidity from the soils and diurnal temperatures and fruit forward tones from long summer days account for the flavor profile of Sangiovese. That’s what I want to mimic to create the perfect wine.