Today I will be writing a short blog on soil. What type of soil do grape vines like best? If I grow grapes in the Desert how important can soil really be? Is the soil in Las Vegas good? Today we will look into this subject. Lets start off this article with the "perfect soil" for grapes. One of the first things to look for in determining if your soil is appropriate is to determine what you are wanting to grow. There are 4 basic soil types these are sand, silt, clay and loam. In this case we are discussing growing grapes. One of the items we look for in our determination process is something called pH.
What is pH? Soil pH or soil reaction is an indication of the acidity or alkalinity of soil and is measured in pH units. The pH scale goes from 0 to 14 with pH 7 as the neutral point. From pH 7 to 0 the soil is increasingly more acidic and from pH 7 to 14 the soil is increasingly more alkaline or basic. A pH in the range of 5.5 to 7.0 is ideal for most varieties. Everything below 7 is considered to be acidic. Everything above is considered to be alkaline. The reason a pH between 6 and 7.5 is optimal for garden plants is that between 6 and 7.5, phosphorus in the soil is soluble meaning that it dissolves in water and is taken up by the plants roots. Now that we know this lets find out what makes soil acidic. There are three things that make a soil acidic and they are the items that decay in your particular soil. The second way is excessive rainfall or irrigation. Too much water can cause important nutrients to be washed away. One other way for soil to become acidic is the use of high-nitrogen synthetic fertilizers. These fertilizers are usually ammonia based which also increases soil acidity. By the way Jack Sanders , owner of the Sanders Family Winery in Pahrump who has extensive experience with vineyards in Napa Valley informed me that for the soil in Las Vegas I would need a 15-15-15 fertilizer which is also know as "Triple Fifteen". These numbers are also known as N-P-K ratios. The numbers stand for the following. 15% ammoniacal nitrogen, Available Phosphate (P2O5) - 15% & Soluble Potash (Potassium) (K20) - 15% as well as Sulfur (S) 9%. While we are talking about these nutrients here is a short explanation of what each does. Lets take Nitrogen first. Nitrogen is essential for the growth of leaves and helps keep the green. Nitrogen gets lost from soil very easily. Phosphorous stimulates root growth, promotes development of flowers, fruit (grapes) and seeds. Phosphorous does not get flushed as easily. Potassium helps the vines tolerate changing weather conditions (warm to hot). It also assists the vines with fighting pests as well as help strengthen the plant itself. Potassium does leach from the soil but not as fast as Nitrogen. What causes a soil to have high or low pH? One thing that increases soil acidity is cover crops because they require high amounts of nutrients like Potassium, Magnesium and Calcium. Rain also increases high pH nutrients and makes soil more acidic. In order to lower soil pH there is something called Ground Algime which is a powder form of Lime. Now that we have looked into pH lets see some other interesting things about our vineyard soil. To start off with almost any soil can be improved with the incorporation of organic matter. Heavy clay and silty soils will benefit from vegetable and manure compost, chopped hardwood or pine bark, leaf mould and small amounts of pea gravel. Excessively sandy soils will benefit from composted organic materials, peat moss and humus. Do not amend clay soils with large amounts of sand, because this will inhibit drainage even further and may turn your grape garden into a brickyard. Avoid enriching the soil with high nitrogen supplements, which may lead to healthy green grapevines at the expense of fruit production. Drainage is also very important in our soil. While we want the roots of the vines to actually get the water we are giving them we on the other hand do not want them sitting or soaking in water since this can be the cause of some diseases such as Root Rot. We need a soil that will drain but yet not so quickly that the roots will not have a chance to get the very water we want them to have. Grape vines also do not like it when water pools on the surface of the ground around them When I was planting my vines I actually left small rocks in the hole in order to help with drainage. We can also add mulch. A mulch is left on the soil surface. Its purpose is to reduce evaporation and runoff, inhibit weed growth, and create an attractive appearance. Mulches also moderate soil temperature, helping to warm soils in the spring and cool them in the summer. Mulches may be incorporated into the soil as amendments after they have decomposed to the point that they no longer serve their purpose. The interesting thing here is that soil fertility for vineyards does NOT have to be great since grape vines are naturally vigorous plants and very fertile soils produce overgrown canopy and abundant, but mediocre fruit. These grapes taste diluted because the resources of the vine are being stretched too thin. Ideally, vines will put the majority of their energy into a small amount of grapes. Too many grapes and the vines resources are stretched. Excessive foliage (too much Nitrogen) can also deny grapes the amount of sun-exposure necessary for optimal ripening. Here are a couple of more important things for our soil in our vineyard. The depth of the soil is important. Deeper soils tend to produce more consistently high-quality and subtlety flavored fruit than shallower soils. These vines are also less susceptible to extreme weather patterns. There is one more item to discuss when it comes to vineyard soil and that is the Cation Exchange Capacity (CEC). This is the capacity of the soil and its capability to hold nutrients. Each type of soil will have a unique CEC many of which are difficult if not impossible to measure. Some soils have the inability to have their CEC altered and this is due to the nature of the soil the vines are planted in.
Now lets talk about the soil in Angel Vineyard & Mirror Image Vineyard. I have posted a picture with this article so you can see just one of the types of soil I have to deal with (at least in appearance) her in the vineyard. While planting my vines I came across areas that appeared as if the house was built on top of a rock Quarry. I will post a picture of one of the rocks that I had to dig up which actually took an hour to get out. I couldn't use a shovel because the rock was jammed in by many smaller rocks that stopped it from coming out. It was actually easier to use a hand tool to dig it out. There were other parts of the vineyard that had soil like you see in my hand. There were other parts that had small rocks but not small enough that I wanted to leave them where the vine was going. Then there were others that had small rocks that I was able to leave for drainage. The actual soil composition such as pH I have never looked into to be honest. I am going off the way my original Cabernet Sauvignon vines grew last year, before I learned how to take care of them. I can only assume that if they grew that wonderful with no knowledge of grape vines how well they will grow now that I have at least knowledge on the caring of them. It is also my understanding that for around $30 I can buy a home testing kit to check pH but I (again) am going by past experience in the vineyard and I believe my vines will grow just fine.
Well folks I hope you learned a little bit about soil and how it effects our vines. I hope you will use it to benefit you should you decide to grow a vineyard of your own.
The Desert WIne Guy
No comments:
Post a Comment