Maximum Yield USA September 2018 | Page 60

soil pyramid chart Another issue, in more extreme slow-draining cases, is anaerobic bacteria breed and the wet soil becomes toxic, causing root rot diseases. This creates a terminal situation for whatever plants are located there. Knowing the drainage of the soil before planting is critical when trying to grow in poor soil. Soil Amendments Though water will continue to penetrate after application has stopped, slow-draining soils will usually need 60 to 90 minutes of run time to sink to the depth needed. These soils also stay wet much longer. Secondly, wet soil does not allow for air or oxygen to get to the roots for respiration to occur. The technique to deal with this is usually amending the soil with sand in addition to the organic matter needed. Amending usually calls for mixing the native soil with some other material having a different structure. When clay is high, however, amending can bond these two materials forming an adobe-like soil that is still problematic. When the clay content is more than than 20 per cent, it’s best to replace some or all the native soil to reduce the clay content. Even here we may obtain a reasonably good soil within the planting hole, but still having this surrounded by poor draining soil. This is much like having a tub filled with sand — it still won’t drain. 60 Maximum Yield “A common issue faced when growing in outdoor soil is the drainage rate.” Sometimes there’s a layer of clay soil that can be dug through to create drainage, yet often this is unknown and the attempt to dig a “stovepipe” through the clay can be fruitless. In most of these situations the best option, while still being able to plant successfully, is to create a raised bed, or at least a berm where the planting is above the mean- soil line and so will drain. Materials like sand, compost, coir, peat moss, perlite, or vermiculite are among the amendments available for changing and improving the soil condition. These amendments not only help control drainage but are necessary for the microbial soil life which is so essential for plant health and vigor. Organic matter in the soil is key to sustaining soil microbes. Once bacterial or fungal life is introduced to the soil, it is primarily the organic matter that feeds this life. The reactions created when bacteria feed on organic matter are responsible for nutrient precipitation where it then becomes available for the plant. These reactions also produce acids that work towards lowering soil pH. Even with organics like this, balance is the key. Too much green organic matter is like putting too many logs on the fire and smothering the flames. If, for some reason, it’s necessary to add high levels due to poor native soil, be certain to use organic matter that has completely finished composting and contains low levels of green material.