Keys to Reducing Salts with Improved Leaching Requirements and Infiltration
The ongoing California drought has resulted in many growers irrigating their crops with lower quality water. Other growers have been forced to use well water that has higher then desired amounts of chlorides, boron, bicarbonates, sodium and other dissolved salts. These unwanted water components build up in the soil around the root zone, which reduces crop production and kills plants. Growers with permanent crops are particularly affected due to the limited number of options to fight salt issues, and crops such as almonds, walnuts, grapes and citrus are moderately sensitive to salts. The best management tool for reducing salt build-up is employing a good leaching requirement program. A leaching requirement is defined as the amount of water applied that is needed to flush the excess salts that are present and detrimental to the crop from the root zone. When water drainage is adequate, salinity issues only become a problem when the salts applied with the irrigation water are able to accumulate in the root zone at a level which reduces plant health and yield. In these crops, leaching is the primary factor in controlling soluble salts carried by irrigation water.
Options to help improve water penetration problems include using higher quality water, implementing micro-irrigation and increasing irrigation frequency. Options to help prevent soil crusting include using tillage, improving organic matter, adding cover crops and using various chemicals that can overcome crusting effects improve water infiltration through the crusting.
Another effective option is the use of safe products such as gypsum as a dry soil amendment, irrigation-grade gypsum through the irrigation system, Calcium Ammonium Nitrate 17-0-0 (CAN 17), high quality polymers to improve water infiltration and holding or specially designed water infiltration surfactants. Most of these products improve or maintain the soil structure, resulting in a release of free calcium. They can also stabilize the soil aggregates. The right surfactant system can increase uniform wetting, improve infiltration rates and help move salts below the root zone.
Liquid Chisel® from Helena can increase the solubility of existing calcium in the soil, which can lead to increased water infiltration rates and reduced water ponding and runoff. Liquid Chisel is a blend of soil conditioning agents and potash that increases the solubility of calcium and magnesium salts. By doing so, they displace sodium on clay particles, allowing it to be leached away with irrigation water. With sodium displaced, soil tilth, irrigation efficiency and nutrient availability is improved. Also, unlike similar products, Liquid Chisel contains soil wetting agents to improve water movement in the soil.
Contact your local Helena representative for more information on Liquid Chisel and other options to reduce salts with better leaching and infiltration.
-Don Bandoni, San Joaquin Valley Product Manager