Olives

Careful nitrogen management is important to maintain tree growth and reduce losses to the environment.  For olive trees it is important not to overfertilize with nitrogen as this can lead to excessive vegetative growth and less production of fruit.  However, under-fertilization can also be detrimental and can reduce new shoot growth that will ultimately affect future bud development, flowering and fruit production.  The most important timing for nitrogen fertilization is in the spring- time leading into bloom. 

N-Sure is a liquid slow-release form of nitrogen.  It can be used both as a foliar fertilizer and soil applied.  As a foliar source of N, N-Sure can be applied at key vegetative growth stages.  For olive trees, this is can be done throughout the growing season, but is particularly important in the early spring.  N-Sure is a good tank-mix partner, and can be applied with many fungicides, insecticides and other fertilizers (always check compatibility before mixing and applying).  When soil applied, N-Sure should be blended with other sources of N, including UAN solution and urea solutions.  This will provide some readily available nitrogen to the crop along with slow-release N in N-Sure.

Potassium plays an important role in several physiological processes.  In many fruits, including olives, more potassium is removed in the fruit than any other nutrient.  Ensuring that potassium is available to the tree at key growth stages could increase crop load, leading to higher yield potential. Leaf tissue samples can indicate potassium status and help identify potential deficiencies.  Potassium fertilizer can be applied through irrigation systems or banded along the tree drip line.

KTS and K-Row 23 are excellent sources of potassium and sulfur.  Since they are already in the liquid form, both are excellent choices for injection through micro-irrigation systems. KTS provides both K and sulfur (S) in the thiosulfate form.  Thiosulfate has been shown to help improve availability of nutrients like phosphorous and micronutrients like manganese, zinc, and iron.  Thiosulfate can also help with lowering soil pH when the pH of the soil is higher than 7.0.  K-Row 23 contains half the sulfur and can be applied at higher rates.  K-Row 23 is good option in cases of low soil pH (less than pH 6.0) and when more potassium is required per application.

While calcium is an important nutrient for olive trees, in most olive growing regions, deficiencies are rare.  However, in arid, irrigated regions, calcium application can be an effective way of improving soil physical properties. 

CaTs provides soluble calcium and sulfur to the developing crop.  Timing CaTs applications to first bloom through early fruit set, ensures sufficient calcium levels in the forming fruit. In cases where water infiltration and salinity are issues, CaTs is also an effective soil amendment for managing these problems.  Applications of CaTs in-season have been shown to improve water infiltration and soil aggregation.

As with calcium, sulfur deficiencies are rare in olive trees, but sulfur does play an important role in plant growth, serving many functions in the plant, including formation of amino acids and proteins, chlorophyll production and activating certain plant enzymes important to physiological functions.

Thio-Sul, KTS, and CaTs all contain sulfur in the thiosulfate form.  Thiosulfate is a form of highly available sulfur that will correct any sulfur deficiencies, in addition thiosulfate provide additional benefits to olives planted in calcareous soils.  Thiosulfate is a source of acidity and helps to manage issues that develop in high pH soils.  The acidity generated from thiosulfate applications, can dissolve calcium carbonate, freeing calcium into the soil solution. It can also help solubilize other nutrients that can be less available in calcareous soils. 

• Thio-Sul® - 12-0-0-26S
• CaTs - 0-0-0-10S-6Ca
• KTS® - 0-0-25-17S
• N-Sure® - 28-0-0