Understanding the Nutritional Needs of Olives
Many growers in Australia have experienced their trees not cropping well or not cropping at all. There are many factors that affect the cropping aspects of olive trees but I believe that one important factor of cropping is having balanced soil with available nutrients to ensure microbes are being looked after and trees are in good health.
To achieve great results from your fertilising program it is not just about adding this or that to your soil but understanding other factors around the whole process of the concept of fertilising.
How do you develop a fertiliSing program?
Firstly, it is imperative to look at the data. Some of the data should be obtained by way of soil and/or leaf analysis. Take out the guesswork because this has proven to be not fruitful for commercial production in the past.
Large Enterprise groves actually have soil & leaf analysis many times throughout the year. Monitoring is the key! The information is compared with previous growing years and the conditions for that particular year. If you were to obtain a soil test once a month for a complete year, this would also help you understand what your trees require and when. Your trees are living so feed them according to their needs!
The information also tells you if the inputs that you have applied are improving or if further works will need to be carried out.
Once you have an understanding of your grove, you can then take steps to develop a fertilising program!
There are some points I would like to stress:
Point 1: Don’t follow your neighbor!
The results of the tests are important because the information helps you to determine the specific requirements for your grove. Your soil type and water requirements may be different from that of your neighbour so following their advice may simply lead you up the garden path. Get the help of a professional!
Point 2: Get someone independent for your testing!
Many growers have had these types of soil tests done before and may be wondering why the results simply aren’t there. This may be because many fertilizer companies do carry out soil testing. However, they will only recommend their own formulations which may not be the best application for what olives require. Some of these products may also be very expensive.
Point 3: What type of test is suitable?
Be as comprehensive as possible. Usually the total or complete test is required.
Point 4: How to determine the information!
This is where you need the help of a professional olive consultant to calculate your actual requirements. Remember fertilising is a science… in order to obtain results, the formula must be correct to perform the best each season.
Considerations for your fertiliSing program to achieve overall soil health:
Soil organisms contribute to soil structure, water holding capacity, pH, and nutrient availability, while the physical and chemical soil environment determines what organisms can live in the soil profile. There is a strong interaction between all these components, where changes in one aspect will influence others! The holistic approach of looking at the soil as a system will enable you to use the natural soil processes to improve production, health, and long term yield.
A major function of soil biota (which includes many organisms from microscopic bacteria to giant tunneling earthworms) is the breakdown and release of nutrients of organic matter decomposition. Carbon is a major component of organic matter and is integral to all energy functions/transfer in living matter. An active microbial population is responsible for the rate of this breakdown and the more diverse and abundant the carbon source is the more diverse and abundant the micro-organisms are. Micro-organisms make up 80-90% of the soil’s biological activity and are the end-stage of all decomposition.
Living organisms need to be considered in any soil evaluation and adopting a more sustainable, natural, or organic approach rather than using chemicals as an easy short term fix will certainly help these organisms work for you. You can use organic products and methods even if your grove does not have the certification.
Repetitive use of inorganic chemicals may not promote the ‘beneficial organisms’ in your grove and can build up harmful residues in your soil and rapidly degrade soil structure.
Inorganic chemicals especially in concentrated forms require special care with storage, handling, and application and because of their concentrated nature may pose an unacceptable risk to staff, olive trees, and your final product (i.e. oil or fruit). The health risks associated with unnecessary use of toxic chemicals may have preventable medical, legal, and financial consequences which any grove manager will naturally want to avoid.
Trying to improve microbial activity in the soil is pointless if there is no organic matter (i.e. food or carbon). Most of the new population will simply die. This is why any successful inoculation program has to deal with the business of building a home for bacteria and “stocking the shelves”. Microbial workers always work to increase and multiply – if they can. Thus the soil life profile is always ‘in-process’.
Some components in the soil system are always being taken apart and being put together. The problem is that under certain cropping conditions, many soils become elementally depleted or unbalanced.
Other important factors: When proteins are to be produced – i.e, if nitrogen, and in some cases phosphorus and sulfur are to be coupled up with carbon, hydrogen and oxygen to make this life-carrying, bodybuilding substance – they cannot be built by sunshine using only air and water. The soil must contribute to at least ten elements which include Calcium, Phosphorus, Potassium, Magnesium, Sulphur, Iron, Boron, Manganese, Copper, and Zinc.
Caring for your tree: Grove management done in an appropriate way will bring the best results. Seek the advice of a specialist olive consultant if you are unsure. I know there are growers who have achieved results of up to 30% increased production by appointing a specialist.
Australian Olive Industry, Unproductive Trees: http://www.australianoliveindustry.com/australian-olive-industry-survey-about-the-australian-olive-grove-part-3/#Unproductive_Olive_Trees