The exchange site is not infinitely large. When we reached saturation of exchange sites and steady state of adding nutrients, leaching or precipitate formation will naturally occur.

Joe, the excess above the exchange site might leach, but the exchange site will still contain an over dose. Agree ?

Agree, especially if interception (most likely with containers), chelation, pH modification via root exudates, oxidation-reduction reactions from aerobic to anaerobic microsites (remember, that even potted media, will not be uniform through time), and other container based factors are major avenues for absorbing the otherwise unleachable nutrients from satured sites.

So with all of these, we can only deduce that the 12-7-7 ratio could be problematic, ie, nutrient uptake imbalances, in the long run compared to the 5-1-3 ratio. We should still try to reconcile why the 24-14-14 ratio is working for others.

This is a good discussion. Thanks for your excellent knowledge Millet.

I would add one other point about excess P -- it can bind many of the trace minerals and makes them unavailable-- even with inground trees, too much excess P is not a good idea. Environmentally, it is usually the limiting nutrient in freshwater lakes and rivers where too much leads to eutrophication.

Soda (Phosphoric acid) and cleansing chemicals like detergents (many have phosphorous based chemicals) are common sources of Phosphorous that are already dissolved and often washed into the lakes and streams that would encourage algal blooms.

It is widely known that balanced and adequate fertility for any crop, citrus included, reduces plant stress, improves physiological resistance, and decreases the risk of disease. Management of nutrients is a key factor in improving crop productivity and disease control. Nutrient management in crop production means supplying essential plant nutrients to a crop in adequate amounts and in the appropriate form to obtain maximum economic yield. The socioeconomic circumstances of the farmer and the price of the produce in the market also determine fertilizer recommendations. This means that nutrient management strategies should vary according to the type of soil, climatic conditions, crop species, cultivar, AND socioeconomic factors. Nowadays, a farmer cannot afford to apply fertilization in excess of what a crop requires, for economic and certainly, for ecological reasons. Plants with a nutrient deficiency are often more susceptible to disease than healthy plants, BUT plants receiving a large EXCESS of a required mineral become predisposed to disease. Phosphorus, and other minerals, needs to be supplied in a balanced form with other nutrients according to the nutritional replacement requirements of the crop being fertilized.

Sorry, but soda is NaOH and has nothing to do with phosphoric acid H3PO4,
unless the word soda has a different meaning in the USA.

If you think I am boring don't be shy: say it!

Sylvain.

Does anyone know where to get a 5-1-3 fertilizer? I have searched the internet for hours and have come up empty handed. The closest thing I can find is a 19-6-12. I know this will work, but I would rather have the 5-1-3 if anyone knows where to buy one. Thanks.

Sodium hydroxide, or NaOH, is also called caustic soda; although that is an old name here in the US and not used very much except by us oldtimers in the industry.

that's true Skeet. At one part I helped the Keep Tahoe Blue project, and aside from the ashes of frequent fires, those cleansing agents are excellent sources of soluble P.

Although Phosphorus deficiency rarely occurs in citrus, what does Phosphorus really do? Among other things Phosphorus plays a vital role in many series of enzymatic reactions. When the supply of P is inadequate, cell division slows down. The important function of P is its role in the energy storage and energy transfer through adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Phosphorus is involved in electron transport in oxidation-reduction reactions and plays a big regulatory role in the formation and translocation of substances such as sugars and starches within the tree. It is also important in maturation process and in seed formation.

I think that we can take advantage of Phosphorous effects on fruits, they make the rinds thicker when in excess. So perhaps Meyer lemons can be shipped much better with thicker rinds from excess P. I did exactly that to one of my meyer lemon tree, and indeed the rind is thick like that of Eureka. Will show pics as unscientific proof that the idea indeed works. I hope no one patents the procedure as this post is previous literature.

This is a very informative discussion thread. There are numerous products out there one can use to feed citrus.
To answer a few of the questions raised about the 24-14-14 fertilizer: It should be noted that this is an all-purpose fertilizer and it is not specifically engineered for citrus. It has 18% Water Soluble Organic Nitrogen, and you use it at a ratio of 2 tablespoons per gallon once a month. We are not talking about applying large amounts of chemicals here. I think that Joe is correct in saying that we all need to be careful not to over fertilize our plants in order to limit runoff of toxins and to insure that we are not creating chemical imbalances in the soil.

It is true that the potassium and phosphorous levels are not perfectly matched for citrus, but all I can go on is results. We have sold this formulation of Romeo Fertilizer for forty years and have used it ourselves on our own citrus trees, both in the ground and in containers and have seen that it works. The trees are vigorous, green, and healthy and produce nice abundant crops.

I do find that citrus feed with this product will benefit from an extra boost of micronutrients at least twice a year. There is a product that called Citrus Growers Blend that works well for this purpose. We also recommend that people change the soil of their containerized citrus every 3-5 years because the organic material has usually completely broken down by that point and the trees may be beginning to become root bound, depending on the size of the container. This also helps to eliminate any chemical imbalances that have developed in the soil.

Is 24-14-14 the perfect balance for citrus? Probably not. However, this particular product is one we know to work.

.