Hardly any plant can survive without photosynthesis. The molecule that helps plants carry out the process of photosynthesis is ‘Chlorophyll.’ Magnesium is a major constituent of chlorophyll. Thus, for any plant to convert light energy into food, they need Magnesium. Lack of Magnesium will mean that a plant will not be able to meet its energy requirements and growth will be sub-optimal.

This is because the terms NPK do not denote the amount of Nitrogen, Phosphorus, and Potassium but the amount of Nitrogen, Phosphorus pentoxide (P2O5), and Potassium oxide (K2O) in the mix. Thus, NPK 10-10-10 consists of 10% Nitrogen, 10% Phosphorus pentoxide, and 10% Potassium oxide, remaining 70% being filler or inert matter.

For the sake of understanding, we will consider NPK 10-10-10. As explained above, NPK 10-10-10 consists of :

• Nitrogen - 10%
• P2O5 - 10%
• K2O - 10%

each molecule of P2O5 consists of two atoms of P and five atoms of O. In elementary chemistry classes, we learned that the atomic weight of P is 31 and of O is 16. Thus a molecule of P2O5 will weigh 142 (=31x2 + 16x5) of which 62 is contributed by P (=31x2). Thus the amount of P in P2O5 is 43.6% (=62/142).

Similar calculations for K2O will show that the amount of K (atomic weight 30) in K2O is 83%.

So, in terms of macronutrients, NPK 10-10-10 consists of

• Nitrogen - 10%
• Phosphorus - 4.36%
• Potassium - 8.3%

Having understood this, we can now answer the queries that were posed above

• Which one is better NPK 05-05-05 or NPK 10-10-10?
• None. They both are same. It's just that the former has half the strength of the latter.
• Are both balanced?
• Depends, if you are looking for a balance in N, P2O5, and K2O, then they both are balanced. However, if you are looking for a balance in N, P, and K, then, none of them are balanced.

CityGreens NPK differs on a couple of counts

• Along, with NPK, it has many other vital micronutrients
• When used as instructed, it results in a ratio that provides an almost equal amount of N, P, and K to the plants (instead of an equal amount of N, P2O5, and K2O)

Having said that, just to reinforce, as we had pointed out in our last week's post, there is no perfect nutrient formula that can work wonders with all the plants and in all the situations. What your plant needs may be entirely different from what your neighbours' may need. You will need to experiment to arrive at the best solution for your specific case. We hope you do that.

Happy Growing!

Nitrogen aids in the process of photosynthesis. A lack of nitrogen will lead to chlorosis (a discolouring of leaves) and stunted growth. An adequate amount of nitrogen promotes healthy leaf growth and results in imparting a bright green colour to the leaves.

Phosphorus is necessary for energy transfer and consumption in various parts of plants. Phosphorus helps in promoting root growth, blooming, seed production and improving crop yield.

Potassium can be considered equivalent to a CPU (Central Processing Unit) of a plant. It regulates most of the vital functions within a plant, including internal moisture, water balance, and low-light photosynthesis. Potassium has a high impact on the end-quality of the fruit, including its shape, size, colour, and taste.

Plants draw these nutrients from the growing medium, which is the soil in a majority of the cases. Soil, as such, does not have any nutrients of its own. It, however, acts as a storehouse of nutrients that gets added to it naturally through the atmosphere, weathering of rocks, bacterial conversion, decomposed animal waste etc. or artificially by adding fertilizer, manure, and compost etc.

Yes, you can, if you are growing in fertile soil which may have some stored nutrients. But, once the stored nutrients run out, the plant will begin to grow weak, will be unable to withstand pests, and yield will decrease or become non-existent (plant will focus all its energy on surviving and not on growing as humans will do in case of famine). Thus whether one is growing in soil or outside soil, external nutrition must be provided to plants to ensure a healthy garden/farm. More so, in case of growing in a soil-less medium like Cocopeat, hydrotons, rice husk or water.

For adding these nutrients externally, one can either depend upon Organic sources like bacteria, earthworms, fish excreta, vermicompost, manure etc. or on inorganic ones like fertilizers and precision blends. Again, taking the analogy of humans, one can either provide nutrition through organic means like milk, rice, etc or through inorganic supplements like baby food, Farex, Cerelac, Horlicks, Bournvita etc. or take the best of both worlds, adding a spoon of Horlicks to that milk. Which one to use? It is more a matter of individual preference; some prefer only organic; some prefer precisely measured scientific blends depending upon specific plant needs; some prefer using a mix of both. All of these should work with the plants.

Happy Growing!