NITROGEN for Plants – A Thought Experiment

Nitrogen fertilizers constitutes to about 60% of the fertilizer industry. The market has developed in last century and more so after the second world war.

This Thought Experiment is not to cover the complete Nitrogen cycle, but is very focused seeking an answer to one vital question –

Can we reduce/eliminate Nitrogen Fertilizers and still feed the world population?

Let me start with putting the established facts together, stripping off the technical jargon.

#1. Air remains the Primary source of Nitrogen. All chemical fertilizers harvest Nitrogen from air and chemically arrests it in a formulation. The fertilizers are then transported back to the farm through the distribution network. Huge travel miles are associated with such movement. Thus, from production to distribution it leaves a lot of carbon footprint.

#2. Chemical Fertilizers when applied in crops, release this Nitrogen for plants. In the process some portion (30-60%) of it escapes back to the atmosphere.

#3. There are yet other natural methods in which N can be harvested from Air. This includes nitrogen fixation by microbes, nitrogen conversion during lightening and other natural phenomenon.

#4. Microbial route of Nitrogen fixation take place in soils, roots as well as leaves. There are detailed studies around soil & roots, while there are only a few recent studies indicating the Nitrogen absorption through leaves.

#5. Legumes & Pulses are the group of crops rich in protein (which is rich in Nitrogen). Interestingly, these groups hardly require any nitrogen fertilizers. Microbes form nodules in the roots of these plants and capture nitrogen from the air. This nitrogen is the source of producing protein rich harvest.

#6. Although, we have gradually discovered microbes which fix nitrogen even in non-legume crops. Recently we also are looking at microbes which allow nitrogen absorption directly through leaf.

#7. The carbon foot print of Nitrogen is ZERO.

#8. Animal Excreta and Urine is yet another rich source of nitrogen recycling.

#9. Farm crop residue is also rich in nitrogen which can be recycled.

#10. Nitrogen forms the highest proportion of the crop mass after Carbon, Oxygen and Hydrogen. Naturally nitrogen forms about 70% of total fertilizer cost and subsidy. Currently about 30% of the nitrogen supplied to plants/crops are through chemical fertilizers.

#11. Most farms with commercial farming have very poor soil in terms of soil biology and the eco-system to support soil biology.

Based on the above facts we can draw the following conclusions:

A.      Quantity of Nitrogen required by the plant is real, since most of it is converted into protein. Non-availability of Nitrogen will impact the production for sure. Hence, ensuring the supply of Nitrogen remains a crucial factor. You cannot beat mass-balance over here – nitrogen is only converted within the plant.

B.      Nature way of providing Nitrogen is working well for Legumes, so the possibility of similarly efficient mechanism should be available for other crops. Its only that we are not able to figure it out. Legumes / Pulses leave soil enriched with Nitrogen nodules

C.       Nitrogen fixation at farm level is mostly governed by microbes. Further, pesticides end up killing these microbes and shuts down the nitrogen fixing factory.

Based on the conclusions we look at best solution to reduce Nitrogen Fertilizer.

I.        Get Legumes / Pulses as an integral part on every farm. It will act as the nitrogen supplier replacing the nitrogen fertilizer bag.

II.       Restore the soil biology as well as the biology of the surface of the leaf. This essentially means plants will start getting their fertilizer directly from air.

III. Recycle everything back to the farm – farm waste, organic waste, animal excreta, human excreta etc. Ok.. I forgot to add, it has to be slightly processed or composted before recycling. Urine is super rich in Nitrogen.

IV. All the above can work together beautifully.

V.     During the process of transition supplements of nitrogen fertilizers can be gradually reduced without impacting the productivity.

V.       Though, restoration of soil biology warrants that we move away from pesticides to allow the biology to work. We are stuck here. How can the plants be protected from pests & diseases without using pesticides? We shall cover that in another thought experiment and how is that possible.

Based on the above conclusion, we also evaluate if 1 Ltr of Nano-Urea can replace a 50 Kg Bag of Urea.

I.        1 Bag of Urea (50Kgs) provide 23 Kg of Nitrogen. Even at 30% efficiency it will be about 7 Kgs of Nitrogen.

II.       1 Ltr Nano Urea (4% Nitrogen) provides about 40 gms of Nitrogen. Even at 100% efficiency it can be no more than 40 gms.

III.      It contradicts observation A – absolute supply of nitrogen cannot be reduced to maintain productivity.

So personally, the thought experiment data is so clear that I will not even do a field trial for nano-urea. Or if someone presents some claims, I will look in the details and I am sure anomality will be discovered.

Reducing Nitrogen fertilizer in agriculture makes a lot of sense for most stake holders – farmers (to reduce cost), government (to reduce subsidy), environment (for reduced carbon footprint).

The nitrogen fertilizer manufacturing industry and the associated supply chain will have to lose. May be that can also reflect in contraction of economy with close to 120 million metric ton of nitrogen fertilizer getting replaced by nature’s factory – the microbes.

Thoughts?

Do you see any other aspects worth focusing for Nitrogen for plants?