Yes Manoj ,  I strongly feel , NCU will surely cut the doses of nitrogen to be applied , besides extending the nitrogen availability till grain filling stages , especially in cereals.  Comments of Dr Pram Baboo are valid in the context of whole discussion . 

Dear Manoj,

For paddy crops the NCU is miraculously effective, the paddy production in India is drastically increased due export of Basmati Rice to gulf country and all over the world. In Punjab the farmer are taking double profit first Paddy and then wheat. In paddy crops the water level is always there so there is a chance for leaching the fertilizers the NCU is slow release of Nitrogen and resist to fast dissolve because micro film of Neem oil. The Indian farmers are taking 2-3 crops in a year due to shortage of land day by day, so there is no alternate.

We are Producing 6600 TPD NCU before mandatory we were produced 50 % NCU. But the demand for farmer more and more NCU, we were not capable to supply NCU at that time. The farmer are saying The NCU is better, due to bitter smell the rabbits, rats even Neelgai are escaping from crops when they are applying NCU.

with best regards,

Prem Baboo

Yes Manoj ,  I strongly feel , NCU will surely cut the doses of nitrogen to be applied , besides extending the nitrogen availability till grain filling stages , especially in cereals.  Comments of Dr Pram Baboo are valid in the context of whole discussion . 

Drs. Anoop and Prem Baboo, how much is the residence time of neem oil in the soil?

Residence time will be again guided by the perenniality of the crop , seasonality of root flush , irrigation methodology ..like factors...We ahve tested it citrus during pre-bearing stage of crop, ok i will attach the said PDF. 

Mr.Manojkumar, scientifically there is no dispute on the role of neem or neem oil coated urea.There has been an accumulated scientific information over four  decades from IARI and many agricultural universities on  neem coated urea increasing N use efficiency.Only we have to ensure coating of right amount of neem oil on urea and quality testing.

Dear Manoj Kumar,

an interesting question indeed! However, I do not fully agree with what has been said above:

While the biological effects of neem and neem oil have been proven beyond doubt, I'm very not at all convinced that the doses used in the commercial production of neem oil-coated urea are sufficient. Do the others have convincing evidence that the prescribed doses have significant effects under field conditions? Forget about pot experiment in this regard.

I also do not agree that the Indian farmer, on average, applies ‘many times as much N than needed’, as this would suggest he is using 3 or more times the required amount. The FAI fertiliser statistics 2014-15 indicate that N consumption per unit gross cropped area is 87 kg N/ha. This as such is not excessive, certainly not by a factor of 3 or more, in view of the yield potential. However, the nutrient supply is highly unbalanced as indicated by the low potash use of 13 kg K2O/ha, but that’s another issue.

In my view the strongest argument – at least from the government’s point of view – for introducing neem oil-coated urea is to make the excessively subsidised urea unfit for industrial use. A substantial share of the subsidised fertiliser urea was diverted to the chemical industry. In this regard, neem oil serves merely the purpose of ‘adulterating’ the urea, and how efficient it is in terms of NUE really doesn’t matter.

I agree with Joska , with all the comments , except the  content highlighted in last para .

Neem oil coated urea is more effective due to slow release of Nitrogen which enhances more nitrogen use efficiency and reduces the N loss by leaching and denitrification.

I agree with Dr. Subba Rao Sir and other respected researchers.  An effective N fertilizer management involves the development and production of slow release N fertilizer and or indigenous urease nitrification inhibitors, to inhibit the nitrification process. Inhibiting nitrification could be a key strategy to improve N recovery and agronomic N use efficiency. Neem (Azadirachta indica L. Juss) based fertilizer is one of the best ways for augmenting the N use efficiency, crop productivity, and safeguarding the environment through its nitrification inhibiting properties.