You certainkly right about the need for plant nutrition and its issues change at different stages of the plant.

For initial rooting rooting the starter fertilizer or organic amendment is most critical.

In conventional agricultural this would placed 3 cm to the side of the seed and 3 c em both the seed. Application of 100 kg/ha of 5 20 10 would give about 75% of the total fertilizer response.

N is mostly need from grand period of vegetative growth to the heading stage.

This can be accomplished by lay by application at the 15 to 20 cm plant height and with soil incorporation.

Most K or potassium is need in the flowering to grain fill stage and an ideal application would be at the boot or pregnant ear stage with soil incorporation.

For aggressive rooting and early growth organic earth worm casting are hard to beat if the fertilility is raised with maturing supplemental needs of nutrition can be minimizal.

Earhworm casting and compost can be ppplieddirecting to seeds and seedling without danger of direct toxicity.

Get a soil analysis to direct the fertility programs based on needs according to soil condition.

Plant analysis can be used to determine if their is issue with application optimizing the plant results.

The general recommendation of fertilizer N consisted on application of a dose at sowing is not optimal for achieving high N-use efficiency. Alternatively, application of the first dose at 14 or 21 days after sowing can result in optimal yield along with higher N-use efficiency. The lack of well-developed root systems hampers efficient extraction of soil N at early stage, thereby reducing N uptake efficiency.

The attached study provide an evidence that maize has a remarkable ability to give a better response when postponing the N application of first dose to 14 or 21 days after sowing.

Dear Prof. Paul Reed Hepperly What blessed knowhow!!!

Thank you so much for your enthusiastic efforts and for putting your knowledge to make the world a hopeful place for all humanity, and particularly the poor and helpless farmers of Africa

Dear Sir., just my question to you?

You have said that "For initial rooting, the starter fertilizer or organic amendment is most critical."

But can N wait until the roots start? (e.g. maize takes 6-9 days to emerge). Or do roots emerge before shooting?

For how long does N stay in the soil after its application as fertilizer?

STAY BLESSED!!

Alem

Dear Dr. Ali Mohamed, thanks for your clarification of the subject matter and for sharing such a valuable doc!!

Sir., for how long can N fertilizer stay in the soil? Do you have any information?

STAY BLESSED!!!

Alem

Phosphorus stimulates initial rooting and the roots are needed for nutrient absorption.

The humic materials coming from organic materials also stimulate rooting.

When early rooting is conclusive the vigor and health of the plant is favor.

Rooting preceding the growth and expansion of the foliage.

Starter fertilizer is very important of farmers in developing countries as you get the most response per investment.

A crop like maize will use large amounts of nutrient as Nitrogen during the rapid folarage expansion in maize knee high to flowering.

Small farmers can apply to the soil and make a critical weeding to incorporate the e nitrogen to rfesuce losses by evaporation and washing.

The reproductive element is Potassium which helps the movement of photosynthesis into the gran and strengthens the salks and disease reactions.

Ideally you can make three critical application and optimize the nutrient status of the plants.

Dear Prof.@Paul Reed

Thank you for your enthusiastic efforts.

Prof., yes, plants require more than 60, of which 18 are essential nutrients for the various life processes starting from sprouting to seed coloring to drying.

One thing, phosphorous is immobile in the soil. So we can add it before or at planting and the crops could use it at any time they demand it.

But N is a delicate, easily volatile, and highly mobile nutrient both in the soil and even within the plant.

I think it could stay not for more than 24 hrs. So my concern is on N.

Eagerly waiting for your expertize and blessed heart.

Thanks for understanding my doubt.

Alem

Dependiendo del sistema de riego, gravedad o goteo, se planifica la fertilización mineral y sobre el nitrógeno diremos que mientras mas fraccionado sea el abonamiento mejores resultados podemos esperar iniciándose después de la emergencia, cuando ya se cuenten con raíces que puedan absorber los nutrientes presentes en la solución suelo mejor si son el amonio y luego el nitrato.

Dear Dr. Luis FELIPE Bendezu Diaz

really thank you for your response and I appreciate your valuable clarification on the subject matter that would help us in having the knowledge to make the world a good place for humanity.

I wish I know French.

Dear Sir., would you please translate it to English?

STAY BLESSED!!!

Alem

Dear Dr. Redda,

Very nice and practical question you raised. Normally, agriculturists recommend 50. 100 and 100% of N, P205 and K20, respectively as a basal dose. As you mentioned, until and unless plants have roots they can not utilize the applied fertilizers. Potassium and phosphatic fertilizers takes a little longer time to to be ready to the plants. Therefore they must be applied as basal. There should be wise application of Nitrogenous fertilizers as they are lost through volatilization, leaching and run off water. If Phosphatic fertilizer is complex one with some amount of N, it is not necessary to apply additional N through Urea or other sources. This is the reason, instead of applying 50% N as basal; increase the number of top-dresses at various stages. It will automatically increases the N use efficiency by crop.

Good question. Well, it depends on the crop and other factors.

N fertilizer vanishes quickly by volatilization, nitrification, leaching, run-off, etc. therefore it's difficult to be uptaken by underdeveloped roots.

P and K fertilizers take some time to be available for uptake. Therefore, in my view, the best way to apply these fertilizers is after roots development or at the initiation of new growth.

Another best way is to optimize the combinations of these fertilizers according to the agro-climatic conditions. Please, have a look at my papers where I have optimized NPK fertilization through modeling and RSM techniques.

Regards

Dears Dr. Keshab Babu Koirala and Dr. Ihtisham M.

Thank you all for the nice and valuable explanations you gave to the subject matter. Maybe my minor question to Dr. Ihtisham M., how could it depend on the crop?

And my big question to all RG scientists:

• "For how long does N stay in the soil (after application) and how long (after planting) does it take roots to start absorbing N?"
• We understand that the embryo of the seed has stored food until the roots emerge and start their work.

Thank you for understanding me!!

Sincerely,

Alem

Timing of Nitrogen application is key in nutrient management. In my view, N application should best be applied in spring when plant root establishment in the Rhizosphere is at maximum. N becomes the most limiting factor in developed countries because of untimely application, with over 70% approximated as wastage due to leakage. Nitrogen is considered the most mobile plant nutrient hence timely application is necessary. Phosphatic fertilizer applied during the sowing of seeds is sufficient enough to sustain the seed until spring.

Dear Dr. Shicheyi Philip

Thank you so much. I totally agree with you. Yes N is the most mobile nutrient both in the soil and in the plant too. But my wonder is even some highly professional agriculturalists advise farmers to use as basal (@ planting) and the most wondering fact in my working area, some uneducated (bad word to describe them) do not use urea at planting, rather they use it later.

Dear Sir., could we get references for your valuable concepts? If you have any, please share them with us!!

STAY BLESSED!!!

Alem

Alem Redda Check my previous papers on my profile. I did one in Kenya. It must be noted that basal use of N is recommended if and only if it is combined with a urease inhibitor. The bottom line concept is, 'supply plant nutrient at the right time in the right quantity and quality. Nitrogen is most needed during a plant's vigorous growth stage which obviously is not basal. Moreover, unused Nitrogen in the soil can lead to ammonification which in itself is a source of pollution and CFC.

Dear Dr. Shicheyi Philip

"Basal use of N is recommended iff it is combined with a urease inhibitor."

(Shicheyi Philip)

Well noted and thank you.

Now, back to another issue, do our smallholder farmers own this urease inhibitor?

(of course not to ask you, b/se you have put it as your recommendation).

Wish you all the best this life can deliver!!!

Alem

Alem Redda As you stated, most of our farmers do not possess the technical knowledge of fertilizer application and the science behind every amendment.However,It should be a policy requirement that N fertilizer manufacturers should have a reasonable ratio of urease inhibitors. This will not only control pollution and mitigate impacts of climate emergency but also increase yields.

Alem Redda Thanks for the nice words. Regarding your minor question, I will try to explain it according to my limited knowledge.

It could depend on the crop in a way that if your crop is mostly vegetative for example turfgrass then you can apply N fertilizer quickly after plantation (and P and K fertilizers even before plantation) because normally grass is planted through sprig or sod which has an already established root system that can uptake minerals.

Dear Dr, Ihtisham M.

Sir., do you mean "transplanting"? (If I'm mistaken, correct me!)

If so, I think it's not the type of crop. It has to be the type of planting material (seed, seedling, cuttings, bulb, etc.).

In that way, U R right, b/se they had an already established root.

But the question cemented in my mind was "dry seed" sowing.

Hope you understand my concern!!

With best wishes!!

Alem

Most nitrogen fertilizer are applied after germination,however some nitrogen compound fertilizer can be add before or during planting

Dear Dr. Male Elenest

thank you for your response. But still I am in confussion. Let's say "some N" added before or during planting, what is the advantage of adding that "some". We all know that N is the most mobile (both in the soil and within the plant body) and highly volatile nutrient.

Please, help me and clarify it for me.

Sir., do you have any reference?

STAY BLESSED!!!

Alem

We all know that the period of maximum demand for N from crops (I am going to focus my ideas on corn and wheat in the central region of Argentina), coincides with elongation of stems, flowering, and filling of grains. In this region, the rains, (spring-summer-autumn), abundant between sowing and V6 in corn, tell us that it is not advisable to apply N before sowing because it would leach in depth without being taken up by the roots. The recommendation in this situation is to apply it between V4 and V6 (30-40 days after sowing, if possible incorporated between rows). In wheat the situation is different. Between sowing and stem elongation, there are no rains to ensure the incorporation of the urea broadcast applied . Therefore in this crop the recommendation is to apply N (almost always urea) before, or during sowing (if possible incorporated and immediately before the last autumn rain.

Dear Dr. Carlos Martín Galarza ,

thank you for your informative information.

You've thought me that scenarios matter.

Here, in Africa, we have only one main rainy season. For all crop types, farmers wait this rainy season. Farmers practice dry sowing, expecting enhanced moisture from the rain. But farmers use urea during sowing. As you said, this is the wrong b/se the maize plants didn't establish roots for 6-9 days (emergence).

Lucky, I'm doing my Ph.D. on maize and I should have good contact with you.

I have no experience of wheat similar to your cases. I think the wheat in your case used residual moisture or the area looks very much cool.

STAY BLESSED!

Alem