@ Wajid, the plant root cells contain in their cell walls a special molecule (called a carrier) with the ability to recognize each specific nutrient ion. Thus, the cell comprises a variety of these special carrier molecules, with one for each different nutrients. Plants take up nutrient elements from the soil through their roots and from the air (mainly consisting of nitrogen and oxygen) through their leaves. Nutrient uptake in the soil is achieved by cation exchange, wherein root hairs pump hydrogen ions (H+) into the soil through proton pumps.

What i understand from your answer, you are talking about acquisition but i want to know the mechanism how plant comes to know that the specific nutrient is present in specific direction. Simply you can say how plant search nutrients in soil. Does root send signals and receive back some information and react accordingly in that specific direction?

Vegetable plants transpire water from their leaves, creating suction on the water at the root surface that draws the nutritious surface soil solution toward the plant roots. This process of mass flow caused by leaf transpiration explains how most plant nutrients (98 percent) move from the soil to the root surface.

How do you know when you are hungry that there is food in the pot in the kitchen? It's the same for the plant. Even if the plant has no neurons to think, it has the capacity to explore a defined volume of soil (rhizosphere) to search for food. When it does not find nutrients in this rhizosphere, it exhibits deficiency symptoms corresponding to the deficient mineral in the soil. Man can interpret the symptoms observed to compensate for the deficiency by providing the appropriate input. If there is a specific mechanism by which the roots are informed of the availability of nutrients in the soil, I would also like to know.

very good discussion Carine Temegne Nono Mukul Barwant Steven L. Larson

@Carine, we can't compare ourselves with plants. We have brain, we know where is our kitchen. moreover our source (kitchen) dose.t change its location but in field we can find variability regarding nutrients availability. Rest of your answer is understandable but my question is still there, what is mechanism to know where nutrient is available in soil and where plant has to spread its root because if the spread of roots in soil is unplanned then, it is just wastage of energy.

Mukul Barwant , It is normal mechanism in majority of plants which is associated with acquisition of nutrients not with searching of nutrient in soil.

Steven L. Larson , Your answer making sense...but need more clarity whether this is only the reason or not.

There is not a "mechanism" that we are aware of that lets plants know where nutrients are in the soil. Nutrients reach plant roots by one of 3 ways, diffusion of nutrients (a slow random dispersion of molecules), root interception (the search party finds nutrients) or mass flow (nutrients moving with water).

Roots grow and find nutrients. When they find nutrients they become more dense in that area until the nutrients are depleted. Yes, if the nutrients aren't there then it is wasted energy. If doesn't find enough nutrients then all of the wasted energy results in the plants death.

Steven L. Larson You are right. Its really interesting aspect we are discussing and we need to explore the different mechanisms and processes to improve our understanding how plant transmit information for acquiring available resources for its growth and development .

Wajid Mahboob How plants root sense water and nutrients are largely unknown. But from the article below, describing a study, might offer us some hints (see below). Is it possible that nutrient-sensing for plant roots also involves a master gene??

"Roots are critical for plants to acquire water and soluble nutrients from the soil. Plants are able to adapt to different soil moisture conditions by altering their root architecture, but up until now, it was not understood how this is done. Root branches only form when in direct contact with soil moisture using an adaptive response termed 'hydropatterning'. Professor Malcolm Bennett of the University of Nottingham, and Professor Ari Sadanandom from the Department of Biosciences at Durham University, discovered that hydropatterning is controlled by a branching master gene called ARF7. Their teams observed plant roots lacking ARF7 were no longer able to hydropattern. The researchers concluded that when roots are exposed to moisture ARF7 remains active and promotes root branching, but when exposed to air, ARF7 is modified and inactivated, blocking root branching. " (2018 December)

https://www.sciencedaily.com/releases/2018/12/181222180749.htm

Yuan-Yeu Yau Yes dear nutrient-sensing for plant roots also involves genes. furthermore, root branching not only form when in direct contact with soil moisture but N forms also act synergistically to regulate root system architecture, as localized ammonium provokes higher-order lateral root branching while nitrate stimulates primarily lateral root elongation.

Anyhow, you shared an interesting article, it can really be exciting for researcher to explore possible mechanism behind this processes of nutrient sensing

Review the mechanisms of the transformation of minerals at the nanometric level and the chemical and genetic responses of plants. Besides, you have to read about the changes in the communities of soil organisms and their relationship with plants. It can be very helpful to read about those topics.

هذا سوال فيه عدة احتمالات افتراضية ربما يعود إلى تاثير الجينات في تحكمها في العمليات الحيوية في داخل النبات وعند وجود نقص في أحد عناصر الغذائية الضرورية فإن الجينات تقوم في تحفيز المستقبلات الكيميائية في منطقة الجذور في البحث عن هذا العنصر. واحد وسائل البحث هو زيادة نمو الجذور في وضع طولي تعرضي وزيادة الشعيرات الجذرية من أجل الحصول على أكبر كمية ممكن من الغذاء

See the attached article. I hope it will help you...

nice discuss for this topic.good answer are wajjd bhai . i agree with wajjid bhai.

A good topic for discussion. I have one more doubt. In generally it is being told that Arid crops extend root system (Particularly longitudinal) in search of water and nutrients. Is it their genomic concern or if we irrigate them, then their root will stop growing ?

@ Debashis, it is not genomic concern, if you irrigate them then their root behavior would be the same to the similar crop growing in other areas. but some arid trees have the root growth habit longitudinal may be due to the lower soil depth under arid reason.

Just like we humans found our food in home / outside. All living organisms have consciousness. Fine. Think of Birds. They fly high yet come down swiftly to gather the food on spotting it.