It is true that a small amount of exchange of materials does take place between xylem and phloem because se tissues are not completely isolated from each or. Therefore, it is possible for xylem to carry organic materials while phloem to carry inorganic nutrients.

The process of absorption of minerals is demarcated into two main phases. The first is uptakes of ions into outer space of cell- apoplast via passive process. The second phase is slow uptake of ions into inner space of cell? symplast via active process.

Plants take ir nutrition from minerals present in soil. Many macro and micronutrients are present in soil. The soil also harbors nitrogen fixing bacteria that fix nitrogen in order for uptake by plants. It performs several or functions like holding water and supplying air to root?s respiration. It also acts as a matrix for stabilization of plant.

Nitrogenase is an important enzyme for process of nitrogen fixation. It is basically a Mo-Fe protein. It catalyses conversion of atmospheric nitrogen into first stable form that is ammonia.

Fe is an essential element belonging to group of micronutrients. Micronutrients consist of elements which are necessary for plant?s survival and are required in less than 10 mmole Kg^-1. Na, Co and Si are beneficial elements required in very small amounts and are present in only few varieties of plants.

Mg is absorbed by plants in form of divalent. It is a constituent of structure of ribosome and acts as a binding component. Cu is involved in electron transport chain of photosynsis. Mn is component of oxygen evolving complex. Cl is responsible for anion-cation balance in cells.

Zinc is required for synsis of Auxin hormone. Zinc is absorbed in form of divalent form. It activates various enzymes such as alcohol dehydrogenase and carboxylases. Deficiency symptoms.

Pseudomonas is organism is capable of carrying out denitrification. Beijernickia is free-living nitrogen fixing aerobic nitrogen fixer. Nitrobacter convert nitrite to nitrate form. Nitrosomonas convert ammonia to nitrite form.

The direction of food in phloem is bi-directional as leaves which synsise food need to transport organic materials or food to shoot as well to root apex which lie in opposite directions.

After active or passive absorption of all mineral elements, minerals are furr transported through transpiration stream. Transpiration pull is main mineral transporting force across entire parts of plants.