Phosphorus scarcity vis-a-vis urban food growing solution

This blog is the result of demand from some of my EVOKEr friend who wanted my opinion on urban food growing solution in view of phosphorus scarcity (both in terms of availability in soil as well as market). Here I go…..

First I must admit that phosphorus management is tricky. It gets fixed in acid soil by oxides of iron and aluminium. In salt affected soil, although it is available but plant suffers from its availability because of poorly developed root system and osmotic potential.

Acid soil, however offers unique opportunity to use rock phosphate as such which will be available to plant. More the acidic the soil is, more availability of rock phosphate will be there.

In sodic (alkali) soil with high pH, we must go for gypsum application for neutralization of sodicity. Alternatively, one may use pressmud (sugar factory byproduct) and pyrite.

Further, we have to think for alternate source of phosphorus. Phosphate solubilising microorganism and mycorrhiza offers best choice. Ecto-mycorrhiza for foresty plants/road side plants is good. Endo-mycorrhiza for field crops is suitable.

Also we must propagate for integrated nutrient management involving vermicompost (please refer my post), biofertiliser (please refer my post), compost and agro-industrial waste along with inorganic sources for synergistic effect.

A proper cropping sequence is also must. Shallow rooted crops must be followed by deep rooted ones. This helps in recycling of subsoil nutrient especially phosphate sources to surface soil.

Well, last but not the least, practice makes a man perfect. Let’s do it!