Will a plant grow when watered with vegetable oil and water mixed together?

Question

Will a plant grow when watered with vegetable oil and water mixed together?

Answer 1

It depends on how much oil it used.

If it's just a little bit of oil with a lot of water, it's OK.  The tiny bits of oil drops will be plant food later.  If there is too much oil, like a quart oil with a quart of water, it'll give the roots a hard time.  

Here is the chemistry/microbiology involved in the process.  Vegetable oil needs to be decomposed into smaller substances for the plant to absorb as nutrients.  The micro-organisms in the soil will do the job for you.  However, in this process, they(bacteria, etc) need oxygen to live and to work.  If too much oil is dumped in the soil at once, the soil micro-organisms will have a splurge of grow and choke up the plant roots by using up all the oxygen.  They also produce heat in the process and it can hurt the roots, too.

The same concept is behind composing.  People put coffee grounds or clipped grass or animal manure in mounds to make compost.  They don't apply these directly to soil. The material needs to stay in the pile for days, sometimes weeks to let the microorganisms do their job.  Then the compost would be transformed into stuffs that contains more nutrients which are available for plants.