Let us know how it goes. The black plastic does cause a problem with applying fertilizer in the regular manner. The fertigation, because it is salt in solution, may cause clogging of drip lines. Under plastic, you won't know until that plant shows signs of stress. What do you do then? Just getting watering right under plastic is hard enough. Over-watering kills more plants than anything. JMHO Aloha

Check EnviroYard at www.solutions4earth.com. EnviroYard is a liquid fertilizer designed for fertigation systems (see also www.YardFeeder.com). It's best described as a low pH, non-salt liquid fertilizer and soil conditioner. The low pH helps dissolve bicarbonate buildup to keep lines and emitters clear, while the carbon and organic materials help fuel increased soil health. That makes more nutrients available to plant roots. It's a good balance of effective, environmentally responsible, and affordable. It's should be available on line in April in states where phosphorus is still allowed.

I just installed a similar system for our new strawberry patch. My patch was small enough that I just went with 1/2" poly tubing with 1/2gph drip emitters every 12 inches. So far it is working pretty well.

Setting your time is just a matter of trial and error. I started at 20min twice a day @ 40psi. In 2 days I had mushy mud. I installed a 10psi regulator and went to 5 minutes a day. The ground under the plastic mulch dried out too much. I upped the timer to 10 minutes twice a day. That worked well for a few weeks. I just adjusted my timer to 15 minutes twice a day because it is getting a lot hotter. I will check it in a couple of days to make sure the soil is not too damp.

For fertilizing I ordered a 2 gallon Easy-Flo fertigation system online for $60.

I have no ideal how much to fertilize so I will start small. I tilled in a couple of yards of compost, several bails of peat moss and many bags of perilite so I am comfortable I could do very well with not fertilizer at all this year. I am thinking of using fish emulsion for fertilizer... but I haven't researched what fertilizer is compatible with the drip emitters yet (what won't clog them).