Quick N fix for yellowing rice?

Hi, while I'm taking care of my experimental organic rice patch (fukuoka-inspired, but really just mulched with compost until I can grow pintoi peanuts as cover crop) the 3 main rice fields have gone through the whole herbicide and constant weeding thing.
Now one of the workers here told me to buy a certain fertilizer because the rice is going yellow. They didn't have it at the store, but when I asked what is usually given for rice, he told me urea or ammonium nitrate. That's all? I was about to spend $30 for urea when I have 9 cows here peeing for free.
I really don't understand conventional agriculture. When I told the worker I could totally perceive his skepticism. The mentality that chemical means effective and natural is just... something is so engrained.
Anyway, I was thinking of spraying a fresh manure tea. We also have carao fruits here (google it up!) which is an amazing energizer and rich in Magnesium (to build chlorophyll), so maybe I'll add that juice, too.
Meanwhile, I read that N applied to wet soil or in rainy weather (which is now here) will just evaporate, and that fresh manure has the wrong kind of N.

Any insight? I may have to buy urea on Wednesday after all (I got until Wed because I'll go to town again to pick someone up at the airport), but until then is there anything I can do so the rice won't die?

Thanks!

Sorry for the trick Just hoping that if I push this post to the top someone will notice it and help me out. I realize it's totally not the permaculture approach, I was just hoping in someone's knowledge of this kind of chemistry in general.

There is so much naturally occurring nitrogen in soil and air, perhaps it just needs more moisture?
Is there enough calcium in the soil?  Is there enough humus in the soil to hold nutrients?  From what you said, I assume there is mulch already on it so there should be enough microbial life to convert nutrients to a form the plants can uptake it.  Activated aerated compost tea works very fast.  We are blessed in the area where I live because a well known ag consultant who teaches organic/biodynamic lives here and gives us free classes. 

Just did a farm tour on a farm he helped plan and saw a gorgeous crop of all knids of veggies with picture perfect leaves and NO insects.  Totally organic.  Just the right mix of organic matter (they used shredded leaves), with compost, trace minerals.  You could put your hand down into the dirt over 12 inches deep with no effort.  The soil was loose and friable and loaded with white strands of mycorrhiza fungus.  It was amazing.  Even the peach tree was untouched by insects and had never been sprayed with anything, just had good soil. 

No, my organic patch is just fine. I am talking about the rice in the conventional fields. They were first sprayed with herbicides, because the two new fields were gotten out of a piece of forest and the local workers didn't feel like chopping all by machete, and now they planted rice, all spaced so they can weed inbetween, and weeding they are, constantly. So the scenario is bunches of rice growing out of barren soil, that washes off at every rain, and it's the rainy season.
That's why I needed a quick fix.
I guess I will have to buy solid urea after all. All I can apply is foliar spray, but...

Let's hope for the best.

Most commercial fertilizers depend on urea as their source of N.  It is probably a byproduct of the CAFO and dairy industries.

I always tell people that "Miracle-gro is just Piss & Vinegar...just kidding...no vinegar!"