Some timely rain has helped my sweet corn and sunflowers come up and theyseem to be doing well. I will be adding 50 pounds of urea to a small area where I plan to plant turnips for this fall, but I have a question about my garden. How much shouldI spread on the sweet corn and sunflowers if its 30x20 foot garden. Only 1/2 of the corn is planted, the other half will be planted this weekend. I just don't wanna over-do it, but I think they could use the nitrogen. Also, when is the best time to add the urea, pre or post-emergence?

Thanks for any info