Giving exact recommendations for nitrogen (N) on cotton over a range of soil types and moisture conditions is difficult since soils, rotations, and other management vary tremendously from farm to farm and year to year. However, managing N in cotton is important for profit as well as preventing nitrates from leaching below the root zone and into ground water. Timing and rates of N applied to cotton was studied for several years observing nitrate movement on both sandy and sandy clay loam soils with and without irrigation. Studies had N rates ranging from 0 to 180lbs./A and use of starter N as well as timing throughout the season. Results varied with soil type and time of application. Excessive N rates increased nitrate levels in the soil below the root zone. It was difficult to follow the nitrate surge on the sandy soil as the nitrate moved too quickly through the profile to follow, while nitrate in the sandy clay loam soil stayed in the root zone longer and could be monitored. A winter cover crop of wheat reduced the nitrate level in the soil profile by storing N in the plants for recycling in the summer crop. Monitoring soil nitrate N is helpful in evaluating potential ground water contamination and determining crop needs. Time of N application was very important for most efficient yield response. Fertilizer applied before planting may be leached below the root zone on sandy soils, while applying N after the 4^th week of bloom may reduce yields due to excessive vegetative growth. If only one sidedress application of N is made, the optimum time is about 6 weeks after planting. When several N applications are made on sandy soils, they should be made about 3 weeks apart with the last one no later than 10 weeks after planting. Studies indicated that lower N rates should be used on unirrigated fields as compared to irrigated ones since dry weather may delay its utilization. No more than 140 lbs./A of N is needed for irrigated crops on sandy if proper splitting of applications is done. Irrigated cotton on sandy soils should have 20 lbs N./A as a starter followed by 20 lbs. N/A three weeks later, followed by 60 lbs. N/A 6 weeks after planting and 40 lbs. N/A at 9 weeks after planting. Irrigated cotton on sandy clay loam soil should have 30 lbs. N/A at planting followed by 90 lbs. N/A at 6 weeks after planting. Generally, the unirrigated fields do not need an application after the 6 week application.