Effect of Urea Coating and Irrigation Scheduling on Efficiency of Water Use and Nitrogen Fertilizer by Using Neutron Probe


Field study was conducted at soil and water resources center research station, Ministry of Science and Technology, 30 km east of Baghdad , ( longitude 44.140 east, latitude 33.140 north altitude 34m over sea level), in a clay loam soil classified as Fine loamy, Mixed, hyperthermic, typic, Torrifluvents. Completely randomized block design was used with three replicates. Access tubes of neutron probe was installed in each plot to 120 cm depth, the tensionic tube was also installed around the access tube ( three tube to each plot at three depth 0 -20, 20 – 40, 40 – 60 cm ). Corn seeds (zea mays L.) were cultivated by using 53333 plant/h as average. Amount of required irrigation water was added based on depletion 60% of available water to moistening 0–40 cm from planting to flowering stage and from 0-60 cm from flowering to the end of growing season. Nitrogen was applied in tow levels 100,200kg N/ha as urea ( U ) and coated Urea ( coated by crude oil + phosphoric acid + phosphogypsum ) ( UPFG ) to all treatment .Results showed using Neutron probe give us a perfect quantity determination of irrigation water application in each irrigation and reducing of water loses out of root zone. High levels of Nitrate detected in 13.1, 15,1 Kg / ha and 18.0, 23.9 kg / ha for the tow levels 100, 200 kg N / ha respectively in the depth 0 – 20, 20 – 40 , in the first period of application for all treatment .Results also showed that fertilizer use efficiency decrease from 57.8 to 31.2 kg seed / kg N and 61.8 to 36.37kg seed / kg N for the tow levels 100 to 200 kg N / ha respectively but water use efficiency increased from 0.85 to 0.91 and from 0.906 to 1.066 kg seed/m3 in the same treatment for Urea and coated Urea respectively. Both water use efficiency and fertilizer use efficiency increased by using coated urea as compared with urea.


Urea, Neutron prode