— 24 IREC Farmers' Newsletter No. 200 — Spring 2018 Nitrogen performance Soil nitrogen Interestingly for most of the farms where the trials were conducted, there was much more nitrogen in the soil at the tail drain end of the field compared with the head ditch as shown in Figure 1. In fact, the tail drain often had more than twice the amount of nitrogen compared with the head ditch. With the pre-season soil test showing such a potential difference between the top and bottom, perhaps this should be considered when developing a nitrogen budget for the field. In the Darling Downs and Gwydir (Moree) trials, irrigation did not change the relative proportions of nitrogen within the field, a scenario that is ideal for good nitrogen management. Figure 1. Distribution of soil nitrogen in the field following the equivalent of two irrigations Results Darling Downs MacIntyre Gwydir_Weemelah Gwydir_Moree Namoi Macquarie MIA 100% 50% 0 50% 100% 150% 200% 250% 300% Soil test results — 24 IREC Farmers' Newsletter No. 200 — Spring 2018 Save water and nitrogen on cotton Irrimate flow meter used in the trials. Flow rates and other data collected allowed volume of runoff, infiltration and deep drainage to be calculated.