Abstract: Effects of local irrigation in root zones on absorption and use of nitrogen from different root zones were studied on maize grown in split-root containers. Maize was irrigated in both halves of the pot (control, C) or water was continuously supplied to the one-half of the pot and the other half kept dry (fixed partial root zone irrigation treatment, F), or water was alternatively supplied to two halves of the pot (alternative partial root zone irrigation treatment, A). (15NH4)2SO4 was applied to one of the two root zones and (14NH4)2SO4 to another root zone. The results was as follows: For A treatment, during the first five days when irrigation water was supplied or re-supplied to one half-root zone, the nitrogen inflow of the root system in the irrigated zone was significantly increased as compared with that of the control and other root zones, suggesting that A stimulated the compensation of nitrogen uptake again and again. Take a long view, the amount of N absorption from two root zones of A almost equalized, and the use and residue and also lose efficiency of N fertilizer applied to two zones was close to each other. As for F treatment, the N in plant was mainly from the irrigated root zone. The use and lose efficiency of N fertilizer applied to the irrigated zone increased obviously as compared with the non-irrigated zone, while the residue efficiency was the contrary. The use efficiency of N fertilizer for A was higher than that of the non-irrigated zone of F, and lower than the irrigated zone. As compared with C, both F and A increased the N use efficiency of maize.

Key words: Maize (Zea mays L.), The method of local irrigation in root zones, Different root zones, Nitrogen, Absorption and use