Abstract: To clarify the effects of soil type and nitrogen (N) application level on rice yield and N use efficiency, we conducted a field experiment with four N application levels (N₀ (0 kg N·hm^-2), N₁ (180 kg N·hm^-2), N₂ (270 kg N·hm^-2) and N₃ (360 kg N·hm^-2)) under yellow clay and sandy loam soils with rice cultivars ‘Nanjing 9108’, ‘Yangjing 4227’, ‘Zhendao 18’ and ‘Nanjing 46’ as experiment materials. The results showed that, except for the N₂ treatment of ‘Zhendao 18’, the yields of the other varieties under all N treatments under the yellow clay were significantly higher than that under the sandy loam. The yields of ‘Nanjing 9108’, ‘Yangjing 4227’, ‘Zhendao 18’ and ‘Nanjing 46’ under the yellow clay soil were 23.1%-87.4%, 12.2%-39.8%, -1% to 34.7% and 2.2%-20.9% higher compared with the yields under the sandy loam soil, respectively. The number of panicles and seed setting rate of all ricevarieties were higher under the yellow clay soil, while the number of grains per panicle was higher in sandy loam soil. Soil type and its interaction with N application level significantly affected rice yields and yield components. The positive effects of N addition on yield were stronger in sandy loam soil than that in yellow clay soil. Nitrogen use efficiency was decreased with increasing N fertilizer application level, while the lower agronomic utilization of N was found in yellow clay soil for all rice varieties. Soil type had a significant effect on the agronomic utilization of N, while soil type and N level interacted to affect N apparent utilization.

Key words: rice, yellow clay soil, sandy loam soil, nitrogen application level, yield, nitrogen use efficiency.