But nitrogen use efficiency was gradually decreased, and that of treatment W0 was the highest while there was no significant difference among treatment W2, W3 and W4.

• 而氮素利用效率则呈逐渐降低趋势，其中W0处理的氮素利用效率显著高于其他处理，W2、W3、W4处理间无显著差异。