Pot experiments were carried out to study the effects of N forms on root characters in two wheat varieties with different N efficiency.The results indicated that N uptake efficiency of two varieties was different,and the effects of N forms on it were different,the order of N efficiency in QinMaill among N form treatments was CONH_2—N>NH_4~+—N>NO_3~-—N,and the order of that in Yang9817 was CONH_2—N>NO_3~-—N>NH_4~+—N.The results also indicated that root volume,root dry weight, root activity,total absorbing ar...