施氮量和基本苗对小麦干物质积累量和产量及氮肥利用率的影响

以高产优质小麦济麦20为试材,研究了冬小麦不同施氮量和基本苗的干物质积累量、产量和氮肥农学利用率的变化。结果表明,同一基本苗条件下,施氮量在0~240 kg/hm2范围内,随施氮量的增加干物质积累量增加;施氮量增至300 kg/hm2干物质积累量降低。同一施氮量条件下,当施氮量为180 kg/hm2(N1处理)和300 kg/hm2(N3处理)时,666.7m2基本苗在10万(M1处理)至15万(M2处理)范围内,随基本苗增加干物质积累量增加;当施氮量为240 kg/hm2(N2处理)时,666.7m2基本苗10万和15万两处理的干物质积累量和籽粒产量无显著差异,并且获得了最高产量,前者的氮肥利用率高于后者。本试验中,过量施氮和过多基本苗均导致产量和氮肥农学利用率降低,综合考虑籽粒产量、经济系数和氮肥农学利用率等因素,以M1N2和M2N1处理较优。

Effects of Nitrogen Rate and Seeding Number on Dry Matter Accumulation, Grain Yield and Nitrogen Use Efficiency of Wheat

The effects of nitrogen rate and seeding number on dry matter accumulation,grain yield and nitrogen use efficiency of wheat cultivar Jimai 20 were studied.The results showed that,under the same seeding number,the amount of dry matter accumulation increased when the nitrogen rate increased from 0 to 240 kg/hm~2(N_2),and decreased when nitrogen rate increased to 300 kg/hm~2.At the same nitrogen rate of 180 kg/hm~2(N_1) or 300 kg/hm~2(N_3),the amount of dry matter accumulation increased when the seeding number increased from 1×10~4(M_1) to 1.5×10~4(M_2) in 666.7m~2 field.At the same nitrogen rate of 240 kg/hm~2(N_2),M_1 and M_2 treatments showed no significant difference in the amount of dry matter accumulation and the yield.Compared with the other treatments,M_1N_2 and M_2N_2 gained the highest grain yield,and the nitrogen agronomical use efficiency of M_1N_2 was higher than that of M_2N_2.With the yield,economic index and nitrogen agronomical use efficiency were considered,the treatments of M_1N_2 and M_2N_1 were recommended.And excessive nitrogen or seeding number would reduce the yield and nitrogen agronomical use efficiency.