Abstract: In order to clear the effects of biochar addition on yield formation in early rice, a field experiment was conducted with Zhongzao 39 as material in early season in 2015 and 2016. The grain yield, yield components, dry matter production and harvest index were compared between with biochar （C1, 20 t/hm2） and without biochar addition （C0, 0 t/hm2）under three nitrogen levels（N0, 0 kg N/hm2; N1, 90 kg N/hm2; N2, 150 kg N/hm2）. The results showed that C1 treatment produced lower grain yield than did C0 treatment except N1 level in 2015. The average grain yield under C1 treatment was 12.85% lower than that of C0 treatment in 2016. C1 treatment had lower 1000-grain weight than C0 treatment by 2.46%～4.12% and 2.55%～3.76% in 2015 and 2016, respectively. C1 treatment had higher dry matter production after heading than C0 treatment, while harvest index was lower in C1 treatment than in C0 treatment. The maximum difference in harvest index between C1 treatment and C0 treatment was 5.33 percentage and 4.00 percentage in 2015 and 2016, respectively. These results indicated that biochar addition could decrease 1 000 grain weight and harvest index, and consequently reduce the grain yield of early rice.

Key words: biochar, early rice, grain yield, grain weight, harvest index

摘要： 为探明生物炭施用对早稻产量形成的影响，以中早39为材料，于2015年和2016年早季在湖南省浏阳市永安镇开展大田试验，在不同施氮水平下（N0，0 kg N/hm2；N1，90 kg/hm2；N2，150 kg N/hm2）对施炭（C1，20 t/hm2）和不施炭（C0，0 t/hm2）处理早稻的产量、产量构成、干物质生产和收获指数进行了比较。结果表明，除2015年N1水平外，C1处理的产量均低于C0处理，其中，2016年C1处理的平均产量比C0处理低12.85%；2015年和2016年C1处理的千粒重分别比C0处理低2.46%～4.12%和2.55%～3.76%；齐穗后 C1处理干物质生产量高于C0处理，但其收获指数低于C0处理，2015年和2016年C1处理与C0处理的收获指数最大相差5.33个和4.00个百分点。由此可见，施用生物炭显著降低了早稻千粒重和收获指数，进而导致早稻减产。

关键词: 生物炭, 早稻, 产量, 粒重, 收获指数