周年秸秆还田量对南方双季稻生长及产量的影响

Effect of Annual Straw Returning Amount on Growth and Yield of Double Cropping Rice in South China

为探究适合南方双季稻高产稳产的秸秆还田量,连续2年(2016—2017)通过大田试验研究不同秸秆还田量对早稻和晚稻分蘖、株高、干物质积累量及产量构成的影响。试验设置5个不同比例秸秆还田量:CK:秸秆不还田;S1:25%早、晚稻秸秆量还田;S2:50%早、晚稻秸秆量还田;S3:75%早、晚稻秸秆量还田;S4:100%早、晚稻秸秆量还田。结果表明:全量秸秆还田抑制早稻分蘖而显著促进晚稻分蘖,25%、50%及75%量还田对早、晚稻生长前期的分蘖促进效果不显著,在中后期促进作用显现;75%量还田及全量还田较CK显著促进晚稻株高增长,平均提高了8.15 cm;不同秸秆还田量较不还田处理均提高了早、晚稻成熟期的干物质累积量,且半量还田在早稻季差异达显著性水平(P<0.05),较CK提高了8.0%,50%、75%及100%量还田在晚稻季差异达显著性水平,平均提高了13.3%,但不同还田量之间差异不显著(P>0.05);早、晚稻产量在不同秸秆还田量下均高于秸秆不还田,半量还田促进早稻产量方面的效果最显著,与不还田处理相比差异达显著水平(P<0.05),增产6.92%;50%、75%及100%量还田较CK均显著提高了晚稻产量(P<0.05),增产幅度分别5.33%、7.50%和8.23%,不同秸秆还田量间在促进早、晚稻增产方面的效果差异不显著(P<0.05)。研究结果显示,短期看,在南方双季稻生产中,半量早稻和晚稻秸秆均还田对提高早稻产量效果最优,而全量还田对晚稻最优,而秸秆还田对水稻产量的长期效应如何,还需要进行长期定位试验研究。

To explore the straw returning amount suitable for high and stable yield of double cropping rice in South China,the effects of rice straw returning amount on tiller number,plant weight,dry matter accumulation and early and late rice yield were studied through a 2 years(2016 to 2017)field experiment.5 different ratios of straw returning were set up in the experiment:no straw addition(CK),25%straws returning(S1),50%straws returning(S2),75%straws returning(S3)and 100%straws returning(S4).The results showed that 100%straws returning inhibited early rice tillering and promoted late rice tillering;25%,50%and 75%straws returning treatments had no significant effect on early and late rice in early growth period,but showed positive effect at the middle and late growth stages.The late rice plant height of 75%and 100%straw returning treatments were significantly higher than that of no straw addition treatment,with the average increase of 8.15 cm.Compared with no straw addition,the dry matter accumulation of early and late rice under all straw returning treatment increased,and the difference of 50%straw returning treatment in early rice was significant(P<0.05),which was 8.0%higher than that of CK;50%,75%and 100%straw returning treatments averagely increased the dry matter accumulation by 13.3%,and the difference was significant(P>0.05);however,no difference of dry matter accumulation was observed between different amounts of straw returning.Both the yield of early and late rice in straw returning treatments were higher than that of CK,among them,50%straws returning treatment had the highest early rice yield,with the increase of 6.92%;for late rice,50%,75%and 100%straw returning treatments increased the yield by 5.33%,7.50%and 8.23%,respectively;however,no difference was observed between different amounts of straw returning treatments in both early and late rice.Under this experiment,rerunning 50%straw is the best for increasing early rice yield while 100%is the best for late rice in short time.The long-term effect of straw returning on rice yield needs to be further explored.