不同测墒补灌处理对冬小麦产量及光合特性的影响

为了明确测墒补灌对冬小麦产量和干物质积累的影响,以高产优质冬小麦‘烟农999’为材料,试验设置5个水分处理：W0全生育期不浇水,Wck为传统灌溉处理（对照）,W70、W75、W80为测墒补灌处理,于拔节期和开花期分别补灌至土壤相对含水量的70%、75%、80%。结果表明：（1）各处理之间相比较,W75籽粒产量和水分利用效率最高,分别为11438.85 kg/hm ²、25.78 kg/(hm ²·mm),比传统灌溉处理提高了12.12%、21.2%。（2）W75处理开花期和灌浆期的叶面积指数、灌浆期的旗叶净光合速率、开花期干物质转移率、灌浆期营养器官对籽粒的贡献率显著高于其他处理。综合分析,本试验条件下W75是‘烟农999’获得高产高水分利用效率的灌溉方案。

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

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.