施硅量对旱作水稻产量和干物质积累的影响

【目的】明确直接播种雨养为主的旱作水稻的硅肥最佳施用量并揭示硅肥增加产量的机制。【方法】以绥粳18为材料进行两年大田试验,设计0、15、30、45、60和75 kg/hm ²的有效硅用量(用Si₀、Si₁₅、Si₃₀、Si₄₅、Si₆₀和Si₇₅表示),研究不同硅肥用量对旱作水稻生理指标、干物质转运和产量构成因素的影响。【结果】施加硅肥显著增加了旱作水稻的产量,二次回归方程分析表明施用有效硅量47.68 kg/hm ²可获得最大理论产量,当有效硅用量为30~47.68 kg/hm ²时,硅肥显著提高了根系活力、叶片SPAD值和叶面积指数,协调了茎叶干物质向穗部的转移,延缓了后期叶片的衰老,每穗粒数提高了23.62%~24.63%,千粒重提高了8.94%~10.08%,优化了穗粒结构进而增产38.42%~110.20%;有效硅施用量为47.68~75 kg/hm ²时,生育后期加快了茎叶干物质向穗部转移,加速了叶片衰老,不利于籽粒的持续性灌浆,影响了每平方米穗数、每穗粒数和千粒重进而影响产量。【结论】对于绥粳18而言,适宜吉林省中部地区旱作水稻高产高效的最佳有效硅肥施用量为30~47.68 kg/hm ²。

Effect of Silicon Application Rate on Yield and Dry Matter Accumulation of Rice Under Dry Cultivation

【Objective】It is very important to clarify the best application amount of silicon fertilizer in upland rice and reveal the yield-increasing mechanism of silicon fertilizer.【Method】A two-year field experiment was conducted with Suijing 18 as material at the effective silicon levels of 0, 15, 30, 45, 60 and 75 kg/hm ²(labeled as Si₀, Si₁₅, Si₃₀, Si₄₅, Si₆₀ and Si₇₅), to study the effects of different silicon fertilizer rates on physiological indexes, dry matter transport and yield components of rice under dry cultivation.【Result】Silicon fertilizer application significantly increased the yield of rice under dry cultivation. The quadratic regression equation analysis showed that the maximum theoretical yield could be obtained at the effective silicon level of 47.68 kg/hm ². At the levels ranging from 30 to 47.68 kg/hm ², silicon fertilizer significantly increased root activity, SPAD value and leaf area index, coordinated the transfer of dry matter from stem and leaf to panicle, and delayed the senescence of leaves in late growth stage. Meanwhile the number of grains per panicle increased by 23.62%–24.63%, and 1000-grain weight increased by 8.94%–10.08%, the panicle-grain structure was optimized, and the yield increased by 38.42%–110.20%. When the amount of effective silicon was more than 47.68–60 kg/hm ², the effective tiller number was low, the dry matter transfer from stem and leaf to panicle was accelerated during late growth stage, as well as the leaf senescence, which was not favorable to the continuous grain filling. As a result, the number of panicles per square meter, the number of grains per panicle and 1000-grain weight were negatively affected, causing a drop in grain yield. 【Conclusion】For Suijing 18, the optimal silicon fertilizer application amount suitable for high yield and efficiency of rice under dry condition is 30–47.68 kg/hm ² in the central region of Jilin Province.