钾硅肥不同用量对水稻-油菜生长、钾素吸收及钾素平衡的影响

Effects of Different Potassium-Silicon Fertilizer Application Rate on Rice-Rape Growth, Potassium Absorption and Potassium Balance

利用盆栽试验研究了钾硅肥不同用量对水稻-油菜轮作模式下作物生物量、钾素吸收利用和土壤钾素平衡的影响。结果表明,当施钾量为1.5g K_2O/盆,钾硅肥与硫酸钾效果相同,水稻-油菜生物量与对照相比显著增加,水稻生物量增加41.0%~42.2%,油菜生物量增加19.7%~20.8%,两季作物钾素吸收量也显著增加,钾硅肥用量增加一倍后两季作物生物量增加幅度均最高,分别为46.9%和21.4%,当钾硅肥施用量为3.0g K_2O/盆时,两季作物钾素吸收量也最大,分别为1.36和0.54g K_2O/盆。随着钾硅肥用量的增加,水稻-油菜的钾素真实利用率呈降低的趋势,钾硅肥施用量为1.5和3.0g K_2O/盆时,钾素真实利用率分别为59.1%和53.5%,经过两季作物种植后,硫酸钾处理、钾硅肥处理和2倍钾硅肥处理其偏钾平衡值分别为1.1、0.9和0.6,表明硫酸钾处理土壤钾素处于亏缺状态,而施用钾硅肥的处理土壤钾素均处于盈余状态,其中当钾硅肥施用量为3.0g K_2O/盆时,土壤钾素盈余量最大。与对照比较,施用钾硅肥可以显著增加土壤速效钾和缓效钾含量,且随着钾硅肥用量增加二者含量明显增加。钾硅肥可以替代硫酸钾施用,当季施用量应和硫酸钾含钾量相等或略低于硫酸钾含钾量,连续种植第二季作物时,应适当补施钾硅肥或硫酸钾。

A pot experiment was conducted to study the effect of different potassium-silicon fertilizer application rate on rice-rape growth, nutrient absorption and soil potassium balance. The results showed that when potassium application was at 1.5g K2O/pot, there were similar results for potassium-silicon fertilizer and potassium sulfate treatments. Both fertilizers significantly increased the biomass and potassium accumulation of rice and rape, the rice biomass was increased by 41.0%-42.2%, the rape biomass was increased by 19.7%-20.8%. Increase of potassium- silicon fertilizer application by one fold, the rice and rape biomass increased by 46.9% and 21.4%, respectively, which were the highest. When potassium-silicon fertilizer application rate was at 3.0g K2O/pot, the potassium accumulation amount of rice and rape were at the highest, which were 1.36 and 0.54g K2O/pot, respectively. The real nutrient utilization efficiency was reduced with the increase of application rate of potassium-silicon fertilizer. When potassium- silicon fertilizer application rate was at 1.5g K2O/pot and 3.0g K2O/pot, the real nutrient utilization efficiency were 59.1% and 53.5%, respectively. After rice-rape harvest, the partial K balance of potassium sulphate, potassium-silicon fertilizer and two times potassium-silicon fertilizer treatments were 1. 1, 0.9 and 0.6, respectively. The soil potassium of potassium sulphate treatment was deficient, the soil potassium of potassium-silicon fertilizer and two times potassium- silicon fertilizer treatments were at surplus. The content of soil available K and slowly available K increased with the application of potassium-silicon fertilizer. The potassium-silicon fertilizer could replace water-soluble potassium fertilizer, the application rate were equal or slightly lower than the same potassium nutrient supply with water-soluble potassium fertilizer. When the second quarter crop is being planted, the potassium-silicon fertilizer and water-soluble potassium fertilizer should be supplied.