镁肥用量对直播冬油菜产量和镁肥利用率的影响

Effect of different Mg fertilizer application on yield and magnesium fertilizer utilization rate of direct-sowing rapeseed

设置5个镁肥用量处理,研究施镁对直播油菜(Brassica campestris L.)产量和镁肥利用效率的影响。结果表明,施镁可以显著提高直播油菜产量(P<0.05),MgO用量为45 kg/hm^(2)时产量达最高,比不施镁对照增加387 kg/hm^(2),增长了18.0%。同时,施镁可以提高油菜子粒和角壳占比,降低茎秆占比。施镁明显增加了油菜的单株角果数和每角粒数,2个指标分别在施镁45 kg/hm^(2)和施镁30 kg/hm^(2)达最大,比不施镁对照增加了17.8%和12.1%。施镁增加了油菜各部位镁含量和累积量,角壳和子粒的增加幅度均明显大于茎秆。镁肥表观利用率呈先增加后降低的趋势,MgO用量为30 kg/hm^(2)时达最大,为21.4%,农学效率在MgO用量为15 kg/hm^(2)时最大,为11.7 kg/kg。综合增产效果、养分吸收利用率等因素,该区域应注重镁肥的施用,合适的MgO用量在40~45 kg/hm^(2)。

Five magnesium fertilizer rates were set to study the effect of Mg application on yield and magnesium fertilizer utilization rate of direct-sowing rapeseed(Brassica campestris L.).The results showed that Mg application could significantly increase the yield of direct-sowing rape(P<0.05),and the maximum yield was reached at 45 kg/hm^(2) of MgO,and the yield increase was 387 kg/hm^(2) compared with no Mg application,with a yield increase of 18.0%.Also,Mg application increased the biomass proportion of seeds and pods and decreased the proportion of stems.Mg application significantly increased the number of pods per plant and seeds per pod of rapeseed,reaching the maximum at 45 kg/hm^(2) and 30 kg/hm^(2) of MgO,respectively,which increased by 17.8% and 12.1% compared to the treatment without Mg application.Mg application increased Mg content and accumulation in all parts of rapeseed,and the increase of horn sell and grain was significantly greater than that of the stem.The apparent utilization rate of Mg fertilizer tended to increase first and then decrease,reaching a maximum of 21.4%at 30 kg/hm^(2) of MgO,and the agronomic efficiency was greatest at 15 kg/hm^(2) of MgO,which was 11.7 kg/kg.Comprehensively considering yield,nutrient absorption and utilization,Mg application should be emphasized in this area,and the appropriate MgO application rate was 40~45 kg/hm^(2).