Effects of fertilizer application patterns on the seedling rape freezing resistance

[Objectives]A field experiment was conducted to study the effects of fertilizer application patterns on the seedling rape freezing resistance and yield,so as to provide a reference basis for guiding the efficient fertilization,freezing resistance and increasing yield on rape. [Methods]Under the condition of certain total amount of K and P fertilizer application in the whole growth period of rape,the experiment set seven treatments according to different ratio of K and P application in base and seedling fertilizer.[Results]The results showed that compared with CK treatments where all the K and P were applicated in base fertilizer,the catalase activity,the contents of proline,chlorophyll,soluble sugar in the leaf of seedling rape were significantly higher( P0.05) under three treatments including 150 kg·hm-2P and 90 kg·hm-2K application in base fertilizer( T1),75 kg·hm-2P and 180 kg·hm-2K application in base fertilizer( T2),and 75 kg·hm-2P and 90 kg·hm-2K application in base fertilizer( T3),but the content of MDA was significantly lower( P0.05). In T3 treatment,the catalase activity,the contents of proline,chlorophyll,soluble sugar in the leaf of seedling rape were significantly higher than other treatments,but the content of MDA was significantly lower than others. Under three treatments including 180 kg·hm-2K with no P application in base fertilizer( T4),150 kg·hm-2P with no K application in base fertilizer( T5),neither P nor K application in base fertilizer( T6),the catalase activity,the contents of proline,chlorophyll,soluble sugar in the leaf of seedling rape were significantly lower( P0.05) than CK,but the content of MDA was significantly higher( P0.05). In T3 treatment,the rape yield was significant higher than other treatments. [Conclusions]By setting suitable ratio of K and P application in base and seedling fertilizer under certain total amount of K and P fertilizer application,the seedling rape freezing resistance could be significantly improved,and this is also very meaningful for the utilization of fertilizer and ecological protection.