Effects Of Soaking Seed And Spraying Foliar Fertilizer On Growth And Yield Of Rapeseed Under Rice Straw Returning To Field Condition

Straw returning to the field is an effective way to realize the utilization of agricultural waste resources,but straw returning to the field increases the soil porosity,increases the risk of drought,low temperature,and other disasters at the seedling stage of rape,resulting in low seedling emergence rate and seedling formation rate,and inhibits the growth and development of rape.To alleviate the adverse effects of straw returning to the field on the emergence of rapeseed,and explore technical approaches to improve the quality of rapeseed emergence and cultivate strong seedlings under the condition of straw returning to the field,this study used“Fengyou 737”,a popular variety of Brassica napus,as the material.The effects of gibberellin,Organic Potassium Fertilizer soaking seed,and foliar application of Organic Potassium Fertilizer and New America Star on seedling quality,growth and development,seedling physiological characteristics,and yield compositions of rapeseed under straw returning condition were studied.The main research results are as follows:(1)By comparing the effects of different dilution ratios of Organic Potassium Fertilizer solution on the germination of rapeseed,it was found that the seed germination potential was significantly increased by 1:100 times the solution,and the seed germination index and vitality index were increased by 6.7%and 17.1%,respectively.The germination rate under low-temperature condition was significantly improved by 100 times liquid soaking seeds,and the vigor index under drought conditions and seedling growth under low-temperature drought conditions were significantly improved by increasing the activity of antioxidant enzymes of seedlings,indicating that the 1:100 times liquid Organic Potassium Fertilizer soaking seeds was beneficial to improve the vigor and stress resistance of rapeseed during the germination period.The effects of soaking seeds in a 40 mg/L gibberellin solution on the vitality and stress resistance of rapeseed seeds were examined based on the lab’s prior findings.The germination index and vitality index of rapeseed seeds were found to have grown dramatically by 14.7%and 23.0%,respectively,while the peroxidase content in rapeseed seedlings had increased significantly.The content of MDA was decreased under low-temperature drought stress,which significantly improved the growth and development of seedlings under low-temperature drought stress.(2)The seed soaking with 40 mg/L gibberellin solution and 1:100 times liquid Organic Potassium Fertilizer.Under rice straw returning the effects of 40 mg/L gibberellin solution and 1:100 times solution Organic Potassium Fertilizer soaking seeds on field emergence rate of rapeseed were analyzed.It found that the two soaking treatments significantly increased the field emergence rate of rapeseed under straw returning condition by 59.3%and 23.9%,respectively,and also increased SPAD,leaf area,plant height,and root length of rapeseed seedlings under straw returning condition.These findings suggested that the two types of soaking may greatly enhance the quality of emergence and effectively reduce the negative impacts of straw returning on the emergence and growth of rapeseed seedlings.(3)After soaking seeds combined with Organic Potassium Fertilizer 750 ml/hm~2 and New America Star 900 ml/hm~2 were applied on the leaf surface twice before overwintering and at the regreening stage,the effective number of kernels,the number of kernels,the 1000-grain weight and yield,the grain oil content and the grain protein content of rapeseed at maturity stage were increased.Among them,the Organic Potassium Fertilizer soaking seed under straw returning combined with spraying foliar fertilizer Organic Potassium Fertilizer increased the yield the most,and the final yield per unit area increased to 3457.61 kg/hm~2.In conclusion,soaking seed and spraying foliar fertilizer together can effectively reduce the negative effects of straw returning on rapeseed emergence and growth,improve rapeseed yield and quality,and offer a technical method for raising rapeseed yield and income under the condition of straw returning.