Study On The Nutrient Solution Selection And Key Techniques Of Floating Seedling Raiseing For Chinese Cabbage

The off-season vegetable cultivation is the leading industry and main source of income for local farmers in Taibai county.Since 2009,the county's Chinese cabbage,cabbage,broccoli,broccoli and radish and other cruciferous vegetables are endangered by clubroot disease.The infected area of vegetables has gradually expanded,and the degree of damage has increased year by year,which has severely restricted the development of local vegetable industry.In 2015,the county introduced the floating seedling raising technology and promoted the use of alpine vegetable production,which has found an effective method for the prevention of cruciferous root disease.In this paper,we studied the growth characteristics and physiological indexes of Chinese cabbage seedlings through different tests of different nutrient solution formulations,comparative experiments with different formulation matrices,and common problems in floating seedlings and overcoming measures.The effect of culture medium on the growth and development of Chinese cabbage seedlings was aimed at screening out the best nutrient solution formula for floating cabbage seedlings and the matrix formula that made full use of local natural resources.The research summarized status of vegetable industry suitable Taibai Mountainous region,soil,climate,etc.for Chinese cabbage floating seedlings supporting technology.The results of the study are as follows:1.According to the required fertilizer characteristics of Chinese cabbage,five kinds of soilless nursery nutrient solution formulas were designed.The'Hoagland'standard formula was used as a control to study and analyze the comprehensive trait indexes of Chinese cabbage seedlings grown from different formulations of nutrient solution.The experimental study showed that Formula V?Ca?NO₃?₂ 707 mg/L,KNO₃ 140 mg/L,NH₄NO₃ 134 mg/L,KH₂PO₄ 169 mg/L,K₂SO₄120 mg/L,MgSO₄ 243 mg/L?,Universal trace elements formula(EDTA-2NaFe 30 mg/L,H₃BO₄ 2.86 mg/L,MnSO₄ 2.13 mg/L,ZnSO₄ 0.22 mg/L,CuSO₄0.08 mg/L,?NH₄?₆Mo₇O₂₄ 0.02 mg/L)Floating cabbage seedlings can increase plant height and stem diameter,increase the amount of bioaccumulation in the aboveground and underground parts of Chinese cabbage seedlings,and are more conducive to promoting root development,cultivating strong seedlings,and shortening time for seedling cultivation after field planting.As a nutrient solution for floating cabbage seedlings,it is popularized and applied.2.The local alpine humus soil in the Taibai Mountain area was selected as the main matrix supplement material,and mixed with the commodity matrix in different proportions,and floating seedling tests for the substrates with different ratios were conducted.The results showed that the treatment of J3?50%Taibai local humus soil and 50%of the substrate?in the Chinese cabbage germination rate,seedling plant height,stem growth,and aboveground and underground bioaccumulation the root-shoot ratio and chlorophyll content all performed best.It can be seen that application of local humus soil as a supplemental substrate for vegetable seedlings has a wide range of sources,convenient materials,and low cost,and has a certain value for implementation.3.In response to problems such as blue-green algae and salinization produced during the production of floating seedlings,different methods of prevention and control were used for testing.The test results showed that adding a certain concentration of CuSO₄ and Al₂?SO₄?₃ in the floating pool,a certain amount of pine needles,cypress leaves can inhibit the green algae produced during floating seedling raising;by adding appropriate amount of Taibai native humus soil and a certain proportion of nutrient solution are beneficial to prevent salinization during nursery.