The Balance Of Nutrient Between The Strawberry Absorption And Soil Supply Under The Intelligent Control Model

High fertilizer amount caused the deterioration of soil physical and chemical properties in greenhouse soil.The problem of soil secondary salinization raised,which seriously affected the normal cultivation and management of plants.Therefore,six groups of different dosage of nitrogen,phosphate and potash were set up in the greenhouse experiment with strawberry as the material.There were S-A(N 0 kg·hm^-2、P₂O₅120 kg·hm^-2、K₂O 160 kg·hm^-2)、S-B(N 180 kg·hm^-2、P₂O₅0 kg·hm^-2、K₂O kg·hm^-2)、S-C(N 180 kg·hm^-2、P₂O₅kg·hm^-2、K₂O 0 kg·hm^-2)、S-D(N 90 kg·hm^-2、P₂O₅60 kg·hm^-2、K₂O 80 kg·hm^-2)、S-E(N 180 kg·hm^-2、P₂O₅120 kg·hm^-2、K₂O 160 kg·hm^-2)、S-F(N 270 kg·hm^-2、P₂O₅180 kg·hm^-2、K₂O kg·hm^-2).Soil and plant samples were collected at seedling stage,bud stage,swelling stage,early result,mid-term result,late result and end period of strawberry to explore the dynamic change rule of plant and soil nutrient index during the growth period and the relationship between fertilization and fertilizer amount.It provides theoretical guidance for the intelligent greenhouse fertilization control system,which can fundamentally reduce the occurrence of soil salinization.The results indicated that:1.Different fertilization treatments had significant effects on soil 0～20cm,20～40 cm soil EC,nitrate nitrogen,available phosphorus and available potassium（P<0.05）,and EC value was significantly correlated with nitrate nitrogen,available potassium and available phosphorus content.All the values increased significantly with the level of fertilization.When the level of fertilization reached S-F,the EC value of 0～20cm soil layer reached1.255m S·cm^-1,and the nitrate nitrogen content reached 532.5mg·kg^-1,which resulted in the accumulation of nitrate nitrogen at the end of growth stage,and increased the risk of soil salinization.2.The proportion of nutrient accumulation of N,P and K during the whole growth period was 1 to 0.71 to 1.97.P was the largest,the nitrogen was the second,and K was the least.Nutrient accumulation in various organs was that the stems and leaves were the highest,followed by the flower and fruit,and the final was the root.During the growth period,the ratio of nutrient absorption in the whole growth period was 5%,22%,4%,7%,32%and 18%.The three peaks of nutrient absorption occurred at seedling stage to bud stage,the end fruit stage and the end stage,respectively,which coincided with the increase of dry matter accumulation rate and the dry matter distribution ratio of flower and fruit.3.There was no significant difference in total nutrient accumulation under different treatments.However,phosphorus and potassium accumulation in S-B and S-C were significantly lower than those in other treatments.The difference of fruit yield and nutrient accumulation under different treatments was significant,and the treatment of S-E was significantly better than that of other treatments.4.Based on the change of soil nutrient law and yield and nutrient uptake and distribution of plants,it was determined that S-E(N 180kg·hm^-2、P₂O₅120 kg·hm^-2、K₂O160 kg·hm^-2)under medium nitrogen,phosphorus and potassium ratio was more conducive to plant uptake and soil salinization.