Research Of Fertilizer Demand Of Strawberry With Substrate Culture In Different Periods

By employing the Quadratic regression general rotation design, this experiment studiedthe effects of different growth stages with different application ratio of N, P and K fertilizeron vegetative growth, fruit quality and yield per plant of Allstar strawberry using vermiculiteas the substrate culture. The ternary quadratic regressions were established according todifferent application ratio of N, P and K and the yield per plant equations. Also searched theoptimum combinations of N, P, K by the software on computer. The obtained results weresummarized as follows:1The regressive model of seedling stage is:=96.05459+4.30426X₁-1.37380X₂+1.79097X₃-5.54936X₁²-6.77442X₂²-3.42450X₃²-2.98500X₁X₂-1.59750X₁X₃-1.02750X₂X₃Regressive analysis shows that Strawberry’s yield per plant can reach96.1gwhenthenutrient content was N3.3mmol/l, P0.4mmol/l, K1.5mmol/l. With the regard to main effecton yield, the three kinds of fertilizers were showed in the order as N>P>K. To the interactiveeffects on yield, the three kinds of fertilizers in the order as NP>NK>PK. When the level of Nis from6.6mmol/L to7.8mmol/L，the level of P is from0.7mmol/L to0.9mmol/L，the levelof K is from2.5mmol/L to3.1mmol/L，the probability is95%that the yield of plant exceeds85.3g.2The results shows that different application ratio of N, P and K fertilizer of squaring stage’snutrient fluid were not significant to effects of strawberry yield.3The regressive model of flowers and the fruiting is:=93.00506+4.31681X₁-0.72497X₂+1.28375X₃-6.22027X₁²-6.56817X₂²-352902X₃²-2.62500X₁X₂-1.37500X₁X₃-1.12500X₂X₃Regressive analysis shows that Strawberry’s yield per plant canreach189.41gwhen thenutrient content was N10mmol/l, P4mmol/l, K10mmol/l. With the regard to main effect onyield, the three kinds of fertilizers were showed in the order as N>P>K. To the interactiveeffects on yield, the three kinds of fertilizers in the order as NP=NK>PK. When the level of Nis from12.8mmol/L to14.4mmol/L，the level of P is from2.9mmol/L to3.2mmol/L，thelevel of K is from9.5mmol/L to12.7mmol/L，the probability is95%that the yield of plantexceeds84.57g.4The regressive model of fruiting period is: y=69.5627073-8.84711636X₁+4.79278323X₂+1.384556437X₃+5.64955919X₁²+3.21357640X₂²+13.11307104X₃²-7.75000000X₁X₂-7.75000000X₁X₃Regressive analysis shows that Strawberry’s yield per plant can reach93.1g whenthenutrient content was N14mmol/l, P3mmol/l, K11.5mmol/l. With the regard to main effecton yield, the three kinds of fertilizers were showed in the order as N>K>P. To the interactiveeffects on yield, the three kinds of fertilizers in the order as NP>NK>PK. When the level of Nis from14.1mmol/L to15.4mmol/L，the level of P is from2.8mmol/L to3.2mmol/L，thelevel of K is from9.5mmol/L to11.7mmol/L，the probability is95%that the yield of plantexceeds81.86g.5Picking timeThe results shows that different application ratio of N, P and K fertilizer of harvestperiod’s nutrient fluid were not significant to effects ofstrawberry yield.