Studies On Fertilization Index For Tomato Cultivation In Solar-Greenhouse Under Spring Growing Season

With tomato "Jinpeng No.1" as experimental materials, the experiment had set4treatments: the conventional fertilization as control and3different fertilization levels （T1: N711.1g, P₂O₅1511.1g, K₂O462.2g, cow dung46.67kg per plot; T2: N1066.7g, P₂O₅2266.7g, K₂O693.3g, cow dung70kg per plot; T3: N1422.2g, P₂O₅3022.2g, K₂O924.3g,cow dung93.33kg per plot; each plot area was4.7m2） as treatments. By means of thedetermination of tomato fruit yield, quality and the nutrition element contents in differentperiods and different organs of tomato plants, this research studied the effects of differentfertilization levels on tomato yield, quality and nutrient absorption in solar-greenhousecultivation in spring and provided the reasonable fertilization index to improve tomato yieldand quality in solar-greenhouse cultivation. The results were as follows:1. Different levels of fertilization on tomato yieldIn certain fertilization amount（N1182.0kg、P₂O₅655.5kg、K₂O835.5kg、cow dung168.75t per hm2）, with the increase of fertilization amount under same N, P, K ratio, the yieldof tomato significantly improved, and the amount of fertilizer further rose, the yield fell.Compared with the control treatment, tomato yield under T1, T2, T3treatments increased by11.5%,43.4%and25.5%, respectively. Furthermore, the single fruit weight, fruit number andyield per hm2under T2treatment were higher than those of T1and T3treatments.2. Different levels of fertilization on tomato qualityWith the increase of fertilizer amount, the content of NO₃^--N, soluble sugar, solublesolids and the ratio of sugar and acid of tomato fruit all decreased, the content of lycopene andorganic acid ascended. The content of VCincreased first and then decreased with the increasingof fertilizer amount. The content VCunder T2treatment was the highest, soluble solids contentwas higher, the ratio of sugar and acid was medium, while the NO₃^--N content was lower,thus the fruit quality under T2treatment was relatively better.3. Different levels of fertilization on nutrient absorption of tomato plantsWith the increasing of fertilizer amount, the content of N, P₂O₅and K₂O showed anupward trend. Nutrient elements of fruit were varied with different growth stages and fertilization levels. The nutrient element contents of S1, S5and S6fruit increased with theincrease of fertilizer amount; while the nutrient element contents of S2, S3and S4fruit weredifferent because of the differences of tomato yield among treatments.In different growth period, the nutrient element contents of tomato plant in differentorgans were different. In seedling period, the contents of nutrient elements were maximums;and with the increase of fertilization amount, the contents of nutrient elements increased. Indifferent organs, the content of N and P₂O₅was: leaf> stem> root; and the content of K₂Owas: stem> leaf> root. When time went on to the blossom and fruit period, the distribution ofN and K of tomato plant was similar to that in seedlings period, but the content of P₂O₅increased in stem, P₂O₅content in different organs was: stem> leaf> root. As to fruit period,in different organs, the uptake of N and P was: fruit> leaf> root> stem, the uptake of K was:fruit> stem> leaf> root. In addition, in wane period, the N and P₂O₅content of roots andleaves slightly elevated and P₂O₅content significantly increased, the allocation of nutrientelements in the remaining organs was same to that in fruit period.Taken yield and quality into consideration, T2was the optimum amount of fertilizer.Thus, the recommended fertilization quantity for each hm²was: N1182kg, P₂O₅655.5kg,K₂O835.5kg, cow dung168.75t; Under this fertilization level, tomato had higher yield andbetter quality; meanwhile, the nutrient absorption value of tomato plant per kg （dry weight）was: nitrogen absorption capacity25.03g, total phosphorus absorption capacity4.02g, totalpotassium absorption capacity54.57g, which meant the absorption of N, P₂O₅and K₂O was1.38kg,0.22kg and3kg per1000kg respectively. Therefore, the nutrient demand of tomatoplant was K> N> P.