Effects Of The Different Slow-release Fertilizers On Over-Summer Cultivation And Soil Nutrients Of Tomato In Greenhouse

Tomato(Lycopersicon esculentum Mill)is widely cultivated and consumed vegetable crop in the world and China is the world’s largest country on producing and consuming of tomatoes;April～October are the main seasons for tomato cultivation in cold northern China.In recent years,the cultivation of tomato over-summer in greenhouse has gradually become an important crop for rotation;In planting,the growth period of tomato is long,the phenomenon of blind and excessive fertilization is very common,the amount of common chemical fertilizer is too large,the number of topdressing times is more and the utilization rate of chemical fertilizer is low,which greatly wa stes all kinds of resources and reduce the yield and the quality of tomato products in summer and autumn such as excess level in nitrate.Therefore,how to solve the above problems becomes a hot research.Slow-release fertilizer has the advantages of long nutrient release period,difficult to volatilize,leaching and fixation,and high utilization rate.The application of slow-release fertilizer can offer the nutritional needs of the whole crop growth period without or only a small amount of topdressing,reduce the cost of fertilizer,and have a wide range of applications,and can increase production and efficiency for most of crops.At present,the main research and application for slow-release fertilizer in China is focusing on tobacco,grain crops(wheat,corn,rice,potato,etc.)and a few fruits(apple,banana,citrus,grape,peach,etc.),but the application and research on vegetable crops are relatively few.Hence,it is necessary to launch the study of slow-release fertilizer on tomato production of summer and autumn in order to realize the strategic goal that reduce the application of chemical fertilizer and enhance the efficiency of chemical fertilizer in national vegetable production.In this experiment,a plastic greenhouse field test was conducted with tomato as the material,and 6 kinds of slow-release fertilizers were applied(Sazuoling slow-release fertilizer,Olv No.1 slow-release fertilizer,Olv No.5 slow-release fertilizer,Ultramax slow-release fertilizer,Woshibao slow-release fertilizer,Pradan slow-release fertilizer),with no chemical fertilizer treatment and conventional ordinary compound fertilizer treatment as control,over-summer tomato cultivation in the greenhouse.The effects of the six different slow-release fertilizers tested for the over-summer cultivation of tomatoes in greenhouses were specifically studied.The growth,physiology,fruit yield and quality of tomatoes were regularly tracked and monitored.At the same time,the effects of different slow-release fertilizers on soil nutrient and nitrogen utilization in greenhouse were studied;aimed to clarify the actual effect of slow-release fertilizers in the production of over-summer tomatoes in greenhouses and screen ou slow-release fertilizers,to provide the technical basis for reducing the use of fertilizer and extending the application of slow-release fertilizer in the production of protected tomato.The results of this study are as follows:(1)Different slow-release fertilizers have different effects on the cultivation of tom ato oversummer,and suitable slow-release fertilizers can replace common fertilizers.(2)The suitable sustained-release fertilizer can promote tomato growth,among which the Olv No.1 slow-release fertilizer has the most significant effect,which increased the plant height,stem diameter and leaf number;promoted dry matter accumulation of root;enhanced the dry matter accumulation rate of tomato in the later stage of tomato growth.(3)In the later stage of tomato growth,the level of alkali-hydrolyzed nitrogen,available phosphorus and available potassium of soil treated with 6 kinds of slow-release fertilizer were increased in different degrees compared with that of common fertilizer.Meanwhile,the tracking determination showed that compared with common fertilizer,6 kinds of slow-release fertilizer increased the nitrogen utilization rate of tomato plants in the middle and later stage.(4)Compared with common fertilizer treatment,slow-release fertilizer treatment reduced the early yield of tomato fruit,but increased the middle and late yield and total yield of tomato.The average yield per plant of the Woshibao slow-release fertilizer was the highest,which was 21.4% higher than that of common fertilizer.(5)The cost of producing tomato per unit yield was reduced by 6 kinds of slow-release fertilizer,and the Woshibao slow-release fertilizer has a lowest cost for processing tomato per unit yield,which lowered the cost by 58.17% comparing common fertilizer.In conclusion,two kinds of slow-release fertilizer,Olv No.1 slow-release fertilizer and Woshibao slow-release fertilizer,were selected for over-summer cultivation in greenhouse tomato.