Fertilization is an important part of Li Shu’s comprehensive management. Practice has proved that reasonable fertilization can make the tree body develop well, promote flower bud formation, reduce flowering and fruit drop, obtain higher yield, and make the fruit good quality, high sugar content, good color, extend the results of years, enhance the tree to the bad Environmental and pest resistance. 1, fertilization type: Every year, Li Shu draws a lot of nutrients from the soil. In addition to nitrogen, phosphorus, and potassium, these nutrients need calcium, magnesium, iron, and other trace elements. In the sapling stage, Li Shu is required to apply more phosphorus and potassium fertilizers. During the fruit period, nitrogen is the main fertilizer, and the amount of phosphorus and potassium fertilizer should also be guaranteed. 2, fertilization period: (1) Base fertilizer application period: early application of autumn basal fertilizer is generally applied after fruit harvest (August-September), so that it can absorb and store more nutrients, which is conducive to restoring tree vigor and promoting root growth and flower buds. The formation has a significant effect on promoting the growth and flowering of new shoots in the following year. (2) Dressing time: In early spring before flowering (inflorescence has stretched out), the first time to recover fertilizer, mainly nitrogen, phosphorus and potassium. The proportion of three elements depends on the tree potential. The tree vigor is more prosperous and nitrogen is less, and the tree vigor has more flowers and more nitrogen. In the rapid expansion of young fruit, that is, the new vigorous growth period, the second time to top dressing, mainly nitrogen fertilizer. After the fruit is harvested, organic manure is applied to topdressing phosphorus and potash fertilizers. In addition to the above several top dressings, each time the pesticide is used to control pests and diseases, extra-root dressing is carried out, and 0.5% to 1% compound fertilizer and urea are added to the liquid medicine. This can be used to supplement the tree's nutrition at any time. 3, fertilizer amount: Li Shu’s demand for fertilizers is related to the increase in age, the increase or decrease in the amount of results, and changes in environmental conditions. Therefore, it is necessary to look at trees for fertilization and fertilization. (1) Determine the amount of fertilizer according to the size of the tree: The annual small trees that are planted, and apply 50 kg of base fertilizer every spring and fall. And apply 0.1 kg of compound fertilizer, and then increase year by year. After fruiting, fruit trees can produce about 50 kilograms of organic manure each fall, and there are 0.5 kg to 1 kilograms of nitrogen, phosphorus, and potassium compound fertilizers before flowering or during the expansion of young fruit. (2) Determine the amount of fertilizer according to the yield: If the fruit production period is 600 kg to 1,000 kg per mu, apply 2000 kg to 2500 kg excreta, 25 kg to 30 kg urea, 20 kg to 30 kg potassium fertilizer, and phosphate fertilizer. 40 kg to 60 kg. (3) Determine the type and quantity of fertilization according to the phenological period: 1 Fertilization time: from mid-late September to early October; Phenophase: After fruit harvest, flower buds differentiate at the later stage; Fertilizer amount: Each plant applies 50 kg to 100 kg of pre-crop fertilizer. 2 Fertilization time: early April; phenophase: flower buds germinate until flowering; fertilization amount: 0.5 kg-1 kg of chemical fertilizer per plant or 25 kg of young fruit compost of human fecal urine. 3 Fertilization time: from late May to mid-June; phenophase: young fruit and shoots grow rapidly; amount of fertilizer applied: 0.5 kg chemical fertilizer per plant, leaf surface fertilizer. 4 Fertilization time: from late May to the end of August; phenophase: fruit growth, flower bud differentiation, new shoot growth; amount of fertilizer: combined with the fight drugs to add 0.5% of urea or compound fertilizer. Venlo structure is a popular one at present. This architecture uses horizontal girder as main bearer, forming a stable structure with columns. There is consolidation between horizontal girder and column, and hinge is used to connect column and foundation. Pc Board Venlo Greenhouse,Venlo Greenhouse,Venlo Type Pc Sheet Greenhouse JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , http://www.spgreenhouse.com
In Venlo Greenhouse, foundation is made of reinforced concrete and the side wall is made of brick or reinforced concrete plate. The steel frame always use hot dip galvanized light steel. Roof beam adopts horizontal girder structure and using herringbone connection. The horizontal girder bears 2 or more roofs, which is made of aluminum alloy. This material is used as roof structure material and also glass inlay material. Other beams using gutter style to minimize the section. Delighting material of the roof and side wall using the hollow double-layer or multilayer PC board.
PC board is mainly made of PC/PET/PMMA/PP materials, it need sun screen coating to resist ultraviolet resist and ageing, and it is also required to be anti condensation and antidrug.
As a kind of light material, use PC board can greatly reduce the weight of greenhouse structure, and corresponding reduced the size of the steel frame, which saving the cost of steel.