Citrus fruit is an evergreen fruit tree with a long growth period and large nutrient consumption. It has its own special fertilizer requirement law. Rational fertilization can increase tree vigor, increase resistance, and achieve the purpose of high quality, high yield and stable yield. Several issues in local fertilization are now discussed as follows: 1, the rational application of organic fertilizer and inorganic fertilizer. Due to the large amount of organic fertilizers, relatively insufficient fertilizer sources, high transportation costs, and high fertilization rates, some growers reduce their costs and randomly reduce the amount of organic fertilizers, resulting in a lack of organic matter in some orange orchards and affecting tree growth. And fruit quality. If the orchard only applies chemical fertilizers for a long time, it will cause acidification of the soil, reduce fertilizer retention and fertilizer supply capacity, and is not conducive to improving and fertilizing the soil, which is not conducive to the sustainable development of the citrus industry. Therefore, we should adhere to the rational application of organic and inorganic fertilizers to improve the physical and chemical properties of the soil, improve soil fertility, fertilizer supply capacity, improve nutrient utilization. In order to increase the organic matter of the soil, it is possible to build up manure by raising more livestock and poultry; heap up manure by using resources such as straw, weeds, leaves, etc.; and promote green manure by cultivating orchard, fruit trees, and other plants. Cushioning or abdomen returning to the field: Biogas digesters are being built in the area to develop organic fertilizer sources to ensure that organic fertilizer is applied to no less than 3 tons per acre. 2, comprehensive factors determine fertilization appropriate period. Some fruit growers put the basal fertilizers into the spring and topdressing them all together for the purpose of saving labor and saving time, commonly known as “one shellingâ€. The amount of fertilizer is larger, the parts are deeper, and they are not evenly mixed, causing the citrus fruit trees to “starve†wintering. The fertilizer effect moves backwards. When the winter temperature is low, it is often subjected to freezing injury, which is not conducive to the normal growth and development of fruit trees. Fertilizers should be applied in a timely, appropriate, and scientific manner according to the soil fertility status and the needs of nutrients at various stages of citrus growth and development. The absorption peak of nitrogen in adult trees of Satsuma mandarin is in summer, accounting for 60-80% of the total absorbed nitrogen in the whole year. The peak of phosphorus absorption is in August and October, and the peak of potassium absorption is in June-August. If citrus fertilization is applied twice a year, a reasonable period of fertilization should be: strong fruit fertilizer from late June to early July, dominated by nitrogen and potassium fertilizers: wintering fertilizer is applied from mid-to-late October to mid-November. Nitrogen fertilizers, phosphate fertilizers, and organic fertilizers dominate. Special early-season sweet oranges (Taura, Yamakawa, Shimane, etc.) should be applied about 20 days in advance. The fertilization key period should be determined according to the type and nature of fertilizers. If chemical fertilizers are the main factors, summer fertilizers should be re-applied; if organic fertilizers are used as soil, the application of overwintering fertilizers should be emphasized. Should generally focus on wintering fertilizers. 3, pay attention to fertilizer methods to increase fertilizer utilization. Some fruit farmers fertilize as they like, regardless of organic fertilizers and inorganic fertilizers. They do not apply too far and fertilizers are scattered. They are too shallow and too close, and fertilizers are too concentrated. Fertilizer is wasted, and fertilizer damage occurs from time to time. The method of fertilizing the soil should be compatible with the distribution characteristics of the root system, the period of fertilization, the type of fertilizer, the nature of the fertilizer, the amount of rainfall, and the soil texture. The depth of fertilization should be determined according to the depth of root distribution. The location of fertilization should be in the vertical soil layer around the crown. As the soil deepens, the depth of fertilization is gradually deepened; as the crown expands year by year, the fertilization point is gradually moved outwards. It is necessary to exchange direction and position successively; in order to induce deep and broad root development, expand the range of nutrient absorption, and increase the stress resistance of the tree, the fertilizer can be applied to the slightly deeper, farther position of the concentrated distribution area of ​​the root system. In general, the basal fertilizer should be applied deeply, top dressing should be applied shallowly in the growth period, and the phosphate fertilizer that is easily fixed by the soil should be applied deepest to the site where the roots of the hair are most distributed; the citrus field in the paddy field should be applied lightly in the rainy season, and should be deepened in the dry season; Orange gardens should be replanted, and sandy soils need to be applied sparingly. Close planting of saplings is an early result, and it is advisable to use a shallow ring for the growth of horizontal roots. 4. According to the conditions of the garden and tree body, use formula fertilization. The habit of non-application of potassium and trace elements to diazo light phosphorous formed by some fruit farmers for many years resulted in extremely low levels of phosphorus, potassium and trace elements in the soil, resulting in tree malnutrition, debilitating tree vigor, and various diseases often appearing. Fertilization technology can effectively solve this problem. Formula fertilization is the use of modern agricultural science and technology, according to the law of citrus fertilizer, "enough, reasonable, balanced nutrition" principle, in order to maintain or increase soil fertility and biological activity, to meet the needs of citrus for various nutrients for the purpose Fertilization technology. The specific measures are based on the soil fertility, age, tree vigor, and the state of growth results. "The tree is set to yield, nitrogen is set, and phosphorus and potassium are set by nitrogen to make up the deficiency." Local 1-3 year-old saplings should be treated with 100-400 g pure nitrogen per plant, and the ratio of nitrogen:phosphorous:potassium should be 1:0.3:0.5, and the amount of fertilizer should be increased from less to more year by year; Application of pure nitrogen 6-8Kg, nitrogen, phosphorus, potassium ratio of 1:0.6:0.8 is appropriate. The annual output of citrus trees from 4 to 6 years is controlled between 1000 and 1500 kilograms, and the output of parks below 7 years is controlled between 3000-3,500 kilograms. In addition to the three elements of orange, phosphorus, and potassium, citrus also needs some minor and trace elements (such as calcium, magnesium, sulfur, iron, zinc, boron, etc.). Due to the long-term fixed growth of citrus fruit trees, the fruits take away certain nutrients year after year. These elements can easily cause lack of, and the tree performance should be considered as appropriate to supplement, so as to avoid the symptoms of deficiency, affect the growth and development of citrus, reduce the body Resistance to stress, induced pests and diseases resulting in decreased fruit quality. 5, citrus common fertilizer common sense. (1) The organic fertilizer should be thoroughly cooked before it is applied, and at the same time, attention should be paid to maintaining nutrients. The use of unfamiliar organic fertilizer may infect pathogens and cause heat and damage the roots; the use of non-decomposed organic fertilizers in the planting hole will cause sinking of soil and soil, inhibiting the development of roots, and excessive decomposition will cause loss of nutrients in fertilizer due to decomposition and volatilization. : It is advisable to apply a thin mud heap or a shed to cover the organic fertilizer. (2) The application of cake fertilizer needs to be crushed in advance, and it is best to pour in thin human excreta. Mix it evenly and stack it for 5 to 10 days. (3) Ammonia needs to be used after diluting water, and should be kept away from the tree body when watering, so as to avoid smoked leaves. Timely soiling after application, otherwise it will cause loss of nutrient volatilization (4) Fertilizer should follow the principle of a small number of times. Drought should be mixed with water or dissolved in human waste. Avoid agglomeration or application in one place, resulting in a high concentration due to local concentrations of fertilizer (5) fish residue fertilizer, compost, garbage fertilizer often contain toxic substances or higher salt, should be diluted, stacked after the application. (6) Urea as top dressing, the use of concentration is controlled to 0.25% or less, to avoid contracture gland poisoning. In addition, in the production of green food (citrus), fertilizers should be selected and applied according to the principle of fertilizer application of green food (citrus). Make sure that the selected fertilizer does not have adverse consequences on the environment and the quality of citrus fruit before use. (Zhang Xiaowei) Hole Digger,Tree Hole Digger,Hole Digger Tractor,Tractor Drived Hole Digger Shandong Dahua Machinery Co.,Ltd , https://www.agrodahua.com