How to apply Biogas Fertilizer to planting Jujube

Yulin area in northern Shaanxi is a well-known jujube producing area in the country, with an area of 75000 hectares and an annual output of 56500 tons of fresh dates. Jujube areas are mainly distributed in Jiaxian, Suide and Qingjian counties along the Yellow River, which belong to the loess plateau with poor soil and poor farming conditions. In recent years, we have strengthened the construction of rural biogas in jujube areas, built a total of 12000 household biogas digesters, and carried out experiments and demonstrations of biogas fertilizer application in jujube orchards, and achieved good results.

Effect of biogas fertilizer on jujube. Biogas fertilizer is not only rich in nitrogen, phosphorus, potassium and other elements, but also contains boron, copper, iron, manganese, calcium, zinc and other trace elements that play an important role in the growth of jujube, as well as a large number of organic matter, a variety of amino acids and vitamins. The application of biogas fertilizer to jujube can meet the nutrients needed for jujube growth, and the nutrients can be easily absorbed and utilized; increasing the organic matter in the soil and using it year after year can improve the soil structure, improve the soil water and fertilizer conservation and drought resistance, increase jujube yield (increase the yield by about 18%), enhance stress resistance, significantly reduce diseases and insect pests, uniform fruit size, bright color, delicious and sweet taste.

Fertilization methods. There are two kinds of biogas fertilizer commonly used, one is biogas residue as base fertilizer, and the other is biogas slurry used as topdressing and foliar fertilizer.

Base fertilizer. The application of base fertilizer should be carried out in the fruitless period, generally at the beginning of April or the end of November every year (during the discharge or reloading of the biogas digester). According to the size of the tree, each jujube tree applies 15,30kg of biogas dregs. The specific method is to dig 6 pits around the jujube tree with a depth of 30rel 40cm, fertilize and irrigate, and cover the soil and fill it in time after the water seeps out, so as to protect the fertilizer effect and prevent frostbite.

Top dressing. The application time of biogas slurry as topdressing fertilizer is in the sprouting period in May, flowering and fruit hanging period in June-August and strong fruit stage in September, applying 3 Mel 5 times a year, each time about 40 kg of biogas liquid per plant. The specific method is: dig a strip ditch along the root or dig 6 pits around the tree, or dig an arc ditch, 30 cm deep and 20 cm wide, and cover the soil in time after the biogas slurry seeps out. During this period, fertilization is beneficial to flower bud differentiation, increase the number of effective flowers, supplement more nutrients, improve fruit setting rate and promote fruit growth.

Spray fertilizer on the leaves. Foliar spraying can be carried out at the stage of sprouting, flowering, young fruit and strong fruit, and the amount of fertilizer per plant is generally 10mur15kg. The middle biogas liquid, which produces gas for more than one month and is clarified and filtered, is sprayed on the crown every 10 minutes and 20 days, and it is suitable for the back of the leaf to be wet but the fertilizer does not drip. Foliar fertilizer spraying can make jujube leaves thicker and darker, significantly reduce the occurrence of diseases and insect pests, and enhance stress resistance. Spraying during the fruit growing period can increase the yield and improve the quality of jujube fruit.

Points for attention. When using ① biogas residue and biogas slurry as base fertilizer and topdressing fertilizer, it should keep a certain distance from the tree root to prevent the root from being dug up and burned. The time of foliar spraying of ② should be carried out when the temperature is low in the morning or afternoon, but not in the period of high temperature at noon. If there are diseases and insect pests in ③, pesticides can be mixed into biogas slurry to spray. It is difficult for ④ to spray on the leaves of jujube trees which are too high, so attention should be paid to safety.