Management of Fertilizer and Water in planting Longan

Scientific fertilization is required according to longan growth characteristics and annual growth results, which is the basis of early fruit, high yield and high quality of longan trees. The experiment shows that the longan orchard with 1 ton of fruit per mu applies 25 kg of pure nitrogen per year (of which the nitrogen of organic fertilizer accounts for about 40% of the total nitrogen application in the whole year). The reasonable proportion of nitrogen, phosphorus pentoxide, potassium oxide, calcium oxide and magnesium oxide is 10: (5mur6): (10Mel 11): 8:4, which shows that the demand for potassium, calcium and magnesium fertilizer in longan is obviously higher than that in other fruit trees. Longan annual cycle fertilization is mainly divided into three periods.

1. Early flowering.

It is applied during the period of flower bud differentiation and before flowering to promote flower bud differentiation, flower ear development, and reduce flower and fruit drop. Nitrogen and potassium account for 20%, 25% of the annual application, and phosphorus accounts for 25%, 30% of the annual application.

two。 The young fruit stage.

Promote fruit growth, reduce physiological fruit drop, and promote summer shoot extraction. Fertilization in this period should appropriately increase the proportion of nitrogen, which accounts for about 25%, 30%, 40% and 50% of the year, respectively.

3. Fat before and after fruit picking.

In order to quickly restore the tree potential and promote the spitting of robust autumn shoots, fertilization in this period should appropriately increase the proportion of nitrogen, accounting for 45%, 55%, 35% and 25% of the annual nitrogen, phosphorus and potassium respectively.

In addition, from May to June, foliar fertilizer is sprayed every 15 minutes or so in combination with spraying. The fertilizers are generally potassium dihydrogen phosphate, magnesium sulfate, potassium sulfate and so on, to supplement the demand of trees for fertilizer.

Irrigation.

Combined with fertilization, watering. Longan fruit enters the period of rapid growth of pulp in July, but drought often occurs in July in some years. If there is no timely water supply, the normal increase of fruit will be affected. In case of summer drought, water should be irrigated once every 7 miles every 10 days, with 40 cents per square meter of projected canopy area (equivalent to 40 meters of 50 mm rainfall) to keep the soil moist. This also helps to prevent serious fruit cracking before harvest. "the Beginning of Autumn" rains heavily before and after harvest, often breaking the pericarp due to sudden water absorption of the pulp. Rain Water should drain water and prevent waterlogging in time.

Reasonable intercropping.

The longan orchard, which has been planted for four years, can make use of idle rows for reasonable intercropping to increase short-term benefits, including dwarf crops such as soybeans, mung beans and peanuts, but not tall crops such as corn and sorghum, as well as vegetable crops that require more water. In addition, green manure can also be intercropped to improve the soil environment.