(1) Pipeline Drip Irrigation Fertilization Technology
Pipeline drip irrigation fertilization technology is to transport soluble fertilizer directly to the soil near the roots of fruit trees under low pressure by means of drip irrigation pipeline system through equidistant thin tubes and emitters. The fertilizer solution entering the soil has a high nutrient concentration in the soil near the emitter, which can gradually spread to the soil around the root system by capillary force and be directly absorbed by the root system, with high fertilizer efficiency and water and fertilizer saving. Adjust the amount of water and fertilizer by controlling the number and flow of drippers. At present, this technology has a large investment and high technology content, and is mostly used in fruit production in large orchards and smart greenhouses, with high economic benefits (Figure 6-7). Generally, drip irrigation fertilization saves about 60% water than sprinkler irrigation fertilization, saving energy and reducing nutrient loss. At the same time, when fruit trees need a lot of nutrients in the vigorous growth period, they can be transported to the soil around the roots in time, which plays a dual role in saving water and fertilizer. Because the clogging of drip irrigation emitter and pipeline maintenance are key issues, it is necessary to grasp the technical difficulties such as fertilizer quality, fertilizer solution preparation and irrigation water quality.
Figure 6-7 Drip Irrigation Fertilization for Fruit Trees
The drip irrigation system consists of three parts: ① The first hub: self-pressure drip irrigation must build a pressure pool, and mechanical pressure drip irrigation must be pressurized by a water pump. The first auxiliary equipment includes a flowmeter, a fertilizer tank, a pressure gauge and a filter. ② Piping system: generally divided into three levels: main pipe, branch pipe and capillary pipe. 3 drippers.
When applying fertilizer by drip irrigation, the application concentration should be determined according to the absorption intensity of fruit tree roots, fertilizer demand characteristics and fertilizer types. If the concentration of potassium fertilizer is 2 mg/kg, drip irrigation will continue for 4-5 hours after fertilization. After 5 days, potassium can move to the lower soil up to 80 cm, and move above 150 ~ 180 cm. When the concentration of ammonium nitrate is 1 ~ 2 mg/kg, it will move to the lower soil after fertilization, and it will move to about 120 cm.
(2) Simple drip irrigation fertilization technology
① Make plastic bag fertilizer water reservoir: plastic bag with fertilizer water capacity of about 30 ~ 50kg (which can be replaced by impermeable fertilizer bag), and prepare some thin iron wires for binding. The dropper is a plastic tube with a diameter of 3 mm. Each tree needs 3-5 water bags (depending on the crown size), and each water bag needs to be equipped with a plastic dropper with a length of 10- 15cm.
Cut the plastic dropper into small pieces of 10 ~ 15cm, cut one end into a horseshoe shape, leave a small hole of about 3 ~ 5mm (the size of sorghum grain) at the end of the horseshoe shape, bake the rest with fire, insert the other end of the dropper into a plastic bag of about 1.5 ~ 2.0cm, and then tie it tightly with thin iron wire. Pay special attention to tightness when binding. Too tight will lead to slow drainage, too loose will lead to fast drainage or water leakage. The water yield is about 2kg/ hour, which is about 1 10 ~ 120 drops/minute.
(2) Burying plastic bag water reservoir: Dig 3-5 pits with equal distance on the ground vertically projected on the periphery of the tree crown, with a depth of about 20 cm and an inclination angle of 25, and the width depends on the size of the water bag, and put the prepared water bag in into the pit. Don't level the water, because the pressure of leveling is small and it is difficult to get out of the water. After placing, bury the dropper in a soil layer 40 cm deep. The position of the dropper should be below the outer edge of the crown, which is beneficial to the root system to absorb fertilizer and water. In order to prevent plastic bags from aging, plastic bags can be covered with plastic film or with old fertilizer bags or thin soil.
Practice has proved that the apple tree fertilized by plastic bag drip irrigation is irrigated with urea twice (concentration 0.3% ~ 0.5%) during the fertilizer demand period, and the chlorophyll content and fruit setting rate are higher than those without urea.
(3) Simple osmotic fertilization technology
Simple infiltration irrigation fertilization technology is a water-saving irrigation fertilization method developed by fruit farmers in Yimeng Mountain area of Shandong Province and Yuncheng County and Linyi County of Shanxi Province on the basis of pipeline drip irrigation according to local actual production conditions. This method is particularly effective in correcting element deficiency disease of fruit trees.
① Construction of reservoir: A reservoir is built above the ground, with a radius of 1.5m, a height of 2.0m and a water storage capacity of about1.3t. The seepage pipe is a plastic pipe with a diameter of 2cm. Every 40 cm, drill three needle-sized holes (aperture 1.0 mm) on both sides and above, and bury the infiltration pipe about 40 cm underground. Orchards with a row spacing of 3.0 meters can be buried in each row; Bury two rows in each row, with a row spacing of more than 4.0 meters. Install a filter screen on each leakage pipe to prevent blocking the pipe. The infiltration depth is about 90 ~ 100 cm, and the lateral infiltration depth is 155 cm. When applying fertilizer according to the growth needs of fruit trees, the fertilizer can be directly put into the storage tank, or it can be dissolved and filtered and then put into the waterway. The fertilizer solution penetrates into the rhizosphere soil of fruit trees with the water flow and is directly absorbed by the root system, which is fast in fertilizer efficiency and saves labor and water.
(2) Buried dish emitter: The fruit tree buried dish emitter can also be used for infiltration irrigation (it has obtained domestic invention patent). The vegetable washer is a kind of clay pot, which can hold 20 kilograms of water. Put the fertilizer into the pot and slowly penetrate into the soil layer at the root of the fruit tree with the water. The water seepage radius is 100 cm. The fertilizer storage solution 15 kg will permeate in 7 days.
(4) Root-fed fertilization technology
Root-fed fertilization technology is a first-aid measure based on the principle of osmotic fertilization when fruit trees lack some trace elements and other fertilization methods are difficult to work. Especially the correction of fruit tree yellowing disease in calcareous soil, the effect is particularly obvious.
Operation method: In early spring, before the fruit trees germinate, bury the bottle or plastic bag (containing about 200 ~ 300ml fertilizer solution) equivalent to spraying fertilizer solution on the leaves at a distance of about 1.0m from the trunk (depending on the spreading area of the crown and horizontal roots), cut off the absorbing roots with a diameter of about 5mm, put them into the bottle or plastic bag and bury them.
Apples, pears, peaches and oranges cultivated on calcareous soil by root-feeding fertilization method are particularly effective in correcting iron deficiency and chlorosis. The best application time is after defoliation of fruit trees or before germination in the following spring. When root irrigation is carried out during the growth period of fruit trees, the concentration of fertilizer solution must be strictly controlled to prevent fertilizer damage.