The facilities used in the protected areas have large amounts of fertilizer, and there are many times of fertilization. As the irrigation salts move upward, they accumulate on the surface of the soil. In addition, in the shed, it is not washed by rainwater, the environment is confined, the temperature is high, and the amount of soil moisture evaporates. The soil salt will also accumulate more and the concentration of soil solution will increase. In the greenhouse where the same kind of vegetables are grown for many years, the content of salt in the soil will continue to accumulate. When the salts are accumulated to a certain degree, the growth and development of the vegetables will be hindered. Damaged plants generally grow short and have poor root development, dark green leaves, white waxy leaves on the surface of the leaves, or wavy yellow marks on the edge of the leaves, and the lower leaves are reeled or drooped, and the plants are wilted at noon, sooner or later. Recover until dead. The main measures are: 1, increase the maturity of organic fertilizer, increase soil organic matter content, reduce salt damage. 2, deepen the soil tillage. After the crops are harvested, deep turning is carried out to turn salt-rich topsoil to the lower layer and to turn the lower soil with relatively less salt to the top, which can greatly reduce salt damage. 3, the use of change in space, remove the film and rain or salt irrigation salt irrigation. In the summer, the shelters of the protected areas can be removed, and the rain can be used to evacuate the salt in the soil. The flood irrigation method can also be adopted, and ditches can be dug around the protected areas so that the salt content of the soil can drain away. Not only can wash the salt, but also can kill bacteria, is conducive to high yield and stable production. 4, promote root dressing. Top dressing without roots does not increase salt in the soil and should be strongly promoted. Urea and superphosphate, as well as potassium dihydrogen phosphate and some trace elements, are suitable fertilizers for top-dressing. JRT OEM Digital Laser Range Finder can measure faster, easier, and more effectively! Our Professional R&D team has over 16 years of experience on the laser and measurement field , so we can supply perfect OEM/ODM service according to user requirement ,and we have made out the mini size module in the world. Handheld Laser Meter,Handheld Laser Distance Meter,Laser Range Meter,Laser Distance Measurer Chengdu JRT Meter Technology Co., Ltd , https://www.infrareddistancesensor.com
The handheld laser distance measurer can measure distance,area,volume and pythagorean, and can switch to meter/feet/inch mode as you like.
Specially, there is three best-sale styles:
* Mini: D30 with our mini module U81 in it achieved the smallest size Laser Distance Meter in the world, which outlook is the same as a key,quite portable and cute. USB chargable design.
* Bluetooth: Diy Laser Range Finder With Bluetooth has been used to measure distances accurately in the both daily usage and industry application. The handheld laser distance measurer is widely used in variety areas, like project surveying, construction measuring, railway application etc.
* Longest: 150m equipped with a precise,easy- to-read digital LED display, which metal case brings you great hand feel.Power Supply: 2 x 1.5V AAA batteries.