The main characteristic of saline-alkali land is that it contains more water-soluble salts or alkaline substances. Due to the high salt content and high alkalinity, the soil humus is leached and the soil structure is damaged. It is sticky when wet and hard when dry. There are often white salt accumulations on the soil surface, poor ventilation and water permeability, and severe plant wilting. , poisoning and root rot death, so soil improvement must be carried out on saline-alkali soil. The principle of improving saline-alkali soil is to actively fertilize the soil while draining, isolating and preventing salt. The main measures are:
1. Drainage. For low-lying saline-alkali land, part of the soil salt can be taken away by digging drainage ditches to discharge surface water.
2. Fill with water and wash with salt. According to the law of "salt comes with water, salt goes with water", water is poured into the ground to form a water layer of a certain depth on the ground, so that the salt in the soil is fully dissolved, and then the dissolved salt is drained away from the drainage ditch. Thereby reducing the salt content of the soil.
3. Plant rice. Planting rice in saline-alkali lands with sufficient water sources is also an effective improvement measure. Because after planting rice, the water layer in the field must be maintained regularly, and the soil water content is in a saturated state. Under the same soil salt content, the salt concentration in paddy fields is lower than that in dry fields. Therefore, water exchange through long-term flooding and drainage , the salt in the soil can be leached and discharged.
4. Apply more organic fertilizer. Organic fertilizers can increase the humus in the soil, facilitate the formation of aggregate structures, and improve the ventilation, water permeability and nutrient status of saline-alkali soils. The organic acids produced after decomposition can also neutralize the alkalinity of the soil. Planting green manure is more effective.
5. Plow deeply and deeply. Deep plowing and deep loosening of saline-alkali land and deepening the plowing layer can accelerate salt leaching, prevent salt return, enhance the ability to retain moisture and resist drought, and improve the nutrient status of the soil. During deep plowing, care should be taken not to turn dark alkali to the surface.
6. The guest soil presses the alkali. Hakka soil means exchanging soil. Guest soil can improve the physical properties of saline-alkali land, and has the functions of inhibiting salt, leaching salt, suppressing alkali and increasing soil fertility. It can reduce the salt content of the soil to a level that will not harm crop growth. As the saying goes: "Sand presses alkali, and gold plate is used" This is the truth.
7. Reasonable planting. When planting crops on saline-alkali land, the crops should be planted according to their adaptability to saline-alkali, drought, and floods, and should be planted in a reasonable layout. Give full play to the potential of increasing agricultural production. Sunflowers, cereals, sugar beets, barley, etc. are crops with strong salt-alkali tolerance. They have high cell osmotic pressure and can absorb enough water in high-salt solutions without causing physiological drought and death.