1, loess characteristics
Loess is generally viscous, poor in permeability, strong in water and fertilizer conservation, easy to accumulate water, high in potential nutrients, slow in decomposition of organic matter, easy to accumulate, long in fertilizer efficiency and small in temperature difference between day and night.
2. Preparation steps of improving loess
(1) Soil PH value test
Test the PH value of the soil, and determine the fertilizer to improve the soil according to the pH value of the soil. According to the standard of qualified planting soil, the salt content is ≤2% and the PH value is 7-8.5. The PH value of loess varies from 6.9 1-8.06, with an average value of 7.47, which is weakly alkaline and meets the growth requirements of plants in northern China.
(2) loess characteristic test
① Porosity: Because loess is mainly composed of tiny powder particles, the combination between them is not close under dry and semi-dry climate conditions. Generally, the naked eye can see all kinds of pores and holes with different sizes and shapes between particles, so some people usually call loess macroporous soil.
② Strong water permeability: Generally, typical loess has strong water permeability, while loess-like rocks have weak water permeability; Collapsible loess has strong water permeability, while collapsible loess has weak water permeability. The permeability of loess is inseparable from its structural characteristics such as porosity and vertical joint development. The more porous loess and vertical joints develop, the higher the vertical permeability of loess layer and the weaker the horizontal permeability. In addition, when there is a soil layer or a loess nodule layer in the loess layer, it will also lead to poor water permeability of the loess layer and even produce an impermeable layer.
③ Sedimentation: Loess often has unique sedimentation, and silty property is one of the biggest characteristics of loess particle composition. Powdery indicates that the combination of loess powder particles is not tight enough, so whenever the soil layer is soaked or under the action of gravity, the loess layer itself loses its consolidation performance, which often causes strong settlement and deformation, and the permeability of loess becomes weak.
Step 3 improve the method
(1) One is to apply organic fertilizer again, and the other is to press sand to reduce the viscosity of loess. According to the ratio of organic fertilizer 1t (including straw), river sand 1t and loess 7.5- 10m3. Add peat soil before planting. Trees, shrubs and other places should be equipped with peat soil in different proportions, including 4 bags of big trees (10kg/ bag), 2 bags of small trees, shrubs 1 bag, 1kg/_.
(2) Taking the big tree as an example, after digging the planting hole, before planting, evenly spread 1 bag peat soil at the bottom of the pit; Then scatter the remaining three bags on the soil to be backfilled by the pit, stir them evenly, and then fill them in when planting seedlings. Shrubs are like trees. Lawn and ground cover, spread peat soil evenly on the soil surface, then turn it over 30cm and rake it evenly.
Second, can loess grow vegetables?
1, loess can grow vegetables. Loess has a uniform texture, mostly light to medium loam, and some are sandy loam. The nutrient content of plough layer is high, and the organic matter content is generally less than 1%. The whole section has lime reaction and is alkaline, and there are carbonate nodules in the deep part.
2. The loess has good arable property, is loose and easy to cultivate, and is suitable for long cultivation period. Because the soil color is light and the soil temperature changes greatly, the crops turn green early in early spring and are easy to emerge. Disadvantages are low soil fertility and backward crops. Soil and water conservation is the main yield-increasing measure to improve fertility in loessial soil.
3. Loess is mostly sandy soil, which is suitable for planting tuber crops such as potato and sweet potato, grain crops such as sorghum, millet, corn, soybean, wheat, rice, barley, buckwheat and peanuts, and common vegetables such as radish, cabbage, cucumber, beans and tomatoes.