In addition to the significant effects on soil seed germination and root growth, soil aeration also affects soil microbial activity and nutrient conversion. When the soil air is deficient in oxygen, the released quick-acting nutrients are limited, the nitrifying bacteria are inactive, and may also cause denitrification and cause nitrogen loss. Under anoxic conditions, only the anaerobic nitrogen-fixing bacteria activity with weak nitrogen fixation ability is inhibited, while the activity of rhizobium and aerobic auto-nitrogen-fixing bacteria with strong nitrogen fixation ability is inhibited.
Soil aeration also affects redox conditions. Some nutrients such as nitrogen, sulfur, iron, manganese and phosphorus in the soil are in an oxidized state when the soil is well ventilated, and in a reduced state when the ventilating is poor. If the soil is poorly ventilated, the state of reduction is too strong and the content of nitrate nitrogen drops sharply. For example, when the paddy field is flooded, the ammonium nitrogen is oxidized to nitrate nitrogen in the oxide layer, and after being infiltrated into the reducing layer under water, it can be reduced to free nitrogen or nitrogen oxide and escape. In addition, poor ventilation produces excessive reducing substances such as hydrogen sulfide, which are toxic to crop roots.
All factors affecting soil porosity such as soil texture, structure, organic matter content, tightness and soil moisture content can affect soil aeration.
Therefore, agricultural production often uses organic matter to increase the content of organic matter, promote the formation of good structures, and properly deep-turn, cultivating loose soil, breeding carp, drainage and other measures to regulate soil. Ventilation and improved soil air conditions.
In general, for sandy soils with good aeration and poor fertilizer retention properties, the base fertilizers may be applied with some cold fertilizers such as cow dung or organic fertilizers with poor maturity. Nitrogen application should master the principle of “small number of times” to reduce nutrient loss and improve fertilizer utilization. In the later stage, nitrogen fertilizer should be properly applied to prevent crops from decreasing due to premature aging; for clay soils with poor aeration and good fertilizer retention performance The base fertilizer can be applied with hot manure such as horse manure or organic fertilizer with good decomposing degree. In the later stage, nitrogen topdressing should not be too much or too late, so as to avoid late cropping or lodging of crops.