Decoding Soil Issues Through the Eight Characters

At present, soil issues can be summarized in eight characters: compacted, nutrient‑poor, infertile, shallow, acidic, saline, polluted, and heterogeneous.

I. board ： Soil compaction— the more you plant, the more compacted it becomes.

Soil compaction refers to the disruption of soil structure, resulting in a hardened plow layer with poor aeration and water infiltration, which severely impedes the normal growth of crop root systems.

Main reasons:

① Severe underapplication of organic fertilizers: Low soil organic matter content and deteriorated soil structure impair microbial activity, thereby hindering the formation of soil aggregate structures and leading to soil compaction.

② Long-term excessive application of chemical fertilizers: Prolonged overuse of chemical fertilizers damages soil structure, prevents the timely replenishment of soil organic matter, and leads to soil compaction and cracking.

③ Agricultural practices such as tillage, plowing, and irrigation can disrupt the aggregate structure of the topsoil.

Main hazards:

① Reduced root vitality. When the soil becomes compacted, oxygen deficiency leads to a decline in root activity, hindering normal root development, weakening respiration, and impairing nutrient uptake.

② Causes nutrient deficiencies. As root function declines and the ability to absorb nutrients and water weakens, coupled with reduced soil porosity and poor nutrient availability following soil compaction, crops become prone to nutrient deficiencies.

II. Craving ： Imbalanced mineral nutrition ratios make crops increasingly nutrient‑hungry.

Crop growth requires 17 essential nutrients, yet in routine management, only nitrogen, phosphorus, and potassium fertilizers are emphasized, while micronutrient fertilizers are neglected. This leads to the depletion of micronutrients in the soil and the accumulation of macronutrients.

The main manifestation is that, despite increasingly heavy fertilizer inputs, the yield and quality of fruits and vegetables have not improved; instead, they have shown a declining trend.

Main hazards:

① Physiological nutrient deficiencies, such as those of calcium, magnesium, and iron.

② Poor crop growth and reduced agricultural product quality, among other issues.

III. Poor ： Low organic matter content— the more you plant, the poorer the soil becomes.

Soil organic matter is an essential component of soil structure and a key indicator of soil fertility.

Main reasons:

Currently, the number of crop rotations has increased, with excessive application of chemical fertilizers and a severe shortage of organic fertilizers, coupled with improper application practices.

Main hazards:

Severe loss of soil organic matter, disruption of soil aggregate structure, and reduced soil water‑holding capacity, nutrient‑retention ability, permeability, and buffering capacity all seriously compromise crop yields and economic returns.

IV. Shallow ： The plow layer is becoming shallower, and with each planting, it grows even thinner.

Main manifestations:

Due to the long-term use of rotary tillers, the plow layer of most soils has become shallower, with an effective topsoil depth of only 15 to 20 centimeters.

Main hazards:

The formation of a plow pan impedes the vertical movement of soil moisture, nutrients, and air, restricts the downward extension of crop root systems, diminishes the soil’s water‑holding capacity, and progressively reduces its drought‑resistance.