Soil is the most critical physical foundation for producing high-quality, high-yield agricultural products; however, with the ongoing deterioration of cultivated land environments, soil improvement has become urgently necessary.
How can soil be improved?
1. Improvement of Soil Physical Structure
(1) Soil conditioner
The function of soil conditioners is to bind fragmented soil particles into small aggregates, thereby restoring the soil’s aggregate structure. In practical application, this is quite convenient: vegetable growers can either apply the conditioner before or after tilling, spreading it directly on the surface and then watering. Under the influence of water, the conditioner becomes highly adhesive, forming tiny aggregates that act as soil colloids. These colloids help establish a stable soil aggregate structure, ensuring good aeration and nutrient retention while enabling roots to penetrate more easily.
(2) Straw
In particular, for greenhouses that have been in use for 7 to 10 years, straw proves highly effective—outperforming the use of organic fertilizer alone. Unfortunately, many vegetable growers still rely on uncomposted manure as their organic amendment, which can pose significant risks. Whether it’s chicken manure or cow manure, incorporating straw into the composting process can help accelerate decomposition and fermentation. Taking chicken manure as an example, it is rich in organic matter and essential nutrients such as nitrogen, phosphorus, and potassium. By layering chicken manure with straw and mixing them thoroughly, you can not only reduce the salt content but also further break down organic materials. Moreover, the high‑temperature fermentation effectively suppresses a large portion of pathogenic microorganisms. In fields suffering from severe soil salinization, applying substantial amounts of straw can be beneficial; during decomposition, the straw absorbs some of the salts, thereby mitigating soil salinity.
2. Improvement of Soil Chemical Properties
(1) It is not recommended to use cement or quicklime to adjust soil pH.
Some vegetable farmers choose cement and quicklime as soil-conditioning agents to improve the chemical properties of their soils. When the soil is severely acidified, applying cement or quicklime will indeed raise the pH at the time, giving the appearance that the acidification has been resolved. However, this approach fails to address salinization, while also severely disrupting soil structure, promoting the formation of precipitates, and ultimately exacerbating soil degradation.
(2) Reducing the application of chemical fertilizers: certain alkaline fertilizers, such as magnesium hydroxide, can help regulate soil pH to a certain extent without forming precipitates.
(3) Enhance the efficiency of fertilizer use
Earth Soil chemical properties are closely linked to fertilizer use efficiency. Currently, many older greenhouse facilities exhibit very low utilization rates for compound fertilizers; in some cases, when only compound fertilizer is applied, the uptake rate fails to reach even 15%. In other words, for every 100 jin of compound fertilizer applied, crops can absorb only about 15 jin, while the remaining 85 jin is wasted. Moreover, this wasted fertilizer can exacerbate soil salinization or acidification. It is recommended that, during vegetable cultivation, compound fertilizers be used exclusively as base fertilizer, with water‑soluble fertilizers preferred for topdressing whenever possible.
The factors that determine the quality of water‑soluble fertilizers are: ① raw materials, ② production processes, and ③ efficiency‑enhancing additives. The quality of the raw materials is paramount, while efficiency‑boosting additives are the key to maximizing nutrient use efficiency. For example, Yiprun’s IPE phosphorus‑carrying technology not only ensures optimal uptake of phosphorus in water‑soluble fertilizers but also activates previously immobilized soil phosphorus, converting it into readily available forms and significantly enhancing root absorption and utilization. Similarly, Haifa Company of Israel incorporates ion‑phase antagonism inhibitors that neutralize mutual inhibitory interactions among ions, thereby improving fertilizer absorption and utilization. These unique features help reduce fertilizer application rates, increase nutrient use efficiency, and gradually mitigate soil acidification and salinization.
For vegetable fields in Hebei, especially older greenhouses, the soil typically contains an excess of nitrogen, phosphorus, and potassium—far more than it needs. The key challenge now is how to gradually mobilize the residual nutrients already locked in the soil, making them available for crop uptake, rather than simply over‑applying chemical fertilizers. The guiding principle for topdressing is: it’s not about applying more, but about ensuring efficient absorption. Even with generous applications, if the soil cannot take up the nutrients, the effort is wasted. By calibrating application rates to maximize fertilizer use efficiency—ideally reaching 80%—we can minimize soil degradation. Moreover, soils possess an inherent buffering capacity; with proper management, they will become increasingly fertile and productive over time.
3. Improvement of Soil Biological Properties
Improving the biological properties of soil must start at the root; the most effective approach is to use microbes to control other microbes. To boost crop yields, it’s essential to apply microbial inoculants—biological fertilizers—to the soil. Among these, Bacillus species are the most widely and maturely used in China. As bacteria with a diverse range of strains, Bacillus forms an excellent microbial consortium for alleviating soil‑borne continuous‑cropping obstacles, helping to reduce the incidence of soil‑borne diseases—a truly fundamental solution.
Abroad, bio‑inoculants are predominantly fungal, such as mycorrhizal fungi and Trichoderma species like Trichoderma atroviride. Compared with bacterial products, fungal bio‑inoculants involve more complex manufacturing processes and pose greater challenges in purification. Overseas manufacturers also offer soil‑microbiome‑conditioning agents that, based on the principle of biostimulants, can be applied to the soil via irrigation to stimulate microbial activity, foster a microbiota suited to the local soil environment, increase the abundance of beneficial microbes, and mitigate yield losses and soil‑borne diseases.
In some regions where root diseases are severe, relying solely on biocontrol to suppress pathogens can be slow. Biological control is a gradual process that requires the microbial population to accumulate to a certain threshold before equilibrium is achieved. If the initial inoculum size is relatively low, chemical agents can be applied as a complementary treatment. For example, during integrated water–fertilizer–pesticide management, adding Amisida can be beneficial. Amisida exhibits high soil activity and can effectively reduce a significant portion of residual pathogenic microorganisms in the soil; at this point, supplementing with a biological inoculant allows the microbial community to reach equilibrium more rapidly.
Currently, the domestic biofertilizer market is highly uneven. When making their selection—whether opting for a large or small manufacturer, and regardless of the bacterial count—vegetable growers should always conduct preliminary trials and demonstrations. As a living product, biofertilizers are heavily influenced by external factors. Even with the same formulation, differences in soil texture and environmental conditions can lead to vastly varying results. It’s possible that a particular biofertilizer performs exceptionally well and boasts a high bacterial concentration, yet fails to proliferate in your specific soil, rendering it ineffective. Therefore, determining whether the chosen biofertilizer is compatible with your soil is of paramount importance.
Soil remediation and improvement is a systematic undertaking that cannot be confined to a single approach. It requires addressing the soil’s physical, chemical, and biological properties, clearly defining the intended purpose, and implementing targeted soil amendments. At the same time, sustainability must be prioritized; an overemphasis on rapid见效 should be avoided. Instead, holistic improvements and gradual accumulation are needed to bring the soil to its optimal condition, thereby achieving high yields and superior quality in vegetable production and ensuring bountiful harvests for farmers.
