How to Use Water-Soluble Fertilizers Effectively: Mastering These Techniques Is Essential

  Water-soluble fertilizers offer distinct advantages in enhancing fertilizer utilization, conserving agricultural water, reducing ecological pollution, improving crop quality, and minimizing labor requirements. However, when applying them, it is crucial to understand their characteristics and follow these fertilization techniques.
  Avoid direct application; use double dilution: Water-soluble fertilizers contain higher nutrient concentrations than standard compound fertilizers and require smaller application rates. Direct application can easily cause seedling burn, root damage, stunted growth, and weak seedlings. Double dilution ensures even distribution and improves fertilizer efficiency.
  Apply in small amounts multiple times: Due to their rapid effectiveness, water-soluble fertilizers do not persist long in soil. Applying small amounts frequently is the most important principle, aligning with plants' continuous nutrient absorption and reducing leaching losses from single large applications. Typically, use 3–6 kilograms per mu per application.
  Maintain Nutrient Balance: Water-soluble fertilizers are typically applied via drenching, foliar spraying, or dilution in irrigation water (drip/sprinkler systems). Note that drip irrigation reduces reliance on soil-supplied nutrients due to dense root systems, making crops more dependent on drip-delivered nutrients. Imbalanced fertilizer formulations can impair crop growth. Additionally, water-soluble fertilizers must never be applied through traditional irrigation methods like flood irrigation or surface runoff irrigation to prevent fertilizer waste and uneven distribution.
  Combined Application: Water-soluble fertilizers are fast-acting and generally serve only as topdressing. Particularly in conventional agricultural production, they cannot replace other standard fertilizers. To reduce costs and maximize the benefits of each fertilizer type, integrate basal fertilizer with topdressing, combine organic with inorganic fertilizers, and pair water-soluble fertilizers with conventional fertilizers.
  Use Alone or with Non-Alkaline Pesticides: When vegetables exhibit nutrient deficiencies or poor root growth, many farmers resort to foliar application of water-soluble fertilizers for relief. Note that water-soluble fertilizers should be applied alone or mixed only with non-alkaline pesticides to prevent metal ion reactions that cause precipitation, leading to fertilizer burn or pesticide damage on leaves.
  Avoid excessive irrigation: When irrigating primarily for fertilization, ensure only the root zone is thoroughly moistened. Root zone depths vary significantly between crops; use a shovel to periodically assess the specific depth of the root zone. Excessive irrigation not only wastes water but also leaches nutrients below the root zone, rendering them unavailable to crops and wasting fertilizer. This is particularly true for urea and nitrate nitrogen fertilizers in water-soluble formulations, which are highly prone to leaching.
Prevent surface salt accumulation: Long-term use of drip irrigation for fertilization in greenhouses or plastic tunnels can cause salt buildup on the soil surface, impairing root growth. Sub-mulch drip irrigation can be employed to inhibit salt migration toward the surface layer.