Ding Fangjun, Deputy General Manager of Nongda Fertilizer Co., Ltd.: The Role of Humic Acid in Enhancing Potato Quality and Yield

Deviation in soil properties. The seven “bad” traits of soil—acidic, saline, polluted, infertile, heterogeneous, compacted, and nutrient‑hungry—along with a tendency to prioritize quantity over quality, inorganic over organic inputs, and to focus on nitrogen, phosphorus, and potassium while neglecting other elements, coupled with an emphasis on the intrinsic properties of fertilizers at the expense of their transformations in the soil, result in soils that have a voracious appetite: they take in large amounts but fail to absorb them. In China, fertilizer use efficiency is only about one‑third, and the amount of nitrogen applied exceeds crop uptake by more than twofold. It is essential to view ammonium‑nitrogen (NH4+) and nitrate‑nitrogen (NO3−) correctly.

Over the past two decades, phosphorus accumulation in China’s agricultural soils has increased. The effectiveness of phosphate fertilizers declines rapidly, with as much as 75% of applied phosphorus being immobilized within 30 days. Why does the need for fertilizer keep growing? It stems from a severe deficiency in organic matter—carbon is the critical limiting factor. Compared with N, P, and K, carbon is present in the greatest abundance, yet it profoundly affects microbial activity. Nearly all of the 13 essential nutrients required for plant growth originate from the soil, and current crop nutrition is increasingly imbalanced. Nutrient recycling and fertilizer application patterns differ: nitrogen, phosphorus, potassium, and magnesium are readily mobile and highly recyclable; deficiencies typically manifest on older leaves, making them well suited to soil applications. In contrast, calcium, iron, manganese, and boron are poorly mobile and have limited capacity for internal redistribution; deficiencies tend to appear on new leaves, rendering foliar applications more appropriate.

The four soil-borne diseases: Cardiovascular disease leads to reduced nutrient cycling in the soil; liver disease results in diminished soil metabolic capacity; poisoning causes soil contamination; and the “three highs” (high salinity, alkalinity, and acidity) further exacerbate these issues. Consequently, agricultural products exhibit inferior quality and poor shelf life, are less storage‑resistant, and experience increased incidence of continuous‑cropping disorders and soilborne diseases, thereby hindering secondary crop growth.

The foundation of soil health. Bringing soil to life—humic acid. Humic acid primarily regulates the soil’s “appetite,” making nutrients easier to digest and absorb, while also providing buffering capacity. Soil is the foundation of life; a healthy soil rests on a balanced composition of microorganisms, micronutrients, mesoelements, nitrogen, phosphorus, and potassium, and organic matter.

How can we build a system for improving quality and boosting efficiency? Every crop begins and ends with its roots; a robust, well‑developed root system is the foundation for healthy growth and high yields. Humic acid acts like a nurturing mother, safeguarding the soil by regulating nitrogen, enhancing phosphorus uptake, promoting potassium absorption, replenishing micronutrients, and fine‑tuning the soil’s microbial balance—thereby boosting fertilizer use efficiency. Humic‑acid‑based compound fertilizers supply essential nutrients, improve fertilizer utilization, stimulate plant growth, conserve water and nutrients, promote soil aggregation, and enhance biological activity. Looking ahead, the trend in compound fertilizer development will be to maximize bio‑functionalities, harness synergistic interactions to amplify efficacy, meet both quantitative and qualitative demands, achieve seamless integration of organic and inorganic components, create value from nothing, and share benefits between organic matter and mineral nutrients.