Effects of Intelligent Mechanized Layered Fertilization on Root-Soil Nutrient Distribution and Yield in Wheat Fields

To address the issues of irrational fertilizer application, uneven soil nutrient distribution, low fertilizer efficiency, and suboptimal crop yields in medium- and low-yield fields in North China, the precision fertilization was employed to enhance fertilizer use efficiency, increase wheat yield, and improve soil nutrient distribution.

Based on preliminary pot and field plot experiments, the field trials were conducted using intelligent layered fertilization machinery in Ningjin and Quzhou counties, Hebei Province. Six fertilization treatments were established: conventional farmer practice (MF1), optimized nitrogen (N), phosphorus (P), and potassium (K) fertilization applied in a single layer using conventional machinery (MF2), optimized N, P, and K fertilization applied in two layers using intelligent machinery (MF3), optimized N and P fertilization applied in two layers and K fertilization in three layers using intelligent machinery (MF4), optimized N and K fertilization applied in two layers and P fertilization in three layers using intelligent machinery (MF5), and optimized N fertilization applied in two layers and P and K fertilization in three layers using intelligent machinery (MF6). The study aimed to investigate the effects of precision fertilization on soil enzyme activity, spatiotemporal supply capacity of soil available N, P, and K, wheat root characteristics, fertilizer efficiency, and grain yield.

The layered fertilization significantly increased the content of ammonium nitrogen, nitrate nitrogen, and available phosphorus in the 20-40 cm soil layer by 5.9%-34.5%, 6.4%-25.3%, and 12.9%-91.0%, respectively, while also enhancing the available potassium content in the 40-60 cm soil layer by 3.9%-38.5%. Additionally, layered fertilization significantly enhanced the activities of catalase and urease in the 20-40 cm soil layer by 10.3%-19.7% and 18.4%-31.2%, respectively, improved phosphatase activity in the 0-60 cm soil layer by 18.1%-32.9%, and increased root length, root surface area and root volume in the 20-40 cm soil layer by 13.2%-45.1%, 4.4%-36.4% and 8.7%-45.3%, respectively. Compared with the single-layer optimized N, P, and K fertilization treatment, layered fertilization significantly improved the partial productivity of N, P, and K fertilizers and grain yield, with the MF6 treatment performing the best in both experimental areas.

The intelligent mechanized layered fertilization was an efficient and precise fertilization technique that demonstrated significant advantages in synergistically improving the spatiotemporal distribution of soil nutrients, enzyme activity, and wheat root distribution characteristics, making it highly recommendable for practical agricultural production.