Band application of peanut-specific slow-release compound fertilizer at different soil depths promotes the root growth, yield performance and nitrogen utilization of peanut

Objectives Methods of fertilization in layer and strip were experimented in peanut to investigate effectiveness of slow-release fertilizer for peanut production.

Methods Field experiments were carried out in Ju’nan in 2019 and Jiyang in 2019 and 2020, respectively. Two fertilization methods were used: manual surface broadcast (B) and mechanical band application in different soil layers (L), the tested fertilizer included common compound fertilizer (CF) and slow-release compound fertilizer specific for peanut (SF) in each method, no nitrogen fertilizer served as the control (N₀). The root distribution at 0–10 cm and 10–20 cm soil layers were analyzed, and the yield and yield component were investigated.

Results Compared with CF, SF increased peanut pod yield by 3.6%–11.7% in Ju’nan and 5.5%–13.2% in Jiyang; and L method increased a pot yield by 6.5%–14.8% and 10.4%–20.7% than B method in Ju’nan and Jiyang, respectively. SFL increased peanut yield by 19.0% in Ju’nan, and 24.9% in Jiyang in 2019 and 27.3% in 2020, compared with CFB. SFL treatment resulted in higher total and full pod number per plant and 100-kennel weight than CFB. L method significantly increased the dry weight and length of peanut root at 40–60 cm soil layer between plants and 20–60 cm layer between plant rows, increased the distribution proportion of deep roots along horizontal and vertical direction. SF and L methods enhanced the leaf SPAD values, stimulated the dry matter and N accumulation of plant across the growth stages. Compared with CFB, SFL increased the distribution proportion of dry matter in pods at mature stage by 5.8 and 5.7 percentage points, and increased the distribution proportion of N in pods by 4.2 and 4.6 percentage points in Ju’nan and Jiyang, respectively. It also increased the partial productivity of nitrogen fertilizer by 22.7% and 28.8%–31.2% and increased nitrogen agronomic efficiency by 120.9% and 125.4%–145.1% in Ju’nan and Jiyang, respectively.

Conclusions Fertilizer application in layer and strip by machine is more beneficial than traditional broadcast in terms of root development, dry matter and N accumulation, and the translocation of N to pods. Slow-release compound fertilizer specific for peanut enhances yield than the conventional compound fertilizer. Hence, band application of the slow-release compound fertilizer in different soil layers is an effective way in regulating peanut nutrient supply across growing periods.