Combined application of organic manure and reduced-rate chemical fertilizer improved growth, nutrient use efficiency, biomass accumulation, and carbon sequestration of Zanthoxylum armatum seedlings

Abstract

The possibility of incorporating organic manure (OM) to reduced rates of chemical fertilizers (CF) to augment biomass production and carbon sequestration (Cseq), and the role of nitrogen (N), phosphorus (P) and potassium (K) uptake in vegetation Cseq was investigated through pot experiment with one-year-old Zanthoxylum armatum seedlings. Seven treatments were designed including NPK, PK, NP, NK, OM, MNPK (50%NPK+50%OM), and control (CK, no fertilization). MNPK application improved nutrient uptake of 2.76-fold N, 3.34-fold P, and 2.01-fold K, resulting in the highest biomass production and biomass Cseq (1.65-fold) as compared to CK. Correlation and redundancy analysis revealed that Cseq is significantly associated to biomass production (r = 0.994) and regulated by N and P uptake. The highest NUE was recorded for N (38.8%), followed by K (21.1%), and P (16.4%) under MNPK application. Therefore, MNPK could be an optimum measure regarding fertilizer saving, biomass production and attaining C neutrality.