Long-term application of fertilizer and manures affect P fractions in Mollisol

Xinchun Lu,Xiao-Zeng Han,Jun Yan,Xu Chen,Asim Biswas,Al-Kaisi Mahdi,Wen-Xiu Zou

doi:10.1038/s41598-020-71448-2

Abstract

Application of phosphorus (P), a major plant nutrient, as fertilizer is critical to maintain P level for crop production and yield in most cultivated soils. While, it may impact the dynamics, limited studies have examined the long-term effects of fertilization on P fractions in a soil profile in Mollisol. A long-term field experiment was conducted at the State Key Experimental Station of Agroecology of the Chinese Academy of Sciences in Hailun county, Heilongjiang Province, China. A sequential fractionation procedure was used to determine the effect of fertilizer (types) treatments including no fertilizer (CK), chemical fertilizer (NPK), chemical fertilizer plus straw (NPK + S) and pig manure (OM) on fractions of P and their distribution within 0–100 cm soil profiles. Unlike CK treatment, the long-term application of fertilizers increased the concentration and accumulation of total and available P in 0–20 and 0–40 cm soil depths than deeper soils, respectively. The phosphorus activity coefficient (PAC) ranged from 1.5 to 13.8% within 0–100 cm soil depth. The largest PAC value was observed under OM treatment at 0–40 cm soil depth and under NPK + S treatment at 40–100 cm soil depth. The Ca2-P and Ca8-P concentrations increased significantly by 0.5–7.5 times and 0.5–10.4 times, respectively in OM treatment with the largest value in 0–40 cm soil depth over CK treatment. The Al-P concentration under NPK + S and OM treatments increased throughout the soil profile. The OM treatment increased all Po concentrations in the 0–40 cm soil depth, while NPK and NPK + S treatments increased labile organic P, moderately labile organic P, and highly stable organic P in the 0–20 cm soil depth. Thus, the application of fertilizer and straw, or organic manure may enhance inorganic and organic P pool in a Mollisol in Northeast China. Thus, organic manure application in the subsoil as a potential P source and their impact should be considered in developing management practices and policies regarding nutrient management.

Highlights

Application of phosphorus (P), a major plant nutrient, as fertilizer is critical to maintain P level for crop production and yield in most cultivated soils
Compared to CK, total P concentration in the 0–20 cm soil depth was increased by 26.6%, 4.1%, and 68.2% in NPK, NPK + S, and OM treatments, respectively, while available P concentration was increased by 315.9%, 108.3% and 667.5% in NPK, NPKS and OM treatments, respectively
Phosphorous was accumulated in the 0–40 cm soil depth in both NPK and OM treatments, majority of which was in the cultivated 0–20 cm soil depth (Fig. 2)

Summary

Introduction

Application of phosphorus (P), a major plant nutrient, as fertilizer is critical to maintain P level for crop production and yield in most cultivated soils While, it may impact the dynamics, limited studies have examined the long-term effects of fertilization on P fractions in a soil profile in Mollisol. Based on the availability, P in soil is often classified into different pools including water soluble, labile, and non-labile. Long-term application of animal manures and other organic amendments have shown to increase soil total, available, and soluble P concentrations and at soil d epths[19,20,21]. These processes are dominant at different depths and different parts of the soil profile

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Conclusion