A kind of determination method of bioavailable phosphorus in soil

Abstract

A method for the determination of biologically available phosphorus in soil. Collect plant rhizosphere soil and air-dry it naturally, pass it through a 2mm nylon sieve after grinding, put it into a plastic container, add ultrapure water to make the water content of the soil to be tested reach 60%, mix well, and seal Then place it; add ultrapure water again to make the soil moisture content reach 80%, mix well to make the soil surface in the container smooth, seal it and place it, and obtain the soil test sample; dilute the purified binder solution and put it into the DGT sampling device, use Seal the DGT sampling device with the dialysis membrane; gently twist the DGT sampling device into the surface of the soil test sample so that the DGT sampling device is in good contact with the soil and place it; take out the binding phase and measure the binding phase with ammonium molybdate spectrophotometry The cumulative amount of phosphorus in the soil and the concentration of available phosphorus in the soil are calculated. The method has the advantages that the method uses liquid binding phase film gradient diffusion technology to measure biologically available phosphorus in soil, and the measured biologically available phosphorus is significantly correlated with the absorbed phosphorus in plants.

Description

technical field [0001] The invention relates to a method for measuring biologically available phosphorus in soil, in particular to a method for measuring biologically available phosphorus in soil by using liquid binding phase film gradient diffusion technology. Background technique [0002] Phosphorus is an essential nutrient element for crop growth, and the application of phosphorus fertilizer is an effective measure to increase soil phosphorus content and improve soil quality. Scientific fertilization is related to crop quality, agricultural production cost, soil nutrient balance, etc. In recent years, with the improvement of people's awareness of the importance of protecting resources and the environment, in order to curb the accelerated depletion of phosphate rock resources caused by continuous large-scale application of phosphate fertilizers, phosphorus in farmland soil is used as a non-point source of pollution to cause eutrophication of surface water and pollution of ...

AI Technical Summary

Problems solved by technology

The DGT sampling device is mainly composed of a diffusion phase and a binding phase. The early-developed DGT sampling devices are all solid binding phases, which have two disadvantages: first, the contact between the solid binding phase and the solid diffusion phase is inevitably not close enough, and it is easy to deviate from the theoretical design of DGT; Second, the target substance enriched in the solid-state binding phase needs to be rinsed with acid, which is cumbersome and easily leads to measurement errors

Menzies, Mason and Ding et al. respectively studied the use of solid-state binding phase DGT sampling devices to measure the bioavailability of phosphorus in soil, but the use of liquid binding phase DGT sampling devices to measure the bioavailability of phosphorus in soil has not been reported yet.

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