SU1762209A1 - Method for testing salinity of soil - Google Patents

Abstract

Area of use: agriculture, in particular agrochemical soil. Summary of the invention: indirect measurement of salt concentration based on electrical conductivity measurement. To increase the reliability, the amount of chlorine ions and the amount of sulfate ions are additionally measured, their ratio is calculated, the type of salinity is determined, and taking into account the calibration curve previously obtained individually for this type of salinity, the amount of salts is calculated, 1 sludge.

Description

The invention relates to the field of conductometric analysis of media and can be used in agriculture, particularly in agricultural chemistry of soils.

There is a known method for determining soil salinity, which includes a complete analysis of water extraction of the soil with a 1: 5 ratio of soil to water, in which CO2, HCO3, Cl, SO, Ca, Mg, Na, K ions and dry residue are determined. Then, according to the chemistry of salts, saline soils are divided into types. The type of salinity is determined by the ratio of cations or anions, the degree of salinity is estimated by the amount of total salts.

The method requires time-consuming expensive equipment.

The closest in technical essence is a method for determining the salinity of a post, including the steps of obtaining a water extract, measuring its conductivity and determining the amount of salts as a result of soil measurements.

The disadvantage of the method is the low reliability of the method, since it does not take into account various types of salinization.

The aim of the invention is to increase the reliability of the method.

The drawing shows an experimental graph of the correction factor versus sulfate ratio.

The method for determining the salinity of the soil is carried out as follows: 50 or 100 g of absolutely dry soil (dried and cooled in a desiccator) are weighed on a technical scale. A portion of the soil is placed in a flask or flask with a capacity of 500-1000 ml and a dog is 5 times the amount of distilled water. Water should not contain C02.

The slurry or flask with a sample of soil is closed with a rubber stopper and shaken for 3 minutes, after which the extract is filtered through

SP

with

sJ

about

N3 GO O Yu

dry folded filter. In the resulting stretch, the electrical conductivity is determined using a saline meter, the amount of chlorine ion using the Mohr method using an argnetometric method, and the sulfate ion using a gravimetric or complex metric method. By the ratio

C g

 mg-eq./10 g of soil determine the type

S04

salinity.

Types of salinity are summarized in the table. Next, the amount of salts is determined.

SG

For this in relation

S04

determine the coefficient k, which determines the individual calibration dependence for each type of salinity.

Graph of dependence shown in the drawing.

The empirical relationship for determining the salt content in the soil (C%), taking into account the type of salting of the soil, is

С К- / с, where С - salt content in soil,%;

K — electrical conductivity of the exhaust, MS / cm,

(- the conversion rate of electrical conductivity in the amount of salts.

Claims (1)

The invention of the method for determining soil salinity, which consists in obtaining water extraction of soil, measure its electrical conductivity and determine the amount of salts as a result of indirect measurements, characterized in that, in order to increase the reliability determinations, additionally measure the amount of chlorine ions and the amount of sulfate ions, calculate their ratio characterizing salinity, and taking into account the previously obtained individual salinity for this calibration dependence, calculate the amount of salts. Ratio CI: ZSm 0.2 0.2-1.0 1.0-2.5 2.5 -I L Salinity type Sulfate Chloride Sulfate Sulfate Chloride Chloride