CN113504344A

CN113504344A - Method and device for evaluating long-acting performance of acid soil conditioner

Info

Publication number: CN113504344A
Application number: CN202110949533.4A
Authority: CN
Inventors: 时仁勇; 倪妮; 姜军; 来宏伟; 李九玉; 徐仁扣; 崔秀敏
Original assignee: Institute of Soil Science of CAS
Current assignee: Institute of Soil Science of CAS
Priority date: 2021-08-18
Filing date: 2021-08-18
Publication date: 2021-10-15
Anticipated expiration: 2041-08-18
Also published as: CN113504344B

Abstract

The invention discloses a method and a device for evaluating the long-acting property of an acid soil conditioner, wherein the method comprises the following steps: preparing the soil after S1-1 improvement, carrying out S1-2 leaching reaction, obtaining the leaching amount of a total acid solution according to the pH value and Al content when the soil is critically damaged, and calculating the relative long-acting performance index R ═ V_m/(M₀‑M)+V_n/N)/(V_k/(L₀‑M)+V_land/N). The device includes sour liquid bottle, peristaltic pump and comprehensive simulation case, and the middle part is equipped with the baffle in the comprehensive simulation case, and the baffle top is equipped with places the platform, and the reaction tank is fixed in places bench surface one side, and the opposite side is equipped with a plurality of dishes of placing, and the play liquid end of reaction tank is equipped with the hose, and the hose runs through behind the receiver and is connected with recovery mechanism. The invention has long-term effect on soil conditioner by short-term indoor simulation experiment methodThe evaluation is carried out to obtain the effective age after the modifying agent is applied, the experimental method is scientific and reasonable, the whole device is reasonable in structure, and the operation is convenient and rapid.

Description

Method and device for evaluating long-acting performance of acid soil conditioner

Technical Field

The invention relates to the technical field of soil regulation, in particular to a method and a device for evaluating the long-acting property of an acid soil conditioner.

Background

Nowadays, with the rapid development of urban economy, the population expands rapidly, and the demand for high-quality soil is extremely urgent. At present, about 2.26 hundred million acre of acid soil is distributed in China, and the acid hazard and the aluminum hazard seriously damage the growth of crops. Aiming at the limiting factors of the acid soil, various acid soil conditioners have been developed internationally and domestically to improve the productivity of the acid soil. However, in the industrial and agricultural production process, due to acid sedimentation caused by large amount of N, S atmospheric emission and excessive application of ammonium nitrogen fertilizer, acidic substances can enter the soil again, the effective ingredients in the modifying agent are consumed, the modified acidic soil is acidified again, and the modifying effect is weakened or even disappears. It follows that the longevity of the modifier should be evaluated as a key property.

The long-acting performance of the acid soil conditioner is scientifically, accurately and quickly evaluated, so that the method is helpful for knowing how the long-acting performance of the acid soil conditioner of the variety is long, further provides scientific basis when people select different types of acid soil conditioners, and simultaneously provides reference for the application frequency of the acid soil conditioner. The existing method for evaluating the long-acting performance of the acid soil conditioner mostly adopts field production experience or an indoor simulation experiment, a set of systematic evaluation method and device are not formed, evaluation results are mostly in a one-sided and general manner, indexes of the long-acting performance of the conditioner for scientific evaluation are lacked, and the long-acting performance of the conditioner cannot be clearly reflected, so that the method and the device for comprehensively, effectively and quickly evaluating the long-acting performance of the acid soil conditioner are needed to be provided.

In field experiments carried out in the prior art, for example, the long-term effect of the traditional improver lime and the long-term effect of applying different types of improvers on reducing the mobility of heavy metals in the soil of a mining area are observed, and although the long-term effect of the traditional improver lime is researched, the influence of common improvers on the solubility of heavy metals is also obtained. However, the field test periods are too long, so that the relevance between the experimental conclusion and the actual production is not strong, and the effective evaluation on the long-acting performance of a variety of acid soil conditioner products is difficult to provide.

The patent CN104459085A discloses an indoor multistage simulation elution test method, an indoor multistage simulation elution test device is established, an elution liquid storage device is arranged above a soil container, a graduated scale is arranged on the side surface of the elution liquid storage device, a bottom pinhole of the elution liquid storage device is arranged at the bottom of the elution liquid storage device, and the lower part of the elution liquid storage device is connected with the soil container; the soil body container is arranged between the leacheate storage device and the leacheate collector, the bottom of the soil body container is provided with a hole at the bottom of the soil body container, a permeable stone is arranged on the hole, and a pinhole gasket is arranged at the joint of the upper part of the soil body container and the leacheate storage device; the device can be provided with one or more soil containers according to the test requirements; the leacheate collector is arranged at the lowest part of the device, and a valve is arranged on the outer side of the bottom of the device. And injecting quantitative leacheate into the leacheate storage device, wherein the leacheate flows into the soil body sample through the pinhole gasket and finally flows into the leacheate collector. The invention can load multi-stage undisturbed soil samples and measure leaching depth, and has small disturbance to the samples, simple structure and convenient use. But the evaluation of the long-lasting effect of the acid soil conditioner still has the limitations of long test period and the like.

Disclosure of Invention

Aiming at the existing problems, the invention provides a method and a device for evaluating the long-acting property of an acid soil conditioner.

The technical scheme of the invention is as follows:

a method for evaluating the long-acting performance of an acid soil conditioner comprises the following steps of inputting acid amount by calculating year, preparing a simulated acid solution, reacting the simulated acid solution with a soil sample improved by the conditioner, measuring the pH value and Al content of a product after reaction, and calculating a relative long-acting performance index R according to a leaching volume, the pH value and the Al content, wherein the relative long-acting performance index R is used for evaluating the long-acting performance of different conditioners, and specifically comprises the following steps:

s1-1, preparing the improved soil: taking a proper amount of modifier and Ca (OH)₂Respectively mixing the soil and the same acid soil uniformly to enable the pH of the improved soil to be close and reach 5.5-6.5, adjusting the water content of the soil to 20% by using deionized water, culturing for 15d at 25 ℃, supplementing water once every 3d, and grinding the improved soil sample to pass through a 0.25mm sieve for later use after the culture is finished;

s1-2, leaching reaction: introducing deionized water into closed reaction tanks (4) respectively filled with 1.00g of the soil sample improved by the modifier by a peristaltic pump, adjusting the flow rate to 1mL/min after the closed reaction tanks are full of the mixture and balancing the mixture for 10min, replacing the deionized water with a prepared simulated acid solution, controlling the reaction temperature to be 25 +/-2 ℃, carrying out leaching reaction under the condition of magnetic stirring, collecting the solution after the reaction at a water outlet by using an automatic part collector, wherein the collection frequency is 5-10min, and measuring the pH value and the Al content of the solution after the reaction;

s1-3, obtaining the initial pH of the leachate of the soil improved by the conditioner through the leaching reaction, wherein the initial pH is M₀And L₀Setting the critical hazard pH value to be 4-5, and calculating the total leaching acid solution amount V when the critical hazard pH value M is calculated_mSetting the critical hazard Al content N to be 4-6 mu mol/L, and calculating the total leaching acid solution amount V when the critical hazard Al content N is_n；

S1-4, calculating relative long-term durability index R ═ V (V) according to the measured parameters of S1-2 and S1-3_m/(M₀-M)+V_n/N)/(V_k/(L₀-M)+V_l/N), wherein V_kIs the total leaching solution amount V when the lime treatment is in critical harm pH_lFor the total leaching acid capacity of the critical hazard Al content of lime treatment, dividing the long-acting grade according to the value of R: the difference being R<0.5, less preferably 0.5<R<1, medium R is 1, preferably 1<R<1.5, Excellent is R>1.5。

Further, the method also comprises a step S1-5 of calculating the improvement effect years of the obtained modifier: by changing the background solution of the simulated acid solution into 1M KCl solution, the pH value of the solution is determined by the annual rainfall p mm and unitArea annual proton input z mol m^-2a^-1Obtaining pH-lg (z/p), calculating annual acid solution input V per g soil according to local annual rainfall p₁，V₁The collection frequency was 5min, the critical pH was set to 4.5, the critical cumulative Al release amount was 5.0mmol/kg, and the time t for the modifier to exert its modifying effect under the pH condition was calculated₁＝V_m/V_1，Calculating the time t for the modifier to exert the improvement effect under the condition of critical Al release amount₂＝V_n/V₁Will improve the effect time t₁、t₂Evaluating the duration of the soil improvement effect by comprehensive weighted average, wherein T is (T)₁+t₂)/2。

Further, the KCl solution is treated with HNO₃Or HCl.

Further, root elongation experiments are carried out on the soil samples improved by different acid soil conditioners, and the long-acting performance of different acid soil conditioners is further researched, and the method specifically comprises the following steps:

s2-1, simulating acid rain: adding a simulation acid solution into the soil samples improved by different acid soil conditioners respectively to simulate the acid rain leaching process, taking each soil sample improved by the acid soil conditioners as a group, correspondingly grouping the types of the acid soil conditioners researched as required, and ensuring that the root elongation experiment operation of each soil sample improved by the acid soil conditioners is the same: adding 8.0g of soil improvement sample into a 500ml glass beaker according to the rainfall capacity of receiving 7.5ml of soil per g of soil every year, then adding 300ml of simulated acid solution to simulate the leaching process for 5 years, respectively repeating the leaching-drying cycles for 2, 3 and 4 times, simulating the acid rain leaching process for 10, 15 and 20 years, and taking the added pure water solution as a control;

s2-2, stirring: magnetically stirring the simulated soil suspension after being subjected to acid rain washing for 5, 10, 15 and 20 years, balancing for 3 days after stirring for 24 hours, stirring for 5min every day, and repeating for three times;

s2-3, selecting crops: soaking crop seeds in a disinfectant for disinfection for 20min, then washing the crop seeds with deionized water, soaking the crop seeds in the deionized water for 4h, taking the crop seeds out, carrying out 3d light-shielding germination accelerating water culture in an incubator at 25 ℃, and then selecting a plurality of seedlings with the root length of 5cm +/-0.5 cm to carry out a root elongation experiment;

s2-4, root elongation test: transplanting the seedlings to simulated soil suspension after 5, 10, 15 and 20 years of acid rain washing respectively, culturing for 48h in an incubator at 25 ℃ in a dark place, and calculating the relative root elongation RRE ═ L_i/L₀X 100%, where Li is the root elongation for each treatment with different elution times, i ═ 0, 1, 2, 3, 4, L₀In order to treat root elongation by pure water, the control group replaces the simulated acid rain solution with deionized water, the contrast effect difference is obvious, the experimental data can be further analyzed, and the age of the effect of the modifying agent is determined when the relative root elongation RRE reaches the critical yield reduction.

Furthermore, the simulated acid solution has a pH of 3.5, and the simulated acid solution has the following components in molar ratio: h₂SO₄：HNO₃3-6: 1, the acid rain is closest to the acid rain under the real condition, and the result of the simulation experiment is more real.

Furthermore, the crop seeds in the step S2-1 are corn seeds, the growth speed of the corn seeds is high, and the experimental period can be shortened.

Further, the disinfecting solution in the step S2-3 is H with a mass concentration of 10%₂O₂The solution and the method are simple and convenient, the consumption of the disinfectant is saved, and the disinfection effect is good.

Further, the method further includes step S3, weighted averaging: will improve the effect time t₁、t₂And the long-acting index A is obtained by comprehensively weighting and averaging the data obtained in the root elongation experiment to evaluate the long-acting performance of the soil conditioner,

wherein Y represents the simulation year when the relative root elongation RRE is the critical yield reduction of 80-90%, and the long-term effect index can be used for conveniently and rapidly evaluating the long-term effect quality of the soil conditioner.

The device for evaluating the long-acting performance of the acid soil conditioner by utilizing any one of the methods comprises an acid liquid bottle, a peristaltic pump and a comprehensive simulation box,

the acid liquor bottle is connected with the liquid inlet end of a reaction tank positioned at the upper part in the comprehensive simulation box through an acid liquor pipe, the peristaltic pump is positioned at the middle part of the acid liquor pipe, a partition plate is arranged at the middle part in the comprehensive simulation box, a slidable placing table is arranged above the partition plate, the reaction tank is fixed at one side of the upper surface of the placing table, a plurality of placing discs are arranged at the other side of the upper surface of the placing table, a hose is arranged at the liquid outlet end of the reaction tank, the hose penetrates through a storage box fixed on the outer side wall of the comprehensive simulation box and then is connected with a recovery mechanism positioned at the lower part in the comprehensive simulation box,

retrieve the mechanism including fixing the guide arm of baffle lower surface and the sliding block that is located the guide arm below, the middle part is seted up in the guide arm and is extended to the recess that the guide arm lower surface is used for placing the hose, and the guide arm both sides are equipped with the spout, the sliding block with spout sliding connection, the liquid outlet and the hose end-to-end connection that the sliding block below was equipped with, be located the inside a plurality of receiving flasks that are equipped with of comprehensive simulation incasement portion of retrieving the mechanism below, receiving flask one side is equipped with the thermal reaction storehouse.

Further, reaction tank feed liquor end is equipped with the choke valve, and the middle part is equipped with the filter vat in the reaction tank, the filter vat is from outer and interior filter screen, quartz sand layer, diacetate fiberboard, honeycomb duct of being equipped with in proper order, the honeycomb duct with the hose connection, the inside magnetic stirrers that is equipped with of reaction tank of filter vat below, one end lets in the acid solution and stirs and makes its and soil misce bene to retrieve through the filterable mode of drip washing, the experimental data that obtains is more true accurate.

Further, place the platform below through a set of damping slide rail with baffle sliding connection, it corresponds to synthesize the simulation case lateral wall sour liquid pipe and hose department all are equipped with the fluting of bar, make access glass beaker convenient and fast more through setting up the damping slide rail, and the fluting sets up simultaneously and can not make sour liquid pipe and hose obstruct the slip.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention evaluates the long-term effects of different acid soil conditioners by a short-term indoor simulation experiment method, can evaluate the long-term effects of the conditioner in a few hours, and obtains the effective age of the conditioner after application.

(2) According to the invention, the long-acting time of the conditioner obtained by evaluating the critical hazard pH value, the critical hazard Al content and the relative root elongation is compared and summarized, and the long-acting indexes of soil improvement evaluation and long-acting type are obtained by comprehensive weighting, so that the long-acting quality of the soil conditioner can be conveniently and rapidly evaluated.

(3) According to the invention, by arranging the comprehensive simulation box, the process of the short-term indoor simulation experiment method is simplified, the leaching speed is increased, two experiments can be performed synchronously, the experiment efficiency is improved, the experiment result is more accurate, the whole device has a reasonable structure and multiple functions, the requirements of different experiments can be met, and the popularization and the use are facilitated.

Drawings

FIG. 1 is a schematic diagram of the apparatus and process configuration of the present invention;

FIG. 2 is a schematic diagram of the front internal structure of the integrated simulation chamber of the apparatus of the present invention;

FIG. 3 is a schematic view of the internal structure of the back of the integrated simulation chamber of the apparatus of the present invention;

FIG. 4 is a schematic view of the internal structure of the slider of the apparatus of the present invention;

FIG. 5 shows an experimental example 1 of the present invention, which is example 2, comprising peanut stalk charcoal and Ca (OH)₂As a modifier, the pH value of the leaching solution in the leaching experiment of the red clay by using an acid solution with deionized water as a background solution is changed;

FIG. 6 shows examples 2 of the present invention in Experimental example 1, in which peanut straw charcoal and Ca (OH) are used as raw materials₂As a modifier, the change of the aluminum concentration of the leaching solution in the leaching experiment of the red clay by using an acid solution with deionized water as a background solution;

FIG. 7 shows examples 4 and 5 of the present invention in Experimental example 1, which respectively show peanut stalk charcoal and Ca (OH)₂As modifier, change of pH of leaching solution in leaching experiment of red clay by using acid solution with KCl as background solutionMelting;

FIG. 8 shows examples 4 and 5 of the present invention in Experimental example 1, which respectively show peanut stalk charcoal and Ca (OH)₂As a modifier, soil exchangeable Al changes in the process of leaching red clay by an acid solution with KCl as a background solution;

FIG. 9 is a graph showing the relative root elongation changes during the acidification in Experimental example 1 of the present invention;

FIG. 10 shows the pH change of the leaching solution of the leaching experiment of red clay with an acid solution of KCl as a background solution and straw carbon as a modifier in Experimental example 2 of the present invention;

FIG. 11 shows the change of soil exchangeable Al in the process of leaching red clay with an acid solution with KCl as a background solution by using straw carbon as a modifier in Experimental example 2 of the present invention;

FIG. 12 shows the change of pH of the leaching solution in the leaching experiment of the brick red soil with an acid solution with KCl as a background solution in the experimental example 3 of the present invention;

FIG. 13 shows the change of soil exchangeable Al during the leaching of the brick red soil with an acid solution of KCl as a background solution in Experimental example 3 of the present invention.

FIG. 14 shows the change of pH of the leaching solution in the leaching experiment of red soil with an acid solution using KCl as a background solution in the experimental example 3 of the present invention;

FIG. 15 shows the change of soil exchangeable Al during the washing of red soil with an acid solution using KCl as a background solution in Experimental example 3 of the present invention.

The device comprises a 1-acid liquid bottle, a 11-acid liquid pipe, a 2-peristaltic pump, a 3-comprehensive simulation box, a 31-partition plate, a 32-placing table, a 33-placing disc, a 34-collecting bottle, a 35-thermal reaction bin, a 36-damping slide rail, a 37-slotting, a 4-reaction tank, a 41-throttling valve, a 42-filter barrel, a 43-filter screen, a 44-quartz sand layer, a 45-diacetate fiber plate, a 46-guide pipe, a 47-magnetic stirrer, a 5-hose, a 51-storage box, a 6-guide rod, a 61-groove, a 62-sliding chute, a 7-sliding block and an 8-liquid outlet.

Detailed Description

Example 1

s1-1, preparing the improved soil: taking a proper amount of modifier and Ca (OH)₂Respectively mixing the soil and the same acid soil uniformly to enable the pH of the improved soil to be close and reach 5.5, adjusting the water content of the soil to 20% by using deionized water, culturing for 15 days at 25 ℃, supplementing water once every 3 days, and grinding the improved soil sample to pass through a 0.25mm sieve for later use after the culture is finished;

s1-2, leaching reaction: introducing deionized water into closed reaction tanks 4 respectively filled with 1.00g of soil samples improved by the modifying agent through peristaltic pumps, adjusting the flow rate to 1mL/min after the closed reaction tanks are full of the mixture and balancing the mixture for 10min, replacing the deionized water with a prepared simulated acid solution, controlling the reaction temperature to be 25 +/-2 ℃, performing leaching reaction under the condition of magnetic stirring, collecting the reacted solution at a water outlet by using an automatic part collector at the same time, collecting the frequency for 5min, and measuring the pH value and the Al content of the reacted solution;

s1-3, obtaining the initial pH of the leachate of the soil improved by the conditioner through the leaching reaction, wherein the initial pH is M₀And L₀Setting the critical hazard pH value to be 4, and calculating the total leaching acid solution amount V when the critical hazard pH value M is calculated_mSetting the critical hazard Al content N to be 6 mu mol/L, and calculating the total leaching acid solution amount V at the critical hazard Al content N_n；

S1-4, calculating relative long-term durability index R ═ V (V) according to the measured parameters of S1-2 and S1-3_m/(M₀-M)+V_n/N)/(V_k/(L₀-M)+V_l/N), wherein V_kIs the total leaching solution amount V when the lime treatment is in critical harm pH_lFor the total leaching acid capacity of the critical hazard Al content of lime treatment, dividing the long-acting grade according to the value of R: the difference being R<0.5, less preferably 0.5<R<1, medium R is 1, preferably 1<R<1.5, Excellent is R>1.5；

S1-5, calculating the improvement effect years of the obtained modifier: by changing the background solution of the simulated acid solution into a 1M KCl solutionThe pH value of the solution is determined by the annual rainfall p mm and the annual proton input per unit area z mol m^-2a^-1Obtaining pH-lg (z/p), calculating annual acid solution input V per g soil according to local annual rainfall p₁，V₁The collection frequency was 5min, the critical pH was set to 4.5, the critical cumulative Al release amount was 5.0mmol/kg, and the time t for the modifier to exert its modifying effect under the pH condition was calculated₁＝V_m/V_1，Calculating the time t for the modifier to exert the improvement effect under the condition of critical Al release amount₂＝V_n/V₁Will improve the effect time t₁、t₂Evaluating the duration of the soil improvement effect by comprehensive weighted average, wherein T is (T)₁+t₂)/2。

Example 2

In this embodiment, on the basis of example 1, a root elongation experiment is performed on a soil sample after improvement of different acid soil improvement agents, so as to further study the long-lasting effect of the different acid soil improvement agents, and the method specifically includes the following steps:

s2-3, selecting crops: soaking semen Maydis in 10% disinfectant solution (H) for 20min₂O₂Washing the solution with deionized water, soaking in deionized water for 4h, taking out, performing 3d light-shielding germination accelerating water culture in an incubator at 25 ℃, and selecting 5 corn seedlings with root length of 5cm +/-0.5 cm for root elongation experiment;

s2-4 elongation experiments: transplanting the seedlings to simulated soil suspension after 5, 10, 15 and 20 years of acid rain washing respectively, culturing for 48h in an incubator at 25 ℃ in a dark place, and calculating the relative root elongation RRE ═ L_i/L₀X 100%, where Li is the root elongation for each treatment with different elution times, i ═ 0, 1, 2, 3, 4, L₀In order to treat corn root elongation in a contrast way, the simulated acid rain solution is replaced by deionized water in the contrast group, and the age of the effect of the modifying agent is determined when the relative root elongation RRE reaches critical yield reduction;

s3, weighted average: will improve the effect time t₁、t₂And the long-acting index A is obtained by comprehensively weighting and averaging the data obtained in the root elongation experiment to evaluate the long-acting performance of the soil conditioner,

wherein Y represents the simulated year when the relative root elongation RRE is 80%.

Example 3

The embodiment is based on the method of embodiment 2, and provides a device for evaluating the long-lasting effect of an acid soil conditioner by using the method, which comprises an acid liquid bottle 1, a peristaltic pump 2 and a comprehensive simulation box 3;

the acid liquid bottle 1 is connected with the liquid inlet end of a reaction tank 4 positioned at the upper part in the comprehensive simulation box 3 through an acid liquid pipe 11, the peristaltic pump 2 is positioned at the middle part of the acid liquid pipe 11, a partition plate 31 is arranged at the middle part in the comprehensive simulation box 3, a slidable placing table 32 is arranged above the partition plate 31, the lower part of the placing table 32 is in sliding connection with the partition plate 31 through a group of damping slide rails 36, the reaction tank 4 is fixed at one side of the upper surface of the placing table 32, the other side of the upper surface of the placing table 32 is provided with 10 groups of placing discs 33, the liquid outlet end of the reaction tank 4 is provided with a hose 5, the hose 5 penetrates through a storage box 51 fixed on the outer side wall of the comprehensive simulation box 3 and then is connected with a recovery mechanism positioned at the lower part in the comprehensive simulation box 3, the liquid inlet end of the reaction tank 4 is provided with a throttle valve 41, the middle part in the reaction tank 4 is provided with a filter barrel 42, the filter screen 43, a quartz sand layer 44, a cellulose diacetate board 45 and a guide pipe 46 are sequentially arranged from the outside to the inside, the draft tube 46 is connected with the hose 5, a magnetic stirrer 47 is arranged inside the reaction tank 4 below the filter barrel 42, the magnetic stirrer 47 is a commercially available magnetic stirrer, and strip-shaped slots 37 are formed in the side wall of the comprehensive simulation box 3 corresponding to the acid liquid tube 11 and the hose 5;

the recycling mechanism comprises a guide rod 6 fixed on the lower surface of the partition plate 31 and a sliding block 7 positioned below the guide rod 6, a groove 61 which extends to the lower surface of the guide rod 6 and is used for placing a hose 5 is formed in the middle of the inner part of the guide rod 6, sliding grooves 62 are formed in two sides of the guide rod 6, the sliding block 7 is in sliding connection with the sliding grooves 62, a liquid outlet 8 which is formed below the sliding block 7 is connected with the tail end of the

hose

5, 8 groups of collecting bottles 34 are arranged inside a comprehensive simulation box 3 positioned below the recycling mechanism, the collecting bottles 34 can be replaced, a thermal reaction bin 35 is arranged on one side of each collecting bottle 34, and a commercially available heating and drying device is arranged in the thermal reaction bin 35; the lower part in the sliding block 7 is provided with a motor which is an SGF-100W orthogonal double-shaft speed reduction motor.

The working principle is as follows: preparing a simulated acid solution by using an acid solution bottle 1, introducing the prepared simulated acid solution into a closed reaction tank 4 filled with a soil sample improved by the modifying agent through a peristaltic pump 2, starting a magnetic stirrer 47 to perform step S1-2, leaching, allowing the acid solution to pass through a filter screen 43, a quartz sand layer 44 and a diacetate fiber plate 45, then entering a guide pipe 46 and discharging, and replacing a filter vat 42 with a new one after the experiment is finished to prevent blockage; meanwhile, adding a simulated acid solution into the soil sample after the improvement of the modifying agent to perform a long-term simulated acid rain leaching process, adding 8.0g of the soil improvement sample into a 500ml glass beaker according to the annual rainfall of 7.5ml received by each gram of soil, placing the beaker on a placing disc 33, arranging a group of small magnetic stirrers at the bottom of each group of placing discs 33, and starting the magnetic stirrers to perform the step S2-1, the simulated acid rain and the step S2-2 and stirring; the thermal reaction chamber 35 can dry the soil sample in the simulated acid rain in the step S2-1, and the thermal reaction chamber 35 can complete the step S2-4 elongation experiments under the normal temperature closed condition.

Operation principle of storage box 51: a spiral tube for accommodating the tube 5 is provided inside the accommodating case 51, and when the mount table 32 is slid using the damping slide rail 36, the tube 5 connected to the reaction tank 4 slides in the slit 37 while the accommodating case 51 discharges a part of the tube 5; when the sliding block 7 moves, the hose 5 is driven to move, and a part of the hose 5 is released by the spiral pipe in the storage box 51, so that the automatic release and recovery of the hose are completed by the spiral pipe.

The working principle of the sliding block 7 is as follows: when the leaching reaction is finished by one reaction period in step S1-1, the collected leacheate flows into the collection bottles 34 from the filter barrel 42 through the hose 5 and the liquid outlet 8 to be collected, and when each collection is finished, the motor drives the sliding block 7 to slide forwards along the sliding chute 62 by a distance which is equal to the distance between two sets of collection bottles 34, so as to prepare for the next collection of the leacheate.

Example 4

This example is substantially the same as example 2, except that the critical damage pH M is different, the critical damage Al content N is different, and the critical yield reduction achieved with respect to the root elongation RRE is different.

S1-2, leaching reaction: introducing deionized water into closed reaction tanks 4 respectively filled with 1.00g of soil samples improved by the conditioner through peristaltic pumps, adjusting the flow rate to 1mL/min after the closed reaction tanks are full of the solution and balancing the solution for 10min, replacing the deionized water with a pre-prepared simulated acid solution KCl solution, controlling the reaction temperature to be 25 +/-2 ℃, performing leaching reaction under the condition of magnetic stirring, collecting the solution after the reaction at a water outlet by using an automatic part collector, wherein the collection frequency is 8min, and measuring the pH value and the Al content of the solution after the reaction;

s1-3, obtaining the initial pH of the leachate of the soil improved by the conditioner through the leaching reaction, wherein the initial pH is M₀And L₀Setting the critical hazard pH value to be 4.5, and calculating the total leaching acid solution amount V when the critical hazard pH value M is calculated_mSetting the critical hazard Al content N to be 5mmol/kg, and calculating the total leaching acid solution amount V at the critical hazard Al content N_n；

S3, weighted average: y represents the simulated year when the relative root elongation RRE is 85%.

Example 5

This example is substantially the same as example 2 except that the critical hazard pH M is different and the critical hazard Al content N is different.

S1-2, leaching reaction: introducing deionized water into closed reaction tanks 4 respectively filled with 1.00g of soil samples improved by the conditioner through peristaltic pumps, adjusting the flow rate to 1mL/min after the closed reaction tanks are full of the solution and balancing the solution for 10min, replacing the deionized water with a pre-prepared simulated acid solution KCl solution, controlling the reaction temperature to be 25 +/-2 ℃, carrying out leaching reaction under the condition of magnetic stirring, collecting the solution after the reaction at a water outlet by using an automatic part collector, wherein the collection frequency is 10min, and measuring the pH value and the Al content of the solution after the reaction;

s1-3, obtaining the initial pH of the leachate of the soil improved by the conditioner through the leaching reaction, wherein the initial pH is M₀And L₀Setting the critical hazard pH value to be 5, and calculating the total leaching acid solution amount V when the critical hazard pH value M is calculated_mSetting the critical hazard Al content N to be 4mmol/kg, and calculating the total leaching acid solution amount V at the critical hazard Al content N_n；

S3, weighted average: y represents the simulated year when the relative root elongation RRE is 90%.

Example 6

This example is substantially the same as example 2, except that the simulated acid solution has a pH of 3.5 and has the following composition and molar ratio: h₂SO₄：HNO₃＝3：1。

Example 7

This example is substantially the same as example 2, except that the simulated acid solution has a pH of 3.5 and has the following composition and molar ratio: h₂SO₄：HNO₃＝4：1。

Example 8

This example is substantially the same as example 2, except that the simulated acid solution has a pH of 3.5 and has the following composition and molar ratio: h₂SO₄：HNO₃＝6：1。

Experimental example 1

Indoor use of two different acid soil conditioners according to the methods of examples 2, 4 and 5Simulation experiment shows that the soil is red clay, wherein the peanut straw carbon is recorded as modifier A, and Ca (OH)₂The evaluation was reported as modifier B, and the results are shown in Table 1.

Table 1 duration of use of two different soil amendments in examples 2, 4, 5

Taking example 2 as an example, as shown in FIGS. 5 to 6, the critical hazard pH M was 4, and the amount of acid solution V was input annually₁Ca (OH) at a critical hazard pH M of 4 of 8ml₂Total amount of eluting acid solution V_k115ml, Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V₁14.375; total leaching acid solution amount V of peanut straw carbon when critical hazard pH value M is 4_m182ml, the time t for the peanut straw carbon modifier to exert the improvement effect₁＝V_m/V₁＝22.75；

The critical harm Al content N is 6 mu mol/L, and the annual input acid solution amount V₁8ml of Ca (OH) at a critical hazardous Al content N of 6. mu. mol/L₂Total amount of eluting acid solution V_l80ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₂＝V_l/V ₁10, the total leaching acid solution volume V of the peanut straw carbon when the critical harm Al content N is 6 mu mol/L_nThe volume of the modifier is 100ml, the time t for the peanut straw carbon modifier to exert the improvement effect₂＝V_n/V₁＝12.5；

As shown in FIG. 9, the improvement effect of the modifier A peanut stalk charcoal can be more than 20 years when the relative root elongation RRE is 80%, while the modifier B Ca (OH)₂Can only play for 16 years.

Taking example 4 as an example, as shown in FIGS. 7-8, the critical hazard pH M was 4.5, and the amount of acid solution V was input annually₁8ml of Ca (OH) at a critical hazard pH M of 4.5₂Total amount of eluting acid solution V_k24ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V ₁3; total leaching acid solution amount V of peanut straw carbon when critical hazard pH value M is 4.5_mThe volume of the modifier is 33ml, the time t for the peanut straw carbon modifier to exert the improvement effect₁＝V_m/V₁＝4.125；

The critical harm Al content N is 5mmol/kg, and the annual input acid solution amount V₁8ml of Ca (OH) at a critical Al content of 5mmol/kg N₂Total amount of eluting acid solution V_l75ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₂＝V_l/V₁The total leaching acid solution volume V of the peanut carbon when the critical harm Al content N is 5mmol/kg is 9.375_n106ml, the time t for the peanut straw carbon modifier to exert the improvement effect₂＝V_n/V₁＝13.25；

As shown in FIG. 9, the improvement effect of the modifier A peanut stalk charcoal can be about 18 years when the relative root elongation RRE is 85%, while the modifier B Ca (OH)₂The improvement effect was exerted only 5 years after application.

Taking example 5 as an example, as shown in FIGS. 7 to 8, the critical hazard pH M was 5, and the amount of acid solution V was input annually₁8ml of Ca (OH) at a critical hazard pH M of 5₂Total amount of eluting acid solution V_kIs 14ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V₁1.75; total leaching acid solution amount V of peanut straw carbon when critical hazard pH value M is 5_m9.225ml, the time t for the peanut straw carbon modifier to exert the modification effect₁＝V_m/V₁＝1.15；

The critical harm Al content N is 4mmol/kg, and the annual input acid solution amount V₁8ml of Ca (OH) at a critical hazardous Al content N of 4mmol/kg₂Total amount of eluting acid solution V_l60ml, Ca (OH)₂Time t for improving agent to exert improvement effect₂＝V_l/V₁7.5, inTotal leaching acid solution amount V of peanut straw carbon when critical harm Al content N is 4mmol/kg_n88ml, the time t for the peanut straw carbon modifier to exert the improvement effect₂＝V_n/V₁＝11；

As shown in FIG. 9, the improvement effect exerted by the modifier A peanut stalk charcoal when the relative root elongation RRE is 90% can be about 7 years, while the modifier B Ca (OH)₂The improvement effect is exerted only 4 years after the modifier is applied, and the long-acting index is calculated, so that the long-acting index of the modifier A is larger than that of the modifier B, and the long-acting index can intuitively reflect the long-acting property of the modifier, therefore, the peanut straw carbon of the modifier A is relative to the Ca (OH) of the modifier B₂Has a more lasting improvement effect.

In terms of the selection of the critical hazard value, in combination with the long-term effectiveness index a, the critical hazard value selected in example 2 is most suitable for the actual production needs, and therefore, the critical hazard value selected in example 2 is most reasonable.

Experimental example 2

For comparison, the present experimental example uses straw char as modifier C, and example 2 as an example, and a laboratory simulation experiment was performed on modifier C by the same method as in experimental example 1, and the results of the experiment are shown in Table 2 as compared with modifier B:

TABLE 2 duration comparison of conditioner C to conditioner B

Taking example 2 as an example, as shown in FIGS. 10 and 11, the critical hazard pH M was 4, and the amount V of the acid solution was measured by year input₁Ca (OH) at a critical hazard pH M of 4 of 8ml₂Total amount of eluting acid solution V_kIs 32ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V ₁4; total leaching acid solution volume V of carbon from straw at critical hazard pH value M of 4_m42ml, the time t at which the rice straw carbon modifier exerts the modifying effect₁＝V_m/V₁＝5.25；

The critical harm Al content N is 6mmol/kg, and the annual input acid solution amount V₁8ml of Ca (OH) at a critical hazardous Al content N of 6mmol/kg₂Total amount of eluting acid solution V_l72ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₂＝V_l/V₁The total leaching acid solution volume V of the strawberries when the critical harm Al content N is 6mmol/kg is 9_n116ml, the time t at which the rice straw carbon modifier exerts the modifying effect₂＝V_n/V₁＝14.5。

As can be seen from the relative longevity index R, modifier C straw char is comparable to modifier B Ca (OH)₂Has a more lasting improvement effect.

Experimental example 3

The experimental results obtained in this example are shown in table 3, which are obtained by performing experiments on different soil types using the same experimental method as in example 1:

TABLE 3 duration of two amendments in brick red soil and red soil

Taking example 2 as an example, the soil is brick red soil, as shown in figures 12 and 13, the critical hazard pH value M is 4, the annual rainfall p is 1560mm, and the annual input acid solution amount V₁1560/260 ═ 6ml, Ca (OH) at critical hazard pH M of 4₂Total amount of eluting acid solution V_k92ml, Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V₁15.3; total leaching acid solution amount V of peanut straw carbon when critical hazard pH value M is 4_m120ml, the time t for the peanut straw carbon modifier to exert the improvement effect₁＝V_m/V₁＝20；

The critical harm Al content N is 6mmol/kg, and the annual input acid solution amount V₁6ml of Ca (OH) at a critical Al content of 6mmol/kg N₂Total amount of eluting acid solution V_l136ml, Ca (OH)₂Time for improving agent to exert improving effectt₂＝V_l/V₁22.6, and the total leaching acid solution amount V of the peanut straw carbon when the critical harm Al content N is 6mmol/kg_n175ml, the time t for the peanut straw carbon modifier to exert the improvement effect₂＝V_n/V₁＝29.1；

Taking example 2 as an example, the soil is red-red soil, as shown in FIGS. 14 and 15, the critical hazard pH value M is 4, the annual rainfall p is 1560mm, and the annual input acid solution amount V₁1560/260 ═ 6ml, Ca (OH) at critical hazard pH M of 4₂Total amount of eluting acid solution V_k40ml, Ca (OH)₂Time t for improving agent to exert improvement effect₁＝V_k/V₁6.66; total leaching acid solution amount V of peanut straw carbon when critical hazard pH value M is 4_mThe volume of the modifier is 60ml, the time t for the peanut straw carbon modifier to exert the improvement effect₁＝V_m/V₁＝10；

The critical harm Al content N is 6mmol/kg, and the annual input acid solution amount V₁6ml of Ca (OH) at a critical Al content of 6mmol/kg N₂Total amount of eluting acid solution V_l90ml, then Ca (OH)₂Time t for improving agent to exert improvement effect₂＝V_l/V₁15, the total leaching acid solution amount V of the peanut straw carbon when the critical harm Al content N is 6mmol/kg_n135ml, the time t for the peanut straw carbon modifier to exert the improvement effect₂＝V_n/V₁＝22.5；

According to the relative long-acting index R, the modifier A peanut straw carbon in the brick red soil is relative to the modifier B Ca (OH)₂Has a more lasting improvement effect; similarly, modifier A peanut stalk carbon in red soil is compared with modifier B Ca (OH)₂Has a more lasting improvement effect. Therefore, by comparing fig. 12 with fig. 14, and fig. 13 with fig. 15, it can be seen that the experimental data obtained in the brick red soil and the experimental data in the red soil show the same trend, which indicates that the method of the present invention has certain universality for various types of soil to some extent. Comparing the relative long-term effect parameters in the experimental examples 1, 2 and 3, it can be seen that the peanut straw charcoal is not usedThe R value in the same-matrix acid soil is 1-1.5, which shows that the peanut straw carbon has better long-acting performance and the rice straw carbon has equivalent long-acting performance.

Claims

1. A method for evaluating the long-acting performance of an acid soil conditioner is characterized in that the long-acting performance of different conditioners is evaluated by calculating the annual input acid amount, preparing a simulated acid solution, reacting the simulated acid solution with a soil sample improved by the conditioner, measuring the pH value and Al content of a product after reaction, and calculating a relative long-acting performance index R according to a leaching volume, the pH value and the Al content, and specifically comprises the following steps:

2. The method for evaluating the long-lasting effect of an acid soil amendment according to claim 1, further comprising the step of calculating the improvement life of an amendment by step S1-5: changing the background solution of the simulated acid solution into a 1M KCl solution, wherein the pH value of the solution is determined by the annual rainfall p mm and the annual proton input per unit area z mol M^-2a^-1Obtaining pH-lg (z/p), calculating annual acid solution input V per g soil according to local annual rainfall p₁，V₁The collection frequency was 5min, the critical pH was set to 4.5, the critical cumulative Al release amount was 5.0mmol/kg, and the time t for the modifier to exert its modifying effect under the pH condition was calculated₁＝V_m/V_1，Calculating the time t for the modifier to exert the improvement effect under the condition of critical Al release amount₂＝V_n/V₁Will improve the effect time t₁、t₂Evaluating the duration of the soil improvement effect by comprehensive weighted average, wherein T is (T)₁+t₂)/2。

3. The method for evaluating the long-acting property of acid soil conditioners according to claim 2, wherein the KCl solution is HNO₃Or HCl.

4. The method for evaluating the long-acting performance of the acid soil conditioner as claimed in claim 1, wherein the long-acting performance of different acid soil conditioners is further researched by carrying out root elongation experiments on soil samples improved by different acid soil conditioners, and the method comprises the following steps:

s2-4 elongation experiments: transplanting the seedlings to simulated soil suspension after 5, 10, 15 and 20 years of acid rain washing respectively, culturing for 48h in an incubator at 25 ℃ in a dark place, and calculating the relative root elongation RRE ═ L_i/L₀X 100%, where Li is the root elongation for each treatment with different elution times, i ═ 0, 1, 2, 3, 4, L₀The root elongation is treated by pure water, and the age of the modifier playing the effect is determined when the RRE reaches the critical yield reduction relative to the root elongation.

5. The method for evaluating the long-acting property of the acid soil conditioner as claimed in claim 4, wherein the pH value of the simulated acid solution is 3.5, and the simulated acid solution comprises the following components in molar ratio: h₂SO₄：HNO₃＝3-6：1。

6. The method for evaluating the long-acting property of acid soil conditioners as claimed in claim 4, wherein the crop seeds in the step S2-1 are corn seeds.

7. The method as claimed in claim 4, wherein the disinfecting solution in step S2-3 is H with a mass concentration of 10%₂O₂And (3) solution.

8. Device for evaluating the permanence of acid soil amendments by using the method of any one of claims 1-7, characterized by comprising an acid liquor bottle (1), a peristaltic pump (2) and a comprehensive simulation box (3),

the acid liquor bottle (1) is connected with a liquid inlet end of a reaction tank (4) which is positioned at the upper part in the comprehensive simulation box (3) through an acid liquor pipe (11), the peristaltic pump (2) is positioned at the middle part of the acid liquor pipe (11), a partition plate (31) is arranged at the middle part in the comprehensive simulation box (3), a slidable placing table (32) is arranged above the partition plate (31), the reaction tank (4) is fixed at one side of the upper surface of the placing table (32), a plurality of placing discs (33) are arranged at the other side of the upper surface of the placing table (32), a hose (5) is arranged at a liquid outlet end of the reaction tank (4), the hose (5) penetrates through a storage box (51) fixed on the outer side wall of the comprehensive simulation box (3) and then is connected with a recovery mechanism which is positioned at the lower part in the comprehensive simulation box (3),

retrieve the mechanism including fixing guide arm (6) of baffle (31) lower surface and sliding block (7) that are located guide arm (6) below, middle part is seted up in guide arm (6) and is extended to recess (61) that guide arm (6) lower surface is used for placing hose (5), and guide arm (6) both sides are equipped with spout (62), sliding block (7) with spout (62) sliding connection, liquid outlet (8) and hose (5) end-to-end connection that sliding block (7) below was equipped with, be located the inside a plurality of receiving flask (34) that are equipped with of comprehensive simulation case (3) of retrieving mechanism below, receiving flask (34) one side is equipped with thermal reaction storehouse (35).

9. An apparatus for evaluating the long-lasting effect of an acidic soil conditioner according to claim 8, wherein a throttle valve (41) is disposed at the liquid inlet end of the reaction tank (4), a filtering barrel (42) is disposed at the middle part of the reaction tank (4), the filtering barrel (42) is sequentially provided with a filter screen (43), a quartz sand layer (44), a diacetate fiber board (45) and a flow guide pipe (46) from outside to inside, the flow guide pipe (46) is connected with the hose (5), and a magnetic stirrer (47) is disposed inside the reaction tank (4) below the filtering barrel (42).

10. An apparatus for evaluating the permanence of acid soil improvers as claimed in claim 8, wherein the lower part of the placement platform (32) is slidably connected with the partition plate (31) through a set of damping slide rails (36), and the side wall of the comprehensive simulation box (3) is provided with a strip-shaped slot (37) corresponding to the acid liquid pipe (11) and the hose (5).