Soil amendment suitable for saline-alkali soil and improvement method of soil amendment

Abstract

The invention discloses a soil amendment suitable for saline-alkali soil and an amendment method thereof, and belongs to the technical field of soil amendment, the soil amendment comprises an organic fertilizer, fly ash, biochar, furfural residue, wormcast, humic acid and Kejing. By applying the modifier, the total alkalinity of the soil and the content of HCO3 <-> and Cl <-> are reduced, and the problem of soil salinization is further relieved. After the modifying agent is applied, the emergence rate and the survival rate of the oats are improved, and particularly, the effect of the combined modifying agent is more obvious. The plant height and the stem diameter of the oats are obviously increased, and the elongation and thickening growth of the stems are promoted. The modifier improves the salt absorption capacity of the plants and increases the salt accumulation amount of the overground part and the root system, so that the biological salt elimination effect is enhanced, and particularly, the combined application effect of the fly ash and the organic fertilizer is the best. The improver improves the total yield of the oats, and especially under the condition of combined use, the total yield and the net income are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and more particularly to a soil improver suitable for saline-alkali land and a soil improvement method thereof. Background Art

[0002] Saline-alkali land is a type of land where the soil structure and physical and chemical properties deteriorate due to excessive salt content in the soil. Salinization inhibits plant growth, reduces crop yields, and seriously affects agricultural production and the ecological environment. With global land resources becoming scarce and population growth, improving saline-alkali land to increase land use efficiency and food production has become an important issue.

[0003] Existing methods for improving saline-alkali land include physical improvement, chemical improvement and biological improvement. In physical improvement, mechanical means are usually used to improve the structure and drainage performance of the soil; chemical improvement often uses chemical agents to neutralize excess salt in the soil; biological improvement uses plants or microorganisms to improve soil properties. However, these methods often have problems such as high cost, unstable effect or environmental impact.

[0004] In recent years, soil conditioners have gradually attracted attention as a comprehensive method. This method combines organic, inorganic and biological materials and uses their physical, chemical and biological properties to improve soil structure, reduce salinity and increase soil fertility. In particular, materials such as biochar and humic acid are used to exert their adsorption and slow-release properties to improve the soil's ability to retain water and fertilizer.

[0005] The present invention combines the characteristics of various materials and proposes a soil conditioner suitable for saline-alkali land. Through scientific proportioning and application methods, it effectively improves the salinization problem of soil and improves the growth and yield of crops. This innovative conditioner not only improves the physical and chemical properties of the soil, but also reduces the negative impact on the environment, providing new ideas and technical support for the sustainable utilization of saline-alkali land. Summary of the invention

[0006] 1. Technical problems to be solved

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a soil conditioner suitable for saline-alkali land and a method for improving the same, which can improve the nutrient status of the soil and promote crop growth. In particular, the combined use of biochar and furfural residue has a significant effect on increasing the K+ content, improves the plant's ability to absorb salt, and increases the salt accumulation in the aboveground part and the root system, thereby enhancing the biological salt removal effect. In particular, the combined application of fly ash and organic fertilizer has the best effect.

[0008] 2. Technical solution

[0009] To solve the above problems, the present invention adopts the following technical solutions.

[0010] A soil conditioner suitable for saline-alkali land comprises the following raw materials: organic fertilizer, fly ash, biochar, furfural residue, earthworm castings, humic acid and alkali king.

[0011] Furthermore, the ingredients of the organic fertilizer are as follows: organic matter ≥ 45%, total nutrients (N+P2O5+K2O) ≥ 5%.

[0012] Furthermore, the ingredients of the fly ash are as follows: SiO2 (1.83%), Al2O3 (1.08%), Fe2O3 (1.25%), CaO (1.69%), MgO (1.24%), SO3 (1.76%), Na2O (1.18%), K2O (1.58%), and loss on ignition (1.91%).

[0013] Furthermore, the ingredients of the biochar are as follows: the iodine adsorption value is 900 to 1500 mg·g -1 , acid-soluble content (0.8%), chloride content (0.1%), iron content (0.02%), pH (8-10).

[0014] Furthermore, the furfural residue has the following ingredients: humic acid content 11.63%, lignin content 37.88%, cellulose content 35.84%, pentosan content 2.05%, phosphorus (P2O5) content 0.36%, potassium content 1.18%, ammonia content 0.61%, acetic acid content 3.34%, free acid (S04 2- )1.27%, pH 2.1.

[0015] Furthermore, the ingredients of the earthworm manure are as follows: total nutrients ≥ 6%, organic matter ≥ 60%, and pH -7.

[0016] Furthermore, the ingredients of the humic acid are as follows: fulvic acid ≥ 15%, Ca+Mg+S ≥ 10%.

[0017] Furthermore, the ingredients of the Kejianwang are as follows: 45% organic complex acid, 3% inorganic acid, 3% penetrant, and 3% spreader.

[0018] Preferably, the method for improving the soil conditioner suitable for saline-alkali land comprises the following steps:

[0019] 1) Mix the above materials evenly according to the predetermined proportions. Make sure each component is fully mixed so that their respective properties can be fully exerted;

[0020] 2) Spread the mixed improver evenly on the soil surface of saline-alkali land;

[0021] 3) Use tillage machinery to fully mix the amendment with the soil and perform deep tillage, which can promote the distribution of the amendment in the soil and improve the air permeability of the soil;

[0022] 4) Appropriate irrigation can help the amendment penetrate into the middle layer of the soil more effectively, promoting nutrient absorption and salt dissolution;

[0023] 5) After using the amendment, monitor the soil regularly and add fertilizers in time according to the growth needs of the crops to ensure the nutrients needed for crop growth.

[0024] 3. Beneficial effects

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] 1) Applying conditioners can effectively reduce soil bulk density and increase soil porosity. In particular, the combination of conditioners is more effective in improving soil permeability. Conditioners can significantly reduce soil electrical conductivity and total salt content, thereby improving the degree of soil salinization.

[0027] 2) Amendments increase K+ and Ca in the soil 2+ Mg 2+ The content of water-soluble basic ions such as biochar and furfural residue is beneficial to improve the nutrient status of the soil and promote crop growth, especially the combined use of biochar and furfural residue has an effect on K + The effect of increasing the content is significant.

[0028] 3) The application of amendments reduced soil total alkalinity and HCO3 - , Cl - The content of the soil was further reduced, further alleviating the problem of soil salinization. After applying the amendments, the emergence rate and survival rate of oats were improved, especially the combination of amendments had a more obvious effect.

[0029] 4) The plant height and stem diameter of oats increased significantly, promoting the elongation and thickening of the stems. The amendments increased the plant's ability to absorb salt, increased the salt accumulation in the aboveground part and the root system, and thus enhanced the biological salt removal effect. In particular, the combined application of fly ash and organic fertilizer had the best effect.

[0030] 5) Improvers increased the total output of oats, especially when used in combination, the total output and net income were significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram showing the effect of the improver of the present invention on the bulk density of the cultivated layer soil;

[0032] Figure 2 Schematic diagram of the effect of the modifier of the present invention on the total porosity of the tillage layer soil;

[0033] Figure 3 Schematic diagram of the effect of the improver of the present invention on the electrical conductivity (EC) of the tillage layer soil;

[0034] Figure 4 It is a schematic diagram of the effect of the improver of the present invention on the total salt content of the cultivated layer soil.

[0035] Figure 5 The improver of the present invention is for the potassium ion (K + ) content.

[0036] Figure 6 The improver of the present invention is for the sodium ion (Na + ) content.

[0037] Figure 7 The improver of the present invention is for the calcium ion (Ca 2+ ) content.

[0038] Figure 8 The improver of the present invention is used to improve the magnesium ion (Mg 2+ ) content.

[0039] Fig. 9 The improver of the present invention is used to improve the bicarbonate ion (HCO3 - ) content.

[0040] Fig.10 The improver of the present invention is for the chloride ion (Cl - ) content.

[0041] Fig.11 The improver of the present invention is for the sulfate ion (SO4 2- ) content

[0042] Fig.12 Schematic diagram of the effect of the improver of the present invention on the desalination rate of the cultivated layer soil.

[0043] Fig.13 Schematic diagram of the effect of the improver of the present invention on the organic matter content of the topsoil.

[0044] Fig.14 Schematic diagram of the effect of the improver of the present invention on the emergence rate and survival rate of oats.

[0045] Fig.15 This is a schematic diagram of the effect of the improver of the present invention on oat grass yield. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0047] Embodiment 1:

[0048] The experiment adopted a single-factor randomized block design, with the type of amendment as the experimental factor, and set 12 levels, namely A0: no amendment, A1: organic fertilizer, A2: fly ash, A3: corn straw biochar, A4: furfural residue, A5: earthworm manure, A6: humic acid, A7: Kejianwang, A8: fly ash + organic fertilizer, A9: fly ash + furfural residue, A10: biochar + furfural residue, A11: earthworm manure + humic acid, a total of 12 treatments, repeated 3 times. The amount of amendment is shown in Table 1.

[0049]

[0050] All treatments were fertilized with 112.5 kg·hm2 of nitrogen fertilizer. -2 (N), phosphate fertilizer 75kg·hm -2 (P2O5), potash fertilizer 112.5kg·hm -2 (K2O). The types of nitrogen fertilizer, phosphorus fertilizer and potash fertilizer are urea (N≥46%), superphosphate (P2O5≥16%) and potassium sulfate (K2O≥45%). All fertilizers are used as base fertilizers and are evenly spread on each test plot with the improver before sowing. Sowing is carried out after plowing. The test plot is 5m long, 3m wide and 15m2 in area; the interval between the plots is 40cm, the interval between the blocks is 50cm, and a protective row with a width of 1m is set around the test site.

[0051] The oat sowing rate is 500 kg·hm -2 , row sowing, row spacing 13cm, sowing depth 3cm. Adopt "dry sowing and wet weeding", the irrigation amount is the same in each treatment during the growth period. Manual weeding during the growth period.

[0052] Before demarcation, basic soil samples were collected using the "S-shaped sampling method", and soil samples from the 0-30 cm soil layer of each experimental plot were collected after oats were harvested; 15 representative sample plants were collected from each plot during the heading, flowering and maturity stages of oats, and harvested in different areas during harvest.

[0053] Plant growth characteristics

[0054] Seedling emergence rate: At the seedling stage, the "unit row length method" was used to select 3 rows for each test plot to conduct seedling emergence survey and record, and calculate the seedling emergence rate.

[0055] Survival rate: At the heading stage, the number of surviving oat seedlings in each experimental plot was investigated and recorded, and the survival rate was calculated.

[0056] Plant height and stem diameter: measured at heading, flowering and maturity stages. The plant height was measured with a ruler and the stem diameter (the connection point between the root and the stem) was measured with a vernier caliper.

[0057] Dry matter accumulation: After measuring plant height and stem diameter, the sample plants and their organs (roots, stems, leaves, and panicles) were placed in an oven at 105°C for sterilization, and then dried at 80°C to constant weight, and the dry weight was measured.

[0058] Hay yield: All plants in the plot were mowed at ground level, and then air-dried and weighed under natural conditions.

[0059] Total plant salt: direct ashing method.

[0060] Biological salt excretion (t·hm -2 ) = aboveground salt content (%) × aboveground grass yield (kg·hm -2 )×10 -3

[0061] Salt removal rate (%) = [aerial salt (t·hm -2 ) / (Salt accumulation in aboveground parts (t·hm -2 )+underground salt accumulation)]×100%

[0062] Effects of amendments on soil bulk density

[0063] At the heading stage and after the harvest of oats, the bulk density of the tillage layer treated with amendments showed a general downward trend compared with that without amendments ( Figure 1 ).

[0064] At the heading stage, the bulk density of single application treatments A1 to A7 was significantly reduced by 5.30% to 9.26% compared with A0 without amendment, and the reduction effect was more obvious in A4 and A6 treatments, and there was no significant difference between the results of all single application treatments; the overall reduction trend of soil bulk density in combined application treatments A8, A9, A10 and A11 was obvious compared with the control A0, with a decrease of 9.06% to 12.25%, and there was no significant difference between the effects of A8 and A10 treatments; the bulk density reduction effect under A9 and A11 treatments was better, and the difference in the effect of reducing soil bulk density between the two was not significant, which was 2.74% to 6.60% lower than that of single application of amendment treatment, and there was no significant difference between the combined application treatments. It can be seen that combined application is more conducive to the continuous effect of amendment than single application, and the effect of reducing soil bulk density is more significant.

[0065] As the growth period progressed, the trend of the effect of amendments on the bulk density of the topsoil remained basically unchanged. At maturity, the bulk density of all single-application treatments was 2.57% to 5.91% lower than that of A0 without amendments. Although there was no significant difference among the single-application treatments, A2, A4, A6 and A7 were significantly lower than A0; the combined application treatments A8, A9, A10 and A11 were about 8.20% lower than A0 without amendments (P < 0.05), and 2.29% to 5.63% lower than the single application treatment. Compared with the heading stage, the soil bulk density of A8 and A10 under the combined application treatments decreased, but the decrease was not significant.

[0066] In summary, the application of amendments has a significant effect on loosening the saline-alkali soil plough layer; compared with the single application of amendments, the interactive effect between different amendments is more conducive to the regulation and improvement of soil permeability.

[0067] Figure 1 Different lowercase letters (or letter combinations) indicate significant differences among treatments at the 0.05 level. The same below. In the figure, A0: no amendment, A1: organic fertilizer, A2: fly ash, A3: corn straw biochar, A4: furfural residue, A5: earthworm manure, A6: humic acid, A7: fly ash + organic fertilizer, A8: fly ash + furfural residue, A9: biochar + furfural residue, A10: earthworm manure + humic acid, A11: Kejianwang.

[0068] Effects of Amendments on Soil Porosity

[0069] Application of amendments can significantly increase the total soil porosity at the heading and maturity stages of oats ( Figure 2 ). At the heading stage, the total soil porosity of single application treatments A1, A3, A4, A5, A6 and A7 increased by 7.53%, 12.02%, 8.25%, 9.28%, 11.71% and 7.71% respectively compared with A0 without application of amendment (P<0.05), among which treatments A3 and A6 had a more significant effect on improving the total porosity; the combined application treatments A8, A9, A10 and A11 increased by 8.31% to 12.14% (P<0.05) compared with no application of amendment, and the effects of A9 and A11 were more obvious, but there was no significant difference with the effects of single application treatments A3 and A6.

[0070] After mature harvest, the effect of the amendment on regulating soil permeability was improved compared with the heading stage. In the single application treatment, A3 and A6 had better effects, and the total soil porosity increased by about 8.95% compared with the control A0 (P < 0.05); the effect of the combined application treatment on the total soil porosity was the highest in A8 and A10, which increased by about 13.90% (P < 0.05) compared with the A0 treatment without amendment, and the increase was about 2.24% to 8.68% compared with the single application treatment. Overall, the application of amendments has a certain effect on improving the total soil porosity, and the interaction of amendments can maximize its effect, which is more conducive to regulating and improving soil permeability.

[0071] Effects of amendments on soil electrical conductivity and total salt content

[0072] The electrical conductivity (EC) of the topsoil showed a decreasing trend due to the application of amendments, but the reduction effect varied depending on the type of amendment ( Figure 3 ).

[0073] At the heading stage, the EC of single application treatments A1 to A7 decreased by 6.07%, 11.57%, 16.35%, 4.32%, 7.83%, 10.87% and 3.86% (P < 0.05) compared with the control A0, and A3 had the best reduction effect, which was significantly different from other single application treatments, but there was no significant difference among A1, A4 and A7. Under the combined application conditions, A8 to A11 treatments decreased by 13.90% to 22.31% compared with A0, with A8 and A10 having better effects. Moreover, the combined application of amendments had a greater overall effect on reducing soil electrical conductivity than single application.

[0074] At maturity, the conductivity change trend of each treatment was basically the same as that at heading stage. Under single application conditions, except for A7, the application of other amendments significantly reduced soil conductivity, and the reductions of A1 to A6 were 6.98%, 12.77%, 16.67%, 5.44%, 8.51%, and 12.06%, respectively. The reductions of A2, A3, and A6 on conductivity were greater than those of A1, A4, A5, and A7, and there was no significant difference between A1, A4, and A5. There was no significant difference between A2 and A6 in reducing soil conductivity. Among single applications, A3 had the best reduction effect; among single application treatments, only A7 had no significant reduction effect compared with the control. This may be related to the composition of the amendment Kejianwang in this treatment, as well as the liquid form of the amendment itself. After application, due to the influence of environmental conditions such as temperature, evaporation was faster, which inevitably affected its use effect. From the perspective of the application of amendments, the treatments A8, A9, A10 and A11 were significantly lower than the control A0 (P < 0.05), with decreases of 21.28%, 17.49%, 24.82% and 14.78%, respectively; there were significant differences between the treatments A9 and A11 and the treatments A8 and A10, and their effects on reducing soil conductivity were smaller than those of the latter two; and there was no significant difference in the effects of the combined application treatment A11 and the single application of A3; under the condition that the application amount was half of the two single application treatments, there were significant differences between the combined application and the corresponding single application, except for the effect between A11 and A6. For example, the conductivity of A10 was reduced by 9.79% and 20.50% compared with A3 and A4, respectively.

[0075] Overall, the effect of the combination of two amendments on reducing soil EC was greater than that of a single application. Of course, since this study involved many amendments, the application ratio set in the experiment may not have demonstrated the potential of the combination to reduce the degree of salinization.

[0076] The water-soluble salt content of soil is an important attribute of saline soil and one of the important bases for judging the degree of soil salinity and its impact on crop growth. After applying the amendment, the salt content of the tillage layer soil showed a decreasing trend ( Figure 4At the heading stage, single application of treatments A2 to A7 significantly reduced soil salinity by 4.33%, 6.42%, 4.96%, 7.45%, 6.54% and 5.27%, respectively, with no significant difference among the six treatments; under combined application, the salt content of A8 to A11 was also significantly lower than that of A0, with a decrease of 8.33%, 6.12%, 8.72% and 6.58%, respectively, with no significant difference among the treatments. As the growth period progressed, the reduction of single-application treatments A1 to A7 at maturity became smaller than that of A0, which were 2.85%, 4.13%, 5.46%, 3.40%, 3.67%, 3.85% and 1.97% respectively. The reduction effect of A3 treatment was the largest, and there was a significant difference between it and A1, but there was no significant difference between it and the other single-application treatments. Under the same conditions of A1 (organic fertilizer) and A3 (biochar), due to the large differences in their own physical and chemical properties, there were also significant differences in their effects on soil salt reduction. Compared with A0 without amendments, the salt content of A8, A9, A10 and A11 in the combined application treatments was reduced by 4.67%, 3.17%, 4.87% and 3.36% (P < 0.05). Compared with the single application treatment, only A10 treatment had the largest reduction under the combined application conditions, but there was no significant difference between it and A1 to A7 applied alone. Compared with the heading stage, the soil salt content at the maturity stage decreased, but not significantly. It can be seen that the application of amendments can significantly reduce the salt content of the topsoil, but combined application does not necessarily show a better reduction effect than single application.

[0077] Effects of Amendments on Soil Base Ion Content

[0078] The application of the amendment has a tendency to increase the content of water-soluble K+ in the tested saline-alkali land ( Figure 5 ). Compared with A0 without amendment, except A7, other treatments significantly increased K+ content. The increases of K+ content in A1~A6 of single application treatments were 37.34%, 39.17%, 52.02%, 56.24%, 38.26% and 34.22%, respectively; there was no significant difference in the effect of K+ enhancement between A8, A9, A10 and A11, but they were significantly increased by 66.97%, 60.83%, 88.72% and 70.64% respectively compared with A0 without amendment. A10 had the largest enhancement effect, which was 20.79%~74.32% higher than other treatments except A4 in single application. It can be seen that the application of amendment can enrich the content of water-soluble K+ in saline-alkali soil, showing a trend that the effect of combined application is greater than that of single application, and the synergistic effect of biochar and furfural residue is more conducive to the improvement of K+ content. This indicates that the modifiers are suitable for combination and may produce significant interactions during application to maximize their effects.

[0079] The application of modifiers has a certain replacement and reduction effect on the soluble Na+ and its content in saline soil ( Figure 6). The Na+ content in the A0 treatment without the application of the amendment was the highest. After the application of the amendment, the water-soluble Na+ content in the soil showed a decreasing trend (P<0.05). There was no significant difference in the replacement effect of Na+ among the single-application treatments A2, A3 and A6, and their content was significantly reduced by about 55.42% compared with the A0 treatment. The A1, A4, A5 and A7 treatments were significantly reduced by 35.18%, 48.15%, 42.33% and 6.54% compared with the A0 without the application. The A7 treatment had the smallest replacement effect on Na+, which may be related to the low application rate of the liquid formulation of Kejianwang and the easy evaporation before plowing after application. Compared with A0 without amendment, the water-soluble Na+ content of A8, A9, A10 and A11 treatments significantly decreased, with a decrease of 61.86%, 57.50%, 64.48% and 60.96% respectively, all above 50%, and no significant difference was shown among the four combined treatments; A10 had the lowest Na+ content among all treatments, and there was no significant difference between its effects and those of A2, A3 and A6 treatments applied alone. In summary, the single application of A2, A3 and the combined application of A8 and A10 treatments had the greatest effect on reducing the soluble Na+ content in saline soil; the combined application had a significant difference in the reduction of at least one of the single applications.

[0080] Under the action of the improver, the Ca2+ content in the tested saline-alkali soil showed an upward trend ( Figure 7 ). Except A7, the other treatments with amendments increased the content of water-soluble Ca2+ in the soil. The single application of A1 to A6 increased the content of water-soluble Ca2+ by 11.62%, 13.88%, 15.16%, 12.75%, 9.35% and 6.52% compared with A0 without amendment, and there were significant differences between A2 and A3 and A6 and A7, with A2 and A3 having the largest increase. The Ca2+ content of A8, A9, A10 and A11 with combined application was higher than that of A0 without amendment. 2+ The contents of fly ash and organic fertilizer increased significantly by 15.30%, 14.73%, 13.60% and 15.58% respectively. There was no significant difference among the four treatments, and the effects of the four treatments were similar to those of A2 and A3 applied alone, indicating that fly ash and organic fertilizer can effectively increase the content of Ca in soil, whether applied alone at a high application rate or in combination at a lower application rate. 2+ Compared with the single application of A6 and A7 treatments, the synergistic effect of the amendments was better in increasing the Ca content in the soil. 2+ The effect of improving the content was better, increasing by about 9.82%. It can be seen that the application of the amendment is more beneficial to the soluble Ca in the soil than the single application. 2+ The trend of increasing content.

[0081] The soluble Mg2+ content in the soil tends to increase due to the application of amendments ( Figure 8 ). Under the condition of single application of amendment, except for A6 and A7, A1~A5 increased the content of Mg in soil compared with A0 without amendment.2+ The content of soluble Mg in treatments A1, A4 and A5 increased by 42.43%, 16.37%, 27.20%, 37.42% and 36.55% respectively. (P<0.05) 2+ The content of K was higher than that of A2, A3, A6 and A7. There was no significant difference among the first three, and A7 was significantly lower than that of other single application treatments except A6. This trend is consistent with the effect of A7 on K + 、Na + and Ca 2+ The influence trend was the same as that of single application. 2+ The effect of increasing the content of water-soluble Mg2+ in the soil was A1>A4>A5>A3>A2>A6>A7. Compared with no amendment, the treatments of A8, A9, A10 and A11 significantly increased the content of water-soluble Mg2+ in the soil, with increases of 37.76%, 42.90%, 48.78% and 43.33% respectively. 2+ The content of Mg was the highest, and the effects of the four combined applications were comparable to those of single application of A1 and A4, which were 16.97% to 46.00% higher than those of other single application treatments. 2+ The content has a greater impact effect.

[0082] Root growth environment of crops in saline-alkali land and their absorption of nutrients and CO3 2- 、HCO3 - In this experiment, the CO3 2- The double indicator-neutralization titration method failed to detect it, indicating that its CO3 2- The content is trace. Under the condition of applying the amendment, HCO3 in the soil - The content showed a significant downward trend ( Fig. 9 ). A1 to A7 treated with single application of the amendment reduced HCO3 by 51.72%, 59.77%, 61.91%, 57.84%, 57.69%, 49.72% and 45.68% compared with A0 without the amendment. There was no significant difference among A1, A4, A5, A6 and A7. A2 and A3 treatments had a significant effect on HCO3 - The reduction effect of A8, A9, A10 and A11 was more obvious than that of A0 without application, with the reduction rates of 66.72%, 60.95%, 82.34% and 58.01% respectively, and the reduction rates were all greater than 50%, which was consistent with its effect on Na +The reduction effect of A10 on HCO3- was similar to that of A2 and A3, and A10 had the best effect on HCO3-, which was about 56.11% lower than that of A2 and A3 applied alone. Among them, there was no significant difference in the reduction effect of A8 and A9 on HCO3- between A2 and A3 applied alone. In summary, the single application of fly ash and biochar had a significant effect on reducing soluble HCO3 - The effect of the two fertilizers on HCO3 - The reduction effect is enhanced.

[0083] Depend on Fig.10 It can be seen that all treatments with amendments significantly reduced the soluble Cl in the soil. - Under single application conditions, the effects of A1 and A5, A2 and A4 on Cl - The reduction effects of A3 and A6 were basically the same, and they were reduced by about 43.33% and 49.06% respectively compared with A0 without amendment. There were significant differences among A3, A6 and A7, which were reduced by 64.60%, 26.16% and 36.12% respectively compared with A0. The effect of A3 on Cl - The reduction was the largest and the effect was the best. Under the combined application conditions, the reductions of A8, A9, A10 and A11 were 64.83%, 55.66%, 65.76% and 63.06% respectively compared with A0. There was no significant difference in the reduction effects of A8, A10 and A11, but their reduction effects were all higher than those of A9, which was consistent with the reduction effect of A3 applied alone, and was about 50% lower than that of A6 applied alone. In summary, the application of the amendment had a significant effect on soluble Cl - There was an obvious decreasing trend. At the same time, under the conditions of fly ash and organic fertilizer, biochar and furfural residue, humic acid and earthworm manure, the Cl - The effect is better when the content is reduced.

[0084] SO4 in saline soil 2- The content varies depending on the type of amendment applied ( Fig.11 Except for treatments A4, A6 and A7, the application of the amendments significantly reduced SO4 2- The content of S04 in single application of A1, A2, A3 and A5 was increased by 3.53%, 3.81%, 3.84% and 3.57% respectively compared with A0, and there was no significant difference among the treatments; 2- The content was reduced by 4.49%, 3.89%, 4.22% and 3.77% compared with A0, and there was no significant difference among the four treatments. It can be seen that the application of the amendment reduced the water-soluble SO4 2- The content.

[0085] Effects of Amendments on Soil Total Alkalinity

[0086] The change trend of soil total alkalinity under different amendment treatments was different (Table 2). Under the condition of single application, the soil total alkalinity of A1~A7 treatments showed a decreasing trend, which was significantly reduced by 52.00%, 60.00%, 62.00%, 58.00%, 58.00%, 50.00% and 46.00% compared with A0 without amendment. There was no significant difference between the results of A4 and A5 treatments, and the effect of treatment A2 was the best. Among the combined application treatments, the total alkalinity of A8, A9, A10 and A11 reached a significant difference compared with A0 (P < 0.05), with a decrease of 67.00%, 61.00%, 82.00% and 58.00%, respectively. The decrease of A10 treatment was the largest and the effect was the best, which was significantly reduced by about 56.00% compared with the single application of A2 and A3 treatments; the reduction of soil total alkalinity in A8 and A9 treatments was basically the same as that of single application of A2 and A3.

[0087] The total soil alkalinity was measured as HCO3 - Mainly, because the CO3 in the topsoil 2- The content was too small to be detected.

[0088]

[0089]

[0090] Note: " / " indicates that the CO32- content in the soil was too low to be detected. Different lowercase letters (or letter combinations) indicate significant differences among treatments at the 0.05 level. The same below.

[0091] Effects of amendments on soil desalination rate

[0092] The influence of amendments on soil salinity is generally expressed by soil desalination rate. Fig.12It can be seen that under the action of the amendment, the soil desalination rate was significantly different from that without the amendment (P < 0.05). Under the condition of single application, the soil desalination effect of treatments A1 to A7 was significantly improved by 18.72%, 27.13%, 36.00%, 22.00%, 24.00%, 25.00% and 13.00% compared with the control A0. The desalination effect of treatment A3 was the best, with significant differences from A1, A4 and A7, while there was no significant difference between treatments A1, A2, A4, A5 and A6. The desalination effect of A8, A9, A10 and A11 in the combined application treatments was significantly improved by 31.00%, 21.00%, 32.00% and 22.00% compared with A0; among them, the desalination rate of A8 and A10 treatments was close to that of A2, A5 and A6 applied alone, and there was no significant difference in the reduction effect of salt between A9 and A11 in the combined application treatments and A1 and A4 applied alone, and the desalination effect of the four combined application treatments was equivalent. In summary, under the action of the amendment, the desalination effect of the topsoil was significant, and the A3 treatment had the best effect under the condition of single application, and the desalination rate of A8 and A10 was higher in the combined application treatments.

[0093] Effects of amendments on soil organic matter content

[0094] Organic matter is an important indicator of soil fertility and one of the main sources of various nutrients. Its content is closely related to the sustainable utilization of saline soil. Increasing the content of organic matter has the effect of reducing salt and desalination. Fig.15 It can be seen that the application of amendments can effectively increase the content of soil organic matter. After multiple comparative analysis, the organic matter content of the single application and two-by-two combination treatments of the amendments reached a significant level compared with the control (P < 0.05). In the single application treatment, the soil organic matter content of the A1, A3, A4, A5 and A6 treatments was significantly increased by 44.89%, 28.74%, 35.98%, 39.66% and 44.15% compared with A0 without amendments. There were significant differences between the A1, A3, A4 and A5 treatments, and the effects of A5 and A6 were equivalent; the organic matter of treatments A2 and A7 increased significantly by about 21.04% compared with A0, and there was no significant difference between the two treatments, and the improvement effect of A1 treatment was the best; amendments The two-combination treatments increased the soil organic matter level compared with the control (P < 0.05), and the organic matter content increased by 57.08%, 53.87%, 66.20% and 43.28% respectively; among them, A10 had the largest increase, increasing by 5.80% to 15.99% compared with A8, A9 and A11, and increasing by 14.71%, 37.31%, 29.09%, 22.22%, 19.00%, 15.29% and 37.54% compared with the single application treatments A1 to A7. It can be seen that the combination of organic fertilizer and fly ash, biochar and furfural residue is more conducive to improving the organic matter nutrients in the soil.

[0095] Effects of Modifiers on Oat Seedling Emergence and Survival Rate

[0096] Depend on Fig.14 It can be seen that the emergence rate of oats increased after the application of the modifier, but only A9 and A10 had a significant improvement effect, which was 5.96% and 5.47% higher than A0 respectively; the survival rate of oats also increased after the application of the modifier, and the survival rates of A6, A8, A9, A10 and A11 were significantly higher than A0, with increases of 9.47%, 10.61%, 11.06%, 10.86% and 11.14% respectively; there was no significant difference among the other 10 treatments except A0. It can be seen that the effect of the modifier on the seedling preservation of oats gradually became apparent with the passage of time, from only A9 and A10, which increased the emergence rate by about 5.50%, to A6, A8 to A11, which increased the survival rate by about 10.00%; considering the emergence rate and survival rate, the application of A9 and A10 was most conducive to the seedling preservation of oats.

[0097] Effects of Modifiers on the Growth of Oat Stalks

[0098] The growth of oat stalks varied depending on the type of amendment (Table 3). At the heading and flowering stages, the plant heights of A1, A3, A5 and all combined treatments (A8-A11) were significantly higher than A0, with A8 being the highest, increasing by 3.14%-27.13% and 1.63%-23.03% respectively in the two growth stages compared with the other treatments with amendments; followed by A11. At the maturity stage, the plant heights of A8 and A11 were significantly higher than the other treatments by 8.57%-24.10% and 6.96%-22.26%, but there was no significant difference between the two. In the three growth periods, compared with no application of amendments, A3, A5, A8, A9, A10, and A11 all significantly increased plant height, with increases of 15.14% to 25.16%, 6.57% to 16.85%, and 5.19% to 17.35%, respectively; A8 and A11 were most conducive to the elongation of stems during the reproductive growth period. The application of amendments significantly increased the thickness of oat stems. In the three growth periods, the thickness of A1 to A11 treatments with amendments increased by 19.49% to 20.34%, 11.93% to 20.00%, and 13.98% to 21.61%, respectively, compared with A0. Among them, there were no significant differences among the treatments except A2 and A7 at the heading stage; the stem diameter of A8 and A10 at the flowering stage was significantly higher than that of other treatments, with an increase of 5.33% to 13.59%, and A8 was greater than A10; at the maturity stage, the stem diameter of A8, A10, and A11 was significantly higher than that of other treatments, but there was no significant difference among the three. From the heading stage to the maturity stage, A8 and A10 had better thickening effects, and the increases in the three growth stages compared with no application of the improver were 19.07% to 20.34%, 17.89% to 20.00%, and 21.61% to 47.00%, respectively. It can be seen that A8 and A11 have more significant effects on promoting stem elongation and thickening growth.

[0099]

[0100]

[0101] Effects of Modifiers on Oat Grass Yield

[0102] Depend on Fig.15 It can be seen that the application of amendments significantly increased the grass yield of oats, with the overall trend of A11>A10>A9>A8>A2>A3>A4>A6>A7. The yield increase effect of the combined application treatment was better, which was significantly increased by 16.56%~19.99% compared with no amendment, and significantly increased by 5.26%~8.14% compared with single application of A1, A4, A5, A6 and A7, that is, significantly increased compared with single application treatments except A2 and A3. The significant yield increase effect of combined application compared with single application may be related to the fact that the mixed amendment is more conducive to regulating the rhizosphere environment of oat growth.

[0103] Effects of amendments on salt absorption and biological salt excretion of oats

[0104] Table 4 shows that amendments affect the salt content, salt accumulation and soil salt excretion of oats (i.e., biological salt excretion).

[0105] The relative salt content of oat plants differed between the aboveground and root systems, with the root system showing a higher salt content than the aboveground. The salt content of both the aboveground and root systems was affected by the amendments. Except for the A6 treatment, the application of amendments significantly increased the salt content of the aboveground parts. The six single-application treatments (except A6) increased by 18.51%, 19.78%, 24.27%, 28.53%, 12.75% and 14.65% respectively compared with A0 without amendments. The salt absorption effects of A1, A2 and A3 treatments were basically the same. The salt concentration of the aboveground part of the plant was the highest under A4 treatment, which was 3.42% to 18.01% higher than that of other single-application treatments. The absorption of soil salt by A8, A9, A10 and A11 in the combined application treatments was significantly different from that of A0, increasing by 31.44%, 17.92%, 24.93% and 17.41% respectively. The salt content of plants in the A8 treatment was higher than that in the other three combined application treatments, and there was no significant difference between the A4 treatment and the single application treatment. The salt content of the roots was significantly different from that in A0 except for A5 and A7 (P<0.05). Under the single application condition, A1~A4 and A6 increased by 16.36%, 19.52%, 39.21%, 17.73% and 20.12% respectively compared with A0, and A3 had the best improvement effect, increasing by 15.89%~19.63% compared with other single application treatments.

[0106] The salt accumulation of the aboveground part and root system of the plant was affected by its salt content and biomass. As shown in Table 6, the application of amendments effectively promoted the absorption and accumulation of soil salt by the aboveground part and root system of the plant. Under the condition of single application, the aboveground salt accumulation of A1-A7 was significantly increased by 57.03%, 96.11%, 132.98%, 80.18%, 53.74%, 52.51% and 21.95% compared with A0, and A2, A3 and A4 were higher than other single application treatments, with an increase of 14.75% to 80.32%; under the condition of combined application of amendments, the salt accumulation effect of the aboveground part was increased by 146.54%, 119.10%, 138.19% and 130.67% compared with A0, and the salt accumulation of treatment A8 was the highest, which was significantly increased by 5.82% to 36.83% compared with A2, A3 and A4 under single application. The salt accumulation of the root system was significantly regulated by the amendment, and except for A7, it was significantly higher than the treatment without amendment. The increases of A1 to A6 applied alone were 30.68%, 49.27%, 64.45%, 27.43%, 27.85% and 33.09%, respectively, and A2 had the best salt accumulation effect. The root salt accumulation of A8 to A11 applied in combination increased by 77.01% to 98.85% compared with A0, with significant effects, and the overall increase was 20.92% to 89.24% compared with the single application treatment.

[0107] The salt carrying rate of plants refers to the ratio of the accumulated salt discharged into the field by harvesting. In terms of the effect on salt carrying, the application of amendments increased the carrying rate to a certain extent. Under the condition of single application, the salt carrying rate of A1-A7 (except A6) reached a significant level (P < 0.05) compared with A0, which was 6.21%, 9.21%, 11.46%, 11.47%, 6.32% and 6.93% higher than A0, with A3 and A4 having the highest carrying rate; under the condition of combined application, the salt carrying rate of the four treatments also reached a significant level (P < 0.05) compared with A0, which was 10.98%, 6.24%, 6.08% and 7.06% higher than A0, respectively. There was no significant difference among the four combined applications, and there was no significant difference between the combined application and single application of A3 and A4. In general, the response of salt carrying rate to amendments was less than that of salt absorption and accumulation.

[0108] By harvesting the aboveground parts, the plants produced biological salt removal. The salt accumulation in the aboveground parts showed that the four combined application treatments and A3 alone had more significant biological salt removal effects. The combined application of fly ash and organic fertilizer had the best biological salt removal effect.

[0109]

[0110]

[0111] Economic benefit analysis under different treatments

[0112] The application of amendments should not only consider their soil improvement effects, but also their economic rationality. The application of amendments increased the total output of oats, but due to the difference in the consumption of amendments, the net income of each treatment was significantly different (Table 5). Under the action of amendments, the oat grass yield was generally higher than that of the A0 treatment, which increased the hay income. The total output under the combined application condition was generally higher than that of the single application and the control, with the highest being the A11 treatment, which was 2406.67 yuan / hm2 higher than that of A0. -2 , an increase of 19.98%; under the condition of applying modifiers, the total investment of single application treatment A3 was the highest, followed by the combined application treatment A10; from the perspective of the final net income, single application treatment A4, A6, A7 and combined application A9 and A11 were all higher than A0, 770 yuan / hm2 higher than A0, respectively. -2 353.33 yuan / hm -2 , 866 yuan·hm -2 and 1338.33 yuan / hm -2 1168.67 yuan / hm2 -2 ; The benefits of single-application treatment A3 and combined-application treatment A10 were the lowest, both showing "no gain without gain", which was mainly attributed to the fact that the unit price of biochar applied in A3 and A10 treatments was significantly higher than that of other amendments. Although the net benefits of A1, A5 and A8 were greater than 0, they were all lower than A0 without amendments.

[0113]

[0114] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A soil conditioner suitable for saline-alkali land, characterized in that The raw materials include: organic fertilizer, fly ash, biochar, furfural residue, earthworm manure, humic acid, and alkali-free.

2. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the organic fertilizer are as follows: organic matter ≥ 45%, total nutrients (N+P2O5+K2O) ≥ 5%.

3. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the fly ash are as follows: SiO2 (1.83%), Al2O3 (1.08%), Fe2O3 (1.25%), CaO (1.69%), MgO (1.24%), SO3 (1.76%), Na2O (1.18%), K2O (1.58%), and loss on ignition (1.91%).

4. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the biochar are as follows: iodine adsorption value is 900-1500 mg·g -1 , acid-soluble content (0.8%), chloride content (0.1%), iron content (0.02%), pH (8-10).

5. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The furfural residue has the following ingredients: 11.63% humic acid, 37.88% lignin, 35.84% cellulose, 2.05% pentosan, 0.36% phosphorus (P2O5), 1.18% potassium, 0.61% ammonia, 3.34% acetic acid, and free acid (SO4 2- )1.27%, pH 2.

1.

6. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the earthworm manure are as follows: total nutrients ≥ 6%, organic matter ≥ 60%, and pH -7.

7. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the humic acid are as follows: fulvic acid ≥ 15%, Ca+Mg+S ≥ 10%.

8. The soil conditioner suitable for saline-alkali land according to claim 1, characterized in that: The ingredients of the Kejianwang are as follows: 45% organic complex acid, 3% inorganic acid, 3% penetrant, and 3% spreader.

9. The method for improving a soil conditioner suitable for saline-alkali land according to claim 1, characterized in that The steps include: 1) Mix the above materials evenly according to the predetermined proportions. Make sure each component is fully mixed so that their respective properties can be fully exerted; 2) Spread the mixed improver evenly on the soil surface of saline-alkali land; 3) Use tillage machinery to fully mix the amendment with the soil and perform deep tillage, which can promote the distribution of the amendment in the soil and improve the air permeability of the soil; 4) Appropriate irrigation can help the amendment penetrate into the middle layer of the soil more effectively, promoting nutrient absorption and salt dissolution; 5) After using the amendment, monitor the soil regularly and add fertilizers in time according to the growth needs of the crops to ensure the nutrients needed for crop growth.

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