Preliminary Study On Synchronization Of Rice Seedling Raising And Improvement In Saline Alkaline Soil

Currently saline-alkali soil area in Songnen Plain,the soil used for rice seedlings is mainly low-salt and moderate-pH soils,and most of them are taken from the local river bed soil.Taking soil is bound to face plough damage and vegetation,time-consuming and labor-consuming,and delay,problems such as timing of planting.At the same time,in the saline-alkaline soil area,due to the gradual expansion of the area of cultivated rice developed in recent years,the bed soil that can be used for nursery is almost exhausted,and rice seedlings are faced with difficulties in taking soil.Therefore,reducing the dependence of rice seedlings on riverbed soil and ensuring the safe production of rice is an urgent problem to be solved.The study focused on the heavy saline-alkali land in Qianguo Village of Songnen areas,after analyzing the saline-alkali characteristics of the soil in the study area,using pot experiment,Applying improved substances in heavily salinized soils,namely brown coal humic acid,aluminum sulfate,calcium sulfate and ferrous sulfate.Study applying four modified substances alone and compounding in different proportions,the Growth characteristics of rice after nursery and the changes in physical and chemical properties of soil.To reveal the changing rules of physical and chemical properties of soil under the effect of modified materials and Screening for suitable modifier application rate for rice nursery.It provides scientific basis for rice breeding in the soil improvement of severe Soda saline area in Jilin Province and environmental protection and economic utilization of saline-alkali soil.The main findings of this article are as follows:?1?Zeta potentials of different suspended solids of aluminum sulfate,calcium sulfate,ferrous sulfate,and humic acid suspended in different modifiers were decreased.There was no difference in Zeta potential of rice soil after raising seedlings in the original soil under the different application rates with the Zeta potential of the soil after seedling raising by the nursery soil,except for the two treatments of aluminum sulfate?0.4%?and humic acid?3%?.The absolute value of soil suspended solids treated with pesticides did not change significantly with the change of input of humic acid.In addition,the absolute value of the potential of the soil suspension treated by each of the basic and single inorganic modifiers is similar.The effect of the absolute value of Zeta potential was significantly improved by the single application of calcium sulfate?1.8%of soil weight?and treatment with R3?1.8%CaSO4·2H2O+3%humic acid?.The soil Zeta potential decreased by 18.01mv and 17.93mv,respectively,compared to saline soil control without amendments.Original soil nursery with single improver and mixed application,comparing with severe saline-alkali soil nursery,the main impact on the distribution of soil microaggregates is 0-2?m and 50-100?m,100-250?m.The contents of 0-2?m and50-100?m microaggregates were reduced,and the content of 100-250?m microaggregates were increased in different degrees.It shows that after adding saline-alkali soil amendment,the soil Zeta potential decreases,the soil colloidal stability decreases,the small particle size microagglomeration agglomerates,and the soil structure is improved to some extent.?2?For soil-exchanged sodium,the single application of the amendments aluminum sulfate,calcium sulfate,and ferrous sulfate in the original soil were all reduced to varying degrees.After application of the inorganic modifiers and humic acid,overall the exchangeable sodium in the soil increased to a certain extent compared with the single inorganic amendment machine.Exchangeable sodium was treated with Al₂?SO₄?₃·18H₂O?0.8%?and R₃?1.8%CaSO₄·2H₂O+3%humic acid?was the lowest.?3?The contents of CO₃^2-and HCO₃^-in the heavy saline-alkali soil after the single application of the improving agents aluminum sulfate,calcium sulfate,ferrous sulfate,and inorganic amendments and humic acid combined with the original soil were all to varying degrees.It shows that the ratio of different modifiers can significantly reduce soil CO₃^2-and HCO₃^-.After the humic acid was applied alone,the CO₃^2-concentration in the heavy saline-alkali soil after the original soil nursery was reduced,the content of HCO₃^-in soil decreased when humic acid was input at 1%,and it was significantly higher at 3%and 5%than in the control group.The content of CO₃^2-was significantly lower than that of the control group,the content of HCO₃^-in soil was significantly lower than that of the control group except S₇.The total alkalinity of single application and combined application soil was significantly lower than that of the control group.The single application of CaSO₄·2H₂O?1.8%?and the application of R₃?1.8%CaSO₄·2H₂O+earth weight of soil weight of 1%humic acid?were the most effective.Well,the decrease rate was 90.05%and 89.66%,respectively,compared with the control group.?4?The soil pH was significantly reduced after the single application of the amendments,brown coal humic acid,aluminum sulfate,calcium sulfate,and ferrous sulfate original soil.The effect of reducing pH with calcium sulfate was best,followed by aluminum sulfate,ferrous sulfate,and humic acid.The pH of the soil with the inorganic modifier and humic acid showed different degrees of decrease.The single treatment with CaSO4·2H2O?1.8%?and the mixed treatment with R₉?1.8%CaSO₄·2H₂O and 5%humic acid?had the best effect and the soil pH decreased by 3.255 and 3.92 units respectively.?5?The soil EC values in all experimental groups were within the ideal matrix.After the application of calcium sulfate dihydrate,the EC value increased the most.Single conductivity of aluminum sulfate,ferrous sulfate conductivity and soil conductivity after seedling raising have no difference,the effect is good.The soil electrical conductivity was increased to varying degrees?6?after the combination of inorganic modifier and humic acid.From the perspective of crop growth,increased electrical conductivity did not affect the growth of rice seedlings.This may be due to the addition of the modifier to promote the dissolution of carbonate in the soil,so that the concentration of Ca²⁺in the soil increases,on the one hand to promote the aggregation of soil particles,and secondly to provide rice with the nutrients needed for growth.?7?The four modifiers alone or in combination reduce the Zeta absolute value of soil suspended particles to a certain extent,the composition of the microaggregates in the soil thus changes,and the soil structure improves.This will increase the amount of salt discharged per unit of time in the soil.With the increase of the number of rinsing during cultivation,soil pH,soil CO₃^2-,and total alkalinity gradually decreased,providing a good growth environment for rice seedlings.From the growth of rice,it can be seen that each treatment has significantly improved the seedling quality of rice.For dry fresh weight of rice,the single application and the application of experimental groups were significantly different from the heavy meadow soil control group,there were differences but not significant with the peasant households.For rice plant height,the combination is better than single application.Based on the changes in soil physiochemical properties and the growth of rice seedlings,it is known that the modifier combination R₉ is the amount of amendments suitable for rice seedling raising,that is,the 1.8%soil weight of CaSO₄·2H₂O and the 5%soil weight of humic acid were used for rice seedlings in saline-alkali soil.