Improvement Effect Of Different Improvement Measures On The Salinized Meadow Soil

This test takes the salinized meadow soil in Horqin area as the research object,By setting four improvement measures,such as covering sand,applying organic fertilizer,humic acid and desulfuration gypsum,the positive effects of different measures on soil salt control effect,improving physical properties,increasing soil nutrient content and promoting grass growth of salinized meadow were explored,The results show that:(1)Different improvement measures improved the soil salt control effect of salinized meadow differently.The content of total salt,HCO3-,K++Na+was the lowest under organic fertilizer.The content of total salt in moderate and severe salinized meadow soil was 83%and 76%lower than that of the control,and HCO3-and K++Na+were 25%,50%,61%and 65%lower than that of the control;The results showed that the pH and alkalinity of soil were the lowest under the treatment of desulfurization gypsum,followed by organic fertilizer,sand covering and humic acid treatment.Compared with the control,the pH of moderate and severe salinized meadow soil decreased 0.51 and 0.61,and the alkalinity decreased 20%and 21%,respectively;With organic fertilizer usage,the pH value of moderate and severe salinized meadow soil decreased 0.48 and 0.59,and the alkalinity decreased by 19%and 18%,respectively.(2)To some extent,different improvement measures can adjust soil particle size composition and reduce soil bulk density.The content of silt and clay increased most obviously under desulfurized gypsum,while the content of sand increased obviously under sand covering,which effectively adjusted the proportion of clay sand and reduced the capillary effect;Among the four treatments,the soil bulk density of organic fertilizer was the lowest,and the soil bulk density of moderate and severe salinization meadow decreased 6%and 7%respectively,The contribution of different ways to the reduction of soil bulk density was in the order of organic fertilizer>sand covering>desulfurization gypsum>humic acid.(3)Different improvement measures can improve soil nutrient content in different degrees.Organic fertilizer can significantly increase soil nutrient content,The contents of organic matter,available potassium,available phosphorus,total nitrogen and alkali hydrolyzed nitrogen in the moderate salinized meadow soil increased 60%,98%,148%,21%and 83%respectively,The salinized meadow soil increased 77%,83%,112%,34%and 70%respectively.By analyzing the correlation between soil organic matter and particle size,it is concluded that:There is a strong correlation between soil clay content and soil organic matter content in moderate and severe salinized meadow,and the correlation coefficients are 0.801 and 0.6054,respectively,It shows that fine particles are beneficial to the accumulation of organic matter.(4)The above ground biomass and plant height of herbage were increased by different improvement measures.The above ground biomass of the medium salinized meadow was the highest,increased 141%compared with the control,The above ground biomass of heavy salinized meadow soil treated with organic fertilizer was the highest,increased 97%compared with the control;The plant height of moderate salinized meadow soil treated with desulfurized gypsum was the highest,increased by 32%compared with the control,The plant height of heavy salinized meadow soil treated with organic fertilizer was the highest,which was 71%higher than that of the control.In conclusion,the application of improver combined with supplementary forage had significant positive effects on soil salt control,alkali compression,physical properties improvement,nutrient content enrichment and biomass increase.Considering,In this study area,organic fertilizer is suitable for the improvement of salinized meadow soil,and it is worth to extension the market.