| The saline soil in the Songnen Plain is one of the three major soda saline soil distribution areas in the world.the saline soil area is as high as 2.882×106 hm2,accounting for 39.3%of the total saline soil in the northeast,which seriously restricts grassland ecological restoration and agriculture.Heilongjiang Province has focused on the development of the“two cattle and one sheep”industry for many years,and at the same time it has also caused a certain degree of pollution.therefore,this study has important theoretical and practical significance for solving the fecal pollution of herbivorous livestock in the Songnen steppe area of western Heilongjiang Province,restoration and improvement of alfalfa production in saline-alkali land.This study was conducted in three trials.Test one:Study on the Release Rule of Manure Nutrient in different Saline-Alkali SoilsAdopt the three-factor and three-level design,through indoor culture method study the4-month-old sheep manure,the 6-month-old sheep manure,and the 10-month-old sheep manure in a ratio of 1:2,1:4,1:6 in mild,moderate and severe saline soil,the changes of pH,alkali nitrogen,available phosphorus,available potassium and organic carbon for 15 weeks.The results showed that:1.After the manure was mixed into saline-alkaline soil,the pH of each treatment decreased significantly,the content of alkali nitrogen,available phosphorus and available potassium increased significantly,and the content of organic carbon decreased significantly.Generally speaking,the early?medium-term?changes quickly,and the law tends to be gentle in the later period.2.There were significant differences in pH change,alkali-hydrolyzed nitrogen,available phosphorus,available potassium and organic carbon release in different soil treatment test period?P<0.05?.generally,the maximum change?release?of manure was 1:2,severe saline-alkali soil and 4-month old sheep manure.Test two:Study on the Effect of Temperature and Humidity on the Release of Manure C and N in Saline-Alkali Soil4 months old sheep manure mixed with 1:2 ratio of mild saline soil as the research object,by controlling different temperatures?18?,22?,25?,30?,35??and humidity?30%,40%,50%,60%,70%?carried out indoor aerobic culture,measured the cumulative release of CO2 and NH3 in manure within 35 days,and established a linear regression equation to further determine the external environment temperature and humidity on the release of C and N from manure nutrients.influences.The results showed that:1.There is a significant positive correlation between temperature and humidity and CO2release?R=0.897?.The linear regression equation is:Y1=34.189+2.891X1+1.926X2?R2=0.786?2.There is a significant positive correlation between temperature and humidity and NH3release?R=0.985?.The linear regression equation is:Y2=108.177+6.678X1+4.312X2?R2=0.968?Test three:Effect of Manure Modified Saline-Alkali Soil on Growth Characteristics of AlfalfaUsing L9?34?orthogonal design,planting alfalfa on the basis of 15 weeks of experiment 1,and measuring the relative water content?%?,plant height?cm?,number of branches?sections?,and sections of the alfalfa every other month.The growth index of the number of cells?number?,chlorophyll content?ug/cm2?,and aboveground biomass?g??5 months?was evaluated by the comprehensive evaluation method for the best combination of growth of each month.The results showed that:1.The ratios of different manure,saline-alkali soil and manure had significant effects on the growth characteristics of alfalfa seedlings planted for one month?P<0.05?.The best combination was A2B1C2,which is the ratio of 6 months old sheep manure and mild saline-alkaline soil to 1:4.mixed processing.2.The ratios of different manure,saline-alkali soil and manure had no significant effect on the growth characteristics of alfalfa after 1 month?P>0.05?.According to the trend of growth score,the best combination was 2 months old A2B1C2,3 months old A1B1C1,4 months old A1B1C1,5 months old A1B1C1.. |
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