| In order to study the improvement effect of different straw returning and organic fertilizer application methods on saline-alkali cultivated land,the typical soda saline-alkali soil in West Liaohe Plain of Inner Mongolia was taken as the object,and the effects of different straw returning and organic fertilizer application methods on soil physical and chemical properties,saline-alkali characteristic indexes and corn yield were studied by combining laboratory analysis and field experiment.It is clear that straw returning and organic fertilizer application are more suitable for saline-alkali soil in West Liaohe Plain.The results show that:(1)The soil saturated water content,field water capacity,soil bulk density and total porosity were improved by straw returning and organic fertilizer application.The soil physical indexes of 0～10 cm soil layer were significantly improved by straw +organic manure composting,saturated water content,field water holding capacity and total porosity were increased by 6.57%,5.93% and 4.02%,respectively,and soil bulk density was decreased by 6.6%.Compared with CK,stubble + organic fertilizer significantly improved the soil layer from 10 cm to 40 cm,and significantly increased it by 5.69%,3.86% and 4.25%,and decreased soil bulk density by 6.3%.(2)The p H and alkalinity of 0～40 cm soil and the salt content of 20～40 cm soil were significantly reduced by 31.3%,26.4% and 14.5% in straw + organic manure composting method.The soil salt content in 0～5 cm soil layer was significantly decreased by 26.4% with straw returning directly,and the soil salt content in 5～20 cm soil layer was significantly decreased by 35.5% with stubble + organic fertilizer returning.(3)Compared with CK,the contents of soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,available phosphorus and available potassium were significantly increased by 1.35～3.12%,13%～29%,9%～78%,12%～155% and15.1%～38.2%,respectively.Compared with CK,straw + organic manure composting increased soil nutrient content by 3.12%,29%,78%,155% and 38.2%,respectively.(4)Different straw returning and organic fertilizer application methods could increase corn yield,among which root stubble returning and root stubble + organic fertilizer were the most significant,increasing corn yield by 19.4% and 17.8%compared with CK,respectively.To sum up,the straw composting + organic fertilizer,root stubble + organic fertilizer,straw composting + organic fertilizer can fertilize soil,reduce the harm of salinization and increase crop yield,which is an ideal model for improving and fertilizing salinization cultivated land in West Liaohe Plain. |
