Study On The Effect Of Straw Return On Coastal Saline Soil

Soil salinization has became one of the most common concerns of experts and scholars all over the world.It has great environmental risk,and has a negative impact on the physical and chemical properties of soil and land use.At present,many researches have been done by experts and scholars in order to improve the saline soil,and achieved remarkable economic benefits,environmental benefits and social benefits.Straw returning to improve saline soil is one of the agronomic measures,which has the advantages of simple operation,low cost and better effect.This study chooses the coastal saline soil in Bohai granary test base at Wudi,Shandong province as the research object.And through analyzed and compared the different changes of soil nutrients and water-salt under different treatments.This study selected 5 kinds of straw mulch types(wheat straw,30 cm corn straw,50 cm corn straw,whole corn straw,weed),designed 4 kinds of different straw mulching quantity level(0.3 kg·m-2,0.6 kg·m-2,0.9 kg·m-2,1.2 kg·m-2),with conventional tillage as control,established the straw mulching test area,analysis the effect of different straw mulching on soil salinization status and nutrient status,and established the straw deep processing zone,set up the straw mulching,straw 30 cm burying,straw 30 cm burying+straw mulching and conventional tillage,analysis the water-salt dynamic change with the winter wheat growth,in order to provide theoretical basis and technical support for the improvement of saline soil with straw return.The results indicated that:(1)Effect of straw mulching at the improvement of saline soilAfter one year,straw mulching could improve the quality of saline soil,and different cover types and coverage combinations have different effects on the improvement of saline soil.Straw mulching was an effective measure to reduce the top soil salt content(0-40 cm),and to inhibit surface accumulation of salt,the better coverage with wheat straw,30 cm corn straw,weed were 0.9 kg·m-2,while 50 cm corn straw,whole corn were 1.2 kg·m-2.The soil p H increased significantly with weed,but wheat straw,30 cm corn straw,50 cm corn straw,whole corn had no significant differences compared with CK.Results of this study suggested that the better mulching quantity in production was 0.9 kg·m-2 with the wheat straw.There was little effect on soil p H of wheat straw mulching with the coverage of 0.6 kg·m-2,and the effect was better in the inhibition of soil salt accumulation.The better coverage with wheat straw,30 cm corn straw,50 cm corn straw,whole corn was 0.6 kg·m-2,while weed was 0.6 kg·m-2with available nitrogen content and0.9 kg·m-2 with organic matter content,but had no significant effect on available phosphorus content and available potassium content.wheat straw with the coverage of0.6 kg·m-2 had the most obvious effect with soil organic matter content,availablenitrogen content,available phosphorus content,with 30 cm corn straw with the coverage of 0.6 kg·m-2 to available potassium content.Different treatment could increase soil nutrients,wheat straw with the coverage of 0.6 kg·m-2 had better effect on enhance the soil nutrients.Maize yield increased to varying extents among different treatments,the maize yield increased firstly and then decreased with the quantity increased,and the higher level was 0.9 kg·m-2,especially of the wheat straw mulching with the coverage of 0.6kg·m-2.(2)Effects of straw burying at the improvement of saline soilStraw returning increased soil water storage,the average growth stage soil storage of winter wheat in 0-70 cm soil layers of straw mulching,straw burying and straw mulching+burying were higher than control treatment 8.28 mm,6.86 mm and 13.76 mm,respectively.Straw returning increased soil moisture in 0-30 cm soil layers was apparent before the middle of winter wheat,but the difference between the treatments and the soil water content decreased with the passage of the growing stage.The content of soil salinity was inhibited by straw returning,straw mulching+burying reduced the salt content in 0-50 cm soil salinity significantly,the average soil salt growth were 41.24%,32.08% and 52.77%,respectively,lower than straw mulching,straw burying and control treatment,showed a significant effect of plough layer.Straw returning improved the soil water and salt,increased the yield of winter wheat significantly,showed the order of straw mulching+burying >straw mulching >straw burying >control treatment.straw mulching+burying had the better effect on the improvement of the status of the coastal saline soil.