| As a big agricultural country,total demand for grain sustained increases in recent years in china,improving saline soil has become an efficient way to expand agricultural acreage and increase grain yield.In order to improve the Yellow River Delta region at the same time,the rational use of cited yellow sediment and agricultural waste,in the coastal clayey soil area for field trials,and the sediment dosage was 20(S1),40(S2)t/hm2,1.5(P1),3.0(P2),4.5(P3)t/hm2,the amount of diatom mud was 1.5(D1),3.0(D2),4.5(D3)t/hm2 and the control experiment.The effects of different types of improved materials on the physical properties of coastal clayey soil were studied.Effects of improved materials and dosage on soil particle gradation,bulk density,pore condition,saturated hydraulic conductivity,soil water and salt distribution and cotton yield.The results showed that:(1)The Yellow River sediment can significantly increase the soil sand proportion and improve the soil texture of the clayey soil.Although the crop straw tillage has no significant effect on the soil grade of the modified soil,it can improve the soil structure to improve the viscosity of the clay soil.A little diatom mud that there is no significant effect on the grain gradation of modified clayey soil.(2)The soil bulk density of the three kinds of materials,such as Yellow River sediment,the crop straw and the diatom mud,on the bulk density of the clayey soil were different,and the soil bulk density was increased by 3.0%.while that of the crop straw and the diatom mud.The soil bulk density decreased by 2.0%,4.7% and 6.0%,respectively.The soil bulk density treated by P1,P2 and P3 was lower than that of CK,and the soil bulk density treated by D1,D2 and D3 was lower than that of CK CK decreased by 2.7%,6.0%,7.4%.Three materials had the greatest influence on the soil bulk density of 0-20 cm soil layer,and no significant difference was observed in soil bulk density below 20 cm.(3)Yellow River sediment and crop straw have good effect on the total porosity of modified clayey soil,and the use of diatomaceous earth mud can not increase the total porosity of the clayey soil.The soil treated with diatomite,crop straw and small amount of diatomite mud can significantly increase soil porosity and improve the ventilation of clayey soil.(4)The saturated hydraulic conductivity of S1 and S2 soils increased by 16.55% and 229.9%,respectively.The saturated hydraulic conductivity of P1,P2 and P3 increased by 62.0% and 100.4% And 167.6%,indicating that the addition of yellowing sediment and crop straw had better effect on the saturated hydraulic conductivity of modified clayey soil,and increased with the increase of adding amount.The treatment of D1,D2 and D3 The saturated hydraulic conductivity of soil decreased by 20.8%,55.6% and 74.3% compared with CK,which indicated that the use of diatom mud could not increase the saturated hydraulic conductivity of clayey soil.(5)Yellow River sediment,the crop straw and the diatom mud.The soil salinity of the soils in the soil layer of 0-10 cm was reduced,and Yellow River sediment salinity of S1 and S2 compared with CK,the soil salinity decreased by 32.3% and 29.1%,and the soils of P1,P2 and P3 treated with crop straw were lower than CK by 79.9%,82.8% and 79.6%,and the soils of D1,D2 and D3 treated with diatom mud compared with CK,the salt content decreased by 71.9%,78.7% and 80.0%.The soil salinity of S1 and S2 decreased by 5.3% and 17.2% in 10-20 cm soil layer,The soil salinity of P1,P2 and P3 treated by straw was 65.2%,70.3% and 64.0% lower than that of CK,and the soil salinity of D1,D2 and D3 treated by diatom mud was 44.8%,59.0% and 67.4% lower than CK respectively,indicating that the addition of three kinds of materials inhibited the accumulation of salt in the surface soil and the soil back to salt in 0-60 cm tillage layer.The soil water content of S1 and S2 in the soil layer was 0-10 cm Compared with CK,the soil water content of P1,P2 and P3 treated with straw increased by 18.8%,7.1% and 1.6% compared with CK,and the soil water content of D1 treated by diatom mud was 3.5% lower than that of CK,but the soil water content of D2 and D3 treated by diatom mud was 6.7% and 2.5% higher than that of CK,the soil water content of S1 and S2 in the 10-20 cm soil layer decreased by 19.2% and 31.2% compared with CK,and the straw treatment while the soil water content of P1,P2 and P3 increased by 27.8%,9.2% and 8.9% compared with CK,The soil water content of D1 and D2 decreased by 3.9% and 7.1% compared with that of CK,but the soil water content of D3 soil moisture content increased by 4.5% compared with CK,adding crop straw and diatom mud to maintain soil moisture has a certain role in promoting the addition of yellowing sediment will make the surface soil water content decreased slightly.(6)The cotton yield of S1,S2 increased by 11.1%,16.7%,respectively,compared with CK,and the cotton yield of P1,P2 and P3 increased by 11.1%,16.7% and 5.6%,and the cotton yield of D1,D2,D3 treatment of cotton production than CK decreased by 2.8%,5.0%,11.1%.It can be seen that the yield of cotton can be increased after application of Yellow River sediment and the crop straw into the soil.After diatom mud is applied to the soil,the cotton yield is reduced.There are a lot of fine sand particles in Yellow River sediment to improve the grain composition of the clayey soil,and the application of yellowing sediment and straw can also improve the soil texture and pore conditions,increase the soil saturated hydraulic conductivity,reduce the soil salt The amount of material is to improve the physical properties of the clay material.The application of diatom mud reduced the number and proportion of macropores in the soil and decreased the saturated hydraulic conductivity of the soil,so it was not suitable for improving the physical properties of clayey soil.Therefore,the key to improve the clayey soil is to select the material that can increase the quantity and proportion of soil macropores and increase the saturated hydraulic conductivity of soil.It can be seen that different improved materials have different effects on the hydro--physical properties of the glacier soil in the Yellow River Delta.On the whole,within a certain range,the greater the amount of sediment added,the better the improvement effect;the amount of straw added in the 3t / ha or so,the best effect;a single addition of diatomite mud improvement effect is not ideal. |
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