| Due to the special climate and soil conditions in the Ningxia Yellow Irrigation Area,there is a large area of salinized soil,and obvious results have been achieved after years of treatment,but there are still some problems such as high salinity,poor soil structure,low nutrient content and low crop yield caused by uncoordinated irrigation and drainage.The application of organic and inorganic improved materials and the planting of the pioneer bio-improvement plant Hunan millet is one of the effective ways to solve the above problems.Therefore,in this study,the effects of the combined application of organic and inorganic improvement materials on the physicochemical properties of saline-alkali soil and the growth characteristics of Hunan millet were studied in Pingluo,Ningxia,aiming to provide scientific basis and technical support for the improvement and utilization of medium and severe saline-alkali land in Yinbei,Ningxia.The main findings are as follows:(1)The application of organic and inorganic materials improved the physical properties of the two saline-alkali soils to varying degrees.The soil bulk density of 0～20cm cultivated layer of saline soil at Baofeng test site decreased by 1.28%～7.69%,and the content of water stable large aggregates(R0.25)and the average weight of hydrostable aggregates(MWD)increased by 16.67%～116.67%and 31.25%～100.00%,respectively.The bulk density of the cultivated layer decreased by 7.89%～19.08%,the content of water stable large aggregates(R0.25)and the average weight of water stable aggregates(MWD)increased by 48.15%～144.44%and 43.04%～93.67%of the salinized soil at Huiwei test site,respectively.(2)The chemical properties of the two saline-alkali soils were improved to different degrees by the combined application of organic and inorganic materials.The pH and total salt of the salinized soil of 0～20 cm in Baofeng test site decreased by 2.06%～14.11%,8.99%～48.20%,respectively,and the contents of organic matter,alkaline hydrolyzable nitrogen,available potassium and available phosphorus increased by 21.24%～51.84%,2.63%～69.81%,15.20%～67.65%,and 0.66～5.23 times,respectively.The pH.and total salt of the cultivated layer of 0～20 cm saline soil at Huiwei test site decreased by 0.75%～2.90%,10.63%～30.88%,respectively,and the contents of organic matter,alkaline hydrolyzable nitrogen,available potassium and available phosphorus increased by 74.19%～125.98%,4.84%～84.28%,27.78%～69.31%,140.79%～331.58%,respectively.(3)Under the conditions of saline-alkali soil,the combined application of organic and inorganic materials significantly improved the root vitality and root length of Hunan millet.In the tillering stage of Hunan millet,the root vitality,root length,root surface area and root volume of Hunan millet in the salinized soil of Baofeng test site were 5.34%～86.81%,7.04%～208.77%,17.90%～202.23%,18.18%～40.00%higher than CK.The root vitality,root length,root surface area and root volume of Hunan millet in the salineized soil of Huiwei test site were 3.66%～42.58%,51.07%～170.15%,33.46%～124.22%,15.09%～52.83%higher than CK,respectively.(4)The application of organic and inorganic materials significantly improved the production performance of Hunan millet in saline-alkali land.Under the conditions of saline-alkali soil,the combined application of organic and inorganic materials significantly improved the aboveground characteristics such as aboveground seedling emergence,plant height and stem thickness of Hunan millet,and the increase range of different treatments was different.The seedling emergence rate,plant height,stem thickness and yield of Hunan millet in the salineized soil of Baofeng experimental site increased by 20.90%～65.23%,60.27%～144.41%,60.27%～144.41%,152.32%～787.17%,respectively.The seedling emergence rate,plant height,stem thickness and yield of Hunan millet in the salinized soil of Huiwei test site increased by 1 1.49%～68.24%,8.84%～21.79%,4.17%～25.05%,25.09%～50.07%,respectively.(5)Under both saline soil conditions,treatment D[phosphogypsum(30.0 t·hm-2)+calcium superphosphate(600 t·hm-2)+ rotted sheep manure(30.0 t·hm-2)]had the best results compared to the control in terms of improvement in soil physicochemical properties,performance of alfalfa growth characteristics and The best results were achieved in improving soil physical and chemical properties,growth performance and production performance of Echinochloa frumentace.(6)In this study,through two consecutive years of field experiments on two types of salinealkali soils,we came to the innovative conclusion that the combined application of organic and inorganic materials to medium and severe saline alkali in Yinbei,Ningxia can significantly improve soil physicochemical properties and improve the growth characteristics of Hunan millet.The next step is to carry out in-depth research on the application of organic and inorganic materials,the response mechanism of root water and salt and the structure of soil agglomerates under water-saving conditions. |
PDF Full Text Request