| In view of the problems of high salt content,low soil organic matter content and low crop yield in coastal clayey saline soil,In this study,humic acid fertilizer and organic fertilizer were used as organic improvement materials,and a field experiment of coastal clayey saline soil improvement was carried out for two consecutive years.After applying different amounts of humic acid conditioner and organic fertilizer,changes in soil organic matter,soil salinity and yield components and yield of winter wheat in clayey saline soil in different soil layers and years,proving the improvement effect of two different organic fertilizers on coastal clayey saline soil.At the same time,determine the appropriate amount of fertilization for improving coastal clayey saline soil.The main results of this study are as follows:(1)With the increase of fertilization amount,soil organic matter showed a gradually increasing trend.Compared with the CK treatment,in the 0-20cm soil layer,the soil organic matter of each treatment with humic acid conditioner increased by 20.07%-38.86%,the soil organic matter of each organic fertilizer treatment increased by 6.09%-50.42%,and the difference was significant.The soil organic matter in the 20-40cm soil layer did not change significantly.Both humic acid conditioner and organic fertilizer can significantly increase the organic matter content of coastal clayey saline soil.However,the effect of humic acid conditioner on the improvement of soil organic matter content was significantly faster than that of organic fertilizer treatment.(2)Compared with the CK treatment,in the 0-20cm soil layer,the soil salinity treated with humic acid conditioner decreased by 33.26%-42.92%,respectively.The soil salinity treated with organic fertilizer decreased by 31.89%-36.88%,respectively.The effect of humic acid conditioner on reducing the salinity of 0-20cm topsoil was more significant than that of organic fertilizer.The two fertilizers have a significant effect on increasing the content of soil organic matter in the 0-20cm topsoil,but have no significant effect on the soil organic matter content in the 20-40cm soil layer.The continuous application of humic acid conditioner and organic fertilizer will promote the continuous decrease of the salinity of the coastal clayey saline soil.(3)Both humic acid conditioner and organic fertilizer can increase the number of ears,kernels per ear and thousand-grain weight of wheat.Compared with the T2 treatment in 2020and 2021,the number of winter wheat spikes in the CK treatment increased by 29.95%and26.17%,respectively.Compared with the CK treatment,the number of spikes of winter wheat in the Y2 treatment increased by 41.42%and 32.30%,respectively,and the difference was significant.Compared with CK,the number of grains per spike increased by 22.18%and25.57%in T4 and Y2 treatments,respectively.The 1000-grain weight of wheat increased first and then decreased with the increase of the dosage of humic acid conditioner.Compared with the CK treatment,the 1000-kernel weight of wheat increased by 1.32%-15.70%.The1000-grain weight of wheat treated with organic fertilizer increased by 3.94%-17.84%compared with CK,respectively.(4)In 2020,the yield of winter wheat in each treatment of humic acid conditioner increased by 2.65%-29.18%compared with CK,respectively.Compared with CK,the winter wheat yield of each organic fertilizer treatment increased by 2.65%-23.00%,and the difference was significant.In 2021,the yield of winter wheat in each treatment of humic acid conditioner increased by 16.15%-29.65%compared with CK,respectively.Compared with CK,the winter wheat yield of each organic fertilizer treatment increased by 21.32%-44.03%respectively.Appropriate application of humic acid conditioner or organic fertilizer can significantly increase the number of ears,grains per ear and average grain weight of wheat,and has a significant effect on increasing wheat yield.When it exceeds a certain amount,it will reduce the wheat yield.The above results show that both humic acid conditioner and common organic fertilizer can increase the organic matter content of coastal clayey saline soil and improve soil fertility.At the same time,it can significantly reduce the soil salinity,inhibit the return of soil salt,and have a significant effect on reducing the surface soil salinity.While promoting the growth of winter wheat,it will also significantly increase the number of ears,kernels per ear and thousand-kernel weight,thereby increasing wheat yield.Comparing the effect of increasing crop yield and other factors,it is recommended that the suitable dosage range of organic fertilizer for coastal clayey saline soil improvement is 1800-2700kg/hm~2,Combined with the cost of fertilizer and economic benefit,the dosage of organic fertilizer in saline-alkali farmland improvement is more suitable to 1800kg/hm~2. |
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