Effects Of Special Fertilizers On Soil Improvement And Nutrient Use Efficiency Of Binhai New Beach

Jiangsu coastal beach covers an area of 666,700 ha of total land area,accounting for more than 1/4 of the area covered by the sea in China and silting up continuously every year.The annual accumulated siltation area in Jiangsu Province is 13.3 km2,which is an important reserve land use resource in our country and is important to agronomy development Strategic significance.Coastal salty soil from the coast to the inland followed by salinized soil-Salinization of fluvo-aquic soil-the underlying saline soil,roughly parallel with the coastline.From the coast to the inland direction,the soil salinity become less and less.The composition of salt in the soil is basically the same as that of seawater,with sodium chloride as the main component.Cl-content accounts for 70-90%of the total amount of anions,followed by sulfate,bicarbonate is the least.Coastal saline soil is affected by two aspects:First,salinized soil is directly derived from seawater-infiltrated silt.The soil itself has a high salinity content and is more salty by seawater soaking,with a lower groundwater level and higher salinity.Second,it is affected by seawater,The terrain is low and flat,with poor drainage capacity.Saline soil has poor physical and chemical properties,low soil fertility and serious deficiencies in nutrient content,which seriously hampered the crop growth and low productivity of farmland reclaimed from tidal flats.In this paper,the application of special fertilizers for saline-alkali soil with fulvic acid,organic fertilizer,rational chemical fertilizers and nitrification and urease inhibitors as the main measures,combined with different nitrogen fertilizer levels(low,conventional and high)And different special fertilizers(low,medium and high)at the same nitrogen level.The salinity,pH,soil aggregates,soil nutrients,plant growth and yield indices of salinized soils under different treatments were analyzed.The improvement of coastal saline soil more appropriate measures and better fertilization,while the coastal saline soil nutrient balance and fertilizer utilization efficiency.The main conclusions of this study are as follows:1.Improvement of physicochemical properties of saline soil by special fertilizer and different rotation modesSpecialized fertilizers and drought and drought rotation are more conducive to the coastal beach soil conductivity reduction,300kg/hm2 for the optimal amount of nitrogen;under the same conditions of nitrogen,the increased use of special-purpose fertilizer can effectively reduce the increase in soil conductivity during the dry season.Fertilization will lead to increased soil pH,225kg/hm2 dedicated nitrogen treatment and nitrogen conditions,special fertilizer 300kg/hm2 treatment for the inhibition of pH is more effective.The nitrogen level of paddy field was 375 kg/hm2,which was more formed by aggregates.The nitrogen level of dry land was 225 kg/hm2,and the treatment with special fertilizer at 900 kg/hm2 could significantly promote the formation of aggregates under the same nitrogen level.Treatment significantly enhances soil stability.2.Effects of special fertilizer application on soil nutrients and crops growthThe nitrogen level of 300kg/hm2 and special fertilizer of 600kg/hm2 and 900kg/hm2 both significantly promoted the accumulation of organic matter and soil macro-aggregates,and the accumulation of paddy field was higher than that of dry land.Special fertilizer significantly increased soil nitrogen content,rice nitrogen accumulation in the season was higher than the wheat season.Under the same nitrogen level,the content of available nitrogen increased significantly with the increase of the amount of special fertilizer.Nitrogen level 300 kg/hm2 is more conducive to the accumulation of available phosphorus in soil and significantly increases the yield of rice and wheat.Under the same nitrogen level,the total phosphorus content of the grain increased significantly with the increase of fertilizer application.With the increase of nitrogenous fertilizer,the content of nitrogen and phosphorus in straw and grain increased,the effect of special fertilizer 1 was better than that of special fertilizer 2.Fertilizer 1(900kg/hm2)had the best effect on plant height and stem diameter at different growth stages of maize.Compared with CK,the plant height at jointing and filling stages increased by 11.9%and 10.8%,respectively,Stem diameter up to 7.5cm,compared with CK increased by 12.9%.3.3.Special fertilizer on the apparent balance of nutrients and fertilizer utilizationSpecial fertilizer can effectively improve the apparent nitrogen use efficiency,low nitrogen fertilizer 2 due to containing inhibitors and showed the apparent effect of nitrogen utilization.,With the increase of special fertilization amount of nitrogen,the apparent nitrogen utilization efficiency increased,nitrogen utilization rate of 300 kg/hm2 was the highest,increased by 6.41%compared with CK.The residual nitrogen in coastal saline soil was low,and the special nitrogen fertilizer application 2 promoted the nitrogen residual in soil.The nitrogen loss rate of 300kg/hm2 nitrogen treatment and 900kg/hm2 treatment was the lowest,use.Special fertilizer can effectively promote nitrogen fertilizer yield and grain nitrogen absorption capacity,special fertilizer 2 can effectively improve the efficiency of nitrogen agronomy,the highest nitrogen level 300kg/hm2 treatment,compared with the control increased 53.7%;under nitrogen conditions,the special fertilizer 1 With the increase of fertilizer application,the agronomic efficiency of nitrogen,physiological efficiency of nitrogen use,and nitrogen harvest index decreased.The special fertilizer 2 was the highest when the fertilizer level was 900kg/hm2.