Study On The Preparation And Nutrient Release Characteristics Of Special Fertilizer Stick For Rubber Tree

Hevea brasiliensis belong to tall trees and have a large demand for nutrients.As a long-term economic forest,there are long requirements for fertilizer efficiency.But a large amount of traditional fertilizer can cause the burn of rubber roots to affect the growth of the tree body,and the excessive nutrient release will lead to the waste of fertilizer and the potential pollution of the environment.Too little fertilizer application will lead to insufficient nutrient supply and influence the yield and growth of rubber tree,and frequent fertilizer application will lead to the increase of the management work of rubber tree.To improve the cost of rubber production.Therefore,the development of slow release fertilizer for rubber trees is of great significance to rubber production.In this study,from the effect of different dosage of binder,nutrient release material and raw material fertilizer on compress,powder fluidity and compression,the composition and process parameters of slow-release fertilizer were defined,and 5 kinds of rubber special sustained-release fertilizer rods were produced,and soil column was used to simulate leaching test and field respectively.The nutrient release characteristics,nitrogen nutrient transformation,nutrient vertical migration characteristics and fertilizer application effect of the tested fertilizer were studied by the experiment of nutrient transfer and the potted experiment of rubber seedlings.The main results are as follows:The laboratory parameters experiment showed that with the dosage of 2-6%(the proportion of fertilizer quality),with the addition of the binder to the fertilizer,the repose angle and sliding angle of the slow-release fertilizer could be increased,which resulted in the increase of the stickiness of the fertilizer powder,but it could improve the anti pressure degree of the slow release fertilizer.The addition of urea and formaldehyde to fertilizer with the amount of 25-75%(the proportion of fertilizer nitrogen)can significantly reduce the resting angle and sliding angle of the special fertilizer,and enhance the fluidity of the fertilizer powder,but it will weaken the compression of the fertilizer rod.Comprehensive fluidity and compression ability,6%binder plus more than 50-75%urea formaldehyde fertilizer,fertilizer powder is not sticky very easy to flow powder,excellent fluidity evaluation,at this time suitable for industrial production,fertilizer stick compression ability is 80.98N,suitable for storage and transportation.The simulated leaching test of soil column showed that the 6%fertilizer and 75%urea formaldehyde dosage had the best effect on nutrient release.Nitrogen began to pour out seventh days after the test started.The final nitrogen accumulation rate was 10.94%and the cumulative leaching rate of potassium was 35%.The nutrient release rate of fertilizer bar with binder and urea formaldehyde was lower than that of ordinary mixed fertilizer at the initial stage and middle nitrogen stage.In the initial drenching time,the fertilizer stick containing only the binder was delayed by 4D,while the binder and the urea and formaldehyde stick were delayed by 6D.After the leaching of 42d,the treatment of fertilizer rod with 2%,4%and 6%binder content was 6.98%,10.78%,14.03%lower than that of non binder.The treatment of urea and formaldehyde with 25%,50%,75%and 6%of binder content was 17.61%,25.21%and 3 9%lower than that of the same binder content but without urea formaldehyde.The fertilizer stick containing the binder was delayed by 4D in the time of starting the leaching of potassium.After the leaching of 42d,the treatment of fertilizer rod with 2%,4%and 6%binder content was 19.44%,21.57%,24.12%lower than that of non binder.Nitrogen transformation and nutrient transfer experiments showed that the ammonium nitrogen and nitrate nitrogen in the soil were lower than those in the ordinary mixed fertilizer.The rate of nutrient release and migration was lower than that of ordinary mixed fertilizer.In the topsoil with nitrogen migration,the 30d slow release fertilizer rod had less accumulation of nitrogen than the ordinary mixed fertilizer,while the 135d slow release fertilizer rod was more concentrated than the ordinary mixed fertilizer.In the aspect of phosphorus migration,phosphorus migration is more difficult.Therefore,all treatments were enriched in subsurface soil at various stages,but fertilizer rods had less enrichment.In the aspect of potassium migration,potassium in the mixed fertilizer was transferred and diffused when 30d was applied,and the potassium in fertilizer rods migrated to the subsurface soil.At the time of 135d,potassium release from other treatments had been diffused,but the potassium treated by fertilizer rods was still at a relatively high level on the subsurface soil.The potted experiment of rubber seedlings showed that the special fertilizer stick of 6%binder and 25%and 50%urea formaldehyde can promote the high growth of the rubber seedlings.The height of the rubber seedlings was 142.42cm and 145.55cm respectively,and the Rubber Seedlings of the ordinary mixed fertilizer increased 2.76cm and 5.89cm respectively.6%the fertilizer bar added with 50%urea formaldehyde can promote the thickening of the stem diameter of the rubber seedling,and its rubber seedling stem circumference is 17.96mm,which is thicker than that of the blending fertilizer 0.91mm,When the plant height and stem thickening were increased,the fertilizer rod with 6%binder and 50%urea formaldehyde had the best fertilizer effect.