交趾黄檀容器苗对缓释肥的生长响应与最优施肥量研究OA

The Dalbergia cochinchinensis is a precious hardwood tree species with significant economic value.In the Green and Beautiful Guangdong Ecological Construction Action,this tree species was selected as the preferred precious tree species for the forest quality improvement and stand structure optimization project.This study explores the effect of slow-release fertilizer application amount on the growth of container seedlings of D.cochinchinensis,determines the appropriate fertilization amount,and provides scientific basis and technical support for the efficient cultivation of this precious tree species.Using natural seedlings of D.cochinchinensis as materials,five gradient levels of slow-release fertilizer(with fertilizer amounts of 0,0.8,1.2,1.6,and 2.0 g per plant)were set up.The height,diameter at breast height,root morphology,leaf traits,nitrogen,phosphorus,and potassium contents,and biomass of each organ were systematically measured.The results showed that slow-release fertilizer significantly promoted the growth of the seedlings.The 1.6 and 2.0 g/ind.fertilizer application levels had the best effects,with the height and diameter of the seedlings increasing by more than 87%compared to the control at 6 months.The main root length,main root diameter,main root surface area,and main root volume increased by 57.02%,76.41%,58.87%,and 187.32%respectively at the 2.0 g/ind.slow-release fertilizer application level.Leaf morphology and nitrogen and potassium contents significantly increased with the increase in fertilizer application amount.Phosphorus content did not change significantly.Biomass accumulation increased with the increase in fertilizer application amount,and the root-to-shoot ratio decreased from 1.61 to 1.30-1.38 with the increase in fertilizer application amount.Correlation analysis showed that height,diameter at breast height,nitrogen content,stem biomass,and main root surface area were highly significantly positively correlated(r≥0.97).The membership function evaluation showed that the comprehensive score of the 1.6 g/ind.fertilizer application level was 14.53,close to the 2.0 g/ind.treatment but with a 20%reduction in fertilizer application amount.Slow-release fertilizer can significantly improve the quality of D.cochinchinensis seedlings by optimizing root configuration,promoting leaf formation and nutrient absorption.It is recommended that 1.6 g/ind.is an appropriate fertilizer application amount,which has both growth benefits and economic feasibility,and is suitable for the large-scale container cultivation of this tree species.