| The land of severe erosion degraded red soil is poor in nutrients and physical properties,It's ecological environment is fragile and plants grow slowly.So once the plants are destroyed,it is difficult for them to quickly recover by their own power of growing.Pinus massoniana is a prime species on degraded red soils;and the survival rate of it's seedlings is low.At the same time,Pinus massoniana is affected by poor soil quality f degradation and thus growing slowly.So how to improve soil fertility and promote the growth of Pinus massoniana is a problem that needs to be solved in the land of severe erosion degraded red soil.Nitrogen(N)and phosphorus(P)are the two major nutrient elements that influence plant growth.In recent years,the use of microbial fertilizer is more and more widespread,but the application of nitrogen and phosphorus in forest fertilization is still very limited.So it is of great significance to explore whether the microbial fertilizer can improve the growth of Pinus massoniana and soil nutrients or not.and whether it is worth to use extensively or not.In this study,the research soil is typical red soil from Hetian Township of Changting County,which is severely eroded and degraded.The annual Pinus massoniana seedlings are used as the research object.By using different gradients of N,P fertilizer,different gradients of microbial fertilizer,and setting a control group,to explore the Pinus massoniana seedlings's photosynthesis,growth status,biomass,root morphology,soil nutrient status,and the growth of Pinus massoniana seedlings and soil nutrient response status under different nutrient environment,The study concludes that:(1)The application of N/P fertilizer or microbial fertilizer could increase the net photosynthetic rate of Pinus massoniana seedlings.The net photosynthetic rate with mixed application of N/P is higher than that of using N or P separately,and the highest net photosynthetic rate is with the application of N3P1,.The use of microbial fertilizer with J2 and J3 is better for the enhancement of Pinus massoniana seedlings 's photosynthesis.Based on the net photosynthetic rate of the Pinus massoniana seedling,the application of the microbial fertilizer is better than that of N/P,the maximum net photosynthetic rate with microbial fertilizer is 1.2 times than that of N/P treatment.(2)External addition of N and P fertilizer or microbial fertilizer is conducive to the growth of Pinus massoniana seedlings's growth and biomass.The growth of Pinus massoniana seedlings with mixed application of N/P is better than that with single application,and the collocation of N3P1 can do better to the growth and biomass of Pinus massoniana seedlings.the collocation of 32 can do better to the growth of Pinus massoniana seedlings among the microbial fertilizer.The total biomass which is treated with N/P treatment is higher than microbial fertilizer,but the N/P can improve the aboveground biomass of Pinus massoniana seedling and the microbial fertilizer can promote the growth of underground biomass of Pinus massoniana seedlings.(3)N/P treatments or microbial fertilizer treatments has significant effects on root morphology of Pinus massoniana seedlings.The effect of microbial fertilizer on the root growth of Pinus massoniana seedlings is better than that of N/P application.The application of mixing N/P is better than single application.(4)Application of nitrogen and phosphorus can increase the content of soil nutrients;the application of microbial fertilizer can increase soil N and rapid available phosphorus content,but has no effect on soil TP and soil carbon content.The content of N in soil increases with the increase of nitrogen fertilizer application gradients,and the content of TP increases with the increase of phosphorus fertilizer application gradients.There is no significant difference between different treatments of N,C and TP(P>0.05).The change of soil nutrient is more rapid and effective with N/P fertilizer. |
PDF Full Text Request