| Purple soil is one of the main cultivated soil types in China.It has the characteristics of shallow soil layer,loose surface soil,easy erosion and low organic matter content.Ninghua County is the most concentrated distribution area of purple soil in Fujian Province.Camellia oleifera is an important oil crop in purple soil area of Ninghua.Camellia oleifera income is an important source of income for local residents.Camellia oleifera oil income is an important source of local people's income.The traditional cultivation and management mode of Camellia oleifera plantation is along the slope,combined with artificial weeding,shoveling,loosening soil,low coverage of undergrowth shrubs and grasses and other factors,which easily lead to soil erosion,thus making the purple soil of Camellia oleifera plantation poor fertility and poor growth of Camellia oleifera.Therefore,it is an important issue for the development of Camellia oleifera industry to explore an efficient and reasonable regulation model for purple soil Camellia oleifera plantation.Taking demonstration park for popular science of soil and water conservation of Ninghua county in Fujian Province as the research area,this study designed three control measures: organic fertilizer + ryegrass + compound microbial fertilizer + Chamaecrista rotundifolia(T1),compound fertilizer + ryegrass + Chamaecrista rotundifolia(T2)and compound fertilizer(T3)according to the local conditions,and without any control measures(CK).The physical and chemical properties and stoichiometric characteristics of purple soil in Camellia oleifera plantation under different control measures were studied,and the relationship between the change of growth characteristics of Camellia oleifera and the improvement of soil physical and chemical properties was discussed.The results can provide reference for the selection of regulation measures in purple soil Camellia oleifera plantation.The main results are as follows:(1)During the experiment,the soil water content of T1 and T2 was higher than that of T3 and CK,especially from June to September 2018.Planting Chamaecrista rotundifolia in Camellia oleifera plantation in purple soil area can effectively maintain soil moisture in Camellia oleifera plantation.(2)After one year of experiment,the soil organic carbon content of T1,T2 and T3 increased by 56.26%,42.81% and 34.69% respectively,and the total nitrogen content of T1 was significantly higher than CK.Soil total phosphorus and potassium did not change significantly under different regulation measures during the experiment.In March 2018,the contents of ammonium nitrogen,available phosphorus and available potassium in soil were the highest in T3,while from April to October 2018,the contents of ammonium nitrogen,available phosphorus and available potassium in soil were higher in T1 and T2,and there was no significant difference between T1 and T2.There were two peaks of nitrate nitrogen content in soils treated with T1 and T2 in April and October of 2018.Compared with before the experiment,the content of soil available nutrients in T1 and T2 increased significantly one year after the experiment.It can be seen that organic fertilizer + ryegrass + compound microbial fertilizer + Chamaecrista rotundifolia and compound fertilizer + ryegrass + Chamaecrista rotundifolia have better effect in improving soil nutrients.(3)There was little difference in the stoichiometry characteristics of soil total nutrient among different regulation measures during the experiment.However,soil AN/AP and AN/AK were significantly different among different control measures,showing that T1,T2 and T3 were lower than CK in general.Obviously,organic fertilizer + ryegrass + compound microbial fertilizer + Chamaecrista rotundifolia,compound fertilizer + ryegrass + Chamaecrista rotundifolia and compound fertilizer can promote the balance between soil available nitrogen and available phosphorus,available potassium nutrients.(4)The growth characteristics of Camellia oleifera in purple soil Camellia oleifera plantation changed significantly under various regulation measures.After one year of experiment,the increment of plant height,ground diameter,crown width and new shoot length of Camellia oleifera showed that T1,T2 and T3 were significantly higher than CK(P < 0.05).The increment of plant height,ground diameter,crown width and new shoot length of T1,T2 and T3 were 209.52%~298.29%,132.63%~174.57%,75.19%~98.90% and 42.47%~57.92% higher than CK,respectively,and the difference between T1,T2 and T3 was not significant.SPAD value,leaf water content,fresh weight,leaf length,leaf width were all significantly higher than CK,leaf dry weight T1 was significantly higher than CK,leaf shape index T1 was significantly lower than CK,leaf dry matter content T1,T2,T3 was significantly lower than CK(P < 0.05).It can be seen that organic fertilizer + ryegrass + compound microbial fertilizer + Chamaecrista rotundifolia,compound fertilizer + ryegrass + Chamaecrista rotundifolia and compound fertilizer can promote the growth of Camellia oleifera.(5)The control measures had significant effects on the leaf nitrogen,phosphorus and potassium contents of Camellia oleifera,but had no significant effects on the leaf carbon contents of Camellia oleifera.One year after the experiment,the leaf nitrogen,phosphorus and potassium contents of Camellia oleifera in T1,T2 and T3 were significantly higher than CK;C/N and C/P showed that T1,T2 and T3 were significantly lower than CK,while N/P showed that T1,T2 and T3 were significantly higher than CK,while C/K had no significant difference among different regulation measures.Most of the growth characteristics of Camellia oleifera were positively correlated with leaf nitrogen,phosphorus and potassium content,but less correlated with leaf carbon content.There was a very significant positive correlation between leaf nitrogen,phosphorus and potassium content in Camellia oleifera under different regulation measures.(6)The contents of available phosphorus,available potassium,organic carbon,total nitrogen,clay,total phosphorus and bulk density significantly affected the growth characteristics of Camellia oleifera(P < 0.05),and the contents of available potassium,available phosphorus,nitrate nitrogen,total nitrogen,ammonium nitrogen and bulk density significantly affected the growth characteristics of Camellia oleifera leaves(P < 0.05).Soil available phosphorus and potassium are the key soil physical and chemical factors affecting the growth of Camellia oleifera.There was a significant positive correlation between the leaf phosphorus content of Camellia oleifera and soil available phosphorus content,the leaf potassium contens of Camellia oleifera and soil total potassium content and available potassium content(P < 0.05). |
PDF Full Text Request