不同磷肥施用量对油橄榄根际土壤微环境及生长发育的影响

Effects of different application amount of phosphate fertilizer on olive growth and rhizosphere soil microenviron-ment

探究不同磷肥施用量对油橄榄苗根系形态、根际土壤理化性质、土壤肥力相关酶活性、微生物数量、根系生理及生长发育的影响,以期确定油橄榄苗期最优的磷肥施用量,为油橄榄植株培育提供科学合理的施肥依据。结果显示:(1)增施适量磷肥可降低根际土壤pH值,提高根际土壤有机质、有效磷含量,根际土壤碱解氮含量有所下降;增施适量磷肥还可增强根际土壤碱性磷酸酶、蔗糖酶和过氧化氢酶活性,而脲酶活性降低;增加根际土壤细菌、放线菌、解磷菌数量及细菌与真菌比值(B/F),降低真菌数量,改善油橄榄根际土壤性质;(2)增施适量磷肥可提高油橄榄根系中脯氨酸、可溶性蛋白及可溶性糖含量,增强根系活力,增加根系含水量、油橄榄根长、根表面积和根尖数,促进根系生长,优化根系空间分布;(3)增施适量磷肥使油橄榄株高、茎粗、地上部干重、根干重和根冠比均有一定程度的提高,对植株生长发育起到促进作用。比较6种不同磷肥施用量,以每株施用45 g磷肥对油橄榄幼苗根系生长发育和根际土壤微环境改善效果最佳。综上所述,增施适量磷肥可改善根际土壤理化性质和生物学特性,从而促进油橄榄根系及地上部分的生长发育。

The effects of different phosphate fertilizer application amount on the root morphology,rhizosphere soil physical and chemical properties,soil fertility related enzyme activities,microbial quantity,root physiology and growth and development of olive seedlings were investigated,in order to determine the optimal application amount of phosphorus fertilizer at the seedling stage,and provide scientific and reasonable basis for the cultivation of olive.The results showed that:(1)The pH of the rhizosphere soil was reduced by applying appropriate amount of phosphorus fertilizer,and the content of organic matter and available phosphorus in rhizosphere soil was increased,while the content of alkaline hydrolysis nitrogen was decreased.The activity of alkaline phosphatase,sucrase and catalase in rhizosphere soil was increased,but the activity of urease was decreased.The number of rhizosphere soil bacteria,actinomycetes,phospholipid bacteria and the ratio of bacteria to fungi(B/F)were increased,the number of fungi was reduced,and the soil properties of olive rhizosphere soil were improved.(2)Applying an appropriate amount of phosphorus fertilizer improved the content of proline,soluble protein and soluble sugar in olive roots,enhanced root activity,increased root moisture content,root length,root surface area and number of root tips of olive,promoted root growth and improved the spatial distribution of roots.(3)The plant height,stem diameter,aboveground dry weight,root dry weight and root-cap ratio of olive were all improved by applying appropriate amount of phosphate fertilizer,which promoted the growth and development of olive.By comparing the application amount of six different phosphorus fertilizer application amount,applying 45 g phosphate fertilizer to each plant had the best effect on the growth and development of olive seedlings root system and the rhizosphere soil microenvironment.In short,applying appropriate amount of phosphorus fertilizer could improve the physical and chemical properties and biological characteristics of rhizosphere soil,so as to promote the growth and development of olive roots and aboveground parts.