施用酸性土壤调节剂、腐熟咖啡果皮对咖啡苗生长及土壤养分含量、酶活性的影响

【目的】研究咖啡园施用酸性土壤调节剂、腐熟咖啡果皮对咖啡苗生长及土壤养分含量、酶活的影响,为促进农业废弃物咖啡果皮的综合利用和改良咖啡园酸性土壤质量提供技术支持和理论依据。【方法】采集56年龄咖啡园土壤,添加不同量的酸性土壤调节剂克酸宝(TL)和腐熟咖啡果皮(CP),试验处理分别为:对照CK(表土100%)、 TL1(TL2%)、 TL2(TL4%)、 TL3(TL6%)、 TL4(TL8%)、 CP1(CP4%)、 CP2(CP8%),分析添加TL和CP对咖啡叶片光合参数、干物质积累量、土壤pH值、土壤养分含量及土壤酶活性的影响。【结果】添加TL提高土壤pH值0.8~1.6,添加CP土壤pH值先增后降,种植6个月,土壤pH值比对照降低0.50个单位;土壤速效钾、交换性钙、交换性镁含量随TL和CP施入量增加而显著增加,CP处理全N、碱解氮、速效磷显著高于其余处理,但添加TL处理土壤速效磷显著降低,其中TL4比对照低69.34%。光合参数表现最好的是TL2、 TL3,二磷酸核酮糖(RuBP)酶活性、净光合速率(Pn)分别比对照提高101.16%、135.30%,81.71%、80.35%。其次为CP1、CP2;添加TL和CP土壤酶活性除酸性磷酸酶(ACP)与对照差异不显著外,其余酶活均有不同程度提高。各处理碱性磷酸酶(ALP)是对照的2.05~3.71倍,过氧化氢酶(S-CAT)显著高于对照109.62%~18.60%,由高到低为CP2> CP1> TL4> TL3> TL2。脲酶(S-UE)比对照高18.70%~5.37%,最高为CP2、 CP1,其次为TL1、 TL4。TL2、 TL3、CP1、CP2处理不同程度促进了咖啡植株生长和干物质累积量,其中株高、茎粗比对照提高25.09%~81.29%,叶、根、茎干重和单株总干重比对照提高1.65~5.02倍,效果最显著为CP1处理。【结论】施用适量的TL和CP改善了土壤微生物环境,提高了土壤养分有效性,促进了咖啡植株的生长。但TL添加量增加,土壤交换态钙过高会引起磷的固定,添加CP随着有机氮的矿化,使土壤pH值降低。

The Ability of Phosphate Solubilizing Bacteria Isolated from Coffee Plant Rhizosphere and Their Effects on Robusta Coffee Seedlings

Phosphate solubilizing bacteria isolated from rhizosphere of coffee plants may play an important role in improving phosphate availability for the plants. However, one of the factors influencing the degree of phosphate solubilization by these bacteria is the ability of the microorganisms to utilize phosphate. The objective of this study was to determine the ability of phosphate solubilizing bacteria isolated from coffee plant rhizosphere and their effects on robusta coffee seedling growth. This research was carried out by taking soil samples from Andungsari （Bondowoso District） and Kaliwining （Jember District） coffee plantations, both located in East Java. Liquid medium of Pikovskaya was used for isolation of phosphate solubilizing bacteria from the soil samples. Results of this study showed that 12 phosphate solubilizing bacteria were obtained from this isolation, eight isolates from Andungsari and four isolates from Kaliwining. Selection of those bacteria isolates was based on the qualitative ability in phosphate solubilizing by measuring the clear zone surrounding the colonies and quantitatively by measuring the solubilized phosphate using spectrophotometer. The results showed that four isolates, in the order of PFpKW1, PFpC61, PFsC62a, and PFsB 11, had the highest qualitative ability in solubilizing phosphate, while for the highest quantitative ability the order was PFpKW 1, PFpC61, PFsC62a, and PFsB 11. In a green house study, inoculation of these selected isolates onto Robusta coffee seedlings positively enhanced the coffee seedling growth. Phenotypic test indicated that the four isolates are similar to the genus of Pseudomonas.