土壤养分对澳洲坚果果实品质的影响

Effects of soil nutrients on nut qualities in Macadamia integrifolia

为了探讨土壤养分对澳洲坚果果实品质的影响问题,从而为其科学施肥提供参考依据,连续两年对桂西南澳洲坚果园的土壤养分因子(有机碳、全氮、全磷、全钾和p H值)和果实品质指标(脂肪、蛋白质、油酸、棕榈油酸和二十碳烯酸)进行了调查与分析。测定结果表明:澳洲坚果果实中的脂肪和蛋白质主要受土壤全氮、全磷和p H值的影响,油酸主要受土壤有机碳、全氮和全磷的影响,棕榈油酸主要受土壤有机碳、全氮、全磷和全钾的影响,而二十碳烯酸主要受土壤有机碳、全磷和p H值的影响。通径分析结果表明:直接影响果实中的脂肪、蛋白质、油酸、棕榈油酸和二十碳烯酸的因子分别是土壤p H值和全氮、全氮、全钾;果实各品质指标的剩余通径系数均较大,表明除文中分析的各土壤养分因子外,还存在其他的影响因素。文中因此认为,在土壤管理中,应针对目标果实品质指标的需要,适当提高土壤全氮和全钾的含量,合理控制施肥种类。

In order to discuss the effects of soil nutrients on nut quality in Macadamia integrifolia, and to provide some references for scientific fertilization, soil nutrient factors （organic carbon, total nitrogen, total phosphorus, total potassium and pH value） and nut quality indexes （fat, protein, oleic acid, palmitic acid, and eicosenoic acid） were investigated and analyzed for two continuous years in M. integrifolia nut orchards of Southwest Guangxi. The results showed that protein and fat in M. integrifolia nut were mainly affected by total nitrogen, total phosphorus and pH value in soil, oleic acid in nut was mainly affected by organic carbon, total nitrogen and total phosphorus in soil, palmitic acid in nut was mainly affected by organic carbon, total nitrogen, total phosphorus and total potassium, and eicosenoic acid in nut was mainly affected by organic carbon, total phosphorus and pH value. The results of path analysis showed that fat, protein, oleic acid, palmitoleic acid and eicosenoic acid in nuts were respectively affected by soil pH value, total nitrogen, total nitrogen, and total phosphorus. The residual path coefficient of each nut quality index was larger, so there were some other influencing factors besides soil nutrient factors analyzed. Therefore, aiming need of targeted nut quality indexes, it should be done to properly increase total contents of nitrogen and potassium and to reasonably control fertilizer types in soli management.