低产柑桔园叶片及土壤营养状况分析评价

通过对广西叮当农场低产柑桔园10份柑桔叶片样品的大量、中微量元素和10份土壤样品的土壤pH、有机质及大量、中微量元素进行分析,结果表明:土壤pH偏低,平均为5.26,土壤pH与土壤交换性Ca、Mg之间为极显著正相关;土壤有机质含量丰富,平均为3.02%。土壤有机质与碱解氮之间为显著正相关,土壤与叶片的大量元素N含量适中,但部分样品缺乏P、K而部分超过适量范围;土壤速效N、P、K和植株中的全量N、P、K为负相关关系。土壤和植株叶片中微量元素缺乏较为严重,特别是Zn、B。土壤中的Ca/Mg、K/Mg与植株叶片中全量N、P、K、Ca、Mg、Zn、B都有拮抗作用,说明土壤和植株之间营养元素吸收机理的复杂性,同时也说明了土壤化验和配方施肥的重要性。因此,建议在该农场施用石灰或碱性肥料改善土壤酸碱度,适量增施中微量元素钙、镁、锌肥,特别是应普施硼肥,使柑桔达到优质高产,并为广西低产柑桔园土壤合理配肥提供参考依据。

Evaluation on mineral nutrient status in soil and citrus leaf in low-yield citrus orchard

The pH,the contents of organic matter and elements in 10 soil samples and 10 leaf samples collected from low production citrus in Dingdang Farm in Guangxi were analyzed.The results showed that the pHof soilwas low,and the average value was 5.26.There was significantly positive correlation between pH and exchangeable Calcium (Ca) and Magnesium (Mg).The content of organic matter was high,and the average was 3.02%.There was significantly positive correlation between organic matter and alkaline-hydrolyzed N. The macronutrient nitrogen (N) was suit for soil and citrus plants,but phosphorus (P) and potassium (K) were too below in some samples but too high in the others.There were negative correlations between alkaline-hydrolyzed N in soil and to-tal N in leaves,available P and total P,available K and total K,respectively.The microelements were considerably deficient,especially Zinc (Zn) and Boron (B).There were antagonisms among Ca/Mg,K/Mg in soil and to-tal N,P,K,Ca,Mg,Zn,B in leaves.It indicated too complex absorption mechanism between the citrus plants and soil,and the soil testing and formula fertilization were very important.It also suggested that calcareous and more alkaline fertilizers should be applied to improve the pHof soil,and more Ca,Mg and Zn fertilizers should be suitably added,especially B fertilizer in most of areas in order to increase the yield and quality of citrus fruit,and provide reference basis for rational fertilization to soil in citrus orchard with low-yield in Guangxi.