重庆紫色土硼的有效性及其影响因素分析

The Availability of Boron in Purple Soil and Its Influencing Factors in Chongqing

以重庆地区紫色土壤为对象,研究紫色土硼的有效性及主要影响因素.结果表明：供试土壤有效硼含量在0.076~1.60 mg/kg范围内,平均值为0.183 mg/kg,参照《土壤—植物营养学原理和施肥》进行评价发现,其中有87.16%的土壤样品有效硼含量很低,11.49%有效硼含量低,有99%的供试样品低于缺硼临界值.有机质、pH值、阳离子交换量（CEC）和母岩母质对其有效硼含量均有显著的影响.在pH≥6.5的范围内,有效硼随有机质含量增加而增加,但在pH〈6.5的范围内却随有机质含量增加而减少,pH值的降低和CEC含量的增加,都会使有效硼含量随之增加,其中对硼有效性影响最大的因素是有机质.

Available boron of purple soil and other soil properties were measured to determine their distribution and to identify factors affecting their variability in different regions of Chongqing.The results showed that： the available boron content of soil samples is in the 0.076～1.60 mg·kg-1 range,and average is 0.183 mg/kg,of which 87.16% of the available boron content of soil samples is very low,11.49% is low.There are 99% of the soil samples below the critical value of B deficiency.Organic matter,pH,CEC and the parent rock of its boron content had significant effects.In the condition of pH≥ 6.5,the available B content increased with the increase of organic matter in purple soil.However,and the available B content decreased with increasing of organic matter content while pH6.5.With the decreased pH value and the increased CEC,available boron content was increased.Organic matter is the factor influencing available boron mostly.The theoretical basis of reasonable application of boron fertilizer in Chongqing purple soil region was provided.