红河州植烟土壤养分和土壤肥力变化特征研究

Change characteristics of soil nutrient and fertility in tobacco-growing toil of Honghe prefecture

【目的】明确红河州植烟土壤养分年际间变化特征和土壤肥力状况。【方法】本研究以2014年296个土壤样品和2018年881个土壤样品为研究对象,采用模糊数学原理对土壤养分适宜性进行综合评价,运用t检验和多重比较方法分析了各肥力指标的变异情况。【结果】与2014年相比,2018年平均土壤有机质、碱解氮和速效钾分别增加了2.81 g/kg、9.61 mg/kg和16.74 mg/kg,土壤有效硼和交换性镁则分别减少了0.22和51.69 mg/kg。从养分区组的变化特征来看,微碱性区组(pH 7.5~8.5),有机质含量很高区组(>40 g/kg),土壤碱解氮中等比例区组(100~150 mg/kg)、速效钾含量很高区组(>350 mg/kg)和土壤有效硼含量很低区组(<0.3 mg/kg)在2018年显著高于2014年,分别增加了47.83%、80.59%、12.21%、72.19%和38.84%。2018年有机质含量极低区组(<10 g/kg),土壤碱解氮含量低区组(65~100 mg/kg),土壤有效磷含量很低区组(<10 mg/kg),土壤有效硼含量中等区组(0.50~1.0 mg/kg)和交换性镁含量很高区组(>400 mg/kg)较2014年分别下降了46.0%、17.02%、16.57%、41.36%和30.87%,2014年和2018年有效锌含量属于高和很高的比例达到80.14%和85.37%,交换性镁含量处于中等偏上的比例高达76.05%~83.54%。土壤有机质和碱解氮分别对2014年和2018年植烟土壤的土壤肥力贡献最大,2018年研究区植烟土壤肥力指数均值为0.49,变异系数为26.53%,土壤肥力较低、中等和较高的植烟土壤分别占20.66%、61.29%和17.03%。与2014年相比,土壤肥力较低和较高等级比例在2018年分别增加了3.43%和0.13%,中等等级比例降低了1.88%。各县(市)较低和中等土壤肥力所占比例在2014年和2018年间无差异,仅较高土壤肥力所占比例在弥勒市表现出2018年显著高于2014年。【结论】红河州植烟土壤总体肥力状况良好且变异小,有机质和碱解氮是影响红河州植烟土壤肥力状况的主要因素。全州土壤有效锌和交换性镁含量较高,有机质、碱解氮和速效钾含量丰富,有效硼含量缺乏,建议加大硼肥的使用,合理控制锌肥和镁肥的施用。

【Objective】 This paper aimed to clarify the chronological change in nutrients and fertility of soils grown with tobacco in Honghe prefecture.【Method】 Total of 296 and 881 tobacco-growing topsoil samples were collected in 2014 and 2018, respectively. Soil fertility indexes and nutrients variation characteristics were evaluated and analyzed based on fuzzy mathematical theory, t-test and multiple comparison.【Result】Compared with 2014, the average value of soil organic matter, alkali-hydrolyzable nitrogen and available potassium increased by 2.81 g/kg, 9.61 mg/kg and 16.74 mg/kg, respectively, and soil available boron and exchangeable magnesium decreased by 0.22 mg/kg and 51.69 mg/kg in 2018, respectively. Judging from the variation characteristics of nutrient groups, the group with slightly alkaline(7.5-8.5), the group with very high content(>40 g/kg) of organic matter, the group with moderate content of soil alkaline hydrolyzable nitrogen(100-150 mg/kg), the group with very high content(>350 mg/kg) of available potassium and the group with very low content(<0.3 mg/kg) of soil available boron were significantly higher in 2018 than in 2014, increased by 47.83%, 80.59%, 12.21%, and 72.19%, and 38.84%, respectively. In 2018, the group with very low(<10 g/kg) of organic matter, the group with low(65-100 mg/kg) of soil alkaline hydrolyzable nitrogen, the group with very low(<10 mg/kg) of soil available phosphorus, the group with medium(0.50-1.0 mg/kg) of soil available boron and the group with very high content(>400 mg/kg) of exchangeable magnesium group decreased by 46.0%, 17.02%, 16.57%, 41.36% and 30.87% compared with 2014, respectively. The group with high and very high content of effective zinc reached 80.14% and 85.37% in 2014 and 2018, respectively;And the group with moderate and above exchangeable magnesium content was ranged from 76.05% to 83.54%. The soil organic matter and alkaline hydrolyzable nitrogen contributed the most to the soil fertility of tobacco-growing soil in 2014 and 2018, respectively. In 2018, the average value of soil fertility index for tobacco-growing soil was 0.49, and the coefficient of variation was 26.53%. The soil with lower, medium and higher soil fertility index accounted for 20.66%, 61.29% and 17.03%, respectively. Compared with 2014, the percentage of lower and higher soil fertility index increased by 3.43% and 0.13%, respectively, and the percentage of medium soil fertility index decreased by 1.88%. There was no difference between low and medium soil fertility in each county(city) in 2014 and 2018, only the higher soil fertility grade in Mile city showed significantly higher in 2018 than that in 2014. 【Conclusion】The overall fertility of tobacco-growing soil in Honghe prefecture was good and the variation was small. Soil organic matter and alkaline-hydrolyzable nitrogen content were the main factors affecting the soil fertility of tobacco-growing soil in Honghe prefecture. The soil showed high content of available zinc and exchangeable magnesium, abundant organic matter, alkali-hydrolyzable nitrogen, and available potassium, but lack of available boron content. It is recommended to increase the use of boron fertilizer and reasonably control the application of zinc and magnesium fertilizers.