土壤有机质空间分布预测与草莓种植分区施肥方案——以长丰县为例

Spatial distribution and prediction of soil organic matter and zonal fertilization of strawberry planting area:taking Changfeng County as an example

为了探究土壤有机质含量及空间分布进而实行分区施肥,本研究以安徽省合肥市长丰县的草莓产业为例,利用长丰县的测土配方项目收集了1986个土壤采样点位的有机质数据,借助普通克里格(OK)、随机森林(RF)、随机森林残差克里格(RFRK)3种预测模型,结合与土壤形成相关的地形、植被等6个环境协变量,对研究区的土壤有机质空间分布进行预测,绘制空间分布图,并依据有机质含量划分施肥分区,针对各个分区提出不同的草莓施肥方案。结果表明,3种模型所预测的土壤有机质总体分布趋势基本一致,呈现北高南低的特点,有机质总体含量为8~30 g·kg^(-1)。根据土壤有机质的丰缺程度,将有机质含量为15~25 g·kg^(-1)的地区划定为中等施肥区,建议施用农家肥45.0~52.5 t·hm^(-2);有机质含量高于25 g·kg^(-1)的地区为低施肥区,建议施用农家肥37.5~45.0 t·hm^(-2);有机质含量低于15 g·kg^(-1)的地区为高施肥区,建议施用农家肥52.5~60.0 t·hm^(-2)。本研究根据预测的土壤有机质空间分布划定草莓施肥分区、制定施肥方案,为不同地区的草莓种植提供指导和参考。

In order to explore the content and spatial distribution of soil organic matter to implement zonal fertilization,the study took the strawberry industry in Changfeng County,Hefei City,Anhui Province,as an example,used the organic matter data from 1986 soil sampling sites that collected by the soil testing formula project of Changfeng County and chose three prediction models of Ordinary Kriging(OK),Random Forest(RF)and Random Forest with Residual Kriging(RFRK)with six environmental covariates of terrain and vegetation related to soil formation as auxiliary information to predict the spatial distribution of soil organic matter in the study area,drew the spatial distribution map,divided the fertilization zones according to the content of organic matter and proposed different fertilization schemes for strawberry in each area.The results showed that the overall distribution trend of soil organic matter predicted by the three models was the same,with the characteristics of high distribution in the north and low distribution in the south,and the overall content of organic matter ranged from 8-30 g·kg^(-1).According to the abundance and deficiency of soil organic matter,the areas with organic matter content in the range of 15-25 g·kg^(-1)were medium fertilizer areas and recommended to apply 45.0-52.5 t·hm^(-2)of farm manure.The areas with organic matter content higher than 25 g·kg^(-1)were low fertilizer areas,applying 37.5-45.0 t·hm^(-2)of farm manure.The areas with organic matter content lower than 15 g·kg^(-1)were high fertilization areas,applying 52.5-60.0 t·hm^(-2)of farm manure.Therefore,according to the predicted spatial distribution of soil organic matter,it provided the basis for strawberry fertilization zoning,made fertilization schemes,and provided guidance and reference for strawberry planting in different areas.