Application of NDVI in Digital Mapping of Phosphorus Content in Soils and Phosphorus Supply Assessment in Plants

Аннотация

A method for the digital mapping of phosphorus (total, organic, and labile) content in soils has been developed using spatially distributed NDVI values calculated from Landsat 8 image (30-m resolution). A comparative analysis of the phosphorus content has been performed in high- and medium-humous soils. Medium-humous soil (agrochernozems, agro–dark gray) has been found to have lower contents of the total (by a factor of 1.1) and organic (by a factor of 1.5–1.7) phosphorus compared with high-humous agrochernozems. The reverse trend has been identified for the labile phosphorus; that is, medium-humous soils twice exceeded the high-humous agrochernozems in its content. The plants have been proven to have a sufficient supply of phosphorus, since the element content in the aboveground phytomass of the oat-pea mixture was in the optimal range of 0.23–0.5% on a dry weight basis. No phosphorus deficiency symptoms have been detected in the plants by visual diagnostics. No correlation has been found between the phosphorus content in plants, aboveground phytomass stock of the oat-pea mixture and NDVI.