Estimation of the rootzone depth above a gravel layer (in wild blueberry fields) using electromagnetic induction method |
| |
| Authors: | Fahad S Khan Qamar U Zaman Young K Chang Aitazaz A Farooque Arnold W Schumann Ali Madani |
| |
| Institution: | 1.Department of Engineering, Faculty of Agriculture,Dalhousie University,Truro,Canada;2.Department of Mechanical Engineering,Dalhousie University,Halifax,Canada;3.Citrus Research and Education Center,University of Florida,Lake Alfred,USA |
| |
| Abstract: | Wild blueberry (Vaccinium angustifolium Ait.) fields in the north east Canada are naturally grown in a course textured thin layer of soil and below this layer is a soilless layer of gravel. The root zone depth of this crop varies from 10 to 15 cm. Investigating the depth to the gravel layer below the course textured soil is advantageous, as it affects the water holding capacity of the root zone. Water and nutrient management are the two primary determinants of crop yield and the amount of leaching. The objective of this study was to estimate the depth to the gravel layer using DualEM-2 instrument. A C++ program written in Visual Studio 2010 was used to develop mathematical models for estimating the depth to the gravel layer from the outputs of DualEM-2 sensor. Two wild blueberry fields were selected in central Nova Scotia, Canada to evaluate the performance of DualEM-2 instrument in estimating the rootzone depth above the gravel layer. The mid points of squares created by grid lines were used as the sampling points at each experimental site. The actual depth to the interface was measured manually at selected grid points (n = 50). The apparent ground conductivity (ECa) values of DualEM-2 were recorded and the depth to the interface was estimated for the same sampling points within the selected fields. The fruit yield samples were also collected from the same grid points to identify the impact of the depth to the gravel layer on crop yield. After calibrations, comprehensive surveys were conducted and the actual and estimated depths to the interface were established. The interpolated maps of fruit yield, and the actual (zin) and estimated (\( {\text{z}}_{\text{in}}^{*} \)) depths to the interface were created in ArcGIS 10 software. Results indicated that the zin was significantly correlated with \( {\text{z}}_{\text{in}}^{*} \) for the North River (R 2 = 0.73; RMSE = 0.27 m) and the Carmel (R 2 = 0.45; RMSE = 0.20 m) sites. Results revealed that the areas with shallow depth to the gravel layer were low yielding, indicating that the variation in the depth to the gravel layer can have an impact on crop productivity. Non-destructive estimations of the depth to the gravel layer can be used to develop erosion control strategies, which will result in an increased crop production. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
