SOIL AND CROP VARIABILITY INDUCED MANAGEMENT ZONES TO OPTIMIZE POTATO TUBER YIELD

摘要

Soil variability and the resultant lower potato tuber yield can be mitigated through precision agricultural practices. This study quantified variability of soil and crop properties to construct management zones (MZs) for optimizing tuber yield. Soil was sampled from each grid and analyzed for soil chemical properties. Time Domain Reflectometry (TDR), DualEM-2 sensor, and normalized difference vegetation index (NDVI) meter were used to collect each grid's soil water content (theta), horizontal coplanar geometry (HCP) of the apparent ground electrical conductivity, and NDVI, respectively at various plant growth stages during the cropping season of 2018. Most of the parameters had moderate to high variability in both fields. Tuber yield was 34% higher in Field 1 partly due to two and a half times higher phosphorous (P) and iron (Fe) contents in its soil than yield of Field 2. The other inflicting factor for higher yield in Field 1 included higher %P/Al (P aluminum ratio) of soil of Filed 1 than Field 2. The soil and crop variability data helped establishing MZs that can facilitate site-specific precision nutrient management for improving soil fertility and optimizing potato tuber yield.