Identifying Spatially Variable Crop Growth Constraints to Improve Cropping System Resiliency.

There is a great need for improved in-field nutrient use efficiency and crop productivity in the environmentally sensitive areas of the Chesapeake Bay Watersheds while maintaining the viability of agricultural production. Soil moisture availability to crop roots often limits yields in this region, therefore, precise soil nutrient management and soil improvement practices need to be adjusted according to their in-field spatial variability. We combined multi-year yield assessments, targeted soil sampling, comprehensive soil testing, and in situ soil sensors to 1) map in-field yield stability zones, 2) identify measurable yield constraints, and 3) calibrate the sensors for soil hydraulic property estimation on selected commercial fields in Maryland and Delaware. The standardized principal component analysis (stdPCA) method was tested for exploratory yield analyses as well as determining primary yield constraints including climatic, edaphic, and topographic variables. The soil information was assessed using the combination of Veris MSP-3 Mobile Sensor Platform (apparent electrical conductivity, pH, surface spectral reflectance, and GPS). Calibration samples were collected to a depth of 90 cm at nine locations based on levels of the apparent electrical conductivity. Samples were divided into increments of 0-15, 15-30, 30-45, 45-60, and 60-90 cm. The calibration samples were tested for soil nutrients, EC, and pH along with soil organic matter, texture, water content at -10 kPa, -33 kPa, -100 kPa, and -1500 kPa, water stable aggregation, and bulk density. The Veris MSP-3 was then assessed for its ability to estimate the spatial variability of each variable. We will present initial data showing the potentials of stdPCA in multi-year yield analysis and illustrate the applicability of Veris MSP-3 in estimating yield constraints.