Spatial Analysis of Soil Salinity and Plant Stress Using Reflectance Measurement in Selected BLACK Glaciated Plain (MLRA 55C) Soils.

ORAL PRESENTAION SPATIAL ANALYSIS OF SOIL SALINITY AND PLANT STRESS USING REFLECTANCE MEASUREMENT IN SELECTED BLACK GLACIATED PLAIN (MLRA 55C) SOILS Birru G.1, Malo D1. , Clay D1., Reese C1 Carlson C1,Clay S.1 and DeSutter T2 1 Department of Plant Science, South Dakota State University, Brookings, SD 2 Department of Soil Science, North Dakota State University, Fargo, ND ABSTRACT Remote sensing methods including reflectance signatures from radiometers provide advantages (speed, cost, and nondestructive) over traditional soil and plant sampling methods and analysis. Assessing nutrient deficiency and leaf chlorophyll content using remote sensing has been widely researched. However, the use of spectral reflectance to determine salt level across the landscape/field and plant stress in salt affected soil has been less investigated. The experiment was conducted in SD in Pierpont (Day County) (lat. 44.9250° to 45.4751° N, long. 97.8359° to 98.4760° W, representing MLRA 55C). The dominant soils in the study area were Calciaquolls, Argiudolls, Calciudolls, Endoaquolls, Hapludolls, Natrudolls. A total of 48 points and 169 points were selected in Redfield and Pierpont, respectively. EM38 measurements, chlorophyll content, soil moisture, and reflectance (485-1050 nm of the reflectance bands) readings were done. Crop scan and EM38 readings were done using a 1-acre grid before planting. Additional crop scan readings were done at selected corn (Zea mays) crop stages (V1, V4, and V6). These measurements were also done on a 62 m by 62 m grid (1 acre). At Pierpont, additional measurements were done at varying distances from two center points – 1, 2.5, 5, 10, 20, 40, and 80 m – and in eight different directions – N, NE, E, SE, S, SW, W, and NW from the center point. These samples were further be described as rose samples, due to the likeness of the sampling scheme to a compass rose. All measurements were geo-referenced using a Magellan Professional handheld global positioning system (GPS) unit. Different Indices were compared. Spatial analysis of salinity class was done. Analysis on plant stress was determined. Findings were reported. Keywords: Argiudolls, Calciaquolls, chlorophyll content, EM38, Endoaquolls, Hapludolls, Natrudolls reflectance signatures, salinity, soil moisture, Calciudolls.