USE OF IN-SEASON PROXIMAL SENSING DEVICES TO INDICATE CORN N AND WATER DEFICIENCY

3/26/2019 11:10:12 AM

2019 Conference Proceedings - California Plant and Soil Conference - February 5 & 6, 2019

Taylor Becker1, Mark Lundy1, Michelle Leinfelder-Miles2 1University of California, Davis; 2University of California Cooperative Extension, San Joaquin County

The purpose of this project is to relate nitrogen (N) and water-induced differences in corn productivity to canopy and leaf reflectance measured by proximal sensing devices, and determine if those values indicate crop N deficiency that will affect final yields. Water treatments included 25%, 50%, and 100% evapotranspiration (ET) until the blister (R2) stage after which all received 100% ET. Nitrogen treatments included 28, 118, and 236 kg N/ha. One biomass harvest occurred at R2 with corresponding treatment-specific proximal sensing measurements at leaf, canopy and field scales. Silage and grain yields were determined at R5 and full maturity (R6), respectively. Silage yields measured 23,886 kg/ha of dry matter in the maximum water and N treatment (20.0 inches applied, 236 kg/ha N), 19,231 kg/ha in the low water treatment (10.8 inches applied), and 18,771 kg/ha in the low N treatment (28 kg/ha N). Grain yields were 16,549 kg/ha in the maximum water and N treatment, 11,737 kg/ha in the low water treatment and 9,908 kg/ha in the low N treatment. Biomass yields measured at R2 correlated with silage yields (r2=0.58, p<0.001)

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