Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu
It should have been obvious from observing rainfed fields or dry corners, but our soil moisture has steadily fallen across the region since May (Figure 1). Updated information on soil moisture only went through July 4th as of writing this article, so I can’t be sure what statewide rainfall may have done to bring soils back to balance. According to Figure 1, most of Sussex County has a volumetric water content of 0.15 or less.
Figure 1. Soil moisture continued to dry from May through July 4th (prior to this week’s rainfall).
Over the past three years in Georgetown, the pattern of soil moisture has been the same (Figure 2). A steady drop occurs from April until the beginning of July, when corn begins to pollinate and soybeans begin to flower. However there are differences in how we get to this point. 2021 was very dry in late May, but saw significant moisture in June, while 2020 and 2022 maintained moisture contents above 0.1 for most of May. It is not unusual to have drier soils in early July, but since both corn and beans are entering reproductive stages, any field that can be irrigated will help reduce stress and maintain yields.
Figure 2. Soil moisture in Georgetown April 1st through July 6th (ignore the 2020 year on the x-axis).