Soil salinization due to salt-water intrusion is an increasing problem in agricultural fields along the coast of North Carolina (NC). Farmers these regions are changing cropping systems and even abandoning fields due to the advancement of this issue. This research aims to quantify the reduction of soybean yields with the increase in the soluble salts index (SS-I) measured within the soil. We propose to create a simple method by which the farmer can measure the SS-I in their soil and predict the potential yield loss, thus helping guide management decisions specific to the value of soybeans grown in salt affected fields. This scale will be developed for both salt-tolerant and sensitive soybean varieties. A greenhouse trial will also be setup to determine the tolerance of soybeans to soils saturated with salts driven by coastal flooding and storm surge commonly associated with hurricanes. The trial will test the impact that saltwater concentration and duration of exposure have on plant survival. This information will help growers better understand where, and to what extent, to expect soybean damage resulting from storm surge and flooding from canals. As part of this proposed research, we have secured funding for stipend and tuition of a M.S. student. The student is fully sponsored by a Fulbright Program and the NC State Crop and Soil Sciences Department for a total of $62,000 over two years. To cover the expenses with the research activities, we are requesting from the NC Soybean Producers Association $17,294 in year 1, and $15,294 in year 2 to cover costs with supplies associated with the field and greenhouse trials, travel, technician support, and soil/plant analysis.

1. Determine the reduction of soybean yield with increasing soluble salt indexes using salt-tolerant and –sensitive varieties
2. Estimate the tolerance of soybean varieties to flooding at different salt concentrations and length of exposure
3. Create a table to transform on-farm electrical conductivity measurements to soluble salt index (SS-I)

We will produce at least one extension factsheet about the relationship between soil salt index and soybean yield reduction and how to convert EC (electrical conductivity) measured in the field in SS-I metric, as measured by NCDA.
We will produce at least one short extension factsheet about effect of flooding time and salt concentration in flooding water on the soybean survival during storm surges.
We will provide training for one M.S. student funded by the Fulbright Program.
We will provide training for extension agents about saltwater intrusion.
We will present the results of this applied research for farmers and stakeholders.
We will present the results of this applied research at one national conference.

Soil salinization is an increasing problem in the coastal plain region of North Carolina. What once was a localized issue is rapidly evolving into a more widespread problem involving more acreage and with greater severity in such coastal counties as Hyde, Tyrrell, Washington, and Beaufort. Similar problems are also commonly reported in Northeastern counties like Pasquotank, Camden, and Perquimans. Farmers on low-lying coastal land are now faced with increasingly more difficult decisions due to this increasing problem. They are rapidly losing greater areas of productive farmland, being forced to change crop management, growing less-profitable crops, spending more on salt-tolerant varieties, changing rotations, and even abandoning fields due to the problem. Given current trends in weather and climate, as well tightening budgets, it is now more important than ever to study this problem and to produce the clearly relevant information farmers need to best manage their fields and farming operations.