C# – The given ColumnMapping does not match up with any column in the source or destination

I dont know why I am getting the above exception, please someone look at it ….

DataTable DataTable_Time = new DataTable("Star_Schema__Dimension_Time");

DataColumn Sowing_Day = new DataColumn();
Sowing_Day.ColumnName = "Sowing_Day";

DataColumn Sowing_Month= new DataColumn();
Sowing_Month.ColumnName = "Sowing_Month";      

DataColumn Sowing_Year = new DataColumn();
Sowing_Year.ColumnName = "Sowing_Year";

DataColumn Visit_Day= new DataColumn();
Visit_Day.ColumnName = "Visit_Day";

DataColumn Visit_Month = new DataColumn();
Visit_Month.ColumnName = "Visit_Month";

DataColumn Visit_Year = new DataColumn();
Visit_Year.ColumnName = "Visit_Year";

DataColumn Pesticide_spray_day = new DataColumn();
Pesticide_spray_day.ColumnName = "Pesticide_spray_day";

DataColumn Pesticide_spray_Month = new DataColumn();
Pesticide_spray_Month.ColumnName = "Pesticide_spray_Month";

DataColumn Pesticide_spray_Year = new DataColumn();
Pesticide_spray_Year.ColumnName = "Pesticide_spray_Year";

DataTable_Time.Columns.Add(Pesticide_spray_Year);
DataTable_Time.Columns.Add(Sowing_Day);
DataTable_Time.Columns.Add(Sowing_Month);
DataTable_Time.Columns.Add(Sowing_Year);
DataTable_Time.Columns.Add(Visit_Day);
DataTable_Time.Columns.Add(Visit_Month);
DataTable_Time.Columns.Add(Visit_Year);
DataTable_Time.Columns.Add(Pesticide_spray_day);
DataTable_Time.Columns.Add(Pesticide_spray_Month);

adapter.SelectCommand = new SqlCommand(
    "SELECT SowingDate,VisitDate,PesticideSprayDate " +
    "FROM Transformed_Table " + 
    "group by SowingDate,VisitDate,PesticideSprayDate", con);

adapter.SelectCommand.CommandTimeout = 1000;

adapter.Fill(DataSet_DistinctRows, "Star_Schema__Dimension_Time");

DataTable_DistinctRows = DataSet_DistinctRows.Tables["Star_Schema__Dimension_Time"];

int row_number = 0;
int i = 3;

foreach(DataRow row  in DataTable_DistinctRows.Rows)
{
    DataRow flatTableRow = DataTable_Time.NewRow();

    string[] Sarray= Regex.Split(row[0].ToString()," ",RegexOptions.IgnoreCase);
    string[] finalsplit = Regex.Split(Sarray[0], "/", RegexOptions.IgnoreCase);
    string[] Sarray1 = Regex.Split(row[1].ToString(), " ", RegexOptions.IgnoreCase);
    string[] finalsplit2 = Regex.Split(Sarray1[0], "/", RegexOptions.IgnoreCase);
    string[] Sarray2= Regex.Split(row[2].ToString(), " ", RegexOptions.IgnoreCase);
    string[] finalsplit3 = Regex.Split(Sarray2[0], "/", RegexOptions.IgnoreCase);             

    flatTableRow["Sowing_Day"] = int.Parse(finalsplit[0]);
    flatTableRow["Sowing_Month"] = int.Parse(finalsplit[0]);
    flatTableRow["Sowing_Year"] = int.Parse(finalsplit[0]);

    flatTableRow["Visit_Day"] = int.Parse(finalsplit2[0]);
    flatTableRow["Visit_Month"] = int.Parse(finalsplit2[0]);
    flatTableRow["Visit_Year"] = int.Parse(finalsplit2[0]);

    flatTableRow["Pesticide_spray_day"] = int.Parse(finalsplit3[0]);
    flatTableRow["Pesticide_spray_Month"] = int.Parse(finalsplit3[0]);
    flatTableRow["Pesticide_spray_Year"] = int.Parse(finalsplit3[0]);

    DataTable_Time.Rows.Add(flatTableRow);

    i++;
}

con.Open();

using (SqlBulkCopy s = new SqlBulkCopy(con))
{
    s.DestinationTableName = DataTable_Time.TableName;

    foreach (var column in DataTable_Time.Columns)
        s.ColumnMappings.Add(column.ToString(), column.ToString());

    s.BulkCopyTimeout = 500;

    s.WriteToServer(DataTable_Time);
}