BUSINESS SEGMENTS Our operations are organized into three segments: potash, Trio  , and oilfield solutions. The reportable segments are determined by management based on several factors including the types of products and services sold, production processes, markets served, and the financial information available for our chief operating decision maker. We evaluate performance based on the gross margins of the respective business segments and do not allocate corporate selling and administrative expenses, among others, to the respective segments. Intersegment sales prices are market-based and are eliminated in the "Other" column. Information for each segment is provided in the tables that follow (in thousands). Three Months Ended September 30, 2019 Potash Trio  Oilfield Solutions Other Consolidated Sales $ 29,213 $ 14,637 $ 7,310 $  $ 51,160 Less: Freight costs 4,728 3,996   8,724 Warehousing and handling costs 1,190 972   2,162 Cost of goods sold 18,707 9,315 3,841  31,863 Lower of cost or net realizable value inventory adjustments  1,462   1,462 Gross Margin (Deficit) $ 4,588 $ (1,108 ) $ 3,469 $  $ 6,949 Depreciation, depletion, and amortization incurred 1 $ 6,048 $ 1,517 $ 747 $ 202 $ 8,514 Nine Months Ended September 30, 2019 Potash Trio  Oilfield Solutions Other Consolidated Sales $ 99,090 $ 53,881 $ 19,574 $ (1,319 ) $ 171,226 Less: Freight costs 14,110 15,502 861  30,473 Warehousing and handling costs 3,776 2,852   6,628 Cost of goods sold 59,024 32,988 8,682 (1,319 ) 99,375 Lower of cost or net realizable value inventory adjustments  1,462   1,462 Gross Margin $ 22,180 $ 1,077 $ 10,031 $  $ 33,288 Depreciation, depletion, and amortization incurred 1 $ 18,963 $ 4,595 $ 1,170 $ 605 $ 25,333 Three Months Ended September 30, 2018 Potash Trio  Oilfield Solutions Other Consolidated Sales $ 26,513 $ 10,859 $ 4,038 $  $ 41,410 Less: Freight costs 3,750 3,136   6,886 Warehousing and handling costs 1,207 984 1  2,192 Cost of goods sold 14,467 6,917 1,988  23,372 Lower of cost or net realizable value inventory adjustments      Gross Margin (Deficit) $ 7,089 $ (178 ) $ 2,049 $  $ 8,960 Depreciation, depletion, and amortization incurred 1 $ 5,928 $ 1,612 $ 97 $ 126 $ 7,763 Nine Months Ended September 30, 2018 Potash Trio  Oilfield Solutions Other Consolidated Sales $ 89,174 $ 51,814 $ 12,918 $  $ 153,906 Less: Freight costs 12,091 15,067   27,158 Warehousing and handling costs 3,773 3,285 9  7,067 Cost of goods sold 54,973 37,168 3,313  95,454 Lower of cost or net realizable value inventory adjustments  781   781 Gross Margin (Deficit) $ 18,337 $ (4,487 ) $ 9,596 $  $ 23,446 Depreciation, depletion and amortization incurred 1 $ 18,474 $ 4,870 $ 239 $ 255 $ 23,838 1 Depreciation, depletion, and amortization incurred for potash and Trio  excludes depreciation, depletion and amortization amounts absorbed in or relieved from inventory.