Inventories

6 Months Ended

Jun. 30, 2021

Major classes of inventories are presented below. Readily Marketable Inventories ("RMI") are agricultural commodity inventories such as corn, soybeans, wheat, and ethanol co-products, among others, carried at net realizable value which approximates fair value based on their commodity characteristics, widely available markets, and pricing mechanisms. The net realizable value of RMI is calculated as the fair value (spot price of the commodity in an exchange), less cost of disposal and transportation based on the local market. All other inventories are held at lower of cost or net realizable value.


(in thousands)	June 30, 2021		December 31, 2020		June 30, 2020
Grain and other agricultural products (a)	$	636,380	$	1,025,809	$	452,339
Frac sand and propane (a)	11,265		12,477		6,498
Ethanol and co-products (a)	155,993		114,895		63,195
Plant nutrients and cob products	101,286		139,885		87,346
Railcar repair parts	7,375		7,627		6,945
Total Inventories	$	912,299	$	1,300,693	$	616,323

(a) Includes RMI of $612.2 million, $983.2 million and $418.0 million at June 30, 2021, December 31, 2020 and June 30, 2020, respectively.

Inventories do not include 1.2 million, 3.0 million and 1.7 million bushels of grain held in storage for others as of June 30, 2021, December 31, 2020 and June 30, 2020, respectively. The Company does not have title to the grain and is only liable for any deficiencies in grade or shortage of quantity that may arise during the storage period. Management has not experienced historical losses on any deficiencies and does not anticipate material losses in the future.Lower of cost or net realizable value charges were $2.6 million and $10.9 million for the six months ended June 30, 2021 and June 30, 2020, respectively. The charge in the prior year was a result of lower ethanol market prices and decreased demand as a result of the COVID-19 pandemic