- Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Expires: November 30, 2011 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * DIESCH JOHN HOWARD	2. Date of Event Requiring Statement (MM/DD/YYYY) 8/5/2011	3. Issuer Name and Ticker or Trading Symbol RENTECH INC /CO/ [RTK]
(Last)        (First)        (Middle) 10877 WILSHIRE BLVD. #600	4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                            _____ 10% Owner ___ X ___ Officer (give title below)          _____ Other (specify below) Senior Vice President /
(Street) LOS ANGELES, CA 90024        (City)              (State)              (Zip)	5. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common stock	78923	D

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Option to Purchase Common Stock	7/14/2009	7/13/2016	Common Stock	40000	$4.15	D
Restricted Stock Units	(1)	11/3/2012	Common Stock	85826	$0	D
Restricted Stock Units	(2)	11/17/2012	Common Stock	66667	$0	D
Restricted Stock Units	(3)	12/10/2012	Common Stock	16538	$0	D
Restricted Stock Units	(4)	10/4/2013	Common Stock	70588	$0	D
Option for Common Stock	(5)	10/4/2020	Common Stock	164706	$.95	D

Explanation of Responses:
( 1)	Each restricted stock unit represents a contingent right to receive one share of common stock. 47,681 restricted stock units are vested in consideration for the reporting person allocating a portion of his fiscal year 2008 cash bonus to purchase such units and the remaining 38,145 restricted stock units vest on November 3, 2012, subject to the reporting person's continued employment with the Company on such date.
( 2)	Each restricted stock unit represents a contingent right to receive one share of common stock. One-third of the restricted stock units vested on November 17, 2010 and one-third will vest on each of November 17, 2011 and November 17, 2012, respectively, subject to the reporting person's continued employment with the Company on each such date.
( 3)	Each restricted stock unit represents a contingent right to receive one share of common stock. Fifty percent of the restricted stock units are vested in consideration for the reporting person allocating a portion of his or her cash bonus to purchase such units at the fair market value of $1.69 per unit based on the closing price of the Company's common stock on December 10, 2009, and the remaining fifty percent vest on December 10, 2012, subject to the reporting person's continued employment with the Company on such date.
( 4)	Each restricted stock unit represents a contingent right to receive one share of common stock. One-third of the restricted stock units vest on each of the first three anniversaries of October 4, 2010, subject to the reportins person's continued employment with the Company on each such date.
( 5)	The option vests in three equal installments of common stock on the first, second and third anniversaries of the grant date (October 4, 2010), subject to reporting person's continued employment with the Company on each such date.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
DIESCH JOHN HOWARD 10877 WILSHIRE BLVD. #600 LOS ANGELES, CA 90024			Senior Vice President

Signatures
/s/ John H. Diesch		8/10/2011
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.