Land application of manure and wastewater in Texas is regulated under 30 CFR 321, otherwise known as the “Subchapter B” rules.  The following link excerpts provisions from the Subchapter B rules that pertain specifically to land application, current as of September 2013.  30 CFR 321 selected paragraphs

The Texas Cattle Feeders Association (TCFA), the lead institution on this nonpoint source water quality project, publishes a brochure on manure use as a farmland fertilizer.  Here’s a link to the latest edition of TCFA’s brochure.  TCFA brochure – farmland fertilizer