ABSTRACT

The determination of field sampling locations for COTMAN software is a highly subjective process. COTMAN provides guidelines for sampling with respect to practices and numbers. Many producers do not adhere to the guidelines because of the associated time and logistical requirements. In fields with significant developmental variability, sampling locations that merely represent an average condition of the field fail to address the specific management needs of different regions of the field. In fields with little variability, the general condition of the field can be assessed by a small number of well selected sampling locations. Research was conducted at Texas A&M University (TAMU) in 2003 to explore the utility of using precision farming technologies to assess variability, select sampling locations and monitor plant development throughout the growing season. Test sites which consisted of production irrigated and dryland fields in south and south-central Texas were monitored throughout the growing season by COTMAN and a TAMU developed plant height mapping system called HMAP. Two sampling locations selected from consistently average height regions within a field were able to generate equivalent COTMAN outputs to those generated with three times as many sampling locations from the same field for all sites considered in this study, irrespective of field size.