Research was carried out at the farm level to assess edaphic, abiotic, leaf blade nutrient and color, and plant water status differences between conventionally tilled (CVT) and reduced-tilled (NT) cotton. In 1999, six farmer co-operators established both CVT and NT cotton in companion commercial fields in south Texas. Irrigation was used by one-half of the co-operators. Three sub-sampling areas within each tillage system (sub-plot) were established for access tube placement and sampling measurements. Continuous soil and air temperatures were recorded in each sub-plot between 7 June and 11 July. Results indicated that irrigated fields had lower plant canopy and soil temperatures at 5, 10 and 20 cm depths, higher soil moisture, lower water stressed leaf blades, lighter (less green) leaves, and higher N, P, Ca, and Zn leaf blade nutrient levels than did dry land cotton. No tillage fields had similar plant canopy temperatures, but cooler soil temperatures to 20 cm and less soil moisture at 25 and 50 cm depths (dryland, only) compared to CVT fields. Leaf blade diffusive resistance and Zn levels (irrigated, only) were lower in NT leaf blades than in CVT leaf blades. Lint yields were improved by NT (P<0.24) as was percent lint (P<0.07), compared to CVT fields. Lint yield was significantly correlated with leaf RWC (r=0.71), transpiration (r=0.72), and stomatal conductance (r=0.89). Plant stand was higher in NT fields supplied with irrigation.