Robert J. Lascano

Learn More
This study evaluated microbial communities of soil (0–10 cm) as affected by dryland cropping systems under different tillage practices after 5 years. The soil type was an Olton sandy loam with an average of 16.4% clay, 67.6% sand and 0.65 g kg of organic matter (OM). The cropping systems evaluated were grain sorghum (Sorghum bicolor L.)— cotton (Gossypium(More)
Site-specific soil and crop management will require rapid low-cost sensors that can generate position-referenced data that measure important soil properties that impact crop yields. Apparent electrical conductivity (ECa) is one such measure. Our main objective was to determine which commonly measured surface soil properties were related to ECa at six sites(More)
Indicators of soil quality, such as microbial biomass C and N (MBC, MBN) and enzyme activities (EAs), involved in C, P, N, and S cycling, as affected by dryland cropping systems under conventional (ct) and no tillage (nt) practices were evaluated for 5 years. The soil is sandy loam with an average of 16.4% clay, 67.6% sand, and 0.65 g kg−1 OM at 0–10 cm.(More)
Crop irrigation with subsurface drip (SDI) is increasing in the semiarid Texas High Plains (THP). Information on drip-tubing positioning, irrigation strategies, and wetted soil area is needed to increase rainwater effectiveness when well capacities are inadequate to meet full irrigation requirements. Time and resources necessary to test SDI strategies for(More)
The need to study the shrink-swell and crack properties of vertic soils has long been recognized given their dynamics in time and space, which modifies the physical properties that impact water and air movement in the soil, flow of water into the subsoil and ground water, and generally alter the hydrology of vertic soils. Measurement of crack properties has(More)
Accurate measurement of moisture content is a prime requirement in hydrological, geophysical and biogeochemical research as well as for material characterization and process control. Within these areas, accurate measurements of the surface area and bound water content is becoming increasingly important for providing answers to many fundamental questions(More)
This study was conducted to determine relationships between biotic and abiotic factors and to generate information needed to improve the management of site-specific farming (SSF). The effects of water (80% evapotranspiration (ET) and 50% ET), hybrid (drought-tolerant and -susceptible), elevation, soil texture, soil NO3--N, soil pH, and greenbugs (Schizaphis(More)
K.R. Thorp*, G.W. Wall, and J.W. White, USDA-ARS, Arid-Land Agricultural Research Center, Maricopa, AZ; S. Ale and N. Rajan, Texas A&M AgriLife Research, Vernon, TX; M.P. Bange, CSIRO Plant Industry, Narrabri, NSW, Australia; E.M. Barnes, Cotton Incorporated, Cary, NC; G. Hoogenboom, AgWeatherNet, Washington State University, Prosser, WA; R.J. Lascano,(More)
Inadequate information on factors affecting crop yield variability has contributed to the slow adoption of site-specific farming (SSF). This study was conducted to determine the effects of biotic and abiotic factors on the spatial and temporal variability of irrigated corn grain yields and to derive information useful for SSF. The effects of water (80%(More)