Core Ideas: ImageJ and Canopeo agreed in accurately measuring vegetative ground cover of pasture. Light interception was linearly related to ground cover measurement with ImageJ and Canopeo. ImageJ and Canopeo reduced the time for estimating canopy development by 96%. Digital image analysis (DIA) can potentially provide rapid, objective assessment of pasture canopy development. In pastures of ‘WW‐B.Dahl’ Old World bluestem [Bothriochloa bladhii (Retz) Blake], we compared the DIA programs ImageJ and Canopeo for ground cover estimates, their ability to estimate canopy functions, and their time savings for vegetation analysis relative to a manual method. The DIA procedure involved processing overhead canopy images into two color groupings corresponding to green ground cover and non‐green (dead) cover plus bare ground for ground cover calculation. ImageJ analysis of ground cover agreed with two types of Canopeo applications (r² values of 0.97 and 0.98). The prediction regression for percentage photosynthetically active radiation interception (PARI) using ImageJ, y = 0.94x − 2.91 (r² = 0.72), was not different from Canopeo. Predicted values of leaf area index (LAI) and biomass increased exponentially with ground cover, likely owing to overlapping leaf area in older canopies. Two‐dimensional ground cover had limited power of estimating LAI and biomass when ground cover exceeded 60%, LAI exceeded 1.8, and biomass exceeded 1500 kg DM ha⁻¹. The time required for estimating PARI, LAI, and green biomass using ground cover from both DIA methods was reduced to 3.6% of manual methods. The use of DIA with ImageJ provided measurements of ground cover that are simple and conducive to large batch analyses. Regressions of ground cover were deemed useful for rapid estimations of PARI and LAI, but of lesser value for biomass, especially when canopies developed stems and seedheads.

Core Ideas: A noncalibrated PR2 capacitance probe showed significant deviations from actual soil water content. Calibration improved the accuracy and precision of soil moisture monitoring with the PR2. Calibration was necessary for using the PR2 probe for research‐quality soil water measurements. Multi‐depth capacitance sensors are popular to monitor soil water content for scheduling irrigation thanks to their ease of operation and maintenance. The PR2/6 Profile Probe (Delta‐T Devices) measures soil moisture by using either the manufacturer's built‐in equation or a user‐calibrated equation if the soil is high in clay or organic matter. The objectives were to evaluate the performance of the PR2/6 Profile Probe in a perennial grassland and to develop a site‐specific equation to correct probe measurements in Pullman (fine, mixed, superactive, thermic Torrertic Paleustolls) clay loam soils. Permittivity recorded by the profile probe was regressed on the gravimetrically measured soil volumetric water content (VWC). Parameters were optimized to obtain least RMSEs. The default equation provided by the manufacturer estimated VWC with average RMSE and r² values of 0.053 m³ m^–3 and 0.71, respectively. New calibration coefficients were effective in explaining 91% of the variability in soil VWC measurements and reducing RMSE to 0.017 m³ m^–3. The results indicate that site‐specific calibration of the capacitance probe is necessary to attain research‐quality accuracy and precision when applied to grasslands in Pullman clay loam and associated clay loam soils.

The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon dactylon (L.) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111, 131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD.

Aspergillus flavus refers to a diverse group of saprophytic soil fungi that includes strains producing aflatoxins (toxigenic strains) in the kernels of corn (Zea mays L.) and other crops, causing pre-harvest and post-harvest aflatoxin contamination. Some A. flavus strains are atoxigenic, and the introduction of such strains into the crop environment helps reduce toxigenic aflatoxin contamination. Corn growers in Texas have used the product FourSure™, which contains four atoxigenic strains of A. flavus; however, effects on soil microbial communities associated with these applications are unknown. We compared soil fungal and bacterial communities in corn fields treated with FourSure™ to nearby untreated (control) corn fields in Texas during the summer of 2019. Analysis of soil microbial community structure showed that total fatty acid methyl esters (FAMEs), fungal, and bacterial populations were not significantly different (p = 0.31) between the FourSure™-treated and control fields, yet corn fields located in the northern counties had more (p < 0.05) Gram—bacteria, actinobacteria, and total bacteria than fields in the southernmost county. The Gram—bacteria and actinobacteria were positively correlated (p = 0.04; r = 0.48 and 0.49, respectively) with soil water content. Similar fungal and bacterial abundances between FourSure™-treated and control fields indicated that atoxigenic A. flavus had no negative effects on soil microbial communities.