Crop Science Research Laboratory

Abstract Measuring and assessing soil properties is critical for understanding how changes in agronomic practices affect the capability of soil to support cropping systems. A field study was conducted on a Marietta silt loam soil at the Plant Science Center at Mississippi State University to determine the effects of pelleted biosolids (PBS) relative to poultry litter (PL) and inorganic N fertilizer applied to corn ( Zea mays L.) and cotton ( Gossypium hirsutum L.) in the presence of winter wheat ( Triticum aestivum L.) cover crop (WCC) and winter fallow (WF) on soil properties. Experimental design was a split‐plot randomized complete block with three replications. The whole plots were WCC and WF and the subplots were fertilization. Fertilization treatments included PBS and PL at 11.2 Mg ha –1 and 6.7 Mg ha –1 applied to corn and cotton, a one‐time single application at 37 Mg PBS ha –1 to corn in 2016, inorganic N fertilizer at the recommended rate, and an unfertilized control. Soil cores were collected after harvest and analyzed for nutrient concentrations, water stable aggregate (WSA), and enzyme activities. The WCC reduced bulk density (ρ b ) and penetration resistance (PR) and increased soil total C (TC), WSA, and infiltration rate, as compared with winter fallow (WF). Relative to inorganic N fertilizer, application of PBS decreased soil ρ b and PR by 3 and 20%, respectively, and increased soil TC, WSA, and infiltration by 19, 23, and 45%, respectively. A combination of PBS and WCC improved soil physical and chemical properties under southeast agroecosystems.

Water movement over and through soil is largely driven by topography and soil management across landscapes. This research tested the hypothesis that the water movement determines the potential for P and Ca redistribution and pH variance across landscapes. This hypothesis was evaluated by using digital elevation model-derived terrain attributes in fields after 55 yr of broiler litter applications on pastures in Smith County, Mississippi. Results show that soils receiving broiler litter had mean Mehlich-3 P levels of 1221.8 mg kg at 0- to 15-cm depth and 618.6 mg kg at 15- to 30-cm depth, and Ca with mean values of 768.3 and 645.0 mg kg at 0- to 15-cm and 15- to 30-cm soil depths, respectively. Across fields, soils in areas of predicted convergent flow contained higher P, Ca, and lower pH values in the upper 0 to 15 cm, suggesting contributions via surface overland flow from areas with higher elevation and lower slope gradient. On the other hand, soils in areas with lesser slope and higher elevation also contained high levels of P, Ca, and pH for the subsurface soil depth, suggesting that vertical flow of water on this landscape is a mechanism for movement of P and Ca deeper in the profile. The incorporation of topographic characteristics across fields offers promising results that may be incorporated into improved P indices and management, making them more robust indicators of P mobilization to waterways.

Effects of light sources, photoperiods, and genetic strains on blood physiological variables of broilers grown to heavy weights were investigated in 2 trials. The experimental design was a 4 × 2 × 2 factorial consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), neutral light emitting diode (Neutral‐LED), and cool poultry specific filtered LED (Cool‐PSF‐LED)], 2 photoperiods (Regular/intermittent [2L:2D], and Short [8L:16D], and 2 genetic strains (Ross × Ross 708, Cobb 700). In each trial, 480 (240 males/240 females) 1‐d‐old chicks of each strain from different commercial hatcheries were equally and randomly distributed into 16 environmental control rooms (30 males + 30 females/room) at 50% RH. Each room was randomly assigned one of 16 treatments from d 1 to 56 d of age. Birds were provided similar diets. Feed and water were provided ad libitum. Venous blood samples were collected on d 14, 28, 42, and d 56 of age and analyzed immediately. Cool‐PSF‐LED light sources had significant (P ≤ 0.05) effects on BW, Hb, Hct, electrolytes, angap, and mOsm in comparison with birds reared under ICD, but all these changes were still within the normal acid‐base homeostasis and physiological ranges. Also, the short photoperiod significantly (P ≤ 0.05) reduced BW, pH level, pO2, sO2, and Ca2+, with significantly (P ≤ 0.05) elevated pCO2, Hct, Hb, and McHc concentrations. Acid‐base regulation during short photoperiod exposure had not deteriorated despite higher pCO2 that consequently decreased blood pH due to a respiratory acidosis. In addition, Cobb 700 had significantly (P ≤ 0.05) increased BW, pCO2, Hct, Hb, Ca2+, Cl−, McHc, and angap along with significantly (P ≤ 0.05) reduced pH level, pO2, HCO3−, and glucose in comparison with Ross × Ross 708. Plasma corticosterone was not affected by light sources, photoperiod, genetic strain or their interaction, indicating that exposure of broiler chickens to the short photoperiod markedly affects some physiological blood variables without inducing stress in modern broilers grown to heavy weights. It was concluded that the 3 LED light bulbs evaluated may be suitable for replacement of ICD along with the regular/intermittent photoperiod for commercial poultry facilities to reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights.Support or Funding InformationNoneThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Core Ideas The Tarim Basin is a major source of windblown dust in Asia and China. No studies have previously documented wind erosion from cropland in Tarim Basin. Wind erosion was measured from an irrigated cotton field and red date orchard. Wind erosion from cropland is lower than from China's deserts. Management practices must be developed to control wind erosion in Tarim Basin. The Aksu region within the Tarim Basin is a major source of windblown dust in China due to the arid climate and vast areas under intensive irrigated crop production. Despite the importance of crop production to human subsistence and the local economy, little is known about the amount of soil eroded by wind from agricultural lands in the region. Passive aeolian sediment collectors were used to measure soil loss from an irrigated cotton ( Gossypium spp.) field and red date ( Ziziphus jujuba Mill.) orchard in the Aksu Oasis during high wind events in 2012 and 2013. Mass of sediment trapped by the collectors was best described as a power function of height above the surface in the cotton field and red date orchard. Soil loss from the cotton field ranged from 0 to 142 g m −2 , whereas soil loss from the red date orchard ranged from 0 to 71 g m −2 for single‐ or multiple‐day high wind events. Total soil loss from the cotton field and red date orchard, for the high wind events observed in this study, was 130 and 96 g m −2 , respectively, in 2012 and 305 and 165 g m −2 , respectively, in 2013. Soil loss was similar to that reported from agricultural lands in other regions of the world. Although soil loss is relatively small compared with the Gobi Desert in China, poor air quality in the Tarim Basin necessitates identifying crop and soil management practices for reducing windblown dust and conserving the soil resource.

Spaced‐plant arrangements provide a means of evaluating white clover (Trifolium repens L.) germplasm for a range of characteristics. Growth of spaced white clover plants in monoculture, however, may not be related to growth with grasses. Our objective was to determine the relationships among various growth parameters of white clover grown as spaced plants in monoculture and with contrasting grass swards. Vegetative clones of 47 plants of Southern Regional Virus Resistant white clover germplasm were planted on 1‐m centers in previously established common or hybrid (‘Tifton 44’) bermudagrass (Cynodon dactylon (L). Pers.) swards, in monoculture in a Catalpa silty clay soil (fine, montmorillonitic, thermic Fluvaquentic Hapludoll) in the fall of 1988. Growth of each clone was measured in the spring and fall of 1989, and in the spring of 1990 and 1991. At each sampling, clover dry matter (DM) yield, plant spread, and stolon branching were lower for clones grown with common bermudagrass than with hybrid bermudagrass or in monoculture. Growth of clones with hybrid bermudagrass was intermediate to growth with common bermudagrass and in monoculture, presumably because of the density of aboveground competition from hybrid compared to common bermudagrass (260 vs. 470 g DM m−l2; 5‐cm stubble). Correlations between clover yield and stolon branching, and clover yield and plant spread were greatest for clones grown with common bermudagrass (0.42 and 0.85, respectively). Stolon branching of clones in monoculture was not correlated with stolon branching in either bermudagrass. The influence of the grass on stolon branching and the relationship of branching to persistence suggest the necessity of evaluating white dover germplasm in association with grasses.