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The goal of this research work was to determine widespread impact kiln-produced hardwood biochar has upon temperate agricultural soil characteristics in a long-term field experiment. This dataset is supplementary to the submitted research by [1] and presents select physical and chemical characteristics of the biochar and field plots amended with hardwood biochar. Data on soil gravimetric moisture content (GMC), soil acidity and soil nitrate-N concentration at lower depth of soil under different biochar application rates is presented. Fourier Transform Infrared (FTIR) spectroscopy is provided to demonstrate the difference between fresh and aged biochar in terms of surface functional group content.

Dairy farmers in the northeast face challenges in the application of manure in fall and on-time planting of cool-season grasses to maximize recovery of residual N and nutrients released from fall applied manure. Ammonia emission from animal manure is a serious environmental concern and can be reduced if cover crop is integrated in the farming system. On-time planting of cover crops can reduce ammonia volatilization from fall, surface-applied manure, and prevents N loss to leaching. A two-year study was conducted in 2015 and 2016 to investigate if time of planting of winter annual rye (Secale cereale L.) along with late fall application of manure when air temperature is low can influence ammonia emission and preserve nitrogen (N) to meet the N requirement of forage rape. Three planting dates (16 September, 30 September, and 14 October) of rye cover crop with two manure application treatments including late-fall application and no manure were assessed for mitigating ammonia volatilization, and also yield and recovery of N by forage rape (Brassica napus L.). The highest rates of ammonia volatilization were detected in the first 24 hours after manure spreading regardless of the treatment. The result indicated that cover crop use significantly limited volatilization compared with no cover crop. The earliest planting date produced 3823 kg ha−1 dry matter of winter rye cover crop that was 16 and 35 percent higher than second and third dates of planting, respectively. The manured cover crop accumulated 132 kg N ha−1 when planted early. However, biomass yield of forage rape was more when planted after all cover crop treatments with manure application. Prior to forage planting, the nitrate-N content in all three soil depths (0–20, 20–40, and 40–60 cm) in the plots with manure was higher than plots with no manure. No significant differences in forage rape yield was detected among winter rye planting dates; however, forage rape planted after winter rye was higher than after no-cover crop. The results of this study suggest that when immediate incorporation of manure into soil is not feasible, establishing cover crop early and then applying manure in the late fall, is a practical management to limit nonpoint source pollution from ammonia loss.

Abstract  This study investigates the role of salicylic acid (SA), hydrogen peroxide (H2O2) and calcium chloride (CaCl2) singly or in combination, in inducing naked oat plant tolerance to sodium chloride (NaCl). Two-week-old naked oat plants were pretreated with both single and double of 0.5 mM SA, 0.5 mM H2O2 and 5 mM CaCl2 by adding them to the culture solution for 24 h. At the end of the pretreatment, the plants were subjected to 200 mM NaCl exposure for 7 days. Data were collected on plant biomass, H2O2 level, antioxidant enzyme activity, non-enzymatic antioxidant content and malondialdehyde (MDA) content. Results showed that exposure to salt significantly inhibited plant growth, and the shoot and root dry weights were reduced 47.5% and 63.4%, and the H2O2 levels elevated 5.8 and 2.4 times in comparison with those in the control, respectively. Under the saline stress, the activities of superoxide dismutase (SOD) and catalase (CAT) were induced, but the contents of ascorbic acid (AA) and glutathione (GSH) decreased, and MDA largely accumulated. The various pretreatments efficiently counteracted the salt-caused growth inhibition, especially with H2O2  CaCl2 the shoot and root dry weights reduced only 9.4% and 24.4% of the non salt-stressed plants. The determination of endogenous H2O2 level demonstrated that the pretreatments induced H2O2 accumulation, with H2O2  CaCl2 being most efficient, but the effect was transient. After 7 days of saline stress, the H2O2 contents in the pretreated shoots and roots accounted for 23.7–41.8% and 31.7–57.3% of the non-pretreated plants, varying according to the different pretreatments. Under saline stress, SOD and CAT further increased, AA and GSH maintained higher levels and MDA decreased in the pretreated plants compared to the untreated plants. With application of diphenylene iodonium (DPI) during the pretreatment, which inhibited the accumulation of H2O2, the ameliorative effect of the pretreatment on salt-caused plant growth inhibition was reduced. However, applied DPI at the immediate end of the pretreatment did not alter its favorable role, indicating a H2O2 peak formed at the early time of saline stress might play an important role in regulating plant tolerance to saline stress. [ABSTRACT FROM AUTHOR]

The photosynthetic and photoacoustic properties of leaf samples were studied using a photoacoustic system modified for precise temperature control. Data were collected over a temperature range of −10 °C to +60 °C. A distinct acoustic noise transient marked the freezing temperature of the samples. A positive absorption transient and a brief period of oxygen uptake marked the thermal denaturing temperature of the samples. Between these extremes, the effects of temperature on light absorption, oxygen evolution, and photochemical energy storage were quantified quickly and easily. Oxygen evolution could be measured as low as −5 °C and showed a broad temperature peak that was 10 °C lower under limiting light intensity than under saturating light intensity. Photochemical energy storage showed a narrower temperature peak that was only slightly lower for limiting light intensities than for saturating light intensities. In a survey of diverse plants, temperature response curves for oxygen evolution were determined readily for a variety of leaf types, including ferns and conifer needles. These results demonstrate that temperature-controlled photoacoustics can be useful for rapid assessment of temperature effects on photosynthesis and other leaf properties. [ABSTRACT FROM AUTHOR]