► Biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO4. ► Crop failures lead to excessive nitrate–N accumulation. ► Biosolids application in a no-till managed ...dryland agroecosystem is an efficacious method of recycling this nutrient source.
Dryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial N fertilizer in dryland no-till wheat (Triticum aestivum, L.)–fallow (WF) and wheat–corn (Zea mays, L.)–fallow (WCF) rotations at a site approximately 40km east of Byers, CO. We tested if biosolids would produce the same yields and grain P, Zn, and Ba concentrations as an equivalent rate of N fertilizer, that biosolids-borne P, Zn, and Ba would not migrate below the 10cm soil depth, and that biosolids application would result in the same quantity of residual NO3–N as the equivalent N fertilizer rate. Biosolids and N fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO4. Biosolids application produced greater NO3–N concentrations than N fertilizer in the 30–60 and 60–90cm depths for the WF rotation and all but the 5–10 and 120–150cm depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source.
Endowment of fertile Gangetic alluvial soil and abundant water resources, particularly groundwater resources altogether constitute core components for development of agriculture in Bihar. Efforts ...have been made in this paper to analyze factors responsible for changes in land use pattern, especially increase in current fallows, shrinking net sown area and shifting of land for non-agricultural purposes in the state. A larger concentration of current fallow lands was accounted for in Gaya, Patna, Purnea, Munger, Jehanabad and Kishanganj districts. The rainfall and road length have significant impact on the level of current fallows. Erratic monsoon and labour scarcity during the study period of present century resulted in accumulation of current fallow lands. It was further observed that the non-agricultural use of land was identified as the dominant factor for changes in common lands as it affected the current fallows negatively. It is a challenging task for policy makers to maximize the income of farmers from a continuously declining in net sown area, deteriorating climatic conditions as well as labour scarce conditions, thereby resulting in aggregation of current fallows. In order to boost the production and enhance farmer’s income, it is necessary to discourage the rising tendency in current fallows or to bring current fallows under cultivation.
An individual's future behaviour and fitness are strongly influenced by early life experience. Within the suite of factors that underpin juvenile development, sleep plays a particularly important ...role, fulfilling vital physiological and cognitive functions. Sleep ontogeny is the process by which sleep time becomes shorter and more consolidated into fewer bouts from in utero development to adulthood; however, how sleep quantity, fragmentation and quality develop in neonates in the wild is unknown. We investigated this question in 19 free-ranging fallow deer fawns, Dama dama, during the first 5 weeks of life. Specifically, we examined how sleep developed, how it differed between and within individuals, and how it was affected by environmental conditions, using accelerometer-derived estimates of sleep and a Bayesian hierarchical modelling approach. We showed that sleep duration rapidly decreased and became more consolidated, quickly approaching an adult-like condition. Moreover, fawns exhibited consistent individual differences in sleep quantity, fragmentation and quality, as well as in the rate at which sleep developed. Finally, environmental conditions affecting thermoregulation mediated sleep behaviour; sleep time was reduced and was of lower quality on warmer days, and sleep quality was further compromised in more humid conditions but was higher with greater rainfall. While sleep ontogeny in free-ranging fawns is partially shaped by the environment, our study reveals previously unknown individual differences in sleep behaviour present from birth, and in the rate of sleep development. We suggest that such individual differences may represent pace-of-life syndromes and may have important consequences for individual fitness later in life.
•Fallow deer fawns’ sleep rapidly decreases and consolidates in their first 5 weeks.•Fawns differ in sleep patterns and the rate of development from birth.•High temperature and humidity impair fawns’ sleep.•Individual differences in sleep ontogeny may be related to pace-of-life syndromes.•Minimally invasive biologging is a viable approach to studying sleep in the wild.
Agriculture has increased the release of reactive nitrogen to the environment due to crops' low nitrogen-use efficiency (NUE) after the application of nitrogen-fertilisers. Practices like the use of ...stabilized-fertilisers with nitrification inhibitors such as DMPP (3,4-dimethylpyrazole phosphate) have been adopted to reduce nitrogen losses. Otherwise, cover crops can be used in crop-rotation-strategies to reduce soil nitrogen pollution and benefit the following culture. Sorghum (Sorghum bicolor) could be a good candidate as it is drought tolerant and its culture can reduce nitrogen losses derived from nitrification because it exudates biological nitrification inhibitors (BNIs). This work aimed to evaluate the effect of fallow-wheat and sorghum cover crop-wheat rotations on N2O emissions and the grain yield of winter wheat crop. In addition, the suitability of DMPP addition was also analyzed. The use of sorghum as a cover crop might not be a suitable option to mitigate nitrogen losses in the subsequent crop. Although sorghum–wheat rotation was able to reduce 22% the abundance of amoA, it presented an increment of 77% in cumulative N2O emissions compared to fallow–wheat rotation, which was probably related to a greater abundance of heterotrophic-denitrification genes. On the other hand, the application of DMPP avoided the growth of ammonia-oxidizing bacteria and maintained the N2O emissions at the levels of unfertilized-soils in both rotations. As a conclusion, the use of DMPP would be recommendable regardless of the rotation since it maintains NH4+ in the soil for longer and mitigates the impact of the crop residues on nitrogen soil dynamics.
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Identify splatter/aerosol distribution from dental procedures in an open plan clinic and explore aerosol settling time after dental procedures.
In two experimental designs using simulated dental ...procedures on a mannequin, fluorescein dye was introduced: (1) into the irrigation system of an air-turbine handpiece; (2) into the mannequin's mouth. Filter papers were placed in an open plan clinic to collect fluorescein. An 8-metre diameter rig was used to investigate aerosol settling time. Analysis was by fluorescence photography and spectrofluorometry.
Contamination distribution varied across the clinic depending on conditions. Unmitigated procedures have the potential to deposit contamination at large distances. Medium volume dental suction (159 L/min air) reduced contamination in the procedural bay by 53%, and in other areas by 81-83%. Low volume suction (40 L/min air) was similar. Cross-ventilation reduced contamination in adjacent and distant areas by 80-89%. In the most realistic model (fluorescein in mouth, medium volume suction), samples in distant bays (≥5 m head-to-head chair distance) gave very low or zero readings (< 0.0016% of the fluorescein used during the procedure). Almost all (99.99%) of the splatter detected was retained within the procedural bay/walkway. After 10 min, very little additional aerosol settled.
Cross-infection risk from dental procedures in an open plan clinic appears small when bays are ≥ 5 m apart. Dilution effects from instrument water spray were observed, and dental suction is of benefit. Most settled aerosol is detected within 10 min indicating environmental cleaning may be appropriate after this. Clinical Significance: Aerosols produced by dental procedures have the potential to contaminate distant sites and the majority of settled aerosol is detectable after 10 min. Dental suction and ventilation have a substantial beneficial effect. Contamination is likely to be minimal in open plan clinics at distances of 5 m or more.
Several studies have demonstrated the effects of slash-and-burn agriculture on soil chemical properties immediately or short-term after burning. This study aims to answer if: a) the slash-and-burn ...system affects soil chemical properties; b) management effects remain in a fallow chronosequence; and if c) these effects are restricted to the soil surface. The study was developed in the south-eastern region of the state of Paraná, located in southern Brazil. On-site, the land preparation was made through procedures comprising of fire, cropping, and fallow. The methodology was based on the chronosequence approach by different fallow periods: native forest, 30 days after burning, 2-year fallow, 5-year fallow, 7-year fallow, and 12-year fallow. The soil samples were collected at 0–5 and 5–10 cm depths for chemical analysis (pH, organic matter, ions availability (extractable phosphorus, potassium, calcium, magnesium and aluminum) and cation exchange capacity). The results indicate significant changes at 0–5 cm depth. The soil organic matter levels remained constant throughout the chronosequence. The direct effects of burning led to increased pH and nutrient availability (extractable phosphorus and calcium), which decreased within 2 to 5 years of fallow. The increase in basic cations was sufficient to guarantee the soil nutrient status up to 7 years of fallow. Successive slash-and-burn cycles in the same area caused an increase in soil sand content, and reduced cation exchange capacity.
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•A long-term slash-and-burn agriculture system was evaluated.•The direct effects of fire led to increased pH and availability of P− and Ca2+.•The effects of fire and fallow length did not result in changes to SOM contents.•The increase in basic cations keeps the soil eutrophic for up to 7 years of fallow.•Successive slash-and-burn cycles reduce soil CEC in the long-term.
Take MacGroup-Detroit (http://macgroup.org), the largest of several user groups in the state dedicated to the Apple Macintosh computer and its peripherals. With nearly 400 members, it has so many ...events and training sessions that it offers its members a downloadable calendar that automatically synchronizes activities with their appointment books every day. General meetings are held every third Sunday at 3 p.m. in the Bloomfield Township Public Library, 1099 Lone Pine Road, Bloomfield Hills. The next one is Dec. 21. Membership is $40 a year. SEMCO is one of the oldest computer clubs in the nation (its first meeting was in 1976), and has about 90 regular members. Membership is $30 a year. It publishes the Data Bus, a monthly newsletter filled with software reviews, computer news and tips on how to fix problems.
Crop production systems in the water-limited environment of the semiarid central Great Plains may not have potential to profitably use cover crops because of lowered subsequent wheat (Triticum ...asestivum L.) yields following the cover crop. Mixtures have reportedly shown less yield-reducing effects on subsequent crops than single-species plantings. This study was conducted to determine winter wheat yields following both mixtures and single-species plantings of spring-planted cover crops. The study was conducted at Akron, CO, and Sidney, NE, during the 2012–2013 and 2013–2014 wheat growing seasons under both rainfed and irrigated conditions. Precipitation storage efficiency before wheat planting, wheat water use, biomass, and yield were measured and water use efficiency and harvest index were calculated for wheat following four single-species cover crops (flax Linum usitatissimum L., oat Avena sativa L., pea Pisum sativum ssp. arvense L. Poir, rapeseed Brassica napus L.), a 10-species mixture, and a fallow treatment with proso millet (Panicum miliaceum L.) residue. There was an average 10% reduction in wheat yield following a cover crop compared with following fallow, regardless of whether the cover crop was grown in a mixture or in a single-species planting. Yield reductions were greater under drier conditions. The slope of the wheat water use–yield relationship was not significantly different for wheat following the mixture (11.80 kg ha–1 mm–1) than for wheat following single-species plantings (12.32–13.57 kg ha–1 mm–1). The greater expense associated with a cover crop mixture compared with a single species is not justified.
Conservation systems, such as no-tillage, follow as principles the absence of soil tillage, formation and maintenance of vegetation cover, and crop rotation. Nevertheless, when one principle is not ...adequately adopted there may be alterations in soil aggregation and porosity. Thus, this study aimed to evaluate physical attributes and organic carbon of the soil in an area with tillage and fallow in the off-season and in areas without soil tillage, with fallow and with crop in the off-season. The soil of the three areas was characterized as an Oxisol with clayey texture. For more than 10 years, corn has been the main crop grown in the season period in the three areas: conventional soil tillage system with fallow in the off-season (CTS), no-tillage system with fallow in the off-season (NTS-f), and no-tillage system with grass-grass succession (NTS-g). Each area was sampled at 20 random points and soil samples were collected from the layers, 0–0.1 m, 0.1–0.2 m and 0.2–0.3 m. The data were subjected to multivariate factor analysis, where two factors were identified, called “soil aggregation” and “soil porosity”. Through the “soil aggregation” process, it was found that clay is essential for the formation of aggregates with diameter of up to 2.0 mm, while soil organic carbon influences the formation of macroaggregates. The “soil aggregation” was higher in the area under NTS-g, and lower in the areas under NTS-f and CTS. The practice of fallow in the off-season in a no-tillage system proved to be harmful to soil structuring, especially in relation to soil aggregation. In the area under CTS there was greater "soil porosity" in the 0–0.1 m layer, but this effect is temporary, due to the large amount of microaggregates generated in this system, which over time obstructs soil pores and causes lower porosity than that determined under the no-tillage system.
•Cultivation in the off-season is crucial for the structuring of the soil in a no-tillage system.•Off-season fallow in no-tillage systems is as harmful to soil aggregation as in the conventional tillage system.•In clayey soil, the clay is essential for the formation of aggregates with diameter less than 2.0 mm.•The soil porosity is higher in the conventional tillage system due to soil tillage operations.
With the move towards conservation agriculture, we have seen an increase in weeds such as Salsola kali L., well known as Russian thistle, which are wind spread over fallow land. The emergence of this ...weed species seemed erratic, perhaps connected to climate conditions and management techniques. In order to shed some light on this issue, we carried out a field experiment over 3 years to monitor Russian thistle density in fallow plots, comparing three tillage systems. This study provides an insight about the limitations of assuming no‐tillage techniques within a cropping system that include fallow in the rotation sequence. Our results show that no‐tillage systems are more vulnerable to S. kali. Low spring rain leads to high S. kali density, especially in no‐tillage plots. High spring rainfall reduced the emergence in all tillage systems because of soil water saturation. Minimum tillage technique served to maintain control over this species even in weather conditions that favoured its emergence in other systems. In order to reduce the need for herbicide in fallow lands under conservation systems, we recommend the implementation of minimum tillage to combat Russian thistle infestation.
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