Effect of Holding Temperature on the Structures of Mung Bean Starch Gels and Noodles

The effect of storage temperatures (‐10, +1, and +10°C) on the structural organization of mung bean starch gels and noodles was studied by acid hydrolysis, X‐ray diffractometry, and gel‐permeation chromatography. The gels showed higher susceptibility to acid compared with the noodles as shown by the rate constants of the first stage of hydrolysis (k = 5.37–12.17 × 10^‐2/day and k = 4.19–4.61 × 10^‐2/day for gels and noodles, respectively). Acid hydrolysis showed no difference in the amount of resistant residues of both gels (42–46%) and noodles (44–45%), except for gels (38%) stored at ‐10°C. The acid‐resistant residues of both the gels and noodles had a B‐type X‐ray diffraction pattern (major reflections at 2θ = 19, 24, and 25°). The acid‐resistant residues of the unstored sample and those stored at ‐10°C for both gels and noodles contained chains with DP 46–54 and after debranching yielded two peaks with DP 29–39 and DP 15–19. The acid‐resistant residues of gels and noodles stored at +1 and +10°C contained chains with DP 35–37 and after debranching showed two chain populations with DP 31–33 and DP 14–19. These results indicate the greater participation of amylopectin in the retrogradation process occurring during storage at +1 and +10°C.     

Modeling of the fine‐scale temperature response of arylsulfatase activity in soil

Fine‐scale (1.0–2.2 °C) temperature dependence of soil arylsulfatase activity (arylsulfate sulfohydrolase, EC 3.1.6.1) was measured at 0 to 75 °C in a Danish sandy, arable soil. Assays were done with field‐moist soil samples in the absence of toluene as plasmolytic agent – a procedure that primarily measures the extracellular enzymes. The aim was to evaluate the use of temperature models to describe the temperature response of soil arylsulfatase activity. In addition, we searched for increases in activity at high temperatures (e.g., 50–60 °C), which might be associated with unmasking (exposure) of intracellular enzymes. Arylsulfatase activities ranged from 1.1 to 60.3 μg p‐nitrophenol (g dry weight soil)^–1 h^–1, with an optimum temperature at 58.1 °C. The temperature response below 58.1 °C could be described by the Arrhenius equation (r² = 0.978, n = 83) and the simple Ratkowsky equation (r² = 0.977, n = 83). The expanded Ratkowsky equation, which covered the entire temperature range (0–75 °C), was less satisfactory (r² = 0.958, n = 90) because the model underestimated the reaction rates near the optimum temperature. The activation energy (E_a) calculated from the Arrhenius equation was 42.2 kJ mol^–1. This was higher than previously found for other soils (16.5–34.7 kJ mol^–1), possibly due to the use of toluene in these studies. Further analysis of the temperature response showed that no increase in activity occurred due to potential unmasking of intracellular enzymes by disintegration of bacterial cell membranes at high temperatures. Thus, the use of high incubation temperatures did not facilitate the differentiation between intra‐ and extracellular enzyme activity.     

Landfill Methane Oxidation in Engineered Soil Columns at Low Temperature

Though engineered covers have been suggested for reducing landfill methane emissions via microbial methane oxidation, little is known about the covers' function at low temperature. This study aimed to determine the methane consumption rates of engineered soil columns at low temperature (4–12°C) and to identify soil characteristics that may enhance methane oxidation in the field. Engineered soils (30 cm thick) were mixtures of sewage sludge compost and de-inking waste, amended with sand (SDS soil) or bark chips (SDB soil). At 4–6°C, we achieved rates of 0.09 gCH₄ kgTS^?1d^?1 (0.02 m³ m^?2d^?1) and 0.06 gCH₄ kgTS^?1d^?1 (0.009 m³ m^?2d^?1) with SDS and SDB soils, respectively. With SDS, good movement and exchange of oxygen in porous soil moderated the slowdown of microbial activity so that the rate dropped only by half as temperature declined from 21–23°C to 4–6°C. In SDB, wet bark chips reduced the soil's air-filled porosity and intensified non-methanotrophic microbial activity, thus reducing the methane consumption rate at 4–6°C to one fourth of that at 21–23°C. In conclusion, soil characteristics such as air-filled porosity, water holding capacity, quantity and stabilization of organic amendments that affect the movement and exchange of oxygen are important variables in designing engineered covers for high methane oxidation at low temperature.     

Soil temperature,growth and yield of maize (Zea mays L.) as affected by wheat straw mulch

Maize crop is grown mostly in tropical/subtropical environments where drought adversely affects its production. A field experiment was conducted on sandy loam soil for four years (1999 – 2002) to study the effect of wheat straw mulch (0 and 6 t ha^?1) and planting methods (flat and channel) on maize sown on different dates. Maximum soil temperature without mulch ranged from 32.2 – 44.4°C in channel and 31.6 – 46.4°C in flat planting method. Mulching, however, lowered soil temperature by 0.8 – 7.0°C in channel and 0 – 9.8°C in flat planting. Mulching, on an average, improved leaf area index by 0.42, plant height by 14 cm, grain yield by 0.24 t ha^?1 and biomass by 1.57 t ha^?1, respectively. Mulching improved grain yield only in flat sowing. Interaction between sowing date and planting method was significant. Seasonal variation in biomass were significantly correlated (p = 0.05) with mean air temperature during 0 – 45 days after planting (DAP) (r = ?0.95), pan evaporation during 0 – 15 DAP (r = 0.79) and negative correlation with rainfall in entire cropping season (r = ?0.89), whereas biomass increase with mulch in different cropping seasons had negative relation (r = ?0.74) with amount of rain during 0 – 15 DAP.     

Removal of Copper,Lead, Methylene Green 5, and Acid Red 1 by Saccharide-Derived Spherical Biochar Prepared at Low Calcination Temperatures: Adsorption Kinetics,Isotherms, and Thermodynamics

Spherical biochar derived from saccharides (glucose, sucrose, and xylose) was prepared through two steps: pre-hydrothermal carbonization at 190 °C and calcination at low temperatures (200–325 °C). The spherical biochar was characterized by Brunauer–Emmett–Teller (BET) surface area analysis, Fourier transform infrared spectroscopy, zeta potential, scanning and transmission electron microscopies, and X-ray diffraction. The result indicated that the spherical biochar exhibited low S _BET (15–22 m²/g), but abundant superficial active oxygen-containing functional groups. The spherical biochar possessed a negatively charged surface within solution pH 2.0–11. The adsorption process of Pb²⁺, Cu²⁺, and methylene green 5 (MG5) was strongly dependent on the solution pH and reached fast equilibrium at approximately 60 min. The maximum Langmuir adsorption capacity (Q°_max) exhibited the following order: glucose-biochar > sucrose-biochar > xylose-biochar prepared at 300 °C. The selective adsorption order of glucose-biochar was Cu²⁺ (0.894 mmol/g) > Pb²⁺ (0.848 mmol/g) > MG5 (0.334 mmol/g). The electrostatic attraction played a determining role in the adsorption mechanism of pollutant cations. The adsorption of anionic dye (acid red 1) on the spherical biochar was negligible because of electrostatic repulsion. The spherical biochar can serve as a newer and promising adsorbent to remove toxic pollutant cations from water media.     

Driving factors of temporal variation in agricultural soil respiration

Investigations of diurnal and seasonal variations in soil respiration support modeling of regional CO₂ budgets and therefore in estimating their potential contribution to greenhouse gases. This study quantifies temporal changes in soil respiration and their driving factors in grassland and arable soils located in Northern Germany. Field measurements at an arable site showed diurnal mean soil respiration rates between 67 and 99 mg CO₂ m^–2 h^–1 with a hysteresis effect following changes in mean soil temperatures. Field soil respiration peaked in April at 5767 mg CO₂ m^–2 day^–1, while values below 300 mg CO₂ m^–2 day^–1 were measured in wintertime. Laboratory incubations were carried out in dark open flow chambers at temperatures from 5°C to 40°C, with 5°C intervals, and soil moisture was controlled at 30%, 50%, and 70% of full water holding capacity. Respiration rates were higher in grassland soils than in arable soils when the incubating temperature exceeded 15°C. The respiration rate difference between them rose with increasing temperature. Monthly median values of incubated soil respiration rates ranged from 0 to 26.12 and 0 to 7.84 µg CO₂ g^–1 dry weight h^–1, respectively, in grassland and arable land. A shortage of available substrate leads to a temporal decline in soil respiration rates, as indicated by a decrease in dissolved organic carbon. Temporal Q₁₀ values decreased from about 4.0 to below 1.5 as temperatures increased in the field. Moreover, the results of our laboratory experiments confirmed that soil temperature is the main controlling factor for the Q₁₀ values. Within the temperature interval between 20°C and 30°C, Q₁₀ values were around 2 while the Q₁₀ values of arable soils were slightly lower compared to that of grassland soils. Thus, laboratory studies may underestimate temperature sensitivity of soil respiration, awareness for transforming laboratory data to field conditions must therefore be taken into account.     

Evaluation of alternate menthol mint (Mentha arvensis L.) based intensive cropping systems for Indo-Gangetic plains of north India

The objective of the study was to determine the profitability and employment-generation potential of different cropping systems involving menthol mint (Mentha arvensis L.) as a component of sequential/intercropping in comparison with the most common paddy–wheat–green gram cropping system. Field experiments were conducted at Lucknow, India (26° 5′ N, 80° 5′ E and 120 m above mean sea level) for three years from July 2004 to June 2007. Menthol mint yielded the maximum fresh shoot biomass and essential oil (21.0 t and 151 kg ha^?1, respectively) grown after sweet basil (Ocimum basillicum)–potato followed by paddy–potato–menthol mint (18.9 t and 136 kg ha^?1, respectively) and maize–mustard–menthol mint (17.7 t and 131 kg ha^?1, respectively). Net returns of all the menthol-mint-based cropping systems were 82.6–354% higher than traditional paddy–wheat–green gram cropping system. Maize–garlic–menthol mint + okra was found to be most profitable (77,200 Rs ha^?1) followed by pigeon pea + sweet basil–menthol mint + okra (76,120 Rs ha^?1). Employment-generation efficiency was much higher in cropping systems involving menthol mint and vegetable crops, the highest (2.21 man days ha^?1 day^?1) being in a maize–cauliflower–onion–menthol mint + okra cropping system.     

Study of different climatic conditions to assess the role of solar radiation in reference crop evapotranspiration equations

This study aims to assess radiation-based models versus the FAO Penman–Monteith (FPM) model to determine the best model using linear regression under different weather conditions. The reference evapotranspiration was estimated using 22 radiation-based methods and was compared with the FPM. The results showed that the Stephens method estimates the reference evapotranspiration better than other methods in the most provinces of Iran (nine provinces). However, the values of R² were more than 0.9930 for 24 provinces of Iran. The radiation-based methods estimated the reference evapotranspiration near the Caspian Sea better than other regions. The most precise methods were the Berengena–Gavilan, Modified Priestley–Taylor, and Priestley–Taylor methods for the provinces ES (center of Iran), GI and GO (north of Iran) and the Stephens–Stewart method for IL (west of Iran). Finally, a list of the best performance of each method has been presented to use other regions and next research steps according to the values of mean, maximum, and minimum temperature, relative humidity, solar radiation, elevation, sunshine, and wind speed. The best weather conditions to use radiation-based equations are 23.6–24.6 MJ m^?2 day^?1, 12–20°C, 18–24°C, 5–13°C, and <180 hour month^?1 for solar radiation, mean, maximum, and minimum temperature, and sunshine, respectively.     

Effect of salinity and soil temperature on the growth and physiology of drip-irrigated rice seedlings

Drip irrigation offers potential for rice (Oryza sativa L.) production in regions where water resources are limited. However, farmers in China’s Xinjiang Province report that drip-irrigated rice seedlings sometimes suffer salt damage. The objective of this study was to learn more about the effects of soil salinity and soil temperature on the growth of drip-irrigated rice seedlings. The study consisted of a two-factor design with two soil salinity treatments (0 and 1.8 g kg^?1 NaCl) and three soil temperature treatments (18°C, 28°C and 36°C). The results showed that shoot biomass, root biomass and root vigor were greatest when seedlings were grown with no salt stress (0 g kg^?1 NaCl) at 28°C. Moderate salt stress (1.8 g kg^?1 NaCl) combined with high temperature (36°C) significantly reduced root and shoot biomass by 39–53%. Moderate salt stress and high temperature also increased root proline concentration by 77%, root malonyldialdehyde concentration by 60% and seedling mortality by 60%. Shoot and root Na⁺ concentrations, shoot and root Na⁺ uptake and the Na⁺ distribution ratio in shoots were all the greatest when moderate salt stress was combined with high temperature. In conclusion, high soil temperature aggravates salt damage to drip-irrigated rice seedlings. Therefore, soil salinity should be considered before adopting drip-irrigation for rice production.     

Interactive effects of ammonium application rates and temperature on nitrous oxide emission from tropical agricultural soil

Emissions of nitrous oxide (N₂O), a potent greenhouse gas, from agricultural soil have been recognized to be affected by nitrogen (N) application and temperature. Most of the previous studies were carried out to determine effects of temperature on N₂O emissions at a fixed N application rate or those of N application rates at a specific temperature. Knowledge about the effects of different ammonium (NH₄⁺) application rates and temperatures on N₂O emissions from tropical agricultural soil and their interactions is limited. Five grams of air-dried sandy loam soil, collected in Central Vietnam, were adjusted to 0, 400, 800 and 1200 mg NH₄-N kg^–1 soil (abbreviated as 0 N, 400 N, 800 N and 1200 N, respectively) at 60% water holding capacity were aerobically incubated at 20°C, 25°C, 30°C or 35°C for 28 days. Mineral N contents and N₂O emission rates were determined on days 1, 3, 5, 7, 14, 21 and 28. Cumulative N₂O emissions for 28 days increased with increasing NH₄⁺ application rates from 0 to 800 mg N kg^–1 and then declined to 1200 mg N kg^–1. Cumulative N₂O emissions increased in the order of 35°C, 20°C, 30°C and 25°C. This lowest emission at 35°C occurred because N₂O production was derived only from autotrophic nitrification while other N₂O production processes, e.g., nitrifier denitrification and coupled nitrification-denitrification occurred at lower temperatures. More specifically, cumulative N₂O emissions peaked at 800 N and 25°C, and the lowest emissions occurred at 1200 N and 35°C. In conclusion, N₂O emissions were not exponentially correlated with NH₄⁺ application rates or temperatures. Higher NH₄⁺ application rates at higher temperatures suppressed N₂O emissions.     

Factors influencing the loss of organic carbon from wheat roots

Wheat plants were grown in an atmosphere containing ¹⁴CO₂ at temperatures of 10°C or 18°C for periods from 3–8 weeks. The plant roots were maintained under sterile or non-sterile conditions in soil contained in sealed pots which were flushed to displace respired ¹⁴CO₂. The ¹⁴C content of the shoots, roots and soil was measured at harvest. The loss of ¹⁴C from the roots, expressed either in terms of total ¹⁴C recovered from the pots or ¹⁴C translocated to the roots, ranged from 14.3–22.6%, mean 17.3% or 29.2–44.4%, mean 39.2%, respectively. The presence of soil microorganisms significantly increased ¹⁴CO₂ release from the rhizosphere but had no effect on the ¹⁴C content of the soil. Fractionation of 6 m HC1 hydrolysates from sterile and non-sterile soils showed the presence in all soils of material behaving as neutral sugars and amino acids, in quantities representing 5.9–9.2% and 13.4–17.2% of the soil ¹⁴C content for the sugar and amino acid fractions respectively. It is proposed that a major loss of root carbon resulted from autolysis of the root cortex. Root lysis was increased by soil microorganisms, apparently without penetration of the plant cell walls.     

Effects of warming, wetting and nitrogen addition on substrate-induced respiration and temperature sensitivity of heterotrophic respiration in a temperate forest soil

Soil heterotrophic respiration and its temperature sensitivity are affected by various climatic and environmental factors.However,little is known about the combined effects of concurrent climatic and environmental changes,such as climatic warming,changing precipitation regimes,and increasing nitrogen(N)deposition.Therefore,in this study,we investigated the individual and combined effects of warming,wetting,and N addition on soil heterotrophic respiration and temperature sensitivity.We incubated soils collected from a temperate forest in South Korea for 60 d at two temperature levels(15 and 20℃,representing the annual mean temperature of the study site and 5℃warming,respectively),three moisture levels(10%,28%,and 50%water-filled pore space(WFPS),representing dry,moist,and wet conditions,respectively),and two N levels(without N and with N addition equivalent to 50 kg N ha^-1year^-1).On day 30,soils were distributed across five different temperatures(10,15,20,25,and 30℃)for 24 h to determine short-term changes in temperature sensitivity(Q₁₀,change in respiration with 10℃increase in temperature)of soil heterotrophic respiration.After completing the incubation on day 60,we measured substrate-induced respiration(SIR)by adding six labile substrates to the three types of treatments.Wetting treatment(increase from 28%to 50%WFPS)reduced SIR by 40.8%(3.77 to 2.23μg CO₂-C g^-1h^-1),but warming(increase from 15 to 20℃)and N addition increased SIR by 47.7%(3.77 to 5.57μg CO₂-C g^-1h^-1)and 42.0%(3.77 to 5.35μg CO₂-C g^-1h^-1),respectively.A combination of any two treatments did not affect SIR,but the combination of three treatments reduced SIR by 42.4%(3.70 to 2.20μg CO₂-C g^-1h^-1).Wetting treatment increased Q₁₀by 25.0%(2.4 to 3.0).However,warming and N addition reduced Q₁₀by 37.5%(2.4 to 1.5)and 16.7%(2.4 to 2.0),respectively.Warming coupled with wetting did not significantly change Q₁₀,while warming coupled with N addition reduced Q₁₀by 33.3%(2.4 to 1.6).The combination of three treatments increased Q₁₀by 12.5%(2.4 to 2.7).Our results demonstrated that among the three factors,soil moisture is the most important one controlling SIR and Q₁₀.The results suggest that the effect of warming on SIR and Q₁₀can be modified significantly by rainfall variability and elevated N availability.Therefore,this study emphasizes that concurrent climatic and environmental changes,such as increasing rainfall variability and N deposition,should be considered when predicting changes induced by warming in soil respiration and its temperature sensitivity.     

Risk assessment for volunteer and seedling GM potatoes in the northernmost European growing areas

Abstract

Commercial production of genetically modified (GM) potatoes (Solanum tuberosum L.) could represent a risk to conventional production if volunteer plants develop from tubers or true seeds that survive until the following growing season. We studied such risks under northernmost European conditions and monitored the effects of cultivar, tuber size and tuber depth in the soil on winter survival at MTT Agrifood Research Finland, Jokioinen (61°06′N, 23°02′E) from 2004–2007. Tubers of two non-GM cultivars, Saturna and Asterix, and two size classes, 25–30 mm and 45–50 mm, were planted at depths of 10 and 20 cm in autumn, soon after harvest. In winters 2004–2005 and 2005–2006 all tubers planted in the soil in autumn were killed by frost. In 2005–2006, the field was covered by up to 30–40 cm of snow and the minimum soil temperatures ranged between ?0.4^oC and ?0.9^oC, but only 0.0–3.5% of the tubers survived and there was no difference between cultivars, tuber sizes and planting depths. Under laboratory conditions compared with ?2.0°C and ?2.5°C, treatment at ?3.0°C for 72 h resulted in significantly lower survival rate of the tubers (8.2%). Asterix, a late maturing table potato cultivar, was more resistant to low temperatures than the processing cultivar Saturna. In general, volunteer tubers are not currently a significant risk for coexistence of GM and conventional potato production in northern Europe due to the cold winter conditions but also due to possibilities to control the sporadic volunteers from the next crop. However, we noted that seedlings initiated from true potato seed are able to produce tubers despite the short growing season. Such a risk could be reduced by accepting only non-berry-producing GM cultivars for cultivation.     

Sensitivity of Tundra Carbon Balance to Ambient Temperature

Summer field observations in thenorth-east European region of Russia (1995–1996) proved thatnatural local and temporal warming could cause similarreversible changes of carbon (C) balance pattern ofsouth tundra ecosystems. Thirty-six diurnal chambermeasurements of carbon dioxide fluxes at two differentsites (67°57′N, 64°40′E; 67°20′N,63°44′E) in 4 main types of ecosystems werestudied. Wide magnitude of ambient mean diurnal airtemperature (from +4.1 to +20.2 °C) allowed toobtain significant linear relationship between thisparameter and variation in ecosystems C net flux (from–2.6 (sink) to +2.0 (source) gC m^-2 d^-1, R² = 0.769). In the midst ofthe vegetative season, an increase of mean diurnal airtemperature in the plant canopy over the criticalvalue of +14 °C lead to a change in the C netflux from sink to source. This can revert with atemperature decreases below the critical value. Theabove-mentioned effect is mostly due to thetemperature influenced increase of gross ecosystemrespiration. The summer temperature induced changesmay result in positive (C source) annual C balance insome studied ecosystems. The annual C loss ofshrub-dwarf shrub community in 1996 was estimated at45 gC m^-2 yr^-1. We consider ourresults to be another evidence of possible positivefeed-back between climate warming and C emission tothe atmosphere on short-term and regional scales.     

The otter Lutra lutra in Albania

During a survey in Albania we found signs of otters at 17 (54·8%) of the 31 stations investigated. Otters were widespread in much of the country, and healthy populations were localised in rivers and marshes in the north-west and in the south. Average sprainting activity was 1·7 positive sites per 200 m and 3–6 spraints per 200 m. Frogs, probably Rana ridibunda, as well as fish, appeared to be important prey for otters. In the coastal plains, several rivers were grossly polluted and the growing agricultural and industrial development may endanger the survival of otters.     

Biosorption of Methylene Blue from Aqueous Solutions by Hazelnut Shells: Equilibrium, Parameters and Isotherms

This paper presents a study on the batch adsorption of a basic dye, methylene blue (MB), from aqueous solution onto ground hazelnut shell in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. A contact time of 24 h was required to reach equilibrium. Batch adsorption studies were carried out by varying initial dye concentration, initial pH value (3–9), ionic strength (0.0–0.1 mol L^?1), particle size (0–200 μm) and temperature (25–55°C). The extent of the MB removal increased with increasing in the solution pH, ionic strength and temperature but decreased with increase in the particle size. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by Langmuir isotherm equation. The maximum adsorption capacities for MB were 2.14?×?10^?4, 2.17?×?10^?4, 2.20?×?10^?4 and 2.31?×?10^?4 mol g^?1 at temperature of 25, 35, 45 and 55°C, respectively. Adsorption heat revealed that the adsorption of MB is endothermic in nature. The results indicated that the MB strongly interacts with the hazelnut shell powder.     

Sustainable productivity and profitability of diversified rice-based cropping systems in an irrigated ecosystem

An experiment was conducted at ICAR Research Complex for Eastern Region, Research Farm, Sabajpura, Patna (longitude 85°13′N and 1atitude 25°37′E), Bihar, India for four consecutive years 2004–05 to 2007–08 to develop a diversified cropping system for an irrigated ecosystem in Bihar by introducing pulse/oilseed/vegetables as a second or third crop in 10 rice-based cropping systems. Four crop cycles have been completed for all the cropping systems. During all years of the experiment there were significant variations among the cropping systems. Maximum paddy yield equivalent was recorded in rice–tomato–bottle gourd (40.44 t ha^?1) followed by rice–potato–onion (28.47 t ha^?1), rice–coriander–lady's fingers (26.79 t ha^?1), rice–carrot–cowpea (24.59 t ha^?1) and rice–mustard–tomato (24.44 t ha^?1). A higher value for the diversification index (DI) represents a higher level of crop diversification. It is evident from the results, that DI varies from 0.299 on a medium-sized farm to 0.903 on a small farm, with an average DI value of 0.643 among all farm categories. A survey revealed that the average DI value for small-scale farmers was highest (0.741) compared with the medium- (0.591) and large-scale (0.626) categories, and the differences were negligible. This seems reinforce the view that the smaller the farm, the higher the level of crop diversification.     

Gut load and transit time in Hormogaster elisae (Oligochaeta,Hormogastridae) in laboratory cultures

The gut load and gut transit time (GTT) of the endogeic earthworm Hormogaster elisae in laboratory cultures at 18 °C and 23 ºC were studied. The GTT, 5.25 h ± 0.40 at 18 ºC and 3.63 h ± 0.46 at 23 ºC, was determined by staining the soil with alimentary colouring (tartrazine). The gut load was calculated with two methods: earthworm mass difference, before and after voiding the gut, and dry mass of the gut content. The gut load ranged between 168 and 261 mg wet mass g live earthworm mass^–1 (mass difference method) or 137–196 mg dry mass g live earthworm mass^–1 (dry mass method). With the obtained data a potential annual soil turnover for H. elisae was calculated: 211–470 kg wet soil mass kg live earthworm mass^–1 year^–1 (mass difference method) or 176–325 kg dry soil mass kg live earthworm mass^–1 year^–1 (dry mass method).     

Temperature and moisture dependence of decomposition rates of hardwood and coniferous leaf litter

Samples of fresh (autumn) and of year-old (late summer) deciduous forest-leaf litter and humus, and of Douglas fir fine litter and humus, were wetted to known moisture content, nominally between 200 and 40% water (dry basis), and maintained at constant temperatures between 10° and 40°C. Rates of CO₂ production were measured by KOH absorption and titration. Decomposition rate was found to be a linear function of log — (water potential), and to approach a maximum near 40°C. The temperature-dependence was consistent with models based on irreversible heat inactivation of a rate-controlling enzyme, also with Eyring's “absolute reaction rate” theory for reactions controlled by a reversibly inactivated enzyme. Activation energies were 66.8–67.3 kJ mol⁻¹ for litter, and 61.4–67.5 kJ mol⁻¹ for humus decomposition; for enzyme inactivation energies were 150–154 kJ mol⁻¹.     

Structural and Functional Characteristics of Selected Soft Wheat Starches

Starches from eight soft wheat samples (two parent lines and six offspring) were isolated; relationships between their structures and properties were examined. Branch chain‐length distributions of amylopectins were determined by using high‐performance anion exchange chromatography equipped with an amyloglucosidase reactor and a pulsed amperometric detector (HPAEC‐ENZ‐PAD). Results showed that the average chain length of the eight samples varied at DP 25.6–26.9. Starch samples of lines 02, 60, 63, 95, and 114 consisted of amylopectins with more long chains (DP ≥ 37) and longer average chain length (DP 26.2–26.9) than that of other samples. These starch samples of longer branch chain length displayed higher gelatinization temperatures (55.3–56.5°C) than that of other samples (54.4–54.9°C) and higher peak viscosity (110–131 RVU) and lower pasting temperature (86.3–87.6°C) than others (83–100 RVU and 88.2–88.9°C, respectively). The M_w of amylopectins, determined by using high‐performance size exclusion chromatography equipped with multiangle laser‐light scattering and refractive index detectors (HPSEC‐MALLS‐RI), were similar for all samples (6.17 × 10⁸ to 6.97 × 10⁸). There were no significant differences in amylose and phosphorus contents between samples. These results indicated that physical properties of wheat starch were affected by the branch‐chain length of amylopectin.