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Abstract Variations in 13 C natural abundance and distribution of total C among five size and density fractions of soil organic matter, water soluble organic C (WSOC) and microbial biomass C (MBC) were investigated in the upper layer (0–20 cm) of a continuous grassland soil (CG, C 3 vegetation), a C 3 ‐humus soil converted to continuous maize cultivation (CM, C 4 vegetation) and a C 3 ‐humus soil converted to a rotation of maize cultivation and grassland (R). The amounts of WSOC and MBC were both significantly larger in the CG than in the CM and the R. In the three soils, WSOC was depleted while MBC was enriched in 13 C as compared with whole soil C. The relative contributions to the total C content of C stored in the macro‐organic matter and in the size fraction 50–150 µm decreased with decreasing total C contents in the order CG > R > CM, while the relative contribution of C associated with the clay‐ and silt‐sized fraction <50 µm increased. This reflects a greater stability and physical protection against microbial degradation associated with soil disruption (tillage) of the clay‐ and silt‐associated organic C, in relation to the organic C in larger size fractions. The size and density fractions from the CG soil showed significant differences in 13 C enrichment, indicating different degrees of microbial degradation and stability of soil organic C associated with physically different soil organic matter (SOM) fractions. δ 13 C analysis of the size and density fractions from CM and R soils reflected a decreasing turnover rate of soil organic C with increasing density among the macro‐organic matter fractions and with decreasing particle size. Copyright © 2002 John Wiley & Sons, Ltd.

AbstractWorldwide, tannery sludge management has become a big challenge due to containing heavy metals, especially chromium. In this study, phytoextraction of heavy metals from tannery sludge by Napier grass (Pennisetum purpureum) is presented. Heavy metals‐chromium (Cr), copper (Cu), zinc (Zn), and lead (Pb) in tannery sludge were found at 12686, 371, 265, and 66 mg/kg, respectively. Separately, Napier grass was harvested on raw tannery sludge and garden soil and examined for 16 and 20 weeks after the sowing of seeds. Metal extraction from tannery sludge in Napier grass was found in a series of Cr > Zn > Cu > Pb; the most accumulation was reported in shoot parts of plants in the order of shoots > roots > leaves. Accumulation of Cr in Napier grass at 16 and 20 weeks was 37% and 66%, respectively. An increasing trend of heavy metal gathering in the plant was found significantly by extending the harvesting period from 16 to 20 weeks. Translocation of Cr and Pb was greater than unity (1.623 and 1.339) indicating the suitability of phytoextraction. Further, Napier grass is a rapid‐yielding tropical grass, which showed a high degree of growth tolerance that could be used for treating heavy metals contaminated tannery sludge.

Abstract The greenhouse is a modern agriculture technology that is widely used to provide a favorable microclimate for vegetable growth when an open field is inappropriate for cultivation. Field tests were conducted to test diurnal variations of temperature, relative humidity, and solar radiation and to analyze the microclimate characteristics in naturally ventilated single-sloped greenhouses of different sizes. The results showed that indoor air temperature and humidity under natural ventilation varied from 28.9 °C to 25.8 °C and 96% to 84%, which illustrates that ventilated greenhouses are able to create a favorable self-maintained, energy-balanced environment for vegetable growth. Moreover, it was found that a greater height and shorter span facilitates heat preservation and energy saving in single-sloped greenhouses. In addition, the relationship between the incident solar radiation and indoor air temperature was determined. This study provides a reference for further research to reduce energy consumption and achieve a favorable greenhouse microclimate, leading to higher product quality, improved yield and shorter cultivation time in single-sloped greenhouses.

Yu et al.'s paper showed very interesting effects of high nitrogen (N) on the submerged macrophytes Vallisneria natans: active growth in the growing season enabled the macrophytes partly to overcome the ammonium stress. This result was evident in an experiment using ten pond ecosystems; however, their conclusion that shading induced by high phytoplankton biomass together with the toxicity of high ammonium contributed to the decrease of macrophytes growth was not strongly supported by the data provided in the paper. Three factors influencing how submerged macrophytes respond to high ammonium, not addressed by Yu et al.'s paper, are toxicity of ammonium/ammonia (NH4+/NH3), the precise extent of shading in water and species-specific characteristics of macrophytes. In conclusion, a comprehensive consideration of abiotic and biotic factors that involve in the responses of submerged macrophytes to high N is urged in future studies of the role of high N on the growth of submerged macrophytes.

The extensive use of nonrenewable peat does not meet the strategic goals of sustainable development. This study explores the advantages and disadvantages of using lignocellulose-based agricultural and forestry wastes as peat substitute in substrates for soilless cultivation; further, it also investigates the key factors influencing the physical and chemical properties of the substrates. Accordingly, the physical and chemical properties of four gramineous crop straws and two woody forestry wastes were determined and compared with those of peat and coconut bran. In addition, cellulose, hemicellulose, and lignin were extracted from wheat straw and pine sawdust, and their basic characteristics and structures were compared and analyzed. The results showed that the influence of particle size on the physical properties of substrates was significantly higher (P < 0.01) than the influence of the substrate type, especially with respect to the water-holding and aeration porosities, which had effect sizes (Eta2) of 73.8% and 68.2%, respectively. The electrical conductivity values of the four straws (1.87-3.42 mS/cm) were higher than those of peat and coconut bran (0.50-0.96 mS/cm), which was mainly due to the high hemicellulose contents (28.52%-30.10%) and total nutrient contents (28.46-47.81 g/kg) of the straws. In contrast, the electrical conductivity values of the woody waste substrates were lower (0.28-0.33 mS/cm) than those of peat and coconut bran. Peat and coconut bran contained the lowest cellulose (17.84%-20.95%) and hemicellulose contents (5.14%-7.19%) of all substrates, resulting in a low degradability and good stability. The crystallinity of coconut bran (23.06%) was significantly lower than that of all other substrates (30.36%-43.03%), which mainly contributed to the superior compressibility of coconut bran. The best pretreatment method for biomass waste used as a substrate should be selected according to the target properties of the corresponding components.

Abstract Climate observations inform about the past and present state of the climate system. They underpin climate science, feed into policies for adaptation and mitigation, and increase awareness of the impacts of climate change. The Global Climate Observing System (GCOS), a body of the World Meteorological Organization (WMO), assesses the maturity of the required observing system and gives guidance for its development. The Essential Climate Variables (ECVs) are central to GCOS, and the global community must monitor them with the highest standards in the form of Climate Data Records (CDR). Today, a single ECV—the sea ice ECV—encapsulates all aspects of the sea ice environment. In the early 1990s it was a single variable (sea ice concentration) but is today an umbrella for four variables (adding thickness, edge/extent, and drift). In this contribution, we argue that GCOS should from now on consider a set of seven ECVs (sea ice concentration, thickness, snow depth, surface temperature, surface albedo, age, and drift). These seven ECVs are critical and cost effective to monitor with existing satellite Earth observation capability. We advise against placing these new variables under the umbrella of the single sea ice ECV. To start a set of distinct ECVs is indeed critical to avoid adding to the suboptimal situation we experience today and to reconcile the sea ice variables with the practice in other ECV domains.

The present study investigates the outcomes of bamboo weaving training programs in rural China from 2015 to 2022, employing ethnographic research methods to assess the impact of these programs on the well-being of rural women and their communities. The results indicate that the bamboo weaving training program has significantly improved the scientific literacy and technical skills of rural women, enhancing their self-confidence, income generation, and entrepreneurial endeavors. These improvements contributed to the preservation of intangible cultural heritage, the conservation of biodiversity and ecosystems, economic growth and rural revitalization toward sustainability. Additionally, several instances of constraints and challenges were observed from technical and economic perspectives. The study highlights the role of bamboo weaving training in poverty alleviation and sustainable development, promoting women's empowerment across technical, economic, psychological, and socio-cultural dimensions. Recommendations are provided for training institutions and organizations to enhance the well-being of rural women and foster sustainability in rural areas.

A better understanding of the genetics of seedling characteristics in rice could be helpful in improving rice varieties. Zhenshan 97 and Minghui 63, the parents of Shanyou 63, an elite hybrid developed during the last decade in China, vary greatly with respect to their physiological and morphological traits at the seedling growth stage. In this study, we used a population of 240 recombinant inbred lines derived from a cross between Zhenshan 97 and Minghui 63 to identify quantitative trait loci (QTL) for seedling characteristics. All plant material was grown in hydroponic culture. Data for the following characters were collected at 30 days and 40 days post-sowing: plant height, shoot dry matter weight (SDW), maximum root length, root dry weight (RDW), total dry weight, and root-shoot ratio (the ratio of SDW to RDW). Analysis using composite interval mapping detected 16 QTL for the six traits in 30-day-old seedlings. Of these 16 QTL, Minghui 63 alleles increased trait values at only two of them. The QTL in the vicinity of R3166 on chromosome 5 simultaneously influenced PH, SDW, MRL, RDW, and TDW in the same direction. Twenty QTL were detected for the same traits in the 40-day-old seedlings. However, at this stage Minghui 63 alleles increased trait values at eight QTL. The QTL linked to R3166 also affected PH, SDW, MRL, RDW, and TDW. Only four QTL were common to the two stages. These results clearly indicate that different genes (QTL) control the same traits during different time intervals. Zhenshan 97 alleles had positive effects during the first 30 days of seedling growth, but thereafter the positive effects of Minghui 63 alleles on seedling growth gradually became more pronounced.

This study examined the effects of climate change on rice production in 30 Chinese provinces spanning 1998–2017. The study used the pooled mean group technique to capture the long-run and short-run effects of changing climatic conditions on rice production. It further employed the Dumitrescu–Hurlin panel causality test to examine the path of causality between the key variables and rice production. The study found that, in the long run, average temperature negatively influenced rice production, but average rainfall had a positive effect on rice production. The results indicated that the cultivated area and fertilizer usage were positively related to rice production in the long run. The short-run results accentuated that average temperature favourably influenced nationwide rice production, whereas average rainfall had no substantial effect on national rice production. The cultivated area had a significant positive short-term relationship with rice production, although the impact of fertilizer usage on rice production was negligible in the short run. Besides, the results established a bidirectional causality between rice output and the cultivated area, but there was a one-way causality running from fertilizer usage to rice output. Finally, the results indicated that, except for rainfall, a unidirectional causality exists between temperature and rice production. The study, therefore, recommends that in the case of crop failure due to weather conditions, policymakers could implement a new pricing policy to mitigate the deterioration of the farmers’ income. The government must also develop and implement an insurance scheme that compensates farmers for catastrophes induced by rainfall deficiency.