Responses of plant, insect and spider biodiversity to local and landscape scale management intensity in cereal crops and grasslands

The aim of this study was to determine the relative effects of landscape scale management intensity, agroecosystem type, local management intensity and edges on diversity patterns of functional groups of plants, carabid beetles, spiders and grasshoppers. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional mown meadows. Within fields, plants were surveyed in the edge and in the interior. Carabid beetles and spiders were captured by funnel traps, while grasshoppers were sweep-netted in the meadows. Diversity patterns of study organisms were affected both by local variables (local management, agroecosystem type and within-field position) and by landscape scale management intensity. Species richness of grasses, presumably because of sowing low-diversity mixtures, and hunting spiders decreased with percent cover of IAA. Meadows differed from wheat fields in that they had higher species richness of forbs and grasses, as well as higher densities of hunting spiders. In contrast, more carabid individuals, especially of non-carnivore species, were captured in wheat fields. In field edges with their reduced management intensity and increased immigration, species richness of plants, carabids and spiders was higher than in the interiors regardless of agroecosystem type and management. Organic management enhanced forb richness and cover in both agroecosystem types. Organic management also increased grass cover in wheat fields, but not in meadows, and promoted species richness of non-carnivore carabids and hunting spiders, but not grasshoppers. The results show that agri-environmental management needs to be targeted to the agroecosystem's field size, because higher edge area led to higher species richness. Organic management affected several functional groups positively (forbs, non-carnivore carabids, hunting spiders), while lower landscape scale management intensity only increased species richness of grasses and spiders. The great differences in responses of functional groups to local cereal and grassland as well as landscape management suggest implementing more scale and group specific targets for agri-environmental schemes to improve their efficiency.     

The models of niche and their application

Having studied the definitions of niche proposed by different ecologists, I have proposed a quantitative method of niche which can be applied to plants. Accordingly, the niche of an operational taxonomic unit (OTU) has been described by a mapping from its environmental set to the unit interval [0, 1], which enables a model of niche to be mathematically operational. The concepts of fundamental niche, realized niche, time niche, etc., may be described by using mathematical models related to each other, and the geometrical relationships between them can be revealed by a multi-dimensional surface. The uni-factor models are built upon the condition that the other factors are optimal for OTU, which are particular cases of the multi-factor models. The establishment of the quantitative relationship between these two kinds of models makes it possible to find out the plants' fundamental niche by doing uni-factor experiments. This may simplify the experiments in which the parameters in a practically applied model are to be estimated. The niche index introduced in this paper is related to average level and aftereffect of plant responses to the effects of its environment (i.e. “inertia”), thus it should be the basis of the simulation of plant seed yield and of its environmental evaluation. Accordingly, models of niche index, of plant seed yield, of plant growth and of environmental evaluation have been built which can be applied to the environmental evaluation or the prediction and management of plant (crop) production, etc.As an example of application, the models of wheat yield and its environmental assessment have been established and practically tested. The results of testing the model of wheat yield showed that the relative errors are 8% and 7.2%, respectively, in 1984 and 1986. The results of the environmental assessment of wheat reveal the fact that the insufficiency of the soil moisture at the 2th and 3th stages is the main restriction of the production of the wheat in Dinxi, Gansu Province, China.     

An architectural model of spring wheat: Evaluation of the effects of population density and shading on model parameterization and performance

ADELwheat is an architectural model that describes development of wheat in 3D. This paper analyzes the robustness of the parameterization of ADELwheat for spring wheat cultivars in relation to plant population density and shading. The model was evaluated using data from two spring wheat experiments with three plant population densities and two light regimes. Model validation was done at two levels of aggregation: (a) by comparing parameterization functions used as well as parameter values to the data (leaf and tiller appearance, leaf number, blade dimensions, sheath length, internode length) and (b) by comparing ground cover (GC) and leaf area index (LAI) of simulated virtual wheat plots with GC and LAI calculated from data. A sensitivity analysis was performed by modulating parameters defining leaf blade dimensions and leaf or tiller appearance rate.In contrast to population density, shading generally increased phyllochron and delayed tiller appearance. Both at the level of the organ and at the level of the canopy the model performed satisfactorily. Parameterization functions in the model that had been established previously applied to independent data for different conditions; GC and LAI were simulated adequately at three population densities. Sensitivity analysis revealed that calibration of phyllochron and blade area needs to be accurate to prevent disproportional deviations in output.The robustness of the model parameterization and the simulation performance confirmed that the model is a complete architectural model for aboveground development of spring wheat. It can be used in studies that require simulation of spring wheat structure, such as studies on plant–insect interaction, remote sensing, and light interception.     

林丹在作物和土壤中的残留及其消解

通过不同施药方法,探讨了林丹在小麦、玉米中的残留水平。结果表明,林丹在作物中的残留量随施药量的增加而递增。采用喷雾,4(a.i.)g/亩,林丹在小麦中的残留为0.0073ppm;土壤处理,100(a.i.)g/亩,林丹在小麦中的残留为0.0134ppm;撒颗粒剂,0.015(a.i.)g/株,林丹在玉米中的残留为0.0600ppm.林丹在土壤中消解很快,当土壤处理[200(a.i.)g/亩],林丹在土壤中的半衰期为23.7～25.2d,消解99％需160d左右。作者认为,在我国部分害虫防治中起用林丹不可能对生态环境构成威胁。      

Indigo carmine removal by charcoal from rice bran as an agricultural by-product

On the utilization of agricultural by-product, charcoal from rice bran was produced. The adsorption characteristics of indigo carmine onto charcoals from rice bran were investigated by the batch method. The yield and surface area of charcoal were decreased and increased with increase of carbonization temperature, respectively. The removal ratio of indigo carmine was high with the charcoal carbonized at higher temperature. In the relationship between the amount of indigo carmine adsorbed and the square root of elapsed time, a good linearity was recognized. The kinetic constant of adsorption removal for indigo carmine was rapid in the charcoal carbonized at higher temperature. The adsorption characteristics for indigo carmine removal by charcoal from rice bran were dominated by the value of their surface area.     

Residues of 14C‐γ‐HCH in paddy after dusting,and the fate of γ‐HCH during refining process of rice bran oil

Paddy (rice) plants were dusted with 10% HCH containing ¹⁴C‐Γ‐HCH, at the rate of 2.5 kg a.i./ha and ¹⁴C‐residues were determined in different fractions of rice. Rice bran (0.187 ppm) had more of ¹⁴C‐residues than grain (0.026 ppm) and husk (0.042 ppm). The rice bran oil contained 0.129 ppm HCH residues. While degumming, dewaxing, alkali refining and bleaching had no effect, deodorisation alone eliminated 99.5% of added ¹⁴C‐residues in rice bran the oil during refining process.     

Effect of different pearling times on the quality of hull-less barley rice北大核心CSCD

Hull-less barley is a special food crop rich in various nutrients in Qinghai-Tibet Plateau. Six-pearling is often used to produce commercial hull-less barley rice in order to improve its rough taste and inferior cooking quality. This study evaluated the differences in the nutritional, cooking, sensory, and storage qualities of hull-less barley rice with different pearling times to obtain suitable processing conditions for the production of high-quality hull-less barley rice. With increasing pearling time, the contents of vitamin B6, vitamin E, dietary fiber, iron, zinc, phenols, and flavonoids significantly decreased to a large extent, protein and vitamin B3 decreased slightly, the contents of total starch and β-glucan increased significantly, and γ-aminobutyric acid (GABA) initially increased and then decreased. The peak, trough, and final viscosity of whole grain barley were 1 860.50 cP, 914.50 cP, and 2 150.00 cP, respectively, and increased after six-pearling to 4 219.00 cP, 2 628.00 cP, and 5 074.00 cP, respectively. At the same time, the water absorption and volume expansion of the pearled hull-less barley increased significantly. The hardness of pearled hull-less barley reduced from 4 708.50 g to 2 282.00 g, its adhesiveness increased from 0.00 to -7.33, and its taste and sensory quality exhibited better. The activities of α-amylase, polyphenol oxidase, lipase, and catalase in pearled hull-less barley slightly decreased. Hull-less bran flour is rich in a variety of nutritional components and could be a potential resource with great developmental value. In general, hull-less barley rice obtained from three-pearling has high nutritional value, high cooking quality, low enzyme activity, and low energy consumption; therefore, it can be used to produce high-quality barley rice. This study provides important information for high-quality pearled hull-less barley and further utilization of barley bran flour. © 2022 Science Press. All rights reserved.     

麸皮生物絮团技术在鲢鲤鱼混养鱼塘中的应用

在鲢鲤鱼混养鱼塘内进行增饲麸皮碳源的试验研究,探讨麸皮在常规养殖鱼塘生成生物絮团的效果及对鱼类生长和养殖水体水质的影响。结果显示:增饲麸皮可以显著促进鱼塘生物絮团的生长;与对照鱼塘相比,增饲麸皮的鱼塘鲜鱼产量提高16.32%,其增重率、特定生长率、生长势显著高于对照鱼塘;鲢鱼的生长性能高于鲤鱼,鲤鱼的饲料系数低于对照鱼塘,生物絮团对鲢鱼的促生长作用高于鲤鱼;与对照鱼塘相比,增饲麸皮的鱼塘水体透明度降低、总悬浮物(TSS)浓度上升,NO₂-N、NH₃-N、TN浓度显著降低,养殖水体部分水质指标得到改善。     

Assessment of yield losses in tropical wheat using open top chambers

The present study deals with the evaluation of effects of ambient gaseous air pollution on wheat (Triticum aestivum L. var. HUW-234) growing in a suburban area situated in eastern Gangetic plain of India, using open top chambers. Eight hourly air monitoring was conducted for ambient concentrations of SO₂, NO₂ and O₃ in filtered chambers (FCs), non-filtered chambers (NFCs) and open plots (OPs). Various morphological, physiological and biochemical parameters were assessed during different developmental stages and finally yield parameters were quantified at the time of harvest.Mean concentrations of SO₂, NO₂ and O₃ were 8.4, 39.9 and 40.1 ppb, respectively during the experiment in NFCs. Concentrations of SO₂, NO₂ and O₃ reduced by 74.6%, 84.7% and 90.4%, respectively in FCs as compared to NFCs. Plants grown in FCs showed higher photosynthetic rate, stomatal conductance, chlorophyll content and Fv/Fm ratio as compared to the plants in NFCs and OPs. Lipid peroxidation, proline, total phenol and ascorbic acid contents and peroxidase activity were higher in plants grown in NFCs. There were improvements in morphological parameters of plants growing in FCs as compared to those in NFCs and OPs. Yield of plants also increased significantly in FCs as compared to those ventilated with ambient air (NFCs) or grown in OPs. During the vegetative phase, NO₂ concentrations were higher than O₃, but O₃ became dominant pollutant during the time of grain setting and filling. The study concludes that O₃ and NO₂ are the main air pollutants in the sub-urban areas causing significant yield reductions in tropical wheat plants.     

Improved Cu and Zn sorption on oxidized wheat lignocellulose

We studied the effect an oxidizing treatment of a lignocellulosic substrate, extracted from wheat bran, on the sorption of Cu and Zn. Oxidizing agents, such as potassium permanganate (KMnO₄) or sodium periodate (NaIO₄), creates oxygenated functions, e.g. alcohol and carboxylic acid, which increase the density of functional sites and the binding capacity of lignocellulose towards copper and zinc. We found that the treatment with KMnO₄ is the most efficient, with an increase of about 30–40% metal ion binding, compared to 15–25% using NaIO₄. The investigation of the oxidation process shows that the efficiency of KMnO₄ can be attributed to its affinity towards insaturated double bonds of lignin entities. Oxidized lignocellulose is thus a promising, efficient, and cheap biomaterial for the decontamination of wastewater.