Short-term changes in bacterial community fingerprints and potential activities in an alfisol supplemented with solid waste leachates

We investigated the effect on soil functioning of adding leachates from municipal solid waste incinerator (MSWI) ashes to laboratory columns (bare soil) and to field experimental plots (bare soil or grass cover). Leachate of MSWI-solidified air pollution control residues (SAPCr) contained more salts but less heavy metals than did MSWI-bottom ash (BA) leachate. Leachate-supplemented soils (BA soil, SAPCr soil) and control (water added) soil (W) were analyzed after 30 days. Potential denitrifying activity (PDA) and potential N2 fixation (acetylene reduction assay, ARA) were measured in controlled conditions. PDA was significantly lower in SAPCr soil than in W soil, both in the laboratory (-45%) and in bare soil in the field (-31%). ARA values were lower in bare SAPCr soil (-54%) and in bare BA (-25%) soil. Both activities remained unaffected by leachate supplementation in soil under permanent grass cover. Automated ribosomal intergenic spacer analysis (A-RISA) fingerprints and RFLP of nifH gene pools were used to assess changes in the structure of bacterial community. Multivariate analysis of these fingerprints revealed that SAPCr leachate had a stronger effect than BA leachate on the total and N2-fixing bacterial communities. Similar results were obtained for laboratory and bare soil field plots, but leachates did not affect nifH gene pools from soil under permanent grass cover. The stronger impact of SAPCr leachate on both structure of bacterial communities and activities supports the conclusion that observed effects would result from the abundance of salts rather than from heavy metal toxicity.     

COVER CROPS IN SUSTAINABLE FOOD PRODUCTION

Cover crops are important components of sustainable agricultural systems. They increase surface residue and aid in the reduction of soil erosion. They improve the structure and water-holding capacity of the soil and thus increase the effectiveness of applied N fertilizer. Legume cover crops such as hairy vetch and crimson clover fix nitrogen and contribute to the nitrogen requirements of subsequent crops. Cover crops can also suppress weeds, provide suitable habitat for beneficial predator insects, and act as non-host crops for nematodes and other pests in crop rotations. This paper reviews the agronomic and economic literature on using cover crops in sustainable food production and reports on past and present research on cover crops and sustainable agriculture at the Beltsville Agricultural Research Center, Maryland. Previous studies suggested that the profitability of cover crops is primarily the result of enhanced crop yields rather than reduced input costs. The experiments at the Beltsville Agricultural Research Center on fresh-market tomato production showed that tomatoes grown with hairy vetch mulch were higher yielding and more profitable than those grown with black polyethylene and no mulch system. Previous studies of cover crops in grain production indicated that legume cover crops such as hairy vetch and crimson clover are more profitable than grass cover crops such as rye or wheat because of the ability of legumes to contribute N to the following crop. A comparative analysis of four reduced-tillage corn based cropping systems at the Sustainable Agricultural Demonstration site showed that the cover crop system with corn following hairy vetch produced the largest average gross margin, followed by the conventional no-tillage system, a manure-based system, and a crown vetch living mulch system. The EPIC model to simulate the long-term economic and environmental impacts of incorporating cover crops into grain production systems in mid-Atlantic states was used. Results based on 60 simulation years indicated that there are tradeoffs between the competing objectives of increased profitability, lower soil erosion, and reduced nutrient and pesticide hazards to surface and groundwater supplies. A corn/soybean two-year rotation was found to be the most profitable, while the cover crop system and the manure system were found to be the most environmentally sound.     

COVER CROPS IN SUSTAINABLE FOOD PRODUCTION

Cover crops are important components of sustainable agricultural systems. They increase surface residue and aid in the reduction of soil erosion. They improve the structure and water-holding capacity of the soil and thus increase the effectiveness of applied N fertilizer. Legume cover crops such as hairy vetch and crimson clover fix nitrogen and contribute to the nitrogen requirements of subsequent crops. Cover crops can also suppress weeds, provide suitable habitat for beneficial predator insects, and act as non-host crops for nematodes and other pests in crop rotations. This paper reviews the agronomic and economic literature on using cover crops in sustainable food production and reports on past and present research on cover crops and sustainable agriculture at the Beltsville Agricultural Research Center, Maryland. Previous studies suggested that the profitability of cover crops is primarily the result of enhanced crop yields rather than reduced input costs. The experiments at the Beltsville Agricultural Research Center on fresh-market tomato production showed that tomatoes grown with hairy vetch mulch were higher yielding and more profitable than those grown with black polyethylene and no mulch system. Previous studies of cover crops in grain production indicated that legume cover crops such as hairy vetch and crimson clover are more profitable than grass cover crops such as rye or wheat because of the ability of legumes to contribute N to the following crop. A comparative analysis of four reduced-tillage corn based cropping systems at the Sustainable Agricultural Demonstration site showed that the cover crop system with corn following hairy vetch produced the largest average gross margin, followed by the conventional no-tillage system, a manure-based system, and a crown vetch living mulch system. The EPIC model to simulate the long-term economic and environmental impacts of incorporating cover crops into grain production systems in mid-Atlantic states was used. Results based on 60 simulation years indicated that there are tradeoffs between the competing objectives of increased profitability, lower soil erosion, and reduced nutrient and pesticide hazards to surface and groundwater supplies. A corn/soybean two-year rotation was found to be the most profitable, while the cover crop system and the manure system were found to be the most environmentally sound.     

Viticultural experimentation using whole blocks: evaluation of three floor management options

Background and Aims: Vineyard floor cover crops can affect vine vigour because of their requirement for soil, water and nutrients, as well as their interactions with pests and diseases. An on‐farm trial was established to identify the best floor cover management for an organically certified vineyard in the Clare Valley, South Australia, which was characterised by low vine vigour and yield. In establishing this trial, we also sought to evaluate a new approach to field experimentation in which the entire management unit is used for the experiment rather than small plots. Methods and Results: Three different floor covers were compared: the existing ryegrass cover crop with compost under the vine (control), ryegrass with mulch under the vine, and a replacement of the ryegrass with alternating mid‐rows planted to either cereal (Triticum triticosecale) or legume (Vicia faba), in both cases reverting to bare soil during summer. Spatially variable treatment differences were evident in the second and third year of the trial. The greatest benefits, in terms of enhanced yield and vine vigour, were induced by the cereal/legume treatment, although it was shown that only about half of the experimental area (i.e. only half of the entire vineyard) would have increased yields with the adoption of such a floor management strategy. Conclusions: The whole‐of‐block approach offers both researchers and vineyard managers a means of acquiring considerably more useful information than would be obtained from a conventional plot‐based experiment. In this particular vineyard, differential management with ryegrass retained in the southern part, but with the cereal/legume cover crop used in the northern part, is the ideal management practice. Significance of the Study: This study provides a novel demonstration of an approach that makes use of spatial variability as an experimental tool, and which enables experimental results to be acted upon in a way that recognises and exploits the underlying spatial variability of the vineyard.     

Are food insecure smallholder households making changes in their farming practices? Evidence from East Africa

We explore the relationship between farming practice changes made by households coping with the huge demographic, economic, and ecological changes they have seen in the last 10?years and household food security. We examine whether households that have been introducing new practices, such as improved management of crops, soil, land, water, and livestock (e.g. cover crops, micro-catchments, ridges, rotations, improved pastures, and trees) and new technologies (e.g. improved seeds, shorter-cycle and drought-tolerant varieties) are more likely to be food secure than less innovative farming households. Using data from a baseline household survey carried out in five sites and 700 households in four countries of East Africa (Kenya, Uganda, Tanzania and Ethiopia) across a range of agricultural systems and environments, this study contributes to the evidence base of what smallholders are doing to adapt to changing circumstances, including a changing climate. Lessons from both similarities and differences across sites are drawn. This unique baseline study provides a wide range of indicators of activities and behaviors that will be monitored over time. We found that many households are already adapting to changing circumstances, and their changes tend to be marginal rather than transformational in nature, with relatively little uptake of existing improved soil, water and land management practices. There is a strong negative relationship between the number of food deficit months and innovation, i.e. the least food secure households are making few farming practice changes. This has very different policy and investment implications depending on assumptions made as to the direction of causality.     

A note on the influence of rearing environment on meat quality in pigs

Pigs of stress-resistant and stress-susceptible breeds were reared either under intensive conditions in bare concrete pens or extensively under environmentally enriched conditions in an outside paddock. They were slaughtered at either 60 or 90 kg live weight. Rearing environment had no effect on the ability of the pigs to respond to the stress of preslaughter handling based on measurements of adrenal ascorbic acid and plasma cortisol. Neither did it influence initial or ultimate pH or the water holding capacity of the meat. Pigs reared outside had thinner backfat and slightly darker meat. The latter was not attributable to differences in haem pigment concentration. Overall, differences due to rearing environment were slight and not commercially important.     

Impacts of crop level,soil and irrigation management in grape berries of cv ‘Trincadeira’ (Vitis vinifera L.)

Berry size and crop yield are widely recognized as important factors that contribute to wine quality. The final berry size indirectly affects the phenolic concentration of the wine due to skin surface-to-berry volume ratio. The effects of different irrigation levels, soil management and plant crop level on growth of ‘Trincadeira’ berries were studied. In order to test the influence of different irrigation levels (rainfed, pre-veraison and post-veraison), different soil management (tillage and natural cover crops) and different plant crop levels (8 and 16 clusters per vine), leaf water potential, skin anthocyanin, polyphenols, berry skin and seed fresh weight were measured in fruits. The segregation of berries into three different berry classes: small, medium and large, allowed to identify different levels of contribution of soil management and irrigation level into berry, skin and seeds ratios. As expected, higher water availability due to irrigation and soil tillage management during berry development induced an increase in berry flesh weight and this was more evident in larger berries; however, berry skin and seed fresh weight remained unchanged. Also, anthocyanins did not show significant differences.     

The energy costs of the nitrogen fertilisers used in Britain,the returns received and some savings that are possible

Published estimates suggest that one-third of the energy used in many intensive mechanised systems of arable agriculture is required to produce the nitrogen fertilisers used. The increases in yield that nitrogen fertilisers give in Britain are very profitable to farmers although prices of N are nearly twice those of two years ago. Some of the nitrogen involved in intensive agricultural systems is lost. Losses of nitrate by leaching can be diminished by greater care in timing the application of nitrogen fertilisers. Denitrification, which results in loss of nitrogen and its oxides, is diminished by careful management of soil and crop wastes. Losses of ammonia may be lessened by better handling of organic manures. Nevertheless some loss of nitrate by leaching in winter is inevitable, as is loss of ammonia from animal excreta. Farmers can use fertilisers more efficiently by fitting the amounts applied more closely to local conditions of soil, previous cropping and manuring and to the weather. Increased use of leguminous crops and more efficient use of organic manures will diminish the need for nitrogen. But it is not possible to achieve large yields of non-leguminous crops by relying solely on nitrogen from “natural” sources; fertilisers are essential in modern intensive agriculture.     

楚雄烟区烤烟生态气候因子评析

利用楚雄气象资料,依据影响烤烟种植的主要气候因子,应用标准差计算各气候因子的权重,定量估算气候适生性指数(Climatic Feasibility Indices, CFI),评价烤烟种植的气候适生性,并对楚雄州有代表性的气候条件与国内外优质烟区进行相似性分析,结合经验公式,对楚雄烟区烟叶进行香型定位。结果表明,楚雄烟区烟叶成熟期平均气温为 19.8 ℃,较为适中,雨量分布均匀。烤烟大田期日照时数均超过500 h,日照条件较好。楚雄烟区的气候适生性指数平均值为0.90,变幅为 0.61~1.00,适宜种植烟草。在楚雄烟区 3 个有代表性的烤烟县(市)中,楚雄市、姚安县气候条件与河南许昌相似程度最低,与巴西相似程度最高;元谋县气候条件与河南许昌、美国相似程度最高。楚雄烟区烟叶香型定位K值平均为0.27,分布在0.22~0.43,均为典型的清香型烟叶。     

陕西安康地区农作物重金属浓度空间变异及污染评价

目的 分析陕西安康地区农作物重金属污染状况。方法 通过测定安康区域不同农作物中6种重金含量,对安康区域农作物重金属污染状况进行分析和评价。采用单项污染指数法,按照GB 2762—2017《食品安全国家标准食品中污染物限量》、国家中药重金属及农药残留标准进行检测,分析安康区域内农作物重金属污染的空间变异,评估其污染状况。结果 安康区域内蔬菜类和水果类农作物铅含量超标情况较为严重,其中镇坪地区农作物铬和镉含量超标;安康地区农作物重金属污染成分中,第一主成分为镉、锌、铅、砷,其主要来自以工农业生产为主、交通运输等为辅的人为活动污染源,第二主成分为铬、铜,其主要来自土壤母质源导致的农作物吸收。结论 该区域生态环境总体良好,能满足NY/T 5010—2016《无公害农作物种植业产地环境条件》等相关标准的要求。监测范围除个别区域外,均可做为无公害大田、林果、蔬菜及其他经济类作物、食用菌的生产基地。     

Effects of long-term herbicide use,irrigation and nitrogen fertiliser on soil fertility in an apple orchard

In 1972 an experiment was set up to investigate the long-term effects of herbicide, irrigation and two rates of nitrochalk fertiliser application on soil fertility in a Cox's Orange Pippin apple orchard. Samples taken in 1986 showed that uncultivated soil which had been maintained bare by herbicide had much lower organic C, total N and extractable K and Mg concentrations than soil which had been maintained under grass. Extractable P concentrations were lower in soil under grass than in soil under herbicide. In the absence of grass, soil pH was slightly lower than in its presence. All these effects were much greater at depths above 7·5 cm than below. Irrigation of the grass slightly increased organic C and total N levels at 0–7·5 cm compared with unirrigated grass but had no effect on extractable P, K and Mg. Increasing the fertiliser rate from 63 to 189 kg N ha^?1 had no effect on organic C, total N, extractable P and K. Yet, throughout the soil profile, extractable Mg concentrations were greater at the low than at the high N fertiliser rate. In a seedling growth test on soil taken from the orchard in 1988 (and confirmed to be free from residual herbicide), apple seedlings grown in soil which had previously been under grass grew significantly better than those in soil which had been bare. These differences were ascribed to a greater rate of N mineralisation in the soil formerly under grass. The results of this trial indicate that to safeguard soil fertility it is necessary to maintain a grass cover in the orchard. In addition, fertiliser application on newly planted trees should be adjusted to take account of the presence or absence of grass in the previous soil management treatment.     

农作物中抗生素检测技术的研究进展

随着养殖业的规模化和集约化发展,抗生素作为疾病预防与治疗药物、生长促进剂、饲料添加剂等被广泛用于畜禽养殖和水产养殖业中,进而进入水环境和土壤环境,被农作物根系吸收进入茎、叶中并在植物体内富集,从而通过食物链进入人体内。近年来研究者对农作物中抗生素的研究逐渐增多。目前对农作物中兽用抗生素残留的前处理技术主要包括Qu ECh ERs方法和固相萃取法,检测技术主要包括高效液相色谱法、高效液相色谱-串联质谱法和酶联免疫法。高效液相色谱-串联质谱法具有高灵敏度、高选择性和高准确度,可同时快速测定多个目标物,更适合农作物中兽用抗生素残留的检测。本文对环境中抗生素的来源、农作物中抗生素污染的现状、抗生素残留检测的提取、净化方法以及检测方法的研究进展进行了综述。     

Research Applied to Global Knowledge of Flax Development

Abstract

Environmental factors that regulate development in flax have been little studied. Some important aspects of this more than 9000 years old crop physiology are even unknown. The development for seed crops such as wheat, and many others, has been extensively studied. The same thing did not happen with crops where the stem is harvested as flax, hemp, kenaf, ramie, and jute, etc. Available information is partial and is not useful for different climatic zones and different cultivars. The modern study of the development of these crops needs constructing of usable models in different situations. Modelling phenology is a means of integrating knowledge from various environmental factors into a coordinated whole. If our understanding of biological and environmental processes can be expressed in quantitative terms, then the development processes and their interactions with environment can be combined in a model.     

Influence of vegetation on the environmental partitioning of DDT in two global multimedia models

Two multimedia models are used to investigate the effect of a vegetation compartment on the environmental partitioning of dichlorodiphenyltrichloroethane (DDT): a steady-state unit world model using global averages of vegetation cover and land-to-sea ratio and a dynamic model with latitudinal zones and zone-specific vegetation types and annual temperature courses. The vegetation compartment represents canopies of deciduous and coniferous forests and blades of grasses; the organic carbon content of the vegetation-covered soil is higher than in the bare soil. In the steady-state model, transfer from the air to the vegetation and the underlying soil as well as revolatilization from the foliage and reduced deposition to the soil is observed, depending on the chemical's degradation rate constant in vegetation and the deposition velocities of the gaseous and particle-bound fractions. In both models, a significant effect of the organic carbon content of the vegetation-covered soil increasing the effect of the vegetation compartment is observed. In the steady-state model, the changes in the DDT concentrations in air do not exceed 7% difference between the cases with and without vegetation; the soil concentrations differ by maximally a factor of 2.7. In the spatially and temporally resolved model, however, air concentration differences up to 90% are observed, depending on the type and amount of vegetation in the latitudinal zones. Long-range transport is less pronounced in the model with vegetation.     

Acidity and Power: The Politics of Natural Wine in Nineteenth-Century Germany

This article examines the origins of the natural-wine movement in Germany—the first of its kind in Europe—by exploring the crucial technological and social developments which prompted the use of derided “artificial” winemaking techniques. The forgotten social reformer Ludwig Gall, once known to as the “savoir of the small vintner,” helped to relieve the unreliable dependency of winegrowers on nature by perfecting a deacidification technique which allowed for pleasant wines in any vintage. While Gall's technique became an important part of the road out of impoverishment for many winegrowers in the Mosel River Valley, it had the additional effect of challenging the static nature of the wine trade and the monopolies and economic efficiencies of large landowners. By outlining the initial uses of Gall's technique and the opposition to it, this article reveals the formative debates in the ongoing controversy over the definition of natural wine. In turn, the concepts of “artificial” and “natural” are shown to be grounded more in the social and political spheres of the nineteenth-century German wine trade and less in matters of consumer choice or concerns over the environment.     

Influence of different floor management strategies of the vineyard on the natural yeast population associated with grape berries

Some oenological practices, such as the massive utilisation of commercial yeast and the consequent colonisation of wineries, can contribute to reducing the native yeast biodiversity. In this context, the vineyard could be a reservoir of autochthonous yeasts of oenological interest. Thus, the evaluation of the influence of different agricultural parameters on the biodiversity of yeast population in the vineyard is necessary. This work shows the results of the influence of some floor management strategies of the vineyard in the natural yeast population associated with the grape-berries. With this objective, a three year sampling plan was designed in the Shiraz vineyards of the Madrid region using three floor management strategies: bare soil by tillage, bare soil maintained with herbicides and soil maintained with cover crop. The results of this study have shown that bare soil by tillage could be a sustainable alternative for managing the soil, due to the reduced use of agrochemicals and the resulting high yeasts biodiversity. Nevertheless, the presence of herbicides in the vineyard has a minor impact on the diversity of grape associated yeast communities, and this could have increased the yeast populations. Hence, from the fermentative yeasts' (like Saccharomyces) point of view, in hot and arid environments where soils may be affected by the tillage management, the best option could be the maintenance of the bare soil with the use of herbicides.     

Cadmium studies on the effect of environment, soil and variety on tobacco and cadmium transfer into cigarette smoke

The results as outlined in this paper are based on a 10-year-investigation by the Tobacco Research Institute, Forchheim. Emissions into the environment may lead to higher Cd-content of tobacco and other crops. Geological soil conditions may influence the soil/plant--Cd-transfer. Genetically dependent variety differences in Cd-uptake can be found in field as well as in greenhouse experiments. A comparison between domestic and foreign leaf tobaccos showed Cd-levels at the same order of magnitude. Analyses of German cigarette brands (with and without filter) demonstrated that 0.05 micrograms Cd/cigarette are transferred from cigarette tobacco into the mainstream smoke, corresponding to a mean transfer rate of 5.1%.     

Field experiments with anhydrous ammonia

The results are reported of 50 experiments carried out by the National Agricultural Advisory Service comparing injected anhydrous ammonia with solid ammonium nitrate for arable crops and grass. Autumn-applied anhydrous ammonia was found to be inefficient for arable crops owing to winter loss by leaching. Spring injections for spring cereals and sugar-beet were as effective as ammonium nitrate provided that soil conditions allowed efficient injection. Spring injections for winter wheat were as effective as ammonium nitrate on light and medium textured soils but less so on clay soils. The slow-acting nature of anhydrous ammonia resulted in less lodging than did ammonium nitrate and less resultant yield depression under conditions leading to severe lodging in cereals. In grassland, the slow-acting nature of anhydrous ammonia gave a delayed response compared with ammonium nitrate but did not result in an even spread of growth throughout the season. Early spring injections resulted in a better seasonal distribution of response in high rainfall areas than in areas of low rainfall.     

Occurrence of fumonisins in foods

Fumonisins (FB) are synthesized mainly by different species of the genus Fusarium and FB1 is the predominating fumonisin isolated in foods. FB1 shows different toxicological effects in humans and animals and has been associated with esophageal cancer in different countries. This review presents an overview of the worldwide occurrence of fumonisins in crops and human foods being corn and corn meal the most contaminated foods, and reviews variations of the presence of these mycotoxins in foods and in agricultural crops. In foods, these variations are due to the alkaline solutions, water and temperature. For agricultural crops, the role of climatic conditions and latitude, genotypes, spoilage and other fungal diseases is reviewed.