Integrated farming: why organic farmers should use transgenic crops

The concept of organic farming is summarised and compared as an example to farming with biotechnology-derived crops. If done within an ecological concept, both methods can be seen as environmentally acceptable. Organic farming does not offer consistent arguments for the rejection of transgenic crops. Some arguments (from genomics to biodiversity) are discussed in order to demonstrate that the contrast between both farming systems is rated too high and that it is possible to overcome the divide. In this way the ground is prepared for a proposal on how to merge those otherwise incompatible agricultural management systems, a proposal that also will have to build on a new concept of sustainability. It will be dealt with in the second part of the article in the next issue of New Biotechnology.     

Transient peak in moth diversity as a response to organic farming

Few initiatives to preserve and enhance biodiversity on farmland have been as thoroughly evaluated and debated as the agri-environment schemes (AES). Yet, little is known how confounding factors co-varying with the specific AES measures may affect species responses. Here, we quantify the influence of one such factor, the time since transition to organic farming, on moth diversity patterns. We found that species richness and abundance of moths were higher on new organic farms (years since transition ≤6) compared to old organic (≥15 years) and conventional farms, indicating a transient diversity peak. This correlates with the abundance patterns of the weed Cirsium arvense, which also reached its highest densities on new organic farms. Weeds such as C. arvense constitute a notorious problem in organic farming. However, they also provide various resources for farmland biodiversity, and our results strongly suggest that the transient weed peak may be important in influencing the parallel peak among the moths. This stresses the problem in balancing out production and conservation values. More generally, our results show that rather than having static effects on the environment, AES can have an important temporal component and result in a dynamic interplay between different trophic levels.     

Nitrogen use scenario in India

Nitrogen is one of the major plant nutrients without which the agricultural production is not possible. Nitrogen use in Indian agriculture was nearly 55000 tons in 1950-1951 that increased to 11.31 million tons in 2001-2002. The total food production of the country has also experienced the similar increase from 50.83 to 222 million tons in the respective years. Interestingly the N fertilizer consumption of India remained almost constant during the last six years indicating the possibility of reducing N consumption. The highest N consumption is in North zone owing to the introduction of rice-wheat cropping system followed by West, South and East.The N use efficiency has been reported to be varying between 30% to 50% depending on the crops and the management. But in most of the cases, N use efficiency has been calculated based on the total N removed by the crops (above ground part only) ignoring the N content left in the roots. It has been observed in controlled experiments that the total N uptake by roots varied from 18% to 44% of the total N removed by the above ground parts, i.e. grain and straw. If the root N is also accounted, the N use efficiency will be higher than reported. The management of other organic sources has to be improved so as to increase the fertilizer use efficiency as well as to check the direct release of N in the atmosphere. In this review all these issues will be dealt.     

Nitrogen use scenario in India

Nitrogen is one of the major plant nutrients without which the agricultural production is not possible. Nitrogen use in Indian agriculture was nearly 55000 tons in 1950-1951 that increased to 11.31 million tons in 2001 -2002. The total food production of the country has also experienced the similar increase from 50.83 to 222 million tons in the respective years. Interestingly the N fertilizer consumption of India remained almost constant during the last six years indicating the possibility of reducing N consumption. The highest N consumption is in North zone owing to the introduction of rice-wheat cropping system followed by West, South and East. The N use efficiency has been reported to be varying between 30% to 50% depending on the crops and the management. But in most of the cases, N use efficiency has been calculated based on the total N removed by the crops (above ground part only) ignoring the N content left in the roots. It has been observed in controlled experiments that the total N uptake by roots varied from 18% to 44% of the total N removed by the above ground parts, i.e. grain and straw. If the root N is also accounted, the N use efficiency will be higher than reported. The management of other organic sources has to be improved so as to increase the fertilizer use efficiency as well as to check the direct release of N in the atmosphere. In this review all these issues will be dealt.     

Accuracy of the use of energy conversion factors for compound fish diets

Conversion factors of 23.6, 39.5 and 17.2 MJ/kg for protein, lipid and carbohydrate contents, respectively, are frequently used in fish studies to calculate the gross energy (GE) content of compound diets. Values predicted according to the above resulted in linear relationships of observed GE values with similar R ² and mean prediction error (MPE) values when using either nitrogen-free extract (NFE) (R ² = 0.5713, RMSE = 1.3134, MPE = 0.0741, n = 129, 32 studies) or starch (R ² = 0.5665, RMSE = 1.6768, MPE = 0.0839, n = 190, 45 studies) as measurements of carbohydrate content. Apparent digestible carbohydrate content (either NFE or starch) was found to be linearly-related (R ² values of 0.7531 and 0.7460, respectively) to its dietary content in compound fish diets. Predicted apparent digestible protein (ADP), lipid (DL) and carbohydrate contents, together with energy conversion factors, presented R ² and MPE values of 0.6205 (RMSE = 1.2606) and 0.2051, respectively, between observed and predicted apparent digestible energy (ADE) content with NFE as measurement of carbohydrate content (n = 97, 17 studies, eight fish species). However, with carbohydrates quantified by starch content, an R ² value of 0.7017 (RMSE = 1.7556) and MPE of 0.1055 were obtained (n = 37, 10 studies, five fish species).     

Oecophylla smaragdina food conversion efficiency: prospects for ant farming

Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost‐benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood selling prices these efficiencies led to rates of return from 1.52 to 4.56, respectively, if: (i) protein is supplied from commercial products; or (ii) alternatively supplied from free sources such as insects and kitchen waste. These results suggest that Oecophylla ant farming may become highly profitable and deserves further research.     

Benefits of organic farming to biodiversity vary among taxa

Habitat and biodiversity differences between matched pairs of organic and non-organic farms containing cereal crops in lowland England were assessed by a large-scale study of plants, invertebrates, birds and bats. Habitat extent, composition and management on organic farms was likely to favour higher levels of biodiversity and indeed organic farms tended to support higher numbers of species and overall abundance across most taxa. However, the magnitude of the response varied; plants showed larger and more consistent responses than other taxa. Variation in response across taxa may be partly a consequence of the small size and isolated context of many organic farms. Extension of organic farming could contribute to the restoration of biodiversity in agricultural landscapes.     

Grapevine downy mildew control in organic farming

Cupric products at low dose and alternative compounds have been tested to control the downy mildew in an organic vineyard. It has found that copper compounds control downy mildew in a satisfactory way, reducing, at the same time, the dose of copper metal. The alternative products were not satisfactory to control Plasmopara viticola.     

欧盟有机农业"善待动物"的法律要求

善待动物地进行饲养是有机农业区别于其他生产方式的基本特征之一。《欧洲有机法案》把善待环境和生命的理念落实在动物来源、饲料营养、疾病防治、饲养方式和饲养条件等具体措施中。     

Extraction and conversion pathways for microalgae to biodiesel: a review focused on energy consumption

Numerous life cycle analysis (LCA) studies of microalgae to fuel have been released over the past 3 years in an attempt to determine the environmental sustainability of this novel concept. Despite numerous issues with these LCA studies, they have highlighted that cultivation and dewatering/drying for extraction and conversion are major energy sinks within the process. This paper provides a critical review of extraction and conversion methods discussed in literature and under commercial investigation. The basis of this review is energy consumption, with its purpose to highlight methods that deserve further attention in research and development. This review concludes with an energetic assessment of four conversion processes including pulsed electric field-assisted extraction followed by transesterification, in situ acid catalysed esterification of dry biomass, in situ hydrolysis and esterification of wet biomass and hydrothermal liquefaction. The analysis highlighted that energetically feasible methods do exist for the conversion of microalgal biomass to fuel; however, all require further research to be applied at commercial scale.     

Micronutrient status and fertilizer use scenario in India

India was dependent on external food supplies in the early 1960s. To meet the growing demand for food, fiber and fuel, high yielding cultivars were introduced. These high yielding crop cultivars were highly responsive to fertilizers. Thus, slowly the soils were exhausted of their nutrients. Application of major nutrients (nitrogen, phosphorus, potassium) became common, therefore the crops started responding to micronutrient fertilizers. Concerted efforts have been made through the All India Coordinated Research Project on Micronutrients to delineate the soils of India regarding the deficiency of micronutrients. At present about 48.1% of Indian soils are deficient in diethylenetriaminepentaacetate (DTPA) extractable zinc, 11.2% in iron, 7% in copper and 5.1% in manganese. Apart from the deficiency of these micronutrients, deficiencies of boron and molybdenum have also been reported in some areas. Areas with multi-micronutrient deficiencies are limited, thus simple fertilizers are sufficient to exploit the potential of crops and cropping systems. Based on the extent of deficiency, cultivated area, and crop removal, the micronutrient fertilizer demand in 2025 is projected using sufficiency and maintenance approaches.     

Mineralization of copper, manganese and zinc from rock mineral flour and city waste compost for efficient use in organic farming

Restricted supply of micronutrients is a common constraint for plant growth worldwide, especially in organic farming systems where nutrients supply to crops mostly depends on the mineralization of native soil organic matter, decomposition of applied manures and crop residues. A laboratory incubation study was therefore conducted to investigate the potential release of copper (Cu), manganese (Mn) and zinc (Zn) from the rock mineral flour (RMF) and city waste compost (CWC) as compared to inorganic micronutrient fertilizers for 140 days. Release of the micronutrients from RMF and CWC showed different trends. The results showed that about 4.6% of Cu added as RMF was released irrespective of the quantity of the RMF applied. However, Cu release from CWC increased from 0.7 to 3.5% as the amount of compost added was increased. Copper recovery from copper sulphate was 98%. Manganese release from RMF decreased from 114 to 103% as the RMF level was increased, while the corresponding decrease in Mn release from CWC was from 14 to ?3%. Manganese recovery from manganese sulphate was 100%. Zinc release from RMF increased from 5.8?15.5%, with an increase in the amount of RMF applied, while no Zn was released from CWC. Recovery of Zn from zinc sulphate was 98%. These results show that RMF and CWC could be used to meet Cu, Mn and Zn requirements of organically grown cereals. The results of the investigation have general applicability in organic farming.     

In vitro models for photosynthetic energy conversion

A summary is presented of recent work on the photochemistry of chlorophyll in solution. It is shown that reactions occur which are close counterparts ofin vivo photoprocesses. These are (a) photoproduction of chlorophyll cation radical (analog of photosystem I reaction centre primary photoprocess), (b) one-electron phototransfer from bacterio-chlorophyll to quinone (analog of bacterial reaction centre primary photoprocess), (c) chlorophyll photosensitized one-electron transfer from hydroxylic compounds to quinone (analog of photosystem II reaction centre photoprocess). The mechanisms of these reactions and their implications for photosynthetic energy conversion are discussed.     

Organic N and particulate organic matter fractions in organic and conventional farming systems with a history of manure application

Indicators of soil fertility are needed for the effective management of organic farming systems. Sustainable management hinges upon our gaining an improved understanding of C and N dynamics. The influence of cropping systems and amendments applied in the Lakeland Wisconsin Integrated Cropping Systems Trial on total hydrolyzable organic N (THN) fractions and particulate organic matter (POM) was investigated after a decade in a conventional cash grain system (Conv) of continuous maize amended with inorganic fertilizer, an organic cash-grain system (Org-CG) that relied on legume N, and an organic animal-based system (Org-AN) that included alfalfa and manure additions. Maize yields had consistently ranked Org-CG < Conv < Org-AN. The THN and amino acid-N (AA-N) contents were ranked Org-AN > Org-CG > Conv. Amino sugar-N (AS-N) contents, which reflect microbially derived N, did not differ among systems and concentrations were quite high (346.5 mg AS-N/kg soil in the 0–50 cm depth). This, and soil variability were attributed to the sites’ history of manure application. The amount (1.3 g POM-C/kg soil) and proportion (≈7.5% of total SOC) of POM-C were quite low and did not differ among systems. Failure to accumulate SOC or POM in these soils, even under organic management, is attributed to rapid C decay and/or limited root growth. An N rate study was added the fall before samples were taken and N addition did increase yield in the Conv and Org-CG systems despite evidence of soil N surplus. This suggests that either amino N is unavailable to plants or that root N acquisition is limited by other constraints. Low POM-C contents accompanied by high AS-N and AA-N levels reveal an imbalance in these soils which are likely to be C limited. Based on this, we conclude excess N has prevented use of organic practices from enhancing soil quality at this site.     

Growing green electricity: Progress and strategies for use of Photosystem I for sustainable photovoltaic energy conversion

Oxygenic photosynthesis is driven via sequential action of Photosystem II (PSII) and (PSI)reaction centers via the Z-scheme. Both of these pigment–membrane protein complexes are found in cyanobacteria, algae, and plants. Unlike PSII, PSI is remarkably stable and does not undergo limiting photo-damage. This stability, as well as other fundamental structural differences, makes PSI the most attractive reaction centers for applied photosynthetic applications. These applied applications exploit the efficient light harvesting and high quantum yield of PSI where the isolated PSI particles are redeployed providing electrons directly as a photocurrent or, via a coupled catalyst to yield H₂. Recent advances in molecular genetics, synthetic biology, and nanotechnology have merged to allow PSI to be integrated into a myriad of biohybrid devices. In photocurrent producing devices, PSI has been immobilized onto various electrode substrates with a continuously evolving toolkit of strategies and novel reagents. However, these innovative yet highly variable designs make it difficult to identify the rate-limiting steps and/or components that function as bottlenecks in PSI-biohybrid devices. In this study we aim to highlight these recent advances with a focus on identifying the similarities and differences in electrode surfaces, immobilization/orientation strategies, and artificial redox mediators. Collectively this work has been able to maintain an annual increase in photocurrent density (A cm^− 2) of ~ 10-fold over the past decade. The potential drawbacks and attractive features of some of these schemes are also discussed with their feasibility on a large-scale. As an environmentally benign and renewable resource, PSI may provide a new sustainable source of bioenergy. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: Keys to Produce Clean Energy.