Key soil and topographic properties to delineate potential management classes for precision agriculture in the European loess area

Recent advances in on-the-go soil sensing, terrain modelling and yield mapping have made available large quantities of information about the within-field variability of soil and crop properties. But the selection of the key variables for an identification of management zones, required for precision agriculture, is not straightforward. To investigate a procedure for this selection, an 8 ha agricultural field in the Loess belt of Belgium was considered for this study. The available information consisted of: (i) top- and subsoil samples taken at 110 locations, on which soil properties: textural fractions, organic carbon (OC), CaCO₃ and pH were analysed, (ii) soil apparent electrical conductivity (EC_a) obtained through an electromagnetic induction based sensor, and (iii) wetness index, stream power index and steepest slope angle derived from a detailed digital elevation model (DEM). A principal component analysis, involving 12 soil and topographic properties and two EC_a variables, identified three components explaining 67.4% of the total variability. These three components were best represented by pH, EC_a that strongly associated with texture and OC. However, OC was closely related to some more readily obtainable topographic properties, and therefore elevation was preferred. A fuzzy k-means classification of these three variables produced four potential management classes. Three-year average standardized yield maps of grain and straw showed productivity differences across these classes, but mainly linked to their landscape position. In the loess area with complex soil-landscape interactions pH, EC_a and elevation can be considered as key properties to delineate potential management classes.     

The Level II aggregated forest soil condition database links soil physicochemical and hydraulic properties with long-term observations of forest condition in Europe

Key message

Aggregated, consolidated, and derived soil physicochemical data of 286 ICP Forests Level II plots were completed with soil hydraulic properties for integrated use with forest monitoring data. Database access should be requested at http://icp-forests.net . Metadata associated available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=153e599e-6624-4e2b-b862-8124386ea9cd&hl=eng

Context

The ICP Forests database is one of the most comprehensive forest ecosystem datasets in Europe and contains the accumulated results of more than two decades of harmonised forest monitoring all over Europe.

Aims

The aim of this paper is to share knowledge on the ICP Forests Level II soil data for broader use among forest scientists.

Methods

After standard analysis, quality checks, aggregation, and calculation of derived variables (e.g. nutrient stocks, base saturation, C:N ratio, and water retention parameters), data have been gathered into a static database (AFSCDB.LII.2.2), which will be updated to new versions as soon as new measurements become available.

Results

The database provides a basis for the combined evaluation of up to 130 unique soil variables of 286 plots with dynamic data on tree growth, ground vegetation, foliar chemistry, crown condition, tree phenology, leaf area index, ozone injury, litterfall, soil solution chemistry, deposition, ambient air quality, and meteorological data assessed on the same plots.

Conclusion

The unprecedented comprehensiveness and level of detail in this newly aggregated database may overcome existing restrictions so far impeding the realisation of large-scale forest ecosystem studies in Europe.

     

Integrated pest management of Tuta absoluta: practical implementations across different world regions

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...     

Germination and seedling growth of <Emphasis Type="Italic">Dimorphandra jorgei</Emphasis> MF Silva and <Emphasis Type="Italic">Swartzia macrostachya</Emphasis> Benth. var. <Emphasis Type="Italic">riedelii</Emphasis> Cowan

Dimorphandra jorgei MF Silva (Caesalpinaceae) and Swartzia macrostachya Benth. var. riedelii Cowan (Fabaceae) are tree species from the southern Bahian Atlantic Forest, identified for the restoration of degraded areas. The objective of this research is to study their seed germination and seedling growth to develop simple methods for seedling production in small scale nurseries. Because the species have distinct dormancy and germination characteristics, the seeds were submitted to different treatments. D. jorgei seeds were immersed in hot water, scarified and stored for 12 weeks in the laboratory environment (25°C). S. macrostachya seeds were submitted to different combinations of drying and storage in the laboratory environment or refrigerator (4°C). Seedlings were submitted to two light treatments for 3 months: partial shade (52% of full sun) and full shade (12% of full sun). In D. jorgei, the highest germination occurred for scarified seeds (87%) and for seeds stored for 12 weeks and then scarified (69%). In S. macrostachya the undried control seeds had the highest germination, followed by that of the refrigeration storage treatment, without predrying (99% and 97%, respectively). The average values for the growth parameters were greater in full shade for D. jorgei, while S. macrostachya seedlings showed greater growth rates in partial shade. Two months growth is recommended before D. jorgei seedlings are of the sufficient size and leaf number for field planting. On the other hand, a period of 4 months is recommended for S. macrostachya, due to its relatively slow growth.     

Field resistance to bacterial canker in some cherry seedling populations

In 9–13 year old cherry seedling populations, totalling 1,033 individuals, a preliminary selection was made in 1963, for field resistance to bacterial canker (Pseudomonas syringae van Hall).The field resistance of the three cherry species used, P. avium, P. cerasus and P. avium × P. cerasus, has shown to be low, high and very high, respectively.     

Feature extraction and recognition technique for human pulse signals

In Chinese traditional medicine, the pulse signal plays an important role for diagnosis. To investigate the effective technique for identifying heroin druggers through the pulse signal, the feature extraction algorithm based on the biocepstrum and the third-order cepstrum entropy of the pulse signal is studied. On the basis of concise and rigorous discussion for the algorithm, the biocepstrum-based diagonal slice components are estimated for human pulse signals of 20 heroin druggers and 20 healthy normal subjects. The magnitude of the sample value of diagonal slice at m=n=1 and the third-order cepstrum entropy of magnitudes of sample values of the diagonal slice within a particular region are used as two feature parameters for every human pulse signal to form a feature vector. A classifier based on the criterion of squared Mahalanobis distance is successfully designed. Applying the designed classifier to 40 feature vectors, the correct identification rate reaches 87.5%. The research result shows that the method of the feature extraction and classifier design presented in is valuable for identifying the human pulse signals of heroin druggers.     

Variation for plant characters and for performance of softwood cuttings of Rosa canina ‘Inermis’ seedlings

Summary Thirty, one-season-old Rosa canina Inermis seedlings (8–12 mm in diameter) were grown in the greenhouse. After 5 months, single-node softwood cuttings were made of each plant. Analysis of variance demonstrated marked differences between the internode length, number of leaflets per leaf and the leaf area of the original seedling, and between the time of axillary bud-break, axillary sprout length and weight of adventitious roots of their 23-day-old cuttings. Clonal root weight of cuttings was highly significantly correlated with: number of leaflets per leaf (r=–0.65), leaf area (r=+0.65), and days to axillary bud-break (r=+0.62). The origin of heterogeneity among Inermis seedling rootstocks, its probable effect on the flower production of cut roses and its possible use in the selection for clonal rootstocks are discussed.     

Mid-infrared absorption properties of green wood

There is a lack of quantitative data on the penetration depth and the amount of energy absorbed by green wood under infrared (IR) radiation. This lack of knowledge is a potential barrier to the development of IR heating as an alternative to soaking as a means of warming logs prior to peeling in the manufacture of plywood. Experimental measurements of normal hemispherical spectral reflectance and transmittance over the range 550–5,500 cm^?1 wavenumbers on four wood species, beech, birch, Douglas-fir and spruce have brought new knowledge on mid-infrared absorption properties of green wood and removed some uncertainties. For instance, it is not possible to deliver energy deeper than up to 0.3 mm below the wood surface because 70–90 % of all incident IR radiation on the wood surface is absorbed in this layer. Some wood features, such as surface quality, the presence of knots and of free water in wood (the latter two having a more significant effect) influence the amount of energy absorbed. These results illustrate that IR radiation can heat the surface layers, but then heat penetrates deeper into the inside layers of wood by conduction.     

Electrical stunning followed by decapitation or chilling of African catfish (Clarias gariepinus): assessment of behavioural and neural parameters and product quality

The objective of this study was to assess neural and behavioural responses in farmed African catfish (Clarias gariepinus) upon electrical stunning in combination with decapitation or chilling. To assess the possibility of scaling up one or both experimental methods, two trials were performed in an experimental setting. The product quality of the collected samples was compared with the currently applied industrial method: live chilling. After electrical stunning in combination with decapitation, the fish showed spikes alternated with theta and delta waves on the EEG, followed by minimal brain activity after 20±10 s. The same traces on the EEGs were observed after electrical stunning in combination with chilling. Here, minimal brain activity occurred after 22±11 s. Within a confidence level of 95%, the percentage of African catfish that was effectively stunned after administration of an electrical current of 1.5 A dm⁻², 300 V (50 Hz a.c.), followed by decapitation or chilling was above 91%. The analysis yield and evolution of liquid loss showed significant (P<0.05) differences among the batches, which could be explained by the stunning method used. The course values of the pH in the different batches were significantly (P<0.05) dependent on the stunning method, sex and location (visceral or skin side). It is concluded that African catfish can be stunned effectively using electrical stunning in a water tank, followed by decapitation or chilling in ice. Dutch commercial processors prefer to combine electrical stunning with chilling in flake ice in a rotating tumbler, as the outer slime layer is then removed, which facilitates further processing.