Adaptive migratory orientation of an invasive pest on a new continent

Many species of insects undertake long-range, seasonally reversed migrations, displaying sophisticated orientation behaviors to optimize their migratory trajectories. However, when invasive insects arrive in new biogeographical regions, it is unclear if migrants retain (or how quickly they regain) ancestral migratory traits, such as seasonally preferred flight headings. Here we present behavioral evidence that an invasive migratory pest, the fall armyworm moth (Spodoptera frugiperda), a native of the Americas, exhibited locally adaptive migratory orientation less than three years after arriving on a new continent. Specimens collected from China showed flight orientations directed north-northwest in spring and southwest in autumn, and this would promote seasonal forward and return migrations in East Asia. We also show that the driver of the seasonal switch in orientation direction is photoperiod. Our results thus provide a clear example of an invasive insect that has rapidly exhibited adaptive migratory behaviors, either inherited or newly evolved, in a completely alien environment

Analysis of variance in soil research: let the analysis fit the design

Sound design for experiments on soil is based on two fundamental principles: replication and randomization. Replication enables investigators to detect and measure contrasts between treatments against the backdrop of natural variation. Random allocation of experimental treatments to units enables effects to be estimated without bias and hypotheses to be tested. For inferential tests of effects to be valid an analysis of variance (anova) of the experimental data must match exactly the experimental design. Completely randomized designs are usually inefficient. Blocking will usually increase precision, and its role must be recognized as a unique entry in an anova table. Factorial designs enable questions on two or more factors and their interactions to be answered simultaneously, and split-plot designs may enable investigators to combine factors that require disparate amounts of land for each treatment. Each such design has its unique correct anova; no other anova will do. One outcome of an anova is a test of significance. If it turns out to be positive then the investigator may examine the contrasts between treatments to discover which themselves are significant. Those contrasts should have been ones in which the investigator was interested at the outset and which the experiment was designed to test. Post-hoc testing of all possible contrasts is deprecated as unsound, although the procedures may guide an investigator to further experimentation. Examples of the designs with simulated data and programs in GenStat and R for the analyses of variance are provided as File S1

Disentangling the effect of farming practice and aridity on crop stable isotope values: a present-day model from Morocco and its application to early farming sites in the eastern Mediterranean

Agriculture has played a pivotal role in shaping landscapes, soils and vegetation. Developing a better understanding of early farming practices can contribute to wider questions regarding the long-term impact of farming and its nature in comparison with present-day traditional agrosystems. In this study we determine stable carbon and nitrogen isotope values of barley grains from a series of present-day traditionally managed farming plots in Morocco, capturing a range of annual rainfall and farming practices. This allows a framework to be developed to refine current isotopic approaches used to infer manuring intensity and crop water status in (semi-)arid regions. This method has been applied to charred crop remains from two early farming sites in the eastern Mediterranean: Abu Hureyra and ‘Ain Ghazal. In this way, our study enhances knowledge of agricultural practice in the past, adding to understanding of how people have shaped and adapted to their environment over thousands of years

Identification and expression profiling of Pht1 phosphate transporters in wheat in controlled environments and in the field

Phosphorus (P) is an important macronutrient with critical functions in plants. Phosphate (Pi) transporters which mediate Pi acquisition and Pi translocation within the plant are key factors in Pi deficiency responses. However, their relevance for adaptation to long-term Pi limitation under agronomic conditions, particularly in wheat, remains unknown. Here, we describe the identification of the complete Pi transporter gene family (Pht1) in wheat (Triticum aestivum). Gene expression profiles were compared for hydroponic and field-grown plant tissues of wheat at multiple developmental stages. Cis-element analysis of selected Pht1 promoter regions was performed. A broad range of expression patterns of individual TaPht1 genes was observed in relation to tissue specificity and the nutrient supply in the soil or in liquid culture, as well as an influence of the experimental system. The expression patterns indicate the involvement of specific transporters in Pi uptake, and in Pi transport and remobilization within the plant, at different growth developmental stages. Specifically, the influence of Pi nutrition indicates a complex regulatory pattern of TaPht1 gene transcript abundances as a response to low Pi availability in different culture systems, correlating with the existence of different cis-acting promoter elements

Simulating long-term carbon nitrogen and phosphorus biogeochemical cycling in agricultural environments

Understanding how agricultural practices alter biogeochemical cycles is vital for maintaining land productivity, food security, and other ecosystem services such as carbon sequestration. However, these are complex, highly coupled long-term processes that are difficult to observe or explore through empirical science alone. Models are required that capture the main anthropogenic disturbances, whilst operating across regions and long timescales, simulating both natural and agricultural environments, and shifts among these. Many biogeochemical models neglect agriculture or interactions between carbon and nutrient cycles, which is surprising given the scale of intervention in nitrogen and phosphorus cycles introduced by agriculture. This gap is addressed here, using a plant-soil model that simulates integrated soil carbon, nitrogen and phosphorus (CNP) cycling across natural, semi-natural and agricultural environments. The model is rigorously tested both spatially and temporally using data from long-term agricultural experiments across temperate environments. The model proved capable of reproducing the magnitude of and trends in soil nutrient stocks, and yield responses to nutrient addition. The model has potential to simulate anthropogenic effects on biogeochemical cycles across northern Europe, for long timescales (centuries) without site-specific calibration, using easily accessible input data. The results demonstrate that weatherable P from parent material has a considerable effect on modern pools of soil C and N, despite significant perturbation of nutrient cycling from agricultural practices, highlighting the need to integrate both geological and agricultural processes to understand effects of land-use change on food security, C storage and nutrient sustainability. The results suggest that an important process or source of P is currently missing in our understanding of agricultural biogeochemical cycles. The model could not explain how yields were sustained in plots with low P fertiliser addition. We suggest that plant access to organic P is a key uncertainty warranting further research, particularly given sustainability concerns surrounding rock sources of P fertiliser

The importance of long‐term experiments in agriculture: their management to ensure continued crop production and soil fertility; the Rothamsted experience

Summary Long‐term field experiments that test a range of treatments and are intended to assess the sustainability of crop production, and thus food security, must be managed actively to identify any treatment that is failing to maintain or increase yields. Once identified, carefully considered changes can be made to the treatment or management, and if they are successful yields will change. If suitable changes cannot be made to an experiment to ensure its continued relevance to sustainable crop production, then it should be stopped. Long‐term experiments have many other uses. They provide a field resource and samples for research on plant and soil processes and properties, especially those properties where change occurs slowly and affects soil fertility. Archived samples of all inputs and outputs are an invaluable source of material for future research, and data from current and archived samples can be used to develop models to describe soil and plant processes. Such changes and uses in the Rothamsted experiments are described, and demonstrate that with the appropriate crop, soil and management, acceptable yields can be maintained for many years, with either organic manure or inorganic fertilizers. Highlights Long‐term experiments demonstrate sustainability and increases in crop yield when managed to optimize soil fertility. Shifting individual response curves into coincidence increases understanding of the factors involved. Changes in inorganic and organic pollutants in archived crop and soil samples are related to inputs over time. Models describing soil processes are developed from current and archived soil data

IACR report for 1999

SIGLEAvailable from British Library Document Supply Centre-DSC:4358.860(1999) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Yields of the field experiments 1994

SIGLEAvailable from British Library Document Supply Centre- DSC:9418.37(1994) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Integrated approach to crop research

SIGLEAvailable from British Library Document Supply Centre-DSC:4358.860(1998) / BLDSC - British Library Document Supply CentreGBUnited Kingdo