Arable Plots Research Articles

Adoption of Conservation Tillage on the Semi-Arid Loess Plateau of Northwest China

Conservation tillage is an important approach to prevent water loss and soil erosion and promote soil fertility that has been adopted widely throughout the world. However, despite promotion of the benefits of conservation tillage, obstacles are still encountered in some regions. A survey of 385 farmer households in the semi-arid Loess Plateau of China was conducted to assess the adoption of conservation tillage (ACT). This investigation was located in two counties that have run conservation tillage demonstrations with wheat for at least eight years. A binary logistic regression model was used to quantify the factors determining whether or not farmers adopt conservation tillage. Farmer’s education level, the influence of training, and field demonstrations by agricultural departments had significant positive effects on ACT. Although the adoption rate of conservation tillage in this paper was very high (89%), farmers were reluctant to continue practicing conservation tillage based on their experiences, which is contrary to the expectations of the government. The area available for planting winter wheat and the number of arable plots per household also had significant positive effects on ACT. However, the total cultivated area of land per household had a significant negative impact on ACT. Farmer awareness of conservation tillage technology, the distance from a farmer’s house to the nearest agricultural market, and the size of the active labor force in the family had significant negative impacts on ACT. These results will help in the development of more effective and targeted policies to improve the sustainability of farming systems on the semi-arid Loess Plateau.

Seasonal and Long-Term Features of the Distribution of the Vegetation Index NDVI on Arable Lands in Bryansk Region

The features of the multi-year distribution of vegetation indices are considered as an indicator of the favorable conditions for farming, the correspondence of the set of crops with the soil, geomorphological, microclimatic characteristics of the agrolandscape. The authors presented methodical problems of using information about NDVI for remote determination and monitoring of soil properties through bioproductivity. Methods of collecting and systematizing information on the seasonal and long-term dynamics of NDVI (according to MODIS data) and some factors of the spatial distribution of its mean values were used for a detailed study of the issue. The possible mechanisms of influence of the surface slope (the values are determined by SRTM), the average humus content, the mechanical strength of soils on the NDVI distribution were shown. Information on NDVI arable land changes in the Bryansk region in the years with different meteorological conditions (2010-2015) was given. The general features of NDVI seasonal dynamics within the vegetation period were described – from late March to early November. The influence of meteorological factors on the distribution of NDVI was determined. Synchronous differences in the dynamics of NDVI for groups of arable land plots homogeneous in the state of the surface slope and agrotechnical characteristics of soils were justified from the position of seasonal dynamics of landscapes. A complex ratio of the significance of groups of factors was shown, possible models for explaining their differences in space and time were proposed.

Зміна властивостей ґрунтів у процесі спонтанної сильватизації колишніх орних земель на території Верхньодністровських Бескидів (Українські Карпати)

The peculiarities soil transformation of stages of the spontaneous afforestation in the Upper Dnister Beskid region were evaluated. The afforestation ecosystems represented series of restoration succession of forest ecosystems: arable land → ruderal stage → grassland stage → shrub stage → closed forest. The changes of the basic physical and chemical properties of the brown soils of the Upper Dniester Beskid of different stages of the afforestation within the transect of v. Gvozdenec and v. Topilnytca (Starosambirsky district of the Lviv region) were investigated. It was established that the process of spontaneous afforestation of arable land on the territory of the Upper Dniester Beskid causes an increase in actual, potential and hydrolytic acidity in the direction from the arable land to the closed forest, as well as an increase in the amount of organic matter in the forest soils compared with the arable land. Want of agricultural cultivation of the territory and the process of spontaneous afforestation an increase in the content of organic acids and salts, in particular carbon (H2CO3), in the upper horizons of the soil, which leads to changes in the actual acidity in the soil profi le. In the direction from the arable land to the closed forest there are increases in the actual acidity. Spontaneous afforestation, especially due to coniferous trees, causes a change in the amount of hydrogen and aluminum in the soil solution. The upper humus horizons had higher hydrolytic acidity than humus transitions horizons, which is related plants fall on the soil surface and the redistribution of chemical elements in the soil profile. In post-arable soils, the amount of organic carbon increases due to want of organic fertilization with the economic part of the crops and its annual input from plant fallout. It was established that the arable plots content of organic matter is 2,97–3,32 % in forest areas – 4,02–4,30 %. Key words: brown soils, physical and chemical properties, afforestation, Upper Dnister Beskid.

Non‐invasive estimation of the depth profile of soil strength with acoustic‐to‐seismic coupling measurement in the presence of crops

A traditional penetrometer measurement of soil strength in terms of penetration resistance, a useful indicator of a soil's mechanical property, is invasive and manually laborious. An alternative non‐invasive technique uses an acoustic source, two microphones and a laser Doppler vibrometer to obtain acoustic‐to‐seismic (A–S) transfer functions. Transfer functions between the acoustically‐induced soil vibration and the acoustic signals have been compared, through numerical optimizations, with predictions of a wave‐propagation model for layered poro‐elastic media. The numerically optimized shear modulus of soil was converted to the soil strength equivalent of penetration resistance by applying an empirical relation for the type of soil in question. The A–S and penetrometer measurements were made in experimental fields planted with winter wheat. The depth profiles of A–S‐deduced soil strength agree reasonably with those of penetrometer readings in shallow layers of five arable plots. We have demonstrated that the strength of soil in the presence of growing crops can be measured by this non‐invasive approach.Highlights Measurement of soil strength with a penetrometer is invasive and laborious. Acoustic‐to‐seismic (A–S) coupling has been applied to soil planted with crops. Numerically optimized shear modulus from A–S data can be converted to penetration resistance. Non‐invasive A–S method can be used as an alternative to a penetrometer.

Changes in soil carbon stock under the wheat-based cropping systems at Vojvodina province of Serbia

ABSTRACTThe aim of this study was to assess the changes in soil organic carbon (SOC) stock in relation to the carbon (C) input from nine wheat-based cropping systems and untilled grass. The SOC pool ranged from 32.1 to 49.4 Mg ha−1 at 0–20 cm and from 94 to 171 Mg ha−1 at 0–100 cm for the arable soil, while in untilled grassland, it was higher (54 and 185 Mg C ha−1, respectively). SOC stock was observed to be lower at the unfertilized 2-year rotation and higher at the 4-year rotation with manure and mineral fertilization. The study showed a winter wheat yield decrease of 176.8 kg ha−1 for a 1- Mg ha−1 SOC stock change in the 0–20-cm soil depth. The estimated C input for SOC stock maintenance was from 266 to 340 g C m−2 year−1 for winter wheat and rotations, respectively. Additional C input did not increase the SOC pool, suggesting that arable plots had a limited ability to increase SOC. These results provide guidance for the selection of management practices to improve C sequestration.

Runoff of veterinary pharmaceuticals from arable and grassland—A comparison between predictions from model simulations and experimental studies

Veterinary pharmaceuticals (VPs) are routinely used in livestock breeding. As a consequence, high concentrations of such VPs can be found in liquid manure, which is often applied to arable crops and grassland. From the soil, the VPs may enter surface water bodies via edge-of-field runoff, representing a potential risk to aquatic ecosystems. In the present study, the worst-case runoff predictions obtained by the FOCUS step 3 modeling approach, which is recommended for environmental-risk assessment of VPs in Europe, were compared with fate data obtained from experimental plot studies involving both arable and grassland plots. Five VPs were selected comprising three sulfonamides (sulfadiazine, sulfadimidine, sulfamethoxazole) and two benzimidazoles (flubendazole, fenbendazole). The respective concentrations in runoff were initially estimated using literature data for model parameterization. Subsequently, the scenarios were parameterized specifically for each experimental plot study performed, enabling a direct comparison of the model performance with the close-to-field relevant situation.Generally, substantial variations between the predicted and measured concentrations of VPs in the runoff were uncovered. Although the FOCUS prediction suggested higher concentrations than were actually measured in 65% of the cases, the runoff concentrations of VPs were underestimated in the remaining 35%. This frequent underestimation of runoff concentrations was primarily observed for the grassland plots (85% of the underestimated situations), whereas the FOCUS predictions largely overestimated the measured concentrations for the arable plots. More strikingly, when involving a difference between the measured and predicted concentrations of 10% as a validity criterion for the model, only one (out of a total of 17) runoff concentration among the five VPs (i.e., sulfadimidine) assessed in the seven scenarios fell within this tolerance margin. Thus, these results demonstrate the substantial uncertainties related to the use of the FOCUS surface water modeling approach for the prediction of VPs introduced with manure and their environmental risk.

Evaluation of the sensitivity of the mineralizable pool of soil organic matter to changes in temperature and moisture

The sensitivity of the potentially mineralizable pool of soil organic matter (Cpm) to changes in temperature and moisture has been assessed from the temperature coefficient (Q10) and the moisture coefficient (W10), which indicate how much the Cpm size changes, when the temperature changes by 10°C and the soil water content changes by 10 wt %, respectively. Samples of gray forest soil, podzolized chernozem, and dark chestnut soil taken from arable plots have been incubated at 8, 18, and 28°C and humidity of 10, 25, and 40 wt %. From the data on the production of C-CO2 by soil samples during incubation for 150 days, the content of Cpm has been calculated. It has been shown that, on average for the three soils, an increase in temperature accounts for 63% of the rise in the pool of potentially mineralizable organic matter, whereas an increase in moisture accounts for 8% of that rise. The temperature coefficients of the potentially mineralizable pool are 2.71 ± 0.64, 1.27 ± 0.20, and 1.85 ± 0.30 in ranges of 8–18, 18–28, and 8–28°C, respectively; the moisture coefficients are 1.19 ± 0.11, 1.09 ± 0.05, and 1.14 ± 0.06 in ranges of 10–25, 25–40, and 10–40 wt %, respectively. The easily mineralizable fraction (C1, k1 > 0.1 days−1) of the active pool of soil organic matter is less sensitive to temperature than the hardly mineralizable fraction (C3, 0.01 > k3 > 0.001 days−1); their Q10 values are 0.91 ± 0.15 and 2.40 ± 0.31, respectively. On the contrary, the easily mineralizable fraction is more sensitive to moistening than the hardly mineralizable fraction: their W10 values are 1.22 ± 0.06 and 1.03 ± 0.08, respectively. The intensification of mineralization with rising temperature and water content during a long-term incubation results in the exhausting of the active pool, which reduces the production of CO2 by the soils during the repeated incubation under similar conditions nonlimiting mineralization.

L’agriculture familiale malgache entre survie et développement : organisation des activités, diversification et différenciation des ménages agricoles de la région des Hautes Terres

En milieu rural des Hauts-Plateaux malgaches, les parcelles cultivables deviennent de plus en plus exigues et ne permettent pas d’assurer les besoins fondamentaux des menages. Pour faire face a l’insecurite alimentaire, les menages developpent differentes strategies pour adapter leurs moyens d’existence qui engendrent une differenciation entre exploitations. Les exploitations familiales evoluent. En l’absence de capitaux financiers et physiques, les structures demographiques jouent un role important dans les strategies d’adaptation et creent une differenciation dans l’organisation familiale des activites, les relations de travail et les structures de revenu.

Temporal variations of the distribution of water-stable aggregates, microbial biomass and ergosterol in temperate grassland soils with different cultivation histories

In grassland soils, the temporal dynamics in different fractions of soil organic carbon (SOC) is not completely understood. We investigated the temporal variations of water-stable aggregates, microbial biomass C (Cmic) and ergosterol concentrations (as a proxy for fungal biomass) in loamy sandy soils under grassland (north of Kiel, Germany). Samples were taken six times between October 2010 and October 2011 from i) a permanent grassland, ii) an arable plot converted to grassland and iii) a grassland with a one-time tillage operation (both in September 2010). Water-stable aggregate concentrations were determined by a wet-sieving procedure, Cmic concentrations by chloroform-fumigation-extraction and ergosterol concentrations by ethanol extraction. Temporal variation in aggregate distribution of soil samples from the permanent grassland was considerable: the large macroaggregate (>2000μm) concentrations (mean±standard error, n=3) in the surface soil (0–10cm) were highest in October 2011 (666±12gkg−1) and lowest in May (206±49gkg−1). The tillage operation in grassland led to lower concentrations of large macroaggregates, ergosterol and Cmic in the surface soil than in the permanent grassland. The conversion of arable land into grassland did not affect macroaggregate concentrations, despite an increase in Cmic (1.4-fold) and ergosterol concentration (3.3-fold) in the surface soil. Multiple linear regression analysis described the variations in the large macroaggregate concentration satisfactorily (R2=0.60) and indicated that the gravimetric moisture content and the Cmic concentration had positive effects and the pH a negative effect. While ergosterol concentrations (mean±standard error) showed some temporal variations (values for the surface soil in the grassland ranged from 0.5±0.1 to 1.5±0.1mgkg−1), Cmic concentrations varied much less, indicating a higher sensitivity of ergosterol to soil cultivation or changing environmental conditions.

Identification of areas with significant flood risk at the confluence of Danube and Ipeľ rivers (southern Slovakia)

The village of Chľaba is located in the southwest Slovakia, bordered with the fork of Danube River and Ipeľ River and in the southeast foothill of Burda Mts. This creates a specific rural environment of a Slovak–Hungarian border area. Ministry of Environment of the Slovak republic did not include this village in the list of potential significant flood risk areas, despite the fact that during the time of extraordinary floods, the village of Chľaba is completely separated from the only functional access road. This leads to great damages on arable land plots in the inundation area and consequently to a significant soil erosion. This phenomenon takes place in the area of huge parcels, which are characterized by intensive agriculture activities and harvests. In the paper, we tried to identify the range of the flood affected areas during the time of extraordinary floods (June 2013) and to propose flood protection arrangements within the landscape utilization changes in affected areas. The article presents the resulting map of the sloped and under-flooding areas, based not only on a terrain identification by conventional methods of field research, but also on a comparison of real slopped areas in 2013 with prognostic flood hazard map and flood risk map created by the Danube Floodrisk project. In the conclusion, we propose landscape utilization changes, which could lead to more effective human activities applications in the cadastral territory of the Chľaba village. This attitude might reduce the negative impact of floods in the researched endangered territory.

Potassium leaching from Endocalcari-Endohypogleyic Cambisol as influenced by precipitation rate and crop management

aim of this research was to compare a few crop management systems in respect of potassium leaching in order to reduce the leaching losses. Research was carried out on an Endocalcari-Endohypogleyic Cambisol (CMg-n-w- can) at the experimental site of Lithuanian Institute of Agriculture (currently - Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry). The focus was on the search for factors responsible for leaching, including precipitation amount and rate, and selected soil properties. The highest potassium cation (K + ) leaching with drainage runoff 3.8 kg ha -1 year -1 was determined in the conventional system with high K inorganic fertilization level as compared with 1.9 kg ha -1 year -1 in the treatment with zero fertilization (reference) during the first research period in 1995-1999. However, later, after a few changes in experimental design and under the drier conditions, leaching of K + was low and similar in all crop management treatments on the arable plots (approx. 1.6 kg ha -1 year -1 ). The rate of K and N fertilizers positively influenced the leaching of K + only during the normal and wet years with precipitation rate >450-600 mm. The content of soil aggregates <0.25 mm in topsoil positively correlated with K + leaching losses during the first research period (P < 0.01). During the whole research period the precipitation rate was the factor from the main effects, which explained 64% of the K + leaching variance. The final model explained 76% of K + leaching variance for all data and 65 ± 16% on cross-validation data, showing relatively high and stable accuracy of predictions. Among the variables, the interaction of precipitation rate and content of humus, the interaction between the precipitation rate and content of soil aggregates <0.25 mm were the most important, each explaining more than 60% of the variance of K + leaching losses.

Physical properties of a Rendzic Phaeozem during a ten-year period of fallowing under the conditions of south-eastern Poland

The study was concerned with the physical properties of a soil which was under natural fallow for ten years (1996–2005). The experimental sites were situated on a Rendzic Phaeozem originating from cretaceous bedrock. Two adjoining arable plots (0.2ha area of each) cultivated during the period were compared with the fallowed plot (0.1ha area). The soil under study has been in use as arable land for over 100years. The crops most frequently cultivated included cereals, sugar beet and potato. The primary soil tillage system applied was the conventional plough tillage system. An oat and barley mix was grown on this plot immediately before the fallowing started. The paper provides a presentation of results concerning the following physical properties of the soil: bulk density (BD), total porosity (TP), field air capacity (content of macropores Φ>20μm — FAC), field air permeability (FAP), moisture at the sampling moment (SM), field water capacity (FC), available water retention (AWC), unavailable water retention — wilting point (UWC), and the calculated ratio FC/TP. After the ten-year period of lying fallow the physical condition of the studied soil improved markedly. What should be noted as particularly valuable was the fact that after six years of exclusion from cultivation there was an improvement of soil compaction (BD) and an increase in total porosity (TP), field air permeability (FAP), field water capacity (FC) and available water retention (AWC). The ten-year (1996–2005) mean value of BD of the fallow soil was 1.11Mgm−3, that of the soil from Field I — 1.17Mgm−3, and from Field II — 1.15Mgm−3; TP: fallow — 0.550m3m−3, Field I — 0.531m3m−3, Field II — 0.543m3m−3; FAP: fallow — 104.1×10−8m2Pa−1s−1, Field I — 47.9×10−8m2Pa−1s−1, Field II — 66.9×10−8m2Pa−1s−1; FC: fallow — 0.374kgkg−1, Field I — 0.353kgkg−1, Field II — 0.354kgkg−1; AWC: fallow — 0.221kgkg−1, Field — 0.202kgkg−1, Field II — 0.201kgkg−1.In view of the acquired data it should assumed that long-term fallow of arable fields is one of the methods leading to the physical regeneration of soil. Favourable changes in the physical structure of soil can be achieved through the application of reduced or no-till tillage systems.

Impacts of nitrogen application rates on the activity and diversity of denitrifying bacteria in the Broadbalk Wheat Experiment

Bacterial denitrification results in the loss of fertilizer nitrogen and greenhouse gas emissions as nitrous oxides, but ecological factors in soil influencing denitrifier communities are not well understood, impeding the potential for mitigation by land management. Communities vary in the relative abundance of the alternative dissimilatory nitrite reductase genes nirK and nirS, and the nitrous oxide reductase gene nosZ; however, the significance for nitrous oxide emissions is unclear. We assessed the influence of different long-term fertilization and cultivation treatments in a 160-year-old field experiment, comparing the potential for denitrification by soil samples with the size and diversity of their denitrifier communities. Denitrification potential was much higher in soil from an area left to develop from arable into woodland than from a farmyard manure-fertilized arable treatment, which in turn was significantly higher than inorganic nitrogen-fertilized and unfertilized arable plots. This correlated with abundance of nirK but not nirS, the least abundant of the genes tested in all soils, showing an inverse relationship with nirK. Most genetic variation was seen in nirK, where sequences resolved into separate groups according to soil treatment. We conclude that bacteria containing nirK are most probably responsible for the increased denitrification potential associated with nitrogen and organic carbon in this soil.

Impact of land management practices on high‐affinity methanotrophic bacterial populations: evidence from long‐term sites at Rothamsted

The impacts of land‐use change and long‐term agricultural practices on the bacterial and methanotrophic biomass in the soils comprising the Classical Experiments at Rothamsted Research were investigated by using 13CH4 phospholipid fatty acid stable isotope probing (PLFA SIP). Nine sites were studied, including six arable plots, two regenerated woodlands and a regenerated grassland. The regenerating sites had all been in arable cropping for at least 200 years (and probably much longer) before commencing regeneration approximately 120 years ago. Six sites were plots within the Broadbalk Wheat Experiment, which had been cultivated, and on which winter wheat was grown annually for 163 years with different fertilizer and manure treatments; the field had been in arable cropping for at least 200 years previously. Triplicate soil samples were incubated under 2 ppmv 13CH4 for up to 100 days. Extraction and 13C‐PLFA analysis revealed that overall methanotrophic biomass was smaller in the Rothamsted soils compared with the other mineral soils studied to date, as indicated by poor 13C incorporation. High‐affinity methanotrophs similar to known type II methanotrophs were most abundant in all of the soils studied, except in two plots receiving farmyard manure (FYM and FYM + N). Manuring resulted in a shift to a population similar to known type I methanotrophs. Methanotrophic biomass was elevated in soils that had received the largest input of N fertilizer, though without detectable differences in CH4 oxidation rates, indicating the potential mediation of atmospheric CH4 oxidation by non‐methanotrophs, which are most likely to be nitrifying bacteria.

Distribution of soil carbon and microbial biomass in arable soils under different tillage regimes

We have measured total soil organic carbon (SOC), dissolved organic carbon (DOC), and microbial lipid contents (as indices of microbial biomass and community structure), and their distributions to 60 cm depth in soils from replicated medium-term (2003–2008) experimental arable plots subject to different tillage regimes in Scotland. The treatments were zero tillage (ZT), minimum tillage (MT; cultivation to 7 cm), the conventional tillage (CT) practice of ploughing to 20 cm, and deep ploughing (DP) to 40 cm depth. In the 0–30 cm depth range, SOC content (corrected for bulk density differences between tillage treatments) was greatest under ZT and MT, but over 0–60 cm depth the SOC contents of these treatments were similar to the CT and DP treatments. DOC concentrations declined with increasing depth in ZT and MT above 20 cm, but there were no significant differences with depth in the CT and DP treatments. Beneath 20 cm, there was little change in DOC concentration with depth for all treatments, although for the MT treatment, there was less DOC beneath the depth of cultivation. The total microbial biomass decreased with increasing depth over the 0–60 cm range in the ZT and MT treatments, whereas it decreased with depth only below 30–40 cm in the CT and DP treatments. The microbial biomass was significantly different only between 0–5 cm in the ZT, CT and DP treatments, but not for other depths between all treatments. The bacterial biomass was greater in the ZT treatment than in MT, CT and DP near the soil surface, but not significantly different over the whole profile (0–60 cm). The fungal biomass decreased with depth in the ZT and MT treatments over the whole 0–60 cm depth range, whereas it decreased with depth only below 20 cm in the CT and DP treatments.

Assessing the effects of agricultural management practices on carbon fluxes: Spatial variation and the need for replicated estimates of Net Ecosystem Exchange

Replicated measurements of Net Ecosystem CO 2 Exchange (NEE) were made on four arable plots using two eddy covariance (EC) towers that were moved at regular intervals. Replicated plots were created by dividing a large arable field into four approximately equal areas (∼2.5 ha). Regular adjustments of the EC measurement height (1.5–1.9 m) due to seasonal changes in canopy height ensured that the analyzed fluxes were derived from the individual plots. This was sufficient to make high-quality flux measurements with the energy balance accounting for up to 96% of the available energy in the system. The replicated experiment included two treatment plots managed with conventional tillage practices (CON) and two plots managed with non-inversion tillage (NIT). The mean annual NEE (aNEE) over all plots and years showed a carbon uptake of –163 g [C] m −2 y −1. Plot to plot variability ranged between 9 and 70 g [C] m −2 y −1. Differences in leaf area index (LAI) were the most likely cause of plot to plot variability. For the majority of the experiment spatial variation was greater than treatment effects and provided over half the total annual uncertainty, demonstrating the need to address spatial variability when assessing aNEE using EC techniques. Interannual variation in the measured fluxes was greater than the plot-to-plot or the treatment variations, most likely due to differences in water availability, although this could be confounded by changes in spatial variability due to other environmental factors or management operations. The proportionally large uncertainty associated with spatial and interannual variability when compared to the measured fluxes, suggests that NEE estimates are, in the short term, unlikely to result in sufficiently accurate estimates of net biome productivity (NBP) for assessing the slow accumulation/loss of SOC associated with altered tillage management without a much larger number of replicated plots. Whilst the approach used has limited statistical power it could be modified to accommodate a large number of replicates to provide more robust estimates of treatment differences.

Bettle fauna of agro and forest ecosystems in a tropical rainforest habitat, Nigeria

An investigation was carried out to study the beele fauna of a cultivated farmland and tropical rainforest plot at the Permanent. Site of Nnamd Azikiwe University, Awka for a twelve-month period using the pitfall echnique. Eight pitfall traps made up of plastic containers with mouth diameters of 9.80 cm and 6.20 cm deep were set monthly at random in the two sampling sites. Thetraps, which were filled to one third with 5 % formalin, serving a preservative, were recovered after twenty-four hours and the insects caught sorted and counted under a dissecting microscope.Species of beetle obtained from the cultivated plot were Macrocheilus labrosus, Hyparpalus sp., Carpophilus fumatus, Podagrica uniforma, Tetragonothorax sp., Chlaenius sp., Pheropsophus parallus, Silidas apicalis, Tenebroides mauritanicus, Heteroderes sp., and Heterorynchus licas whileonly Hyparpaus sp., and Mylabris sp., were obtained from the fallow pot. The result of Fisher's Least Significance Difference (F-LSD) test shows that the pitfall catches of beetles from the two samping sies were significanty dierent at p-value of 0.0002 and mean dference of 3.417. The heterogeneity of the beele species at the cultivated plot was traced to nature of vegetation and mode of life of the beetle species. The role of certain beetle families as faunal indicators was highlighted. Other factors, which influenced the beetle species at the arable plot and their non-trapping at the forest ecosystem, were also discussed.Keywords: Beetle fauna, Arable plot, Secondary regrowth forest, Pitfall traps

Interactive evaluation of the main agrotechnical factors in rape production

Our polifactorial rape research was carried out at Látókép Research Centre of Debreceni Egyetem AMTC, 15 km away from Debrecen. The aim was to study the unique effect and the interactive effect of more factors. The research factors were the following: cultivation, time of sowing and nutrient supply. Soil moisture datas proved unambiguously that increasing amounts of chemical fertilizer raise the water consumption of rape, lack of water in fertilized plots were always bigger then the water deficit in control plots. The highest amount of water deficit was experienced in the case of arable plots. However, increasing amounts of chemical fertilizers raised the amount of yield proportionately. We experienced yield depression only in the case of arable plots at the highest level of chemical fertilization. In polifactorial rape research sowing of 24th August 2007 of 2007/2008 was the most optimal in point of the amount of yield. This is most-significant in the case of loosening tillage and disking tillage plots, while the plots of ploughing lag behind those two in point of average yield. We experienced the biggest differences of yield in the case of different tillage plots of sowing on 24t August 2007. Still not even the plot with the highest average reached the limit of 4 tons, which can be attributed to high rate of lodging and the harvest loss caused by this. The biggest amount of yield was experienced in the case of sowing of 24th August 2007, with the highest level of chemical fertilization at loosening tillage plot (3930 kg/ha). We can observe big differences between the tillage methods; plots of loosening show a much better average yield then plots of disking and ploughing tillage. Considering the first observed crop year we can state that alternative tillage methods do have a future in rape growing of Hungary.

Rates of sheet and rill erosion in Germany — A meta-analysis

Knowledge of erosion rates under real conditions is of great concern regarding sustainability of landuse and off-site effects on water bodies and settlements. Experimentally derived rates of sheet and rill erosion are often biased by experimental settings, which deviate considerably from typical landuse, by short measuring periods and by small spatial extensions, which do not account for the pronounced spatio-temporal variability of erosion events. We compiled data from 27 studies covering 1076 plot years to account for this variability. Modelling was used to correct for deficiencies in the experimental settings, which overrepresented arable land and used steeper and shorter slopes as well as higher erosivity than typically found in reality. For example, the average slope gradient was 5.9° for all arable plot experiments while it is only 2.6° on total arable land in Germany. The expected soil loss by sheet and rill erosion in Germany after taking real slopes, landuse and erosivity into account averaged 2.7 t ha − 1 yr − 1 . Annual crops contributed the largest proportion (90%) but hops despite its negligible contribution to landuse (0.06%) still contribute 1.0% due to its extraordinary rapid erosion, which was even faster than the measured bare fallow soil loss standardized to otherwise identical conditions. Bare fallow soil loss, which is often used as baseline, was 80 t ha − 1 yr − 1 when standardized to 5.1° slope gradient, 200 m flow path length, and average German erosivity.

The widespread occurrence of Celtic field systems in the central part of the Netherlands

The detailed elevation model based on airborne laser altimetry (AHN) proved to be a reliable tool to detect well-developed Celtic field systems, characteristic arable plots of the Iron Age. They were detected in the central part of the Netherlands, where only a limited number of Celtic field systems have been recognized in the past. Most of these previously detected systems were identified in the northern part of the Netherlands or in the southern part, but not in this zone. About 1200 ha of well-developed systems could be identified by AHN in the central part of the Netherlands, of which only 136 ha were registered as an archaeological monument. Another 335 ha of archaeologically identified Celtic field systems were not accepted or recognized by AHN, because they were morphologically less well-developed. Most of the around 1050 ha new discoveries occur in rough vegetations and forested areas, and can hardly be identified with previously used geodetic methods and aerial photography. Less well-developed or preserved systems were even more extensive and remnants were traced as fossil arable layers below plaggen soils or on lower slopes incorporated in mediaeval reclamations. The newly identified Celtic field systems, therefore, can be considered as remnants of much larger areas once covered with these arable plots. In the central part of the Netherlands, the estimated area once covered was at least around 4500 ha, more than enough to supply 10,000 people with cereals. Well-developed Celtic field systems started to develop in the late Iron Age with formation intensifying during the early Roman Period. The central part of the Netherlands is situated just north of the river Rhine, the former boundary of the Roman Empire, the Limes. The newly discovered extent of Celtic field systems will have influenced the interaction between different cultures on the border of the Roman Empire in the early Roman Period, about which very little is known. This perspective underscores the need for an integrated conservation policy and in-depth research through excavations in the near future.