Ploughed Soil Research Articles

Simulation of Mouldboard Plough Soil Cutting Based on Smooth Particle Hydrodynamics Method and FEM–SPH Coupling Method

In the field of agricultural machinery, various empirical field tests are performed to measure the tillage force for precision tillage. However, the field test performance is costly and time-consuming, and there are many constraints on weather and field soil conditions; the utilization of simulation studies is required to overcome these shortcomings. As a result, the SPH method and the coupled FEM-SPH method are used in this paper to investigate the mouldboard plough–soil interaction. In this paper, the finite element software LS-DYNA was used to build the SPH model and the FEM-SPH coupling model of soil cutting, as well as to investigate the change in cutting resistance during the soil cutting process. The simulation results are compared with those of the experiments, and the curves of the simulation and experiment are in good agreement, which verifies the reliability of the model. The validated simulation model was used to investigate the effects of the cutting speed, depth of cut, inclination angle, and lifting angle of the mouldboard plough on cutting resistance. The simulation studies show that the SPH model takes 5 h and 2 min to compute, while the FEM-SPH coupled model takes 38 min; obviously, the computational efficiency of the FEM-SPH coupled model is higher. The relative errors between the SPH model and the experiment are 2.17% and 3.65%, respectively. The relative errors between the FEM-SPH coupled model and the experiment are 5.96% and 10.67%, respectively. Obviously, the SPH model has a higher computational accuracy. The average cutting resistances predicted by the SPH model and the FEM-SPH coupled model, respectively, were 349.48 N and 306.25 N; these resistances are useful for precision tillage. The cutting resistance increases with the increase in cutting speed and is quadratic; the cutting resistance increases with the increase in cutting depth and is quadratic; the horizontal cutting resistance and the combined cutting resistance increase with the increase in inclination angle, while the vertical cutting resistance remains essentially constant with the increase in inclination angle; the horizontal cutting resistance and combined cutting resistance increase as the lifting angle increases, while the vertical cutting resistance decreases as the lifting angle increases.

Root rot of spring wheat in field crop rotations in the forest-steppe of the Irkutsk region

The paper presents the results of the studies to assess the prevalence of root rots and yields of spring wheat in the forest-steppe zone of the Irkutsk region in field crop rotations on different back-grounds of fertilization and tillage practices. The experiment scheme: forecrops – fallow in crop rotation (fallow – wheat – oats), pea-oat mixture and corn in crop rotation (pea-oat mixture – wheat – corn – wheat); tillage methods – plowing with PLN-5-35 plow to a depth of 20-22 cm, BDT-3 disking to a depth of 12-14 cm; fertilization - no fertilizer, complete mineral fertilizer N45P45K45. The prevalence of root rot decreased on average for 3 years in the crop rotation with 33 % saturation of wheat and its sowing on a fallow forecrop in comparison with 50 % saturation in pea-oats by 6.1 %, in corn by 0.9 %; disc tillage compared to plowing in fallow forecrop by 11.8 %, in pea oats by 4.7 %, in corn by 9.2 %; on fertilized background in three-field crop rotation in fallow by 4 %, in pea oats by 1.9 %, in corn by 4.8 %. Statistically reliable highest yield of spring wheat was observed in three-field crop rotation with 33 % saturation of wheat on fallow at soil plowing, which is higher than similar soil treatment in crop rotation with 50 % saturation of wheat at sowing on pea and oat mixture by 31.3 %, on corn by 23.8 %. Application of mineral fertilizers N45P45K45 increased the yield, while tillage with discing and the forecrops such as pea and oat mixture and corn decreased the yield. Over the rotation, root rot incidence decreased from baseline with a concomitant increase in yield – with 33 % wheat saturated in the rotations by 9.0 % and 35.0 %, and with 50 % wheat saturated in the rotations by 6.6 % and 45.7 %.

Factors Governing Organic Amendments and NPK Fertilizers Effects on Sweet Maize in Old and Intensively Cultivated Experimental Farm

Applying organic amendment (OA) containing humic compounds (HC) and phytohormones is a promising solution to intensify sustainable food production under increasing global food needs, declining environmental carrying capacity and changing climate. However, most positive claims on OA efficacy often came from controlled, greenhouse experiments. The field trial was conducted on an intensively cultivated experimental farm station, Department of Soil Science and Land Resources, Faculty of Agriculture, IPB University. The OA testing was done on sweet maize (Zea mays L. saccharata) using a fractional factorial randomized block design by comparing five rates of the organic amendment (0, ½, 1, 1½, and 2 standards OA) with three rates of NPK fertilizer (0, 1, and ¾ standards NPK). The results revealed that a single OA application did not significantly boost the growth and biomass of sweet maize, especially when applied to an old and intensively cultivate and organically manured farm. OA had significant interaction with NPK at most of the yields and biomass parameters. Amending soils more than 12 L OA ha-1 could improve the sweet maize’s growth and development while saving 25% NPK fertilizers. Linear mixed effect model and multivariate analysis uncovered higher heterogeneity in trial plots controlled maize growth, biomass, and agronomic effectivity, regardless of the given treatments. This study highlighted three important marks for future research: (1) soil plowing, harrowing and mixing must be intensively done across plots, (2) adequate HC contents must be increased from the OA current rate, and (3) the greater role of phytohormone in stimulating maize growth and production at the OA current rate.

Retrospective Analysis of the History of Agricultural Development and Evaluation of Soil Erosion Rates in the Lokna River Basin, Tula Oblast

—According to published and archival data, the dynamics of soil plowing in Tula oblast in general and in its particular districts has been traced. It has been found that the active agricultural development in the southern part of the modern Tula oblast began no earlier than in the middle of the 17th century. According to the maps of different years, changes in the area of arable land in the Lokna River basin (Plavsk district of Tula oblast) from the end of the 18th century until the present time have been determined. The reliability of our data on the history of plowing of the territory is confirmed by the literature data. The composition of field crops and changes in farming systems during the period under review have been reconstructed, and a significant conservatism of these indicators has been revealed: the fallow three-field system dominated throughout the 19th century and the first half of the 20th century; the predominance of rye among winter crops and oats among spring crops remained until the 1970s. According to the WaTEM/SEDEM and using historical data on changes in the main factors of soil erosion as input parameters, the intensity and volumes of rainfall runoff for the selected stages of development of the Lokna River basin have been calculated. In order to compare the results with the literature data for the period of 1980–1993, the rates and volumes of snowmelt washout have been estimated. An assessment of the reliability of the reconstructed model parameters for remote historical epochs has been carried out. The analysis of historical changes in the factors and rates of erosion indicates that the maximum extent of plowed area and the maximum intensity of erosional processes in Lokna River took place in the last quarter of the 19th–early 20th centuries. The influence of particular geomorphic positions of arable land on the rates and volumes of soil erosion has been revealed.

Teff and Wheat Yield Variation With Phosphorus Application In Jamma District, Ethiopia

Different plant species has different nutrient requirements and utilize nutrients in different ways. Biological activity contributes to P solubilization through mineralization, wheathering, and other physicochemical reactions so that the soil plow layer is the major source of soil availabile P for crops. Ethiopia Ministry of Agriculture and Natural Resource and ATA recommended six types of blended fertilizers (NPSZnB, NPKSB, NPKSZnB, NPSZn, NPSB and NPS) for the Amhara region. Our study was conducted in Jamma districts of eastern Amhara, Ethiopia, during 2018 cropping season to attest the yield of teff (Dega teff) and wheat (Danda’a) due to phosphorus fertilizer application. Fertilizer treatments tested were the recommended dose of N only, recommended dose of NP, 50 kg.ha-1 NPS, 100 kg.ha-1 NPS, and 150kg. ha-1 NPS, set up in a. randomized complete block design with three replication, and conducted on four sites. Our study demonstrated that applications of N and P fertilizers significantly improved grain yield of wheat and teff, and that there was significant yield differences (P < 0.05) between different rates of P fertilizer. Therefore, even though the soil P levels were shown to be sufficient, application of both N and P fertilizer in the Jamma district is essential to increase yield of teff and wheat.

Влияние навозных стоков на почвенные фототрофные микроорганизмы

Soil phototrophic microorganisms (algae, cyanobacteria) play a very important role in functioning of anthropogenic systems. They take an active part in soil self-purification by directly absorbing biogenic elements, as well as by stimulating the activity of mineralizing microorganisms at the expense of disengaged oxygen. The research was carried out at a plough field with sod-podzol soil situated near a large pig-breeding farm. Neutralization took place due to natural microbiological processes during the time of disgorging the liquid fraction in the lagoons. Long-term application of manure runoff from pig-breeding farms into plough soil had an impact on species diversity of phototrophic microorganisms, which was considered in the research. Groups of species tolerant to the impact formed in the soil in course of long-term application of liquid manure fraction. The influence of long-term runoff of manure from pig breeding farms on specious diversity of soil phototrophic microorganisms was assessed. In plough soils affected by liquid manure runoff a group of species tolerant to this impact has formed. Their basis is represented by green algae: Klebsormidium flaccidum, K. nitens, Chlorococcum infusionum, Chlorella vulgaris, as well as by the heterocyst-free cyanobacteria Phormidium autumnale and the diatom alga Hantzschia amphioxys. On the surface of plough soil these species make microscopically marked films, i. e. soil “blooming” takes place. General species diversity of microphototrophs in soil of the experimental site is lower than that of the control site. Jaccard coefficient of the experimental and control sites of the field is 47.8%. Nitrogen-fixing cyanobacteria are not represented in the microphototrophic community; it indicates that the natural microcoenosis is damaged in the plough soils and nitrogen content is high.

Results of studies on the sealing of crop residues of leguminous crops with ploughshares

The article presents the results of experimental studies of the sealing of crop residues and their distribution over the depth of the cultivated soil layer by known general-purpose ploughshares without ploughshares. The research was carried out in fields with agrophones of winter wheat, chickpeas and winter rapeseed. The plowing of dark chestnut soils located in the steppe soil-climatic zone of the Left-Bank district of the Saratov region was carried out by aggregates K-701+PNL-8-40, K-701+PSK-8 and T-150K+PLN-5-35. As a result of field experiments, it was found out that straw, pollen and stubble are embedded in the soil in accordance with established agrotechnical requirements, more than 80%. Crop and plant residues are located in the bulk in the deep layers of the cultivated soil. Part of the stubble in an inclined position is located in the places where the layers of adjacent passages of the plow hulls meet. The design of the ploughshare-dump surface of the housing does not allow managing the upper organic-enriched soil layer.

Biological Basis of High Productivity of Pomegranate Plant

Punica granatum L. is propagated by seeds and cuttings. Propagation of the plant by cuttings is preferred. The main goal of our experiment is to monitor the process of biological development during the reproduction of pomegranate varieties with cuttings and to compare and reproduce the better developing pomegranate varieties. We conclude from the research that pomegranate grows in any soil. But a better developed root system, high productivity occurs in bushes grown in moist and fertile soils. Also, after transplanting young plants (one-year and two-year) to the open air, watering and cultivation of the plant should be done seriously. For this, more attention should be paid to soil plowing, weeding, and agrotechnical rules in the first 3 months.

Field management of Phelipanche ramosa on tomatoes by plowing depth or resistance strategies

Two separate independent experiments were carried out on agronomic approaches for controlling infestation by Phelipanche ramosa: the evaluation of two soil plowing depths (30 and 50 cm) and determining the resistance of two tomato cultivars (SV5197 and SV8840) to this parasitic plant. The experiments were performed in 2014 and 2018 seasons in naturally heavily infested fields in the province of Foggia (Apulia Region, south-eastern Italy). Based on our results, the 50 cm moldboard plowing depth reduced parasite infestation by 41.2% compared to that of 30 cm depth, commonly adopted by local farmers. Higher attachments to the host plants were observed in SV5197 than in SV8840, which could be correlated with the different level of resistance of the host plant. In both experiments, the highest Phelipanche infestation reduced the tomato yield but did not affect the fruit quality.

Evaluation of the efficiency of some pheromone traps in attracting adults of the peach fruit fly Bactrocera zonota (Saunder) (Diptera: Tephretidae) in an orchard in Karbala Province, Iraq

A study was conducted to evaluate the efficiency of the integrated control program for the peach fruit fly. Different attractant pheromone traps and treatments of fungi, biocides and some agricultural operations to attract and catch adult insects in citrus orchards in Karbala during the fall season 2021-2022. The fungi Beuveria bassiana, Metarhizum anisopliae and the pesticide Balizin S165% were used with different pheromone traps Delta trap (Jackson red trap), Tefrey yellow trap, Spanish Olipe trap, and the local trap. Also, within the integrated control program, a study was conducted on the efficiency of attractant pheromone traps with the pesticides Tondexir EC80%, Success 0.02CB, and some agricultural operations such as wrapping the fruits in paper bags, tilling the soil, cleaning the weeds, and covering the soil with polyethene. The treatment of M. anisoplia with the two traps of Jackson (fruit fly pheromone) and Tefrey trap (a new peach fly pheromone) gave 95.8 % of effect through attraction within 6 days. As for the two treatments of the B. bassiana fungus and the pesticide Balizin with the two traps of Jackson and the Trap of Tefrey, the pheromone traps were almost identical in the same effect in attraction and entrapment reached 74.5 and 73.09, respectively. There were significant differences in the number of adults attracted to the traps in the study site, where the efficiency of pheromone traps was characterized by the agricultural operations of covering the soil with polyethene, soil ploughing and cleaning weeds with two Jackson traps (fruit fly pheromone) and the local trap gave the highest rate of effect by trapping the most significant number of adults over 6 days. In a study of the efficiency of all the treatments used in the integrated insect control program in reducing the infection rate on citrus trees, it was noted that all the treatments used caused a decrease in the average number of infected fruits during the first, second, and third weeks. The statistical analysis proved that the rate of infected fruits of citrus trees in the different treatments did not differ statistically among them. Based on the study's results, attractive pheromone traps can target adult insects as one of the components of integrated control programs for the peach fruit fly.

Conservation Tillage Improves Soil Quality and Crop Yield in Hungary

This paper provides an overview of the progress of tillage in Hungary. The local and international impacts on the national practice are summarized, and some adoption of the conservation tillage results is presented concerning Hungary. The interest in conservation agriculture in Hungary dates back almost 120 years; however, any significant changes only occurred in the last 50 years. Interestingly, the factors of progress and restraint in tillage have appeared simultaneously over the years. Among the factors restraining tillage progress, the most retarding were the beliefs that have existed for many decades, as soil conservation was not considered nor was the need to mitigate climate-related hazards. Progress was driven by the commitment to soil protection, the opportunity to raise farming standards, and the need to mitigate climate-related threats. Since the average yield in Hungary was usually sufficient for the domestic need, the main objective of crop production was to avoid yield loss. Long-term experimental data and monitoring results were considered for this study. The impacts of new tillage solutions, elaborated in foreign countries, on tillage modernization were reviewed. The experiences and first results in no-till (direct drilling) and strip-tillage showed that difficulties can gradually be reduced through site-specific technology solutions. The need for subsoiling is not a matter of debate nowadays but rather the timing of operation and the investigation of the duration of the effects. Due to its complex advantages, tine tillage occupies an increasing rank among soil conservation systems. The area of ploughed soils has decreased; however, improved implementation is required.

Increase in Productivity of Chestnut Soils on Irrigated Lands of Northern and Central Kazakhstan

Natural conditions in North and Central Kazakhstan and the energy potential of chestnut soil testify to the efficiency of agriculture, especially on irrigated lands. The humus horizon of chestnut soils is 35–50 cm, and the humus content is 3.0–3.5%. The majority of the humus (75%) is contained in a half-meter layer, which emphasizes the short humus level. The phosphorus content, both gross and mobile, is very low at 0.98–0.031%. Potassium is in elevated amounts. Soils are most susceptible to the application of nitrogen–phosphorus fertilizers. According to the mechanical composition, chestnut soils are predominantly lightly loamy, light clays with substrates of souses. Salinization is low, with a salt content in the 0–100 cm soil layer of 0.10–0.20%. The mass of the arable soil layer is 1.3–1.4 g/cm3. Deep plowing and loosening of soils improve the water and nutrition regime, creating good conditions for arid agriculture. With deep autumn plowing up to 30 cm, the accumulation of sediment and spring meltwater reaches 1200–1500 m3/ha more than in spring disposal. Deep plowing ensures absorption of irrigation water, eliminates run-off during irrigation, and reduces the number of crops requiring extra irrigation. In an average dry year, at 50% water availability and 70% soil moisture content (MC), the number of irrigations is 4, and the irrigation rate is 300–470 m3/ha; at 60% MC, 2 irrigations are performed, and the irrigation rate is 600–650 m3/ha. On irrigated land, the yield of cereals is 2.8–2.6 t/ha; perennial grasses, 3.0–4.5 t/ha; potatoes, 23.2–24.1 t/ha; carrots, 35.0–40.0 t/ha; and cabbage, 50.0–75.0 t/ha.

If Sand Interlayer Acts Better than Straw Interlayer for Saline Soil Amelioration? A Three-Year Field Experiment

An addition of straw interlayer in the 0.40 m soil depth could effectively reduce salt accumulation in the surface soils by regulating water fluxes, thus mitigating the salt stress to the crop growth and development. However, the positive effects of straw interlayer were weakened with straw decomposition, and whether we could use sand (an indecomposable substance) instead of straw for saline soil amelioration still needs further investigation. Therefore, a three-year field experiment was established with straw and sand interlayers, as well as with no interlayer as a control. Straw interlayer demonstrated an increase of 4.85~13.10% of water content, while the sand interlayer increased 12.41~16.48% of water content in the soil layer of 0–0.40 m depth comparing to the control. Salt contents were lowered by 10.69~17.01% in the same soil layer of the straw interlayer and lowered by 7.00~7.59% in the sand interlayer treatment after irrigation. Data also shows that irrigation significantly increased water content and lowered salt accumulation in the soil plough layer, thus increasing the sunflower emergence rate of 10.49~13.54% in the straw interlayer treatment and 12.53~14.78% in the sand interlayer treatment, respectively. Both the straw interlayer and sand interlayer treatments effectively reduced the evaporation of groundwater and established a beneficial plough layer with a lower salt accumulation throughout the sunflower growth period. At harvesting stage, the evaporation fluxes of salt in the straw interlayer and sand interlayer treatments were significantly lower than that in the control treatment. Lower salt accumulation conferred a beneficial promotion for the growth of sunflower, while the grain yields in the straw interlayer treatment were increased by 8.67% in 2018, 11.00% in 2019 and 17.37% in 2020 compared to the no-interlayer soil, respectively. However, the low water content in the soil layer of 0–0.40 m depth in the sand interlayer treatment inhibited the growth of sunflower, resulting in a significant decrease in the seed yields. It is worth noting that the precipitation effectively alleviated water stress on the sunflower at the middle and late growth stage in the sand interlayer treatment. This study suggests that a maize straw burial of 0.05 m thickness at a depth of 0.40 m soil layer could be used as an effective tillage practice that could improve the distribution of water and salt in saline soils.

Sphingomonas sediminicola Is an Endosymbiotic Bacterium Able to Induce the Formation of Root Nodules in Pea (Pisum sativum L.) and to Enhance Plant Biomass Production.

The application of bacterial bio-inputs is a very attractive alternative to the use of mineral fertilisers. In ploughed soils including a crop rotation pea, we observed an enrichment of bacterial communities with Sphingomonas (S.) sediminicola. Inoculation experiments, cytological studies, and de novo sequencing were used to investigate the beneficial role of S. sediminicola in pea. S. sediminicola is able to colonise pea plants and establish a symbiotic association that promotes plant biomass production. Sequencing of the S. sediminicola genome revealed the existence of genes involved in secretion systems, Nod factor synthesis, and nitrogenase activity. Light and electron microscopic observations allowed us to refine the different steps involved in the establishment of the symbiotic association, including the formation of infection threads, the entry of the bacteria into the root cells, and the development of differentiated bacteroids in root nodules. These results, together with phylogenetic analysis, demonstrated that S. sediminicola is a non-rhizobia that has the potential to develop a beneficial symbiotic association with a legume. Such a symbiotic association could be a promising alternative for the development of more sustainable agricultural practices, especially under reduced N fertilisation conditions.

Responses of soil microorganisms, enzyme activities and nutrient contents to inter-row grass ploughing and returning to the field in a natural sod culture apple orchard.

Natural sod culture in orchard is an effective measure to improve the orchard productivity and promote the sustainable production. To explore the effects of inter-row grass ploughing and returning on soil biological cha-racteristics and nutrient contents, we examined the effects of different grass returning to the field on the amount of soil microorganisms, enzyme activities and nitrogen and potassium contents of 0-20 cm soil layer. There are three treatments, cleaning tillage as the control (CK), conventional mowing management (NG), and soil ploughing annually under natural sod culture with conventional mowing condition (NGR) treatments. The results showed that soil microorganisms were dominated by bacteria, followed by actinomycetes, with the least fungi. Compared with CK, both NG and NGR treatments significantly improved the abundance of soil bacteria and fungi, with the strongest effects in NGR treatment, and significantly increased the soil urease, sucrase and catalase activities by 59.0%, 20.7%, 38.3% and 73.5%, 45.9%, 67.8%, respectively. NGR treatment significantly increased soil nitrogen and potassium contents, with the contents of ammonium nitrogen, nitrate nitrogen, particulate organic nitrogen, microbial biomass nitrogen, available potassium and water-soluble potassium being 1.5, 1.8, 1.6, 2.0, 1.3 and 1.4 times of that in CK, respectively. NGR significantly increased soluble sugar content and sugar acid ratio and subsequently improved fruit quality. Overall, NGR increased soil microbial abundance, enzyme activities, nitrogen, potassium contents and fruit quality, which could be a feasible management of inter-row grasses in the natural sod culture apple orchard.

Study on soil cracks in pneumatic subsoiling based on LSTM

AbstractThis paper reports research based on pneumatic subsoiling and the design of a pneumatic subsoiling mechanism to overcome the problems of high resistance and high energy consumption of subsoiling. By analysing soil‐specific resistance, soil disturbance rate and soil bulkiness under different air pressure conditions, it is concluded that pneumatic subsoiling can effectively break the soil plough pan and reduce resistance to subsoiling. In order to analyse the impact of air pressure on subsoiling, in this study, principal component analysis was used to analyse the pneumatic subsoiling disturbance parameters (working air pressure, working depth and working speed), and the test results show that the contribution of air pressure to subsoiling resistance and subsoiling disturbance surface reached 24% and 25%, respectively. An orthogonal test was used to analyse the specific resistance of subsoiling, and its significance coefficient is 0.95. Long short‐term memory neural networks (LSTM) and bidirectional long short‐term memory neural networks Bi‐LSTM. are used to predict the cracks on the disturbed surface of subsoiling. LSTM is a method to predict future occurrence using time series data, which can be used to predict the cracks on the disturbed surface of soil, while Bi‐LSTM network is an innovative computing paradigm, which learns bidirectional long‐term correlation between time step and sequence data, to predict the trend of fissures on the disturbed soil surface. The RSME of LSTM and Bi‐LSTM are 4.80 and 6.55, and their determinative factor R2 is 0.95 and 0.94 respectively, which indicates that LSTM and Bi‐LSTM can effectively predict the cracks of pneumatic subsoiling. By analysing the specific resistance of pneumatic subsoiling, it can be shown that pneumatic subsoiling can reduce subsoiling resistance and expand the disturbance surface of subsoiling so as to achieve the effects of subsoiling, drag reduction and reduction of fuel consumption.

Combining organic and conservation agriculture to restore biodiversity? Insights from innovative farms in Belgium and their impacts on carabids and spiders

Conservation and organic agriculture are two alternative crop management strategies associated with environmental impact reduction, leading theoretically to more biodiversity and higher ecological functioning, underpinning better ecosystem service delivery. The combination of these two farming strategies is increasingly seen as an opportunity to mitigate shortcomings of each of them taken individually. However, combining organic and conservation agriculture is undeniably challenging, since it leaves nocurativeoption (neither synthetic pesticides nor soil plowing) for pest control (phytophagous, pathogens, and weeds). Hence, the latter must be ensured by effective restoration of predatory communities. The present research investigated the potential of combining organic and conservation agriculture to support two major ground-dwelling natural enemy communities: carabids and spiders. We used pitfall traps to sample these two communities in paired adjacent cereal fields conducted under organic-conservation (OC) and conventional (CV) agriculture in Belgium. Community assemblages were significantly different across system types, both in terms of species diversity and functional trait diversity. OC parcels showed higher alpha and beta species diversities for both carabids and spiders and species composition differed between OC and CV parcels. OC systems were associated with higher variation of species assemblages among parcels than CV systems Functional traits also differed across system types for both groups. We found more herbivorous and granivore carabids in OC parcels, and more predator species in CV parcels. We found larger spiders, more hunting spiders and more wetland spiders in OC parcels, whereas we found more web weavers and more forest spiders in CV ones. Functional diversity was higher in OC parcels for carabids, but not for spiders. In brief, OC parcels supported more diverse communities, both taxonomically and functionally. These outcomes show that OC systems are promising systems to support these natural enemy communities. Further studies should assess whether combining organic and conservation agricultural enables sufficient pest control levels to achieve high levels of food production and farmers income.

Response of ground macrolichens to site factors, co‐existing plants and forestry in boreal forests

AbstractAimGround lichens have declined in boreal and temperate Europe. The potential causes of the decline were explored by analysing the response of lichen cover to forest management, site and stand variables as well as co‐existing plants in different boreal vegetation subzones.LocationFinland.MethodsUnderstorey vegetation was surveyed on a systematic network of 1721 sample plots in forests on mineral soil. The response of macrolichen cover to explanatory variables was analysed by generalised linear mixed models (GLMMs).ResultsGround lichens favoured old Pinus sylvestris forests on xeric sites with sufficient light conditions. Intensive forest management regimes, such as regeneration cutting and soil ploughing decreased lichen cover, while lighter scarification methods had less effect on lichens. Lichens benefitted from intermediate cutting on sites with low bryophyte cover. Lichens responded similarly to site and stand variables in all boreal subzones, showing that despite heavy reindeer grazing these response patterns apply also in the northern boreal subzone. Lichens showed both negative (Vaccinium myrtillus, Empetrum nigrum and Calluna vulgaris) and positive (Vaccinium vitis‐idaea) responses to increasing dwarf shrub cover. Generally, lichens negatively responded to increasing bryophyte cover, indicating either that bryophytes benefit from a decline of lichens or that there is real competition between these groups. The negative relationship between bryophytes and lichens strengthened as the tree canopy becomes denser.ConclusionsOur study provides new quantitative insights into the effects of forest management and changes in forest structure as underlying factors for lichen decline both inside and outside the reindeer‐herding area (i.e., the northern boreal subzone). These factors include increased canopy cover with increased shading as well as disturbance caused by regeneration cutting and soil preparation. The possible effects of the long‐term legacy of nitrogen deposition, lack of forest fires and climate change are also discussed.

Spatial patterns of crops in Russia

Information about spatial distribution of agricultural crops in Russia exists only in the form of statistical data aggregated at the level of regions or farms, which does not make it possible to obtain data about the actual distribution of crops. Attempts to use satellite data for mapping of individual crops have not yet been successful either. We have attempted to disaggregate statistical data on crop areas using map of ploughed soils in Russia, information on crop rotations, and assessment of suitability of land for cultivation of specific crops. An analysis was conducted for the 28 most common crops in Russia. Maps of the distribution of these crops in the country were constructed. The maps give an idea of the geography of crops in Russia and can be used to improve approaches to satellite mapping and monitoring of crop areas in the country.

Effect of biochar application method and amount on the soil quality and maize yield in Mollisols of Northeast China

There have been many studies on soil quality and crop yield using different biochar application amounts, but few studies have focused on the combination of different methods and amounts of biochar application in moderately degraded Mollisols. In this study, the methods of mixing biochar evenly with the soil of the plough layer (0–20 cm depth) [homogeneous biochar application (HO)] and burying biochar above the soil plow pan (under 20 cm depth) (heterogeneous biochar application (HE)) were used to reveal how biochar application methods influenced soil quality, crop yield and agronomic characteristics in moderately degraded Mollisols (soil organic matter (SOM), 30.33 g kg−1). The biochar application amounts were 0 (control), 10 (level 1), 20 (level 2), and 40 (level 3) t ha−1 in both the HO and HE treatments. The results showed that, compared with control, HO3 significantly increased maize yield in the first year, and HO2, HO3, HE2 and HE3 continuously increased maize yield in the next three years but not significantly. HO1 and HE1 had the lowest maize yield. HO2 tended to delay maize leaf senescence. There was a positive linear relationship between soil quality index (SQI) and biochar application amount in HO. Compared with other treatments, the pH, EC, SOM, available phosphorus, sucrase and catalase activities were highest in HO3. However, the effects of HE on soil quality and crop productivity were limited at first but gradually increased with time. Overall, HO3 was beneficial for improving the soil quality and crop productivity in Mollisols for short-term cultivation (3-year), while HE showed an effect over time.Graphical