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Cassava (Manihot esculenta Crantz) is a major staple food in many developing countries, including Brazil. However, it faces significant challenges due to diseases such as dry root rot (DRR) and black root rot (BRR) caused by soil-borne plant pathogenic fungi. This study explored the use of cover crops to suppress these diseases and to improve the agronomic traits of cassava. Over four cultivation cycles, various cover crops (sunn hemp, black oat, jack bean, maize, peanut and cowpea) were alternated with cassava varieties 'BRS Kiriris' (resistant) and 'BRS Formosa' (susceptible) in soil infested with DRR (Fusarium oxysporum, F. equiseti, F. verticillioides, F. solani, F. lateritium, F. chlamydosporum) and BRR (Lasiodiplodia theobramae, Neoscytalidium dimidiatum) pathogens. In the 2nd cycle, only germination showed significant differences, but by the 4th cycle, various agronomic parameters, including fresh weight (FW.AP), dry weight (DW.AP) of the aerial part, fresh weight (FW.Root), dry weight (DW.Root) of the roots, and plant vigor. Cowpea was identified as the most effective cover crop for reducing the disease index (DI %) by promoting healthier and taller cassava plants. Jack beans and peanuts also had positive effects on vigor, FW.AP, DW.AP, FW.root, and DW.root. In contrast, maize, black oats, Crotalaria ochroleuca, cassava, and fallow soils had minimal impacts. Throughout these cycles, the selected cover crops consistently contributed to disease reduction and improved the agronomic performance of the cassava. This study highlights the potential of holistic disease management strategies. [ABSTRACT FROM AUTHOR]

Farming management and alterations in land cover play crucial roles in driving changes in biodiversity, ecosystem functioning, and the provision of ecosystem services. Whereas land cover corresponds to the identity of cultivated/non-cultivated ecosystems in the landscape, farming management describes all the components of farming activities within crops and grassland (i.e., farming practices, crop successions, and farming systems). Despite extensive research on the relationship between land cover and biodiversity at the landscape scale, there is a surprising scarcity of studies examining the impacts of farming management on biodiversity at the same scale. This is unexpected given the already recognized field-scale impact on biodiversity and ecosystem services, and the fact that most species move or supplement their resources in multiple patches across agricultural landscapes. We conducted a comprehensive literature review aimed at answering two fundamental questions: (1) What components of farming management are considered at the landscape scale? (2) Does farming management at the landscape scale impact biodiversity and associated ecosystem functions and services? We retrieved 133 studies through a query on the Web of Science, published from January 2005 to December 2021 addressing the broad notion of farming management at the landscape scale. The key findings are as follows: (1) The effect of farming management components at the landscape scale on biodiversity was tackled in only 41 studies that highlighted that its response was highly taxon-dependent. They reported positive effects of organic farming on pollinators, weeds, and birds, as well as positive effects of extensification of farming practices on natural enemies. (2) Most studies focused on the effect of organic farming on natural enemies and associated pests, and reported contrasting effects on these taxa. Our study underscores the challenges in quantifying farming management at the landscape scale, and yet its importance in comprehending the dynamics of biodiversity and related ecosystem services. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the no-tillage system (NT) with different implantation times and vegetation cover on changes in the chemical and structural compositions of soil humified organic matter. Five areas with different NT management histories were studied; for 6 (NT6), 14 (NT14), 22 (NT22) years with succession of soybean/corn crops; for 12 years and 4 more years with corn and Brachiaria (NT+B), pasture for 39 years and native forest. Soil samples were collected at the depths of 0.0–0.05 and 0.05–0.10 m. The changes in the quality of humic acid (HA) were evaluated by several chemical techniques (total organic carbon (TOC), fulvic acid fraction (FA), humic acid fraction (HA) and humin fraction (HU), ionizable functional groups, elemental composition) and spectroscopic techniques (UV–Vis absorption, fluorescence, and Fourier transform mid-infrared photoacoustic spectroscopy, called FTIR-PAS). On the surface, the TOC, carbon of the HA and HU fractions, total acidity, phenolic acidity, Carbon, Nitrogen, Sulfur, Hydrogen and Hydrogen/Carbon ratio were higher in the areas of forest, pasture and NT22. On the subsurface, the responses are the same as on the surface. However, the NT22 system presents higher FA, HA, carboxylic acidity and humification degree (HD). UV–Vis absorption spectroscopy, fluorescence spectroscopy and FTIR-PAS can discriminate soils under different managements and under natural conditions. Agronomic practices have strongly affected the soil organic matter, in which the NT promotes the formation of HA with characteristics closer to those of the forest, as the implantation time increases, such as 22-year-old NT and pasture. This indicates that care must be taken in managing the no-till system to maximize its potential to promote stabilization of organic matter, thereby contributing to carbon sequestration. The humic substances contribute as sustainability indicators in agriculturalsystems Were evaluated no-tillage system (NT) with different implantation times. The UV–Vis, fluorescence and FTIR-PAS discriminate soils under different managements. NT promotes humic acid formation with characteristics closer to those of the forest. [ABSTRACT FROM AUTHOR]

Intensive dairy farming systems in the sandy soil of northwestern Morocco are based on three successive forage crops per year, including corn. The aim was to evaluate the productivity and the quality of different intensive crop successions based on corn in sandy soil. Three forage crops per year (winter, spring, and summer cropping seasons) were tested according to six successions: 1. fallow-corn-corn, 2. oat-corn-corn, 3. berseem-corn-corn, 4. pea/triticale-corn-corn, 5. oat-soybean-corn, and 6. berseem-corn-soybean. Each succession of crops was evaluated in two years field experiment using a randomized complete block design. Results revealed that oat-corn-corn and pea/triticale-corn-corn successions produced the highest dry biomass (46.5 t ha-1 year-1). The crop succession of berseem-corn-soybean resulted in the lowest biomass (30.8 t ha-1 year-1). The highest net energy for lactation was recorded at oat-corn-corn and pea/triticale-corn-corn successions (303 103 MJ ha-1 year-1). The crop successions based on one corn (oat-soybean-corn and berseem-corn-soybean) recorded the lowest net energy for lactation (195.5 103 MJ ha-1 year-1). The oat-corn-corn, pea/triticale-corn-corn, and oat-soybean-corn successions recorded the highest crude protein values (3.9 t ha-1 year-1). Soil organic matter and the content of soil on total N, P, and Mg were similar for the different crop successions at the end of the experimental years.

This study applied the Gebre optimization model to optimize the land and water usage in the Omo-Gibe river basin, Ethiopia, where competition among stakeholders and growing demands pose a challenge. This model was applied through a nexus approach to maximize benefits and minimize conflicting trade-offs. The main objective was to maximize the economic benefit from land and water allocation with the framework of the land-water-food-energy-environment nexus under climate change mitigation and river ecosystem services (LWFEEN). This model takes into account multiple dimensions, including economic, environmental, social, and technical factors, going beyond ordinary optimization models. It also incorporates an innovative crop succession allocation concept not often seen in the literature. This crop succession proposal includes sequences of cropping patterns and fallow land use options that closely resemble real-world farming practices. The results demonstrated that the Gebre optimization model effectively resolves the existing constraint conflicts and maximizes economic benefits by reducing costs, penalties, and environmental impacts, promoting sustainable use of natural resources in the Omo-Gibe river basin and avoiding conflicts among stakeholders. Therefore, this study offered decision-makers a strategic perspective on how to apply the Gebre-model within the context of the land-water-food-energy-environment nexus(LWFEEN) approach in river basins such as the Omo-Gibe, with the ultimate goal of achieving sustainable development. [ABSTRACT FROM AUTHOR]

The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven their efficiency. However, the impact of crop-richness continuity in space and time on pests and natural enemies at a landscape scale remains poorly studied. In a two-year study, we assessed the effect of crop richness (single crop vs. multiple crops) on pest and natural enemy abundance and spillover in a field experiment in north-east China. Overall, we found crop diversity had a limited impact on pest and natural enemy abundance at the spatial scale tested (0.025 vs. 0.2 ha). The total pest and natural enemy abundances were not different between single-crop and multi-crop plots in either year, and the community composition at the functional group level was mostly determined by the crop but not crop diversity. However, we found that crop diversity influenced the numeric response of ladybirds to aphids in wheat; their negative response (higher abundance where aphid abundance was lower, suggesting predation) was attenuated in multi-crop plots (no correlation of aphid and ladybird abundance, suggesting the use of alternative resources). This pattern was not found in maize. Finally, crop succession enhanced the spillover of ladybirds from wheat and maize to cotton plots but with limited benefits for aphid control. Because of these limited impacts, we hypothesized that crop diversity may benefit natural enemy populations and enhance pest control at larger spatial scales; while we found similar abundances of ladybirds between our small (0.025–0.2 ha) plots and in large (2 ha) close-by cotton fields, aphid abundances were more than ten times higher in large cotton fields. Our study highlights the need to accurately estimate the spatial scale at which crop biodiversity may benefit pest control, in relation to the ecology of the target pest and natural enemies. [ABSTRACT FROM AUTHOR]

The widespread cultivation of canola, conventionally still considered a non-host plant for AM fungi, coupled with its increasing frequency in crop rotations, raises concerns about its impacts on soil microbial diversity and overall crop productivity. The main objective of this study is to assess the influence of different crop succession systems, incorporating canola, on AM fungal diversity and community structure in both the roots and in the rhizosphere, as well as on productivity of each crop present within the succession. Doubling the frequency of canola occurrence in a 4-year crop succession did not reduce the productivity of the other crops in the succession, nor did it result in a decrease in AM fungal biodiversity in the roots or rhizosphere of these crops. Interestingly, the diversity of AM fungi was higher in canola roots compared to wheat roots, indicating that canola might serve as a rudimentary host of AM fungi. The succession systems did, however, alter the AM fungal community structure in both roots and rhizosphere environments, exhibiting positive or negative correlations with crop productivity. This suggests that a simple modification of the cropping system could potentially be employed to manipulate root or rhizosphere microbiomes. Results of this study add to the growing body of evidences that plants that were thought to be non-AM fungi host, such as plants from the Brassicaceae family, could in fact interact with AM fungi. • Cropping systems influenced AMF diversity in crops' roots and rhizosphere. • Increasing canola in a crop succession didn't reduce AMF diversity in roots and rhizosphere. • Canola may serve as rudimentary host for AM fungi and interact with it. • Cropping systems could potentially be employed to manipulate root or rhizosphere microbiome. [ABSTRACT FROM AUTHOR]

This study applied the Gebre optimization model to optimize the land and water usage in the Omo-Gibe river basin, Ethiopia, where competition among stakeholders and growing demands pose a challenge. This model was applied through a nexus approach to maximize benefits and minimize conflicting trade-offs. The main objective was to maximize the economic benefit from land and water allocation with the framework of the land-water-food-energy-environment nexus under climate change mitigation and river ecosystem services (LWFEEN). This model takes into account multiple dimensions, including economic, environmental, social, and technical factors, going beyond ordinary optimization models. It also incorporates an innovative crop succession allocation concept not often seen in the literature. This crop succession proposal includes sequences of cropping patterns and fallow land use options that closely resemble real-world farming practices. The results demonstrated that the Gebre optimization model effectively resolves the existing constraint conflicts and maximizes economic benefits by reducing costs, penalties, and environmental impacts, promoting sustainable use of natural resources in the Omo-Gibe river basin and avoiding conflicts among stakeholders. Therefore, this study offered decision-makers a strategic perspective on how to apply the Gebre-model within the context of the land-water-food-energy-environment nexus(LWFEEN) approach in river basins such as the Omo-Gibe, with the ultimate goal of achieving sustainable development.

Methods for crop phenology detection using time series analysis have provided accurate information for large agricultural areas in shorter processing times, which can be useful for agronomic management and supply chain monitoring. Given the crop dynamics in the Brazilian Cerrado, with alternating crop type plantings, crop successions, and crop rotations, as well as climate and crop practices variation between harvest periods, these methods can be useful for detecting subtle land use and land cover changes at farm and crop field scales, improving thematic classifications and the near real-time crop monitoring. In this study, the Time-Weighted Dynamic Time Warping method was applied to recognize patterns in Moderate Resolution Imaging Spectroradiometer (MODIS) time series for land use and cover classification, identifying crop successions and rotations at crop field level in a large-scale agro-industrial agglomerate of farms located at Brazilian Cerrado. We detected and analyzed temporal cropping patterns in training samples to classify the MODIS time series and images, using a robust ground truth data set for validation. The method distinguished Cotton-fallow, Soybean-cotton, Soybean-maize, and Soybean-millet cropping patterns with an overall accuracy above 85% for all evaluated harvest periods. Seasonal variations in the crop fields, caused by interannual succession and rotation, were detected. The method demonstrated the benefit of creating a spatial vector data set for supporting decision-making in several crop management contexts, improving crop and supply chain monitoring.

ABSTRACT Chemical composition and contamination of wheat kernels (Triticum aestivum L.) directly affect the quality of the flour obtained from them, determining its acceptability and use by industry. Field trials were conducted to evaluate the effect of agricultural practices on wheat kernel quality (chemical composition and contamination). Cultivation was carried out following maize or soybean (crop succession), with application of nitrogen doses in topdressing (0, 30, 60, 90, and 120 kg ha-1), using seeds inoculated or not inoculated with Azospirillum brasilense. Data were subjected to analysis of variance (ANOVA), comparison of means by Tukey's test (0.05). Lower protein (-21.6%; p0.80; p

The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven their efficiency. However, the impact of crop-richness continuity in space and time on pests and natural enemies at a landscape scale remains poorly studied. In a two-year study, we assessed the effect of crop richness (single crop vs. multiple crops) on pest and natural enemy abundance and spillover in a field experiment in north-east China. Overall, we found crop diversity had a limited impact on pest and natural enemy abundance at the spatial scale tested (0.025 vs. 0.2 ha). The total pest and natural enemy abundances were not different between single-crop and multi-crop plots in either year, and the community composition at the functional group level was mostly determined by the crop but not crop diversity. However, we found that crop diversity influenced the numeric response of ladybirds to aphids in wheat; their negative response (higher abundance where aphid abundance was lower, suggesting predation) was attenuated in multi-crop plots (no correlation of aphid and ladybird abundance, suggesting the use of alternative resources). This pattern was not found in maize. Finally, crop succession enhanced the spillover of ladybirds from wheat and maize to cotton plots but with limited benefits for aphid control. Because of these limited impacts, we hypothesized that crop diversity may benefit natural enemy populations and enhance pest control at larger spatial scales; while we found similar abundances of ladybirds between our small (0.025–0.2 ha) plots and in large (2 ha) close-by cotton fields, aphid abundances were more than ten times higher in large cotton fields. Our study highlights the need to accurately estimate the spatial scale at which crop biodiversity may benefit pest control, in relation to the ecology of the target pest and natural enemies.

A considerable body of evidence has demonstrated the positive impact of the diversity of plant species on biological control of pests at the field scale. However, very few studies have assessed the effect of crop diversity on natural enemy performance and pest control. In order to test our hypothesis that crop diversity could increase natural enemy development and performance, we examined the mechanisms underlying the effect of two types of crop succession, i.e., multiple-crop succession (tomato, squash and soybean) and mono-crop succession (each crop alone), on population dynamics, predation capacity and spillover of Nesidiocoris tenuis Reuter (Hemiptera: Miridae) in a greenhouse experiment. We found that (1) the polyculture supported lower population growth of N. tenuis and lower predation rates of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs compared to tomato and squash monocultures, but that correspondingly (2) the predator performed better on the polyculture than on the soybean monoculture. These results revealed that crop identity within the succession is a major factor in determining population dynamics and biological control. We found that compared to soybean monoculture, the presence of soybean Glycine max L. (Fabales: Fabaceae) in the polyculture treatment reduced the population dynamics of the mirid predator but increased biological control. This result suggests that non-host crops in a polycultural succession could benefit from the natural enemy populations that were increased by other suitable crops in the succession. [ABSTRACT FROM AUTHOR]

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Soil infiltration regulates surface runoff and on consequence erosion and contamination processes. There are different infiltration equations, being the Green Ampt one of the most used in hydrological and erosion models. The objectives of this work were: 1) Calibrate and analyze the parameters of the Green Ampt infiltration equation under two rain intensities, in different environments and under different land uses, in the upper basin of the Pergamino stream. 2) Compare the degree of efficiency obtained with the Green Ampt model, using the effective matric potential (Ψ) estimated by formula or by its calibration. In different environments belonging to the upper basin of the Pergamino stream, in 2011 and 2013 years, infiltration tests were made using a rainfall simulator. Two intensities were applied: 30 mm h-1 and 60 mm h-1. We worked on soils with agricultural and livestock aptitude. In agricultural plots two contrasting crop successions were evaluated and two landscape positions (hill and hillslope). With the results, the Ke and Ψ of the Green Ampt infiltration model were calibrated. There were important percentage differences in the calibrated Ke values, between the several experimental conditions evaluated. However, only significant differences were observed in this parameter when comparing the results obtained in livestock and agricultural soils, with a higher value of Ke in the latter. The Ψ prediction equation did not generate acceptable coefficients of efficiency, being recommended its calibration from field infiltration tests. [ABSTRACT FROM AUTHOR]

Highlights • A concept to avoid allocation mistakes in 'preceding crop – crop' evaluations. • Results based on four years field trial data in Central Europe. • Defaults for global warming potential of crop cultivation provided. • Defaults for sources of greenhouse gas emission in crop cultivation provided. Abstract The global warming potential (GWP) of crop cultivation (carbon dioxide equivalents (CO 2 eq) associated with the production and use of agronomic inputs + nitrous oxide emissions) should be minimized since a 'climate smart' label will become economically valuable in future. The choice and succession of crops in a cultivation system are rarely included in the comparison of methods for reducing GWP. This study elucidated the effects of different preceding crops (grain pea, silage maize, winter wheat) on GWP by agronomic inputs in sugar beet cultivation. In addition, the relation of the GPW to the energy yield was assessed as the global warming intensity (GWI). The study was done based on a field trial in Germany (Lower Saxony). The GWP of sugar beet cultivation as well as the GWI differed due to preceding crops (2.1–3.1 Mg CO 2 eq ha−1 and 6.9–10.8 kg CO 2 eq GJ-1, respectively). Values were significantly different between treatments with grain pea and silage maize as preceding crops. The cumulative GWP differed between the two years of crop successions (4.9–7.2 Mg CO 2 eq ha-1) with significant differences between the treatments with grain pea and winter wheat. The GWI as the average of the two years of each crop succession was in the range of 9.8–17.3 kg CO 2 eq GJ−1 and differed significantly between the treatments with silage maize and winter wheat. Thus, the choice of the preceding crop can contribute to a climate smart cultivation of sugar beet. Moreover, this study offers a set of values which can serve as defaults for estimating the GWP of different sequences of crop rotations including catch crops, grain pea, silage maize, sugar beet, and winter wheat under Central European conditions. [ABSTRACT FROM AUTHOR]

Due to legume-based systems improving several aspects of soil fertility, the diversification of agrosystems using legumes in crop succession is gaining increasing interest. The benefits of legumes aroused the interest of farmers in the association of the Economic and Environmental Interest Group (EEIG), who introduced the idea of using the winter pea instead of rapeseed in their crop succession. The aim of this study is to evaluate the effects of the winter pea compared to those of rapeseed, as a head crop of the rotation, on soil microbial communities, enzyme activities, nitrogen (N) balance and yields. The field experiment involved two farmer plots that were selected within the EEIG. In each plot, two crop successions, including winter pea–wheat and rapeseed–wheat with fertilized and unfertilized strips, were examined for two years. Three times a year, under the wheat crop, composite soil samples were collected at depths of 0–20 cm, for microbial abundance and enzyme activity analyses, and twice a year at a depth of 0–60 cm, for the measuring of the mineral N. The results showed that the rapeseed–wheat succession maintained or enhanced soil bacterial and fungal biomasses and their enzyme activities. The winter pea–wheat succession enriched the soil’s mineral N content more consistently than the rapeseed–wheat succession. The mineral N enhancement’s effect was maintained under the wheat crop. Overall, the impact of the winter pea was positive on the soil’s N dynamics, but wheat yields were equivalent regardless of the previous crop (winter pea or rapeseed with and without fertilization). In the Normandy region, as rapeseed requires a large amount of N fertilizer and pesticide to maintain the yield and quality of crop products, it is suitable to favor the introduction of the winter pea as the head crop of the rotation, which indirectly allows for a reduction in the costs of input production and use, the working time of farmers and environmental pollution.

Roundup Ready® technology adoption and the cultivation of a second crop have changed chemical control methods and weed management in the southwest region of Goiás State, Brazil. Considering these changes, this study aimed to perform a phytosociological survey in areas with glyphosate resistant soybeans and conventional soybeans as the main harvest and sorghum, maize, millet or fallow in succession as the second harvest. A multivariate matrix of the floristic composition was constructed, and the indicator values of the individual number and dry biomass of species were measured. Based on the number of individuals, the species Chamaesyce hirta, Bidens subalternans, and Cissampelos ovolifolia were typical of areas cultivated with glyphosate-resistant soybean, while Euphorbia heterophyla presented indicator values of areas with conventional soybean cultivation. During the second harvest period, significant indicator values were observed for Crotalaria spectabilis in maize areas, Cenchrus echinatus in sorghum, and Commelina benghalensis, Sida glaziovii, Ipomoea grandifolia, Sida rhombifolia, and Ipomoea cordifolia in areas with millet. The species Conyza bonariensis was typical in the period before the herbicide application at post-emergence in harvest. Volunteer soybean presented as typical for the period before the herbicide application at post-emergence in the second harvest. Weeds that were difficult to control or were tolerant and resistant to the herbicide applications were recorded in the areas studied.

The objective of this study was evaluate the organic carbon stock and chemical and physical properties of soils in management systems with different deployment times under clayey Red Latosol in western region of Paraná, Brazil. Five managed areas and a reference area (native forest) without anthropic action were analyzed in completely randomized design with five repetitions. Management systems include three areas with different time of first adoption of no-till: 6 years – NT6 (transition phase), 14 years – NT14 (consolidation phase) and 22 years – NT22 (maintenance phase); 16 years of no-till, and in the last four years with integration of maize and ruzigrass (Brachiaria ruziziensis) – (NT+B) and an area of permanent and continuous extensive cattle pasture of coast-cross (Cynodon dactylon) – (P). Physical and chemical properties, total soil organic carbon (TOC) stock and carbon stratification index (SI) of soils were evaluated in depths of 0-0.05; 0.05-0.10; 0.10-0.20 and 0.20-0.40 m. The macroporosity (MA) was higher in the area of native forest, ranging from 0.23 to 0.30 m3 m-3 and the microporosity (MI) was higher in cultivated areas. The areas of NT+B and P presented lower ratio macroporosity/total pore volume (MA/TPV). For soil bulk density (BD) and soil penetration resistance (SPR), the managed areas show higher values, suggesting the occurrence of compacted subsurface layers. Native forest area showed the highest TOC levels in the depths of 0-0.05 and 0.05-0.10 m, reaching 30.5 g kg-1 in the 0–0.05 m soil layer. There was negative change on TOC stocks in the managed areas in relation to forest area, being more evident in the more superficial soil layers. The SI was greater than one, however there is a reduction in function of adoption time of no-till. There was higher soil compaction in the managed areas, and the NT in soybean/maize succession system does not contribute effectively to the increase of TOC stocks.

Soil microorganisms play important roles in nutrient cycling and ecosystem functioning. Knowledge on the responses of soil microbial metabolic characteristics to agricultural practices is critical to better understand soil microbial processes in agroecosystems. The study aimed to explore the responses of soil microbial metabolic activities and their carbon utilization under different tillage and crop succession systems in a 12-year field experiment in a clay loam soil of Jilin Province, China. This experiment was set up in a split-plot design with four replicates including no-tillage (NT) and conventional tillage (CT) as main plots and continuous corn (CC) and corn-soybean succession (CS) treatments as subplots. Soil samples were collected from 0 to 5 cm and 5–15 cm depths. The results showed that compared with CT, NT increased soil organic carbon, soil microbial biomass carbon, basal respiration and microbial coefficient at 0–5 cm depth. Greater basal respiration was observed under CC than under CS at both depths. Compared with NTCC, NTCS decreased microbial functional diversity at 0–5 cm depth and increased microbial metabolic quotient at 5–15 cm depth. Redundancy analysis indicated that crop succession management induced the changes in soil microbial carbon utilization. Compared with other soil environmental factors, NO 3 − -N and soil moisture significantly affected soil microbial metabolic activities. No significant correlation was found between microbial carbohydrate utilization and soil organic carbon in this study. Structural equation modeling analysis suggested that corn-soybean succession practice could stimulate the consumption of aromatic acids, which indirectly affected the accumulation of soil organic carbon. [ABSTRACT FROM AUTHOR]

Roundup Ready® technology adoption and the cultivation of a second crop have changed chemical control methods and weed management in the southwest region of Goiás State, Brazil. Considering these changes, this study aimed to perform a phytosociological survey in areas with glyphosate resistant soybeans and conventional soybeans as the main harvest and sorghum, maize, millet or fallow in succession as the second harvest. A multivariate matrix of the floristic composition was constructed, and the indicator values of the individual number and dry biomass of species were measured. Based on the number of individuals, the species Chamaesyce hirta, Bidens subalternans, and Cissampelos ovolifolia were typical of areas cultivated with glyphosate-resistant soybean, while Euphorbia heterophyla presented indicator values of areas with conventional soybean cultivation. During the second harvest period, significant indicator values were observed for Crotalaria spectabilis in maize areas, Cenchrus echinatus in sorghum, and Commelina benghalensis, Sida glaziovii, Ipomoea grandifolia, Sida rhombifolia, and Ipomoea cordifolia in areas with millet. The species Conyza bonariensis was typical in the period before the herbicide application at post-emergence in harvest. Volunteer soybean presented as typical for the period before the herbicide application at post-emergence in the second harvest. Weeds that were difficult to control or were tolerant and resistant to the herbicide applications were recorded in the areas studied. [ABSTRACT FROM AUTHOR]

For agronomic, environmental, and economic reasons, the need for spatialized information about agricultural practices is expected to rapidly increase. In this context, we reviewed the literature on remote sensing for mapping cropping practices. The reviewed studies were grouped into three categories of practices: crop succession (crop rotation and fallowing), cropping pattern (single tree crop planting pattern, sequential cropping, and intercropping/agroforestry), and cropping techniques (irrigation, soil tillage, harvest and post-harvest practices, crop varieties, and agro-ecological infrastructures). We observed that the majority of the studies were exploratory investigations, tested on a local scale with a high dependence on ground data, and used only one type of remote sensing sensor. Furthermore, to be correctly implemented, most of the methods relied heavily on local knowledge on the management practices, the environment, and the biological material. These limitations point to future research directions, such as the use of land stratification, multi-sensor data combination, and expert knowledge-driven methods. Finally, the new spatial technologies, and particularly the Sentinel constellation, are expected to improve the monitoring of cropping practices in the challenging context of food security and better management of agro-environmental issues. [ABSTRACT FROM AUTHOR]

This research was developed in the experimental area of ESALQ-USP, city of Piracicaba , state of Sao Paulo, in a soil of sandy-clay texture and aimed to evaluate the soil physical quality and maize agronomic characteristics with maize crop under different N doses and different tillage systems. The experimental design consisted of randomized blocks with four replicates. Treatments consisted of three nitrogen doses (N) (60, 120, and 180 kg ha-1) and a control. The ammonium sulfate fertilizer was applied at 30 kg ha-1 N during seeding, and the rest was applied as sidedressing when the plants had between six and eight leaves. Were determined the bulk density, microporosity, macroporosity and total porosity of soil, at depths of 0.05, 0.15, 0.25, 0.35 m, and the maize components yield. The soil physical properties tend to change over time and N levels, especially with regard to soil macroporosity and microporosity, conditioned by the structural change of the soil.

The objective of this study was to evaluate the growing of soil improving crops on the population of Rotylenchulus reniformis in naturally infested soil. It was evaluated the effect of 6 species of plants as cover crops in winter and 13 summer species and a fallow treatment on the nematode population under greenhouse. After 60 days, the root system was collected. Then, a sample of soil was taken in order to extract juveniles from the soil and quantification the final population of the pathogen in each pot for determining of the reproduction factor (RF). Fallow and all winter species of green manure, except hairy vetch, reduced the population of R. reniformis after cultivation in infested soil, in comparison to the control. Regarding summer cover crops, it was observed that sorghum ‘SI03204’ (Sorghum vulgare), millet ‘BRS1501’ (Pennisetum glaucum), Brachiaria ruziziensis, finger millet (Eleusine coracana), estylo ‘Campo Grande’ (Stylosanthes capitata x S. macrocephala), peanut ‘IAC Tatu ST’ (Arachis hypogaea) and dwarf velvet bean (Mucuna deeringiana) reduced the population of R. reniformis, when compared to the control, could be used in the management of this nematode.

O uso intensivo de áreas do Cerrado para produção agropecuária aliado ao manejo inadequado tem causado degradação dos solos. Nesse sentido há necessidade da incorporação de sistemas sustentáveis como plantio direto e a integração lavoura-pecuária. Este trabalho objetivou identificar o efeito da sucessão de milho+forrageiras e soja nos atributos físicos do solo. Para tanto foi realizado, em área experimental da Unesp, campus de Ilha Solteira, um ensaio composto do consórcio de milho com quatro forrageiras (Brachiaria brizantha,B. ruziziensis, Panicum maximum cv. Tanzânia e P. maximum cv. Áries) semeadas em três modalidades (na linha de semeadura do milho misturada ao adubo, a lanço simultânea à semeadura do milho e a lanço no estádio V4 do milho) e o milho sem consorciação (testemunha). A soja de verão foi implantada sobre os restos culturais dos tratamentos anteriores. Foram realizadas coletas para determinar a macro e microporosidade, porosidade total e densidade do solo em duas épocas de amostragem, após as colheitas do milho e da soja. Pelos resultados, pôde-se concluir que, em regiões de cerrados, a sucessão de culturas utilizada promoveu a melhoria da macroporosidade, porosidade total e densidade do solo, independentemente da utilização de forrageiras em consórcio com milho.The intensive use of Cerrado soils for agricultural production coupled with an inadequate management has resulted in soil degradation. This created the need for the introduction of more sustainable systems such as no-tillage and crop-livestock integration. This study analyzed the effect of succession of corn+forage and soybean on soil physical properties. For this purpose, four forages (Brachiaria brizantha, B. ruziziensis, Panicum maximum cv. Tanzânia, and P. maximum cv. Áries), were sown in an intercropping trial with maize in three modalities (in the corn row mixed with fertilizer; broadcast at corn sowing; and broadcast in corn stage V4) and corn without intercropping (control), in the experimental area of UNESP, campus Ilha Solteira. Summer soybean was sown on the crop remains of previous treatments. To determine macro and microporosity, total porosity and bulk density soil was sampled twice, after the maize and after the soybean harvest. From the results, it was concluded that in Cerrado region, the crop succession improved soil macroporosity, total porosity and bulk density, regardless of the use of forages intercropped with maize.

For the last forty years oilseed and high-protein crops have undergone important changes in terms of area and localisation in France. On the Seine basin example, we show that the specialisation of the farming systems and the agricultural regions has strongly changed the cropping patterns by reducing grasslands which were replaced by a constant increase of the wheat area in a one hand and by a dramatic increase, from the eighties, of the rapeseed, field pea and sunflower areas in another hand. Then from the nineties, rapeseed has gradually replaced field pea and sunflower, the areas of which have fallen. The decrease in the number of cultivated species has led to a clear trend to the simplification and the shortening of the crop successions: short crop successions based on rapeseed (as rapeseedwheat- barley or rapeseed-wheat-wheat) and cereal successions (as wheat-wheat-wheat, wheatwheat- barley or wheat-barley-barley) have strongly increased on the Seine basin over the last twenty years. The crop succession shortening, that causes crop protection problems towards weeds, insects or diseases, is only possible in relation with an intensive use of pesticides: thus the increase of the rapeseed area is positively correlated with the increase of the average number of plant pest controls, especially with herbicides. These agricultural dynamics have negative impacts on environment and enhance the economical risks the farms have to cop with. As a consequence, a new crop diversification, supported by policy-making and agricultural production networks, seems to be a strong future issue.

Soil is the basis underlying the food production chain and it is fundamental to improve and conserve its productive capacity. Imbalanced exploitation can degrade agricultural areas physical, chemical and biologically. The objective of this study was to evaluate some soil physical properties and their relation with organic carbon contents of a Humic Dystrudept under conventional tillage (CT) and no-tillage (NT), for 12 years in rotation (r) and succession (s) cropping systems. The experiment was carried out in Lages, SC (latitude 27 º 49 ' S and longitude 50 º 20 ' W, 937 m asl), using crop sequences of bean-fallow-maize-fallow-soybean in conventional tillage rotation; maize-fallow in conventional tillage succession; bean-oat-maize-turnip-soybean-vetch in no-tillage rotation; and maize-vetch in no-tillage succession. The experimental design was completely randomized with four replications. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10, and 10-20 cm. The following properties were analyzed: soil density, porosity, aggregate stability, degree of flocculation, water retention, infiltration, mechanical strength, and total organic carbon. Soil aggregation in the surface layer (0-5 cm) was better in the no-tillage than the conventional system, related to higher microporosity, organic carbon contents and water retention capacity, indicating that a periodical tillage of this soil is unnecessary. Infiltration was highest in no-tillage with crop succession.O solo é a base da cadeia produtiva de alimentos, por isso tornam-se necessárias a conservação e manutenção de sua capacidade produtiva. Muitas áreas exploradas de forma incorreta podem apresentar degradação física, química e biológica. O objetivo deste estudo foi avaliar alguns atributos físicos e suas relações com os teores de carbono orgânico de um Cambissolo Húmico alumínico nos sistemas de preparo convencional (PC) e semeadura direta (SD), após 12 anos com rotação (r) e sucessão (s) de culturas. O experimento foi conduzido em Lages - SC, situado a 27 º 49 ' de latitude sul e 50 º 20 ' de longitude oeste, com altitude média de 937 m. As sequências de cultivo foram: feijão-pousio-milho-pousio-soja no preparo convencional rotação; milho-pousio no preparo convencional sucessão; feijão-aveia-milho-nabo-soja-ervilhaca na semeadura direta rotação; e milho-ervilhaca na semeadura direta sucessão. O delineamento experimental foi inteiramente casualizado, com quatro repetições. As amostras de solo foram coletadas nas camadas 0-2,5, 2,5-5, 5-10 e 10-20 cm. As variáveis avaliadas foram densidade do solo, porosidade, agregação, grau de floculação, retenção de água, infiltração, resistência mecânica à penetração e teor de carbono orgânico total. A semeadura direta apresentou melhor agregação do solo na camada surface (0-5 cm) em relação ao preparo convencional, o que está associado à maior microporosidade, teor de carbono orgânico total e retenção de água, não havendo necessidade de revolvimento do solo. A infiltração foi maior na semeadura direta com sucessão de culturas.

For agronomic, environmental, and economic reasons, the need for spatialized information about agricultural practices is expected to rapidly increase. In this context, we reviewed the literature on remote sensing for mapping cropping practices. The reviewed studies were grouped into three categories of practices: crop succession (crop rotation and fallowing), cropping pattern (single tree crop planting pattern, sequential cropping, and intercropping/agroforestry), and cropping techniques (irrigation, soil tillage, harvest and post-harvest practices, crop varieties, and agro-ecological infrastructures). We observed that the majority of the studies were exploratory investigations, tested on a local scale with a high dependence on ground data, and used only one type of remote sensing sensor. Furthermore, to be correctly implemented, most of the methods relied heavily on local knowledge on the management practices, the environment, and the biological material. These limitations point to future research directions, such as the use of land stratification, multi-sensor data combination, and expert knowledge-driven methods. Finally, the new spatial technologies, and particularly the Sentinel constellation, are expected to improve the monitoring of cropping practices in the challenging context of food security and better management of agro-environmental issues.

Os manejos conservacionistas, como o sistema plantio direto (SPD), podem ser considerados uma atividade com potencial para sequestrar C no solo. Os objetivos deste trabalho foram quantificar os estoques de C no solo e, juntamente com a dedução das emissões de óxido nitroso (N2O), calcular o sequestro de C do solo sob SPD com diferentes tempos de implantação em duas sucessões de culturas. O experimento foi instalado na Fazenda Santa Branca, em Tibagi (PR), em um Latossolo Vermelho distroférrico de textura argilosa. Os tratamentos, dispostos em faixas não casualizadas com parcelas subdivididas, foram: plantio direto por 12 anos com sucessões milho/trigo e soja/trigo (PD12 M/T e PD12 S/T, respectivamente) e por 22 anos (PD22 M/T e PD22 S/T, respectivamente). Os estoques de C no solo aumentaram com o tempo de implantação do SPD; o incremento no C do solo em 10 anos foi de 35 %, com uma taxa anual de acúmulo de 1,94 t ha-1 ano-1 . A simulação do estoque de C do solo com o uso do modelo unicompartimental mostrou que o elevado aporte de resíduos culturais e a rotação de culturas com uso de leguminosas reduziram a mineralização da matéria orgânica, o que favoreceu o acúmulo de C no solo. As emissões de N2O foram 25 % mais elevadas na sucessão milho/trigo, em relação à soja/trigo, e os diferentes tempos de SPD não promoveram aumento das emissões do N2O. O balanço entre a taxa de acúmulo de C e a emissão de óxido nitroso mostrou que o sistema apresentou saldo positivo no acúmulo de C no solo, o que significou o sequestro de CO2 de 6 t ha-1 ano-1 .Conservationist soil management systems such as no-tillage (NT) can be considered activities with potential to increase soil carbon sequestration. The objective of this study was to quantify the soil C stocks and, along estimations of the nitrous oxide (N2O) emissions, calculate the soil C sequestration under NT for different times of implantation in two crop successions. The experiment was installed on the farm Santa Branca in Tibagi (Paraná State, Brazil), on a clayey Oxisol (Typic Hapludox). The treatments were conducted in non-random strips with subdivided plots: no-tillage with corn/wheat and soybean/wheat crop successions (NT12 M/T and NT12 S/T, respectively) for 12 years and no-tillage (NT22 M/T and NT22 S/T, respectively) for 22 years. The soil C stock increased with the time of no-tillage adoption; the increase in soil C in 10 years was 35 % and the annual accumulation rate 1.94 t ha-1 yr-1. The simulation of the soil C stock with the use of the unicompartmental model showed that the high input of crop residues and cropping systems with legume species reduced the soil organic matter mineralization that favored soil C accumulation. The N-N2O emissions were 25 % higher in corn/wheat than in soybean/wheat succession, and the different period of NT adoption did not induce higher N-N2O emissions. The balance between the soil C accumulation rate and nitrous oxide emissions indicated a positive balance of the system in the soil C accumulation, representing a CO2 sequestration of 6 t ha-1 yr-1

A atividade agrícola pode alterar a quantidade e qualidade da matéria orgânica do solo (MOS), resultando em emissões de dióxido de carbono (CO2) e óxido nitroso (N2O) do solo para a atmosfera. O sistema plantio direto (SPD) com a utilização de leguminosas em sistemas de rotação é uma estratégia que deve ser considerada tanto para o aumento da quantidade de MOS como para seu efeito na redução das emissões dos gases de efeito estufa. Com o objetivo de determinar os fluxos de gases do efeito estufa (CO2 e N2O) do solo, um experimento foi instalado em Tibagi (PR), em um Latossolo Vermelho distroférrico textura argilosa. Os tratamentos, dispostos em faixas não casualizadas com parcelas subdivididas, foram: sistema plantio direto por 12 anos com sucessões milho/trigo e soja/trigo (PD12 M/T e PD12 S/T, respectivamente) e por 22 anos (PD22 M/T e PD22 S/T, respectivamente). As emissões de CO2 do solo foram aproximadamente 20 % mais elevadas no PD22 em relação ao PD12. As emissões de CO2 apresentaram correlação significativa (R² = 0,85; p < 0,05) com a temperatura do solo, com emissões médias 40 % menores, registradas nos meses com temperaturas mais baixas. As emissões mais elevadas de N2O foram observadas após a colheita das culturas de verão, sobretudo na sucessão milho/trigo, em relação à sucessão soja/trigo. As emissões de N2O foram aproximadamente 25 % maiores após aplicação do fertilizante nitrogenado na cultura do trigo nas duas sucessões e apresentaram correlação significativa (R² = 0,88; p < 0,01) com o grau de saturação de água no solo (Sr %).The agricultural activity can change the quantity and quality of soil organic matter (SOM), resulting in CO2 and N2O emissions from the soil. No-tillage (NT) with legume species in crop rotation is a strategy that should be considered not only to increase the SOM quantity, but also to reduce greenhouse gas emissions. The objective of this study was to determine the soil-atmosphere gas emissions with greenhouse effect (CO2 and N2O). For this purpose, an experiment was installed in Tibagi (Paraná State, Brazil), on a clayey Oxisol (Typic Hapludox). The treatments were conducted in non-random strips with subdivided plots: no-tillage crop successions corn/wheat and soybean/wheat (NT12 M/T and NT12 S/T, respectively) for 12 years and no-tillage (NT22 M/T and NT22 S/T, respectively) for 22 years. The CO2 soil emissions were nearly 20 % higher in NT22 than in NT12. The CO2 emissions were significantly correlated (R² = 0.85; p < 0.05) with soil temperature, with 40 % lower mean emissions in the months of minimal soil temperatures. Highest N2O emissions were observed after the summer crop harvest, mainly in corn/wheat compared to soybean/wheat succession. N2O emissions were approximately 25 % higher after N-fertilizer application to wheat in both crop successions, and were significantly correlated (R² = 0.88; p < 0.01) with soil water-filled pore space (Sr %).

O objetivo deste trabalho foi avaliar a influência do tempo de cultivo de Panicum maximum (cultivar Tanzânia) sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação no período de setembro de 2006 a fevereiro de 2007. Os fatores foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Panicum maximum (cultivar Tanzânia) (0, 60, 80 e 100 dias) e três doses do picloram (0, 80 e 160 g ha-1), totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Após o tempo estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate e soja. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de Tanzânia por 60 dias garantiu crescimento inicial satisfatório das plantas de soja e tomate quando a contaminação inicial não foi maior que 80 g ha-1 de picloram. Acima desse valor, a fitorremediação ocorrida proporcionou menor crescimento das plantas de soja e tomate, sendo necessário maior tempo de descontaminação.The objective of this study was to evaluate the influence of cultivation time of Panicum maximum (cv. Tanzania) on phyto-remediation of soil contaminated with picloram. The experiment was carried out under greenhouse conditions from September 2006 to February 2007, using euthroferric Red Latosol samples as substrate for plant growth. The experiment was arranged in a completely randomized design, with four replicates, with treatments in a 4 x 3 factorial scheme. The treatments comprised twelve combinations of four periods of soil cultivation with the species Panicum maximum (cv. Tanzania) (0, 60, 80 and 100 days) and three doses of picloram (0, 80 and 160 g ha-1). At the end of each pre-established time of soil cultivation with the phyto-remediating species, seeds of tomato and soybean plants, used as bio-indicators of picloram presence, were sown on soil. The bio-indicators showed high sensitivity to picloram in soil, as their cultivation was not feasible without a prior phyto-remediation procedure. The previous cultivation of Tanzania for 60 days ensured a satisfactory initial growth of both soybean and tomato plants when the initial contamination level was lower than 80 g ha-1 of picloram. Above this dose, phyto-remediation provided by Tanzânia plants provide a lower soybean and tomato plants growth, indicating that a longer period of decontamination is required.

O nitrogênio (N) é um dos nutrientes mais requeridos pelo trigo e, muitas vezes, não é suprido nem na quantidade nem na época ideal. Devido à importância da adubação nitrogenada no trigo e à carência de informações disponíveis no Paraguai, foi desenvolvido este trabalho com o objetivo de propor uma recomendação nitrogenada para trigo sob sistema plantio direto. Cinco experimentos em rede foram realizados a campo, durante dois anos, em três departamentos do Paraguai, abrangendo os principais solos (Oxisols, Inceptisols e Ultisols) e regiões produtoras (Alto Paraná, Itapúa e Missiones). Os tratamentos utilizados no trigo (Triticum aestivum) foram cinco doses de N (0, 30, 60, 90 e 120 kg ha-1) após o milho (Zea mays) e a soja (Glycine max), sendo também investigado o efeito residual de N aplicado no milho (0, 60, 120, 180 e 240 kg ha-1) na nutrição do trigo, em parcelas de 5 x 8 m, em delineamento de blocos ao acaso com três repetições. O trigo respondeu economicamente, em média, à dose de 35 kg ha-1 de N após a soja para produtividades em torno de 3.100 kg ha-1; após o milho, respondeu economicamente, em média, até 30 kg ha-1 de N, atingindo produtividade de 2.100 kg ha-1. No solo com teor de matéria orgânica maior que 4 %, verificou-se capacidade de suprir, sem adubação nitrogenada mineral, quantidade suficiente de N para alcançar produtividades de até 2.500 kg ha-1. O trigo respondeu à adubação residual de N aplicado no milho, elevando a produtividade de 1.800 (0 kg ha-1) para 2.300 kg ha-1 (com a dose estimada de 213 kg ha-1 de N aplicado no milho, na média de todos os locais).Nitrogen is one of the nutrients wheat needs most, but is often not supplied neither in the right quantity nor at the right time. Because of the importance of nitrogen fertilization and the lack of information available in Paraguay, this study was developed to establish a nitrogen fertilizer recommendation for wheat under no-till. Six field experiments were carried out over a period of two years, in four Departments of Paraguay, considering the most important soils (Oxisols, Inceptisols and Ultisols) and regions (Alto Paraná, Itapúa, Amambay and Missiones). Five N rates (0, 30, 60 90, 120 kg ha-1) were applied to wheat (Triticum aestivum) after corn (Zea mays) and soybean (Glycine max), and the residual effect on wheat of N applied to the precedent corn crop was evaluated (0, 60, 120, 180 and 240 kg ha-1), in 5 x 8m plots, in a random block design with three replications. Economically, wheat after soybean responded positively to the N rate of 35 kg ha-1 with yields around 3.100 kg ha-1. After corn, wheat responded economically to doses of up to 30 kg ha-1 N and reached a grain yield of 2.100 kg ha-1. When the concentration of soil organic matter is higher than 4 %, a sufficient quantity of N is available without mineral N fertilization, for yields up to 2.500 kg ha-1. Wheat responded to residual N applied to corn with a yield increase from 1.800 kg ha-1 (0 kg ha-1) to 2.300 kg ha-1 (N applied to corn estimated at 213 kg ha-1, averaged across all sites).

Objetivou-se avaliar a influência de sistemas de manejo no rendimento de grãos de feijão em um Latossolo Vermelho de cerrado. A pesquisa iniciou-se em 1997 e a avaliação do rendimento de grãos foi realizada no inverno de 2002. Utilizou-se o delineamento experimental de blocos ao acaso no esquema em faixas com parcelas subsubdivididas. Os tratamentos foram constituídos nas faixas pela combinação de 5 plantasde cobertura (Mucuna aterrima, Pennisetum americanum, Crotalaria juncea, Cajanus cajan e pousio); no outro sentido, as faixas foram subdivididas e constituídas pelo sistema de semeadura direta e convencional (preparo do solo com grade aradora e grade niveladora), as quais, por sua vez, foram subsubdivididas com as culturas de verão milho, soja e algodão. Concluiu-se que as plantas de cobertura, após cinco anos, não influenciaram o rendimento de grãos; a massa de 100 grãos de feijão foi maior na semeadura convencional, porém, orendimento não diferiu entre os preparos; na semeadura convencional, a sucessão com algodão, nos dois primeiros anos agrícolas, proporcionou grãos de feijão mais pesados e maior rendimento; na semeadura direta, a sucessão que incluía algodão ou soja nos doisprimeiros anos agrícolas proporcionou maiores rendimentos ao feijoeiro.This study aimed to evaluate the influence of management on common bean in Oxisol. The research began in 1997 and the yield evaluation was carried out in the winter of 2002. The experimental design was randomized blocks with split split-plot design. The treatments were constituted by the combination of five cover plants, two soil tillages and three crop successions. It was concluded that cover plants, after five years, did not influence the common bean; the 100-grain weight of bean was higher in conventional tillage, but theyield did not show any difference between the tillages; in conventional tillage, cotton crop sucession in the first two years provided larger common bean weigth and yield; in the notillage,the successions with cotton and soybean in the first two years resulted in larger common bean yeld.

Three strict field experiments (2010-2013) were conducted at the Experimental Station of Cultivar Testing in Chrząstowo in Poland (53°11′N, 17°35′E). Diagnosis of fungal pathogens to determine the threats posed by complex of diseases to two wheats, cv. Cytra (bread type) and cv. Monsun (quality type), was carried out. Risk assessment in the context of integrated pest and disease management considering crop sequence, sowing date, and control by fungicide application was carried out. This method also investigates the grain yields of wheat to address the context of disease risk with grain production. The experimental factors were fixed: pre-crop for wheat (sugar beet- B, corn for grain- C, wheat- W), the sowing date: facultative in late autumn ( F) and spring ( S), fungicidal intensification: C1-untreated, C2-one treatment at T2 stage (BBCH 32-65) with fluoxastrobin and prothioconazole, C3-two treatments made at T1 (BBCH 30-32) with prothioconazole and spiroxamine and at T2 (BBCH 41-65) with fluoxastrobin and prothioconazole, C4-three treatments performed at stage T1 (BBCH 29-31) with prothioconazole and spiroxamine, T2 (BBCH 37-51) with fluoxastrobin and prothioconazole, and T3 (BBCH 65-69) with prothioconazole and tebuconazole. A total of 12 wheat diseases were diagnosed, four units for foot and root rot and eight related with leaf and head. The most healthy status reached the crops of cv. 'Monsun': BFC4-C3, BSC4-C3, WSC4-C3, WFC4-C3, CFC4-C2 CSC4-C3, and for root and stem base: BSC4-C1, BFC4-C1, CSC4-C1, CFC4-C1. The lowest risk possessed by root and root rot diseases for cv. Cytra had crops: BFC4-C1, BSC3, CFC4-C3, and due to leaf and ear diseases the crops: BFC2-C4, BSC2-C4, WFC2-C4, WSC2-C4, CFC2-C4, CSC2-C4. Crop sequence was found the prime factor for risk posed by foot and root rot diseases, while the lack of fungicidal control mostly impacted the risk posed by leaf and head pathogens. The highest increases in yield from controlled crops were attributed to facultative wheat followed after beet (49-66 %) or wheat (36-47 %). Wheat responded positively to C2 program with a rise in yield of 26 % for cv. 'Monsun' and 21 % for cv. 'Cytra.' The cost-effectiveness based on two indicators E and Q has been calculated for fungicide treatments on all 48 crops. [ABSTRACT FROM AUTHOR]

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Este trabalho teve como objetivo estimar as perdas de solo e água, nos sistemas de plantio direto e convencional, e foi realizado no câmpus experimental da UFMS, em Dourados - MS, em solo classificado como Latossolo Vermelho distroférrico, no período compreendido entre outubro de 2001 e novembro de 2002. As estimativas das perdas de solo e de água foram feitas utilizando-se do infiltrômetro de aspersão InfiAsper/UFMS, regulado para aplicar chuva com intensidade de 60 mm h-1, correspondendo à energia cinética de aproximadamente 820 Jm-2. Foram utilizados os seguintes tratamentos: sucessão milho-pousio; sucessão milho-trigo; sucessão milho-nabo; sucessão milho-ervilhaca; sucessão milho-aveia, os quais foram avaliados nos sistemas de preparo convencional (PC) e plantio direto (PD). Com os resultados obtidos, foram ajustadas equações de regressão, com as quais foi possível obter valores de perda de solo que variaram de 5,34 g m-2 na sucessão milho-aveia a 47,75 g m-2 na sucessão milho-nabo para o PC, e de 1,09 g m-2 na sucessão milho-trigo a 4,19 g m-2 na sucessão milho-ervilhaca para o PD. As perdas de água variaram de 0,00329 m³m-2 na sucessão milho-aveia a 0,00988 m³m-2 na sucessão milho-nabo, e de 0,00123 a 0,00663 m³m-2 na sucessão milho-pousio para o PC e para o PD, respectivamente.This work was developed in order to estimate the soil and water loss in no tillage and conventional systems. The work was carried out at Experimental Center of the Federal University of Mato Grosso do Sul - UFMS, in Dourados - MS - Brazil, in a soil classified as "Latossolo Vermelho distroférrico", in a period between October, 2001, and November, 2002. Soil and water loss estimations were done using a sprinkling infiltrometer InfiAsper/UFMS, adjusted to apply a rainfall of 60 mm h-1 of intensity, corresponding to kinetic energy of 820 Jm-2. The estimates were calculated in five treatments: corn-rest succession, corn-wheat succession, corn-Raphanus sativus succession, corn-vetch succession, corn-oats succession, for conventional tillage system (PC) and no tillage system (PD). With the results obtained, equations of regression were adjusted. Through these equations soil loss values were observed. They varied from 5.34 g m-2 in corn-oats succession to 47.75 g m-2 in Raphanus sativus-corn succession for PC, and 1.09 g m-2 in corn-wheat succession to 4.19 g m-2 in corn-vetch succession for PD. Water loss varied from 0.00329 m³m-2 in corn-oats succession to 0.00988 m³m-2 in corn-Rhaphanus sativus succession and from 0.00123 to 0.00663 m³m-2 in corn-rest succession for PC and PD, respectively.

Durante nove anos, avaliou-se o efeito de diferentes culturas antecessoras sobre o rendimento de grãos e sobre a estatura de plantas de soja, na EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS. Os tratamentos consistiram em sete sistemas de rotação de culturas, e a soja foi semeada em sucessão à aveia branca, à aveia preta, ao linho e ao trigo. Em 1990, foram adicionadas duas parcelas, uma para completar o sistema II e outra para pousio de inverno antecedendo a soja (sistema VII). As culturas de inverno foram estabelecidas com preparo convencional de solo, e as de verão, em plantio direto. O delineamento experimental foi blocos ao acaso, com três repetições, e parcelas com área útil de 30m². A soja cultivada após linho, na média do período de 1987 a 1989, nos sistemas IV e VI, apresentou menor estatura de plantas e menor rendimento de grãos. Nos períodos de 1990 a 1992 e de 1993 a 1995, não houve diferenças significativas entre tipo de cultura antecessora e rendimento de grãos. A soja cultivada após aveia branca, após aveia preta ou após trigo pode ser incluída, sem prejuízo, nos diferentes sistemas estudados.Different preceding crops on the yield and height of soybean plants was assessed during nine years at EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil. The treatments consisted of seven crop systems, and soybean was sown in succession to white oat, black oat, flax, and wheat. Two plots were added in 1990; one to complement system II and the other as winter fallow preceding soybean (system VII). Winter crops were set up using conventional soil preparation, and summer crops were sown under no-tillage. An experimental design of blocks at random, with three replications and plots totalling 30m², was used. The grown soybean after flax, in the mean of the period 1987 to 1989, in systems IV and VI showed lower plant on height and lower yield. No significant differences were found on the evoluated preceding crops on the yield over the periods 1990 to 1992 and 1993 to 1995. The grown soybean after white oat, black oat or wheat may be included in the different systems studied without any adverse effect.

On a beaucoup parlé, lors de l’examen des demandes d’autorisation de mise en culture de variétés transgéniques de colza, des risques d’hybridation interspécifique du colza avec les crucifères sauvages, et d’introgression de transgènes dans les espèces adventices [1, 2]. Les flux de gènes intraspécifiques ont moins attiré l’attention du grand public; ils sont pourtant bien plus probables. Les transgènes peuvent être disséminés dans le temps, par l’intermédiaire de repousses de colza apparaissant dans les cultures suivant les variétés transgéniques, à cause de la perte d’une partie des graines produites par les cultures de colza avant ou pendant la récolte [3, 4], et dans l’espace, par l’intermédiaire de semences et de pollen disséminés par le vent ou d’autres vecteurs tels que les oiseaux ou les insectes [5-8]. Les semences dispersées peuvent produire directement des repousses de colza dans des champs voisins, tandis que le pollen peut transmettre le transgène en fécondant des plantes de colza présentes dans ces autres champs. Ce flux de gènes peut être à l’origine de différents problèmes tels que l’apparition de repousses de colza résistantes aux herbicides, difficiles à éliminer lorsqu’il s’agit d’un transgène de résistance à un herbicide, ou la pollution de récoltes de colza classique par le transgène, quelle que soit sa nature, et l’impossibilité d’écouler ces récoltes dans une filière « non-OGM ». Il est donc apparu nécessaire et urgent de mieux évaluer ce risque et d’identifier les moyens de le maîtriser. Les premiers éléments de réponse ont été donnés par les plates-formes « plantes transgéniques » des instituts techniques [9, 10]; cependant, ces plates-formes sont limitées dans le temps et l’espace et il n’est pas possible d’y rendre compte de la variabilité régionale des systèmes de culture et de leurs effets sur le devenir des repousses de colza; il n’est pas non plus possible d’attendre les résultats des plates-formes pour estimer des risques à long terme. Pour ces raisons, nous avons entrepris de construire un modèle rendant compte de la répartition spatiale des systèmes de culture ainsi que de leurs effets sur la dissémination, dans le temps et l’espace, d’un transgène (par exemple un gène de résistance aux herbicides ou un gène codant pour un acide gras) et sur sa persistance dans les populations de repousses de colza, sur des parcelles ayant ou non été cultivées avec la variété de colza transgénique. Les autres risques liés aux cultures transgéniques (résistance aux antibiotiques, allergies alimentaires, etc.) ne sont pas considérés dans cette étude. Dans cet article, nous allons présenter les grands principes du modèle d’évolution démographique et génétique des repousses de colza fonctionnant au niveau d’un champ cultivé, puis l’intégration et le fonctionnement de ce modèle au niveau régional. Les exemples décrits lors de la présentation du modèle et des simulations se rapportent généralement à un colza transgénique résistant à un herbicide. Mais le modèle peut également être utilisé pour évaluer le flux de gènes à partir de nouvelles variétés obtenues par sélection classique et/ou pour des gènes codant pour d’autres caractéristiques telles qu’une teneur en acide gras.

A fertilidade do solo foi avaliada, após quatro anos (1990 a 1994), num latossolo bruno álico, em Guarapuava, PR, Brasil, em quatro sistemas de rotação de culturas para trigo: sistema I (trigo/soja); sistema II (trigo/soja e aveia branca/soja); sistema III (trigo/soja, ervilhaca/ milho e aveia branca/soja); e sistema IV (trigo/soja, aveia branca/soja, cevada/soja e ervilhaca/ milho). As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. O delineamento experimental foi de blocos ao acaso com quatro repetições. Através de contrastes, foram comparados os sistemas e as profundidades de amostragem de solo. Em todos os sistemas de rotação de culturas, na camada de solo 0 a 5cm, observaram-se valores maiores de pH e de Ca+Mg e menores de Al (com exceção do sistema III), em relação à camada 15 a 20cm. Houve elevação dos teores de Ca+Mg, de K e de P na camada de solo com a maior concentração de raízes (0 a 10cm). Os valores de matéria orgânica do solo decresceram progressivamente da camada 0 a 5cm para a camada 15 a 20cm.Soil fertility parameters were evaluated after four years (1990 to 1994) on a alic dusky latosol located in Guarapuava, Paraná, Brazil, under four wheat crop rotation systems as follows: system I (wheat/soybean); system II (wheat/soybean and white oats/soybean); system III (wheat/soybean, common vetch/corn, and white oats/soybean); and system IV (wheat/soybean, white oats/soybean, barley/soybean and common vetch/cor). Both winter and summer crops were seeded under no tillage. A randomized complete block design, with four replications, was used. Crop systems and soil samples at different depths were compared using the contrast procedure. All crop rotation systems, in the 0 to 5cm soil layer, higher values were observed for pH in water and Ca+Mg and lower contents for Al (except system III), as compared to the 15 to 20cm layer. Raising in Ca+Mg, K, and P levels occurred in the soil layer with the greatest root concentration (0 to 10cm). The soil organic matter contents decreased with depth from 0-5cm to 15-20cm.

A fertilidade do solo foi avaliada, após dez anos (1984 a 1994), num latossolo bruno álico, em Guarapuava, PR, Brasil, em quatro sistemas de rotação de culturas para cevada: sistema I (cevada/ soja); sistema II (cevada/soja e ervilhaca/milho, de 1984 a 1989, e cevada/soja e aveia branca/soja, de 1990 a 1993); sistema III (cevada/soja, linho/soja e ervilhaca/milho, de 1984 a 1989, e cevada/soja, ervilhaca/milho e aveia branca/soja, de 1990 a 1993); e sistema IV (cevada/soja, linho/soja, aveia branca/soja e ervilhaca/milho). Através de contrastes, foram comparados os sistemas e as profundidades de amostragem de solo. Os sistemas de rotação de culturas para cevada, sob plantio direto, elevaram os valores de matéria orgânica, de P e de K, principalmente na camada 0 a 5cm. Os valores de pH, de Ca+Mg, de matéria orgânica, de P e de K foram mais elevados na camada 0 a 5cm, em comparação aos verificados na camada 15 a 20cm. Tendência inversa foi observada para os teores de Al trocável.Soil fertility parameters were evaluated after ten years (1984 to 1994) of no-tiliage cropping in a latossolo bruno álico, in Guarapuava, state of Paraná, Brazil, under four barley crop rotation systems as follows: system I (barley/soybean); system II (barley/soybean and common vetch/corn, from 1984 to 1989, and barley/soybean and white oats/soybean, from 1990 to 1993); system III (barley/soybean, flax/soybean, and common vetch/corn, from 1984 to 1989, and barley/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1993); and system IV (barley/soybean, flax/soybean, white oats/ soybean and common vetch/corn). Crop systems and soil samples at dijferent depths were compared using the contrast procedure. Barley crop rotation systems, under no-till, raised organic matter. P, and K contents, chiefly in the 0 to 5cm layer. Higher pH and Ca+Mg values were observed in the soil layer 0 to 5cm, as compared to the 15 to 20cm layer. The opposite was observed for exchangeable Al contents.

The aim of this study was to evaluate the effects of green manures on Pratylenchus brachyurus management in soybean. Two experiments were conducted at different periods using a fully-randomized design in a 6 x 2 factorial arrangement, with six plant species (maize (control), velvet bean, crotalaria, stylosanthes, pigeon pea and oil seed radish) and two cropping systems (incorporated and non-incorporated). Simulating crop succession, soybean was cultivated after different plant species, in 2-liter pots containing naturally-infested soil. Vegetative and nematological parameters were evaluated. No significant differences were observed among the treatments for shoot fresh and dry weight and the number of nematodes in 100 cm3 soil. Velvet bean and pigeon pea increased root weight in experiments 1 and 2. All treatments reduced the number of nematode/g root compared to the control, with the best results obtained using velvet bean, crotalaria and stylosanthes. The interaction showed that incorporating the fresh weight of the shoots of pigeon pea and oil seed radish reduced the number of P. brachyurus compared to the non-incorporated system. [ABSTRACT FROM AUTHOR]

Abstract: Landscape ecology has emphasized the key role of spatial heterogeneity as a driver of ecological processes, which has led to a shift from a patch-matrix to a landscape mosaic representation of landscapes. However, in agricultural landscapes, the role of heterogeneity for biodiversity is often studied by considering (semi-) natural elements regardless of the functional heterogeneity of the cultivated mosaic. This mosaic, which emerges from the organization of cropping systems by farmers, is not just heterogeneous in space but also strongly dynamic (i.e. temporally heterogeneous) due to crop phenology, management and sequence. In this paper, based on agronomic and ecological literature we highlight the heterogeneous properties of the cropping system mosaics in space and time, and the implications of this “hidden” heterogeneity for controlling of arthropod population dynamics and persistence. An illustration is then given to propose different methodological approaches to map the hidden heterogeneity of agricultural landscapes. This conceptual and methodological framework concerns various species in agro-ecosystems, including crop and multi-habitat species, as well as species that only disperse through the crop mosaic. This paper suggests that the design of the cropping system mosaics could be complementary to the design of natural areas to manage populations, notably for species of economic interest (pests, natural enemies or pollinators). More empirical work on this topic is crucial, which will require new methodological approaches. [Copyright &y& Elsevier]

Landscape spatial organization (LSO) strongly impacts many environmental issues. Modelling agricultural landscapes and describing meaningful landscape patterns are thus regarded as key-issues for designing sustainable landscapes. Agricultural landscapes are mostly designed by farmers. Their decisions dealing with crop choices and crop allocation to land can be generic and result in landscape regularities, which determine LSO. This paper comes within the emerging discipline called 'landscape agronomy', aiming at studying the organization of farming practices at the landscape scale. We here aim at articulating the farm and the landscape scales for landscape modelling. To do so, we develop an original approach consisting in the combination of two methods used separately so far: the identification of explicit farmer decision rules through on-farm surveys methods and the identification of landscape stochastic regularities through data-mining. We applied this approach to the Niort plain landscape in France. Results show that generic farmer decision rules dealing with sunflower or maize area and location within landscapes are consistent with spatiotemporal regularities identified at the landscape scale. It results in a segmentation of the landscape, based on both its spatial and temporal organization and partly explained by generic farmer decision rules. This consistency between results points out that the two modelling methods aid one another for land-use modelling at landscape scale and for understanding the driving forces of its spatial organization. Despite some remaining challenges, our study in landscape agronomy accounts for both spatial and temporal dimensions of crop allocation: it allows the drawing of new spatial patterns coherent with land-use dynamics at the landscape scale, which improves the links to the scale of ecological processes and therefore contributes to landscape ecology. [ABSTRACT FROM AUTHOR]

Abstract: Assessing the environmental impacts of agricultural practices at the catchment scale increasingly involves the use of spatially distributed models that include cropping systems as input. Use of these models for diagnosis and evaluation requires large datasets at large spatial and temporal scales. The description of spatial dynamics of cropping systems at a fine resolution (i.e. field level) is particularly needed. As these data are scarce or not available, our objective was to propose a model that first reconstructs spatial dynamics of past cropping systems from available data, and second constructs alternative spatial cropping systems, corresponding to agricultural practice scenarios. Classification systems for farms and fertilisation practices were defined to classify farm-level organisation for crop-succession and crop management strategies, in particular nitrogen fertilisation. Winter cover crops and multiple strategies per crop at the farm level can be represented with this model. Cropping systems are modelled in three steps: we modelled crop cover succession in summer with Markov chains based on empirical data and in winter with rules based on expert agronomic knowledge; lastly a Knapsack-based algorithm was used to allocate a crop management system to fields with constraints on several crop management strategies per crop type. Results of a case study performed on the Frémeur catchment (western France) show that this model respects the main constraints for cropping system modelling to assess agricultural practices at the catchment scale. From a scenario discussed with stakeholders and regional authorities characterised by stable areas of summer crops, the decrease in bare soil area in winter and overall reduction in total nitrogen fertilisation for different types of crops and farms we demonstrate the model’s ability to simulate coherent cropping systems. Thus, if faced with a lack of data or knowledge about the local factors that drive changes in cropping systems, the model can construct the spatial dynamics of cropping systems, which can be used as input to distributed nitrate transfer models to assess agricultural practices at the catchment scale. [Copyright &y& Elsevier]

The main goal of this research was to evaluate the response of maize crop in succession to maize + oat crops, with the anticipation of the increasing doses of nitrogen application in the oat culture, in no-tillage system. The experiment was carried out under field conditions at FCA/UNESP, Botucatu Campus, São Paulo, Brazil. The experimental design was arranged in randomized blocks with four replications, in split-plots. The plots were the nitrogen doses applied on the oat crop (0, 20, 40 e 60 kg ha-1), and split-plots, the nitrogen doses applied in the cover (60, 80, 100 e 120 kg ha-1), divided into two different crop stages of the maize crop. The dry matter weight and the C/N ratio were assessed on the oat and maize crops. On the maize crop, the plant nitrogen was quantified before the first covering and 15 days after the second covering, when the dry matter weight of the maize plants was determined. After the harvest, the yield was also calculated. Results indicate that the maize development and yield under no-till system were related to the straw C/N ratio, and the maize crop response to the anticipated N fertilization anticipation varied according to the N doses and application periods. The dry matter weight of the maize plants were influenced by the rates and periods of N applications. [ABSTRACT FROM AUTHOR]