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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.

Nitrogen fertilization in off-season sorghum may have lower cost-benefit ratios than expected due to the residual effect of previous crops. However, the use of growth-promoting bacteria can be an economical alternative to increase crop yields in Cerrado. The objective was to evaluate the response of grain sorghum to nitrogen fertilization and its inoculation by Azospirillum brasilense. This study aims to evaluate grain sorghum responses to nitrogen fertilization and A. brasilense inoculation. The experiment was carried out in a fully randomized block design and 5 x 2 factorial scheme, with five replications. Treatments consisted of applying N recommendation (120 kg N-urea ha-1) split as follows: 100% at sowing, 100% as topdressing, 25% at sowing and 75% as topdressing, 50% at sowing and 50% as topdressing, and a control (without application), all these with and without A. brasilense seed inoculation. We also assessed the morphological and productivity components of grain sorghum. The application of 100% N at sowing promoted taller plants, while 50% -50% splitting shorter ones. Overall, grain sorghum plants did not respond to A. brasilense inoculation. Moreover, yield components of rainfed sorghum grown in succession to soybeans were not affected by A. brasilense inoculation and N supplied at once or split. Nitrogen fertilization in crop sorghum during the off-season may have a lower cost-benefit ratio than expected, due to the residual effect of the predecessor crop. However, the use of growth-promoting bacteria can be an economical alternative to increase crop yield in the Cerrado. The objective was to evaluate the response of grain sorghum to nitrogen fertilization and its inoculation by A. brasilense. A complete randomized block design in a 5 x 2 factorial arrangement was used, with five replications of the following treatments: recommended amount of N (120 kg ha-1 of N-urea), divided into 0 %-100 %, 25 % -75 %, 50 %-50 % and 100 %-0 %, in sowing and coverage, respectively, and the control (without N); with and without inoculation via sorghum seed. The morphological and productivity components of the crop were evaluated. The application of 100 % of N in the sowing provided larger plants and the 50 %-50 % installment provided smaller plants. The plants did not respond to inoculation by A. brasilense. The yield components of sorghum grown in succession to soybean, rainfed, do not change due to A. brasilense inoculation and supply or installment of nitrogen fertilization.

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.

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 0,05). Menor teor de proteína (-21,6%; p 0,80; p

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&ndash, wheat and rapeseed&ndash, 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&ndash, 20 cm, for microbial abundance and enzyme activity analyses, and twice a year at a depth of 0&ndash, 60 cm, for the measuring of the mineral N. The results showed that the rapeseed&ndash, wheat succession maintained or enhanced soil bacterial and fungal biomasses and their enzyme activities. The winter pea&ndash, wheat succession enriched the soil&rsquo, s mineral N content more consistently than the rapeseed&ndash, wheat succession. The mineral N enhancement&rsquo, s effect was maintained under the wheat crop. Overall, the impact of the winter pea was positive on the soil&rsquo, 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.

O objetivo deste trabalho foi avaliar a ciclagem de nutrientes por plantas de cobertura e a sua influência sobre o desempenho da rotação entre arroz de terras altas e soja. As culturas foram implantadas sob plantio direto, em Latossolo Vermelho distroférrico, na região do Cerrado de Goiás. As plantas de cobertura foram semeadas mecanicamente, também em plantio direto, após a colheita da soja (25/3/2008) e do arroz (7/4/2009). Utilizou-se o delineamento de blocos ao acaso, com parcelas subdivididas no tempo e quatro repetições. Os tratamentos consistiram das seguintes espécies de plantas de cobertura, além do pousio: Urochloa ruziziensis, U. brizantha, Pennisetum glaucum e U. ruziziensis + Cajanus cajan. A avaliação dos nutrientes remanescentes na palhada foi feita aos: 0, 15, 30, 60, 90 e 120 dias a partir da data da dessecação das plantas de cobertura. Urochloa ruziziensis e U. brizantha apresentaram maior eficiência no acúmulo e na liberação de nutrientes, principalmente quanto ao potássio. Urochloa ruziziensis é a espécie mais indicada como planta de cobertura antecessora à cultura do arroz de terras altas, em plantio direto. No entanto, nenhuma espécie de cobertura afeta significativamente a produtividade de grãos da soja. The objective of this work was to evaluate nutrient cycling by cover crops and its influence on the performance of the rotation between upland rice and soybean. The crops were sown under no-tillage, in a Rhodic Haplustox, in the Cerrado region of the state of Goiás, Brazil. The cover crops were sown mechanically, also under no-tillage, after the harvest of soybean (3/25/2008) and rice (4/7/2009). A randomized complete block design was used, split-plotted in time, with four replicates. The treatments consisted of the following cover crop species, besides fallow: Urochloa ruziziensis, U. brizantha, Pennisetum glaucum and U. ruziziensis + Cajanus cajan. The evaluation of the remaining nutrient in straw was performed at 0, 15, 30, 60, 90, and 120 days from the desiccation date of the cover crops. Urochloa ruziziensis and U. brizantha were the most efficient in the accumulation and release of nutrients, especially potassium. Urochloa ruziziensis is the most suited species for use as a cover crop previous to upland rice cultivation under no-tillage. However, none of the cover crop species significantly affect soybean grain yield.

The composition of grass-legume associations both modifies and is modified by the N cycle. The identity of the plants in the association has an effect on crop-level fixed-N inputs, N transfer while the association is in place, and the N remaining during the rest of the crop rotation cycle. The N used by the grass that is generated by the legume varies: it can reach 60% in white-clover-based associations, 50% in red-clover-based associations and 40% in lucerne-based associations. The percentage of legumes that optimises N transfer to grasses in grazed pastures (30%) is less than the percentage that maximises N fixation in hay meadows (70%). Making improvements to plants so that they can be used in associations, selecting certain plant varieties, and managing plant cover (e.g., via fertilisation, defoliation) are major tools that can be used to fine-tune the balance between the plants composing grass-legume associations. To some degree, these tools can also be used to influence relative contributions to the N balance of crop rotation systems. Free full text: [http://www.afpf-asso.fr/download.php?type=1&id=2085&statut=0]

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:22Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:31:32Z : No. of bitstreams: 1 2-s2.0-84859958942.pdf: 83277 bytes, checksum: 06131e5a041a2424632a7f52c33a65f6 (MD5) Made available in DSpace on 2014-05-27T11:26:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) 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. Universidade Do Estado de Santa Catarina, Av. Luis de Camões, 2090, Conta Dinheiro, CEP 88520-000, Lages-SC Universidade Estadual Paulista Júlio de Mesquita Filho, Rua José Barbosa de Barros,1780, Fazenda Lageado, CEP 18603-307, Botucatu-SP Vale Do Jurumim (EDUVALE), Avenida Misael Euphrasio Leal, 347, Jardim. América, CEP 18705-050, Avaré-SP Instituto Federal de Educação Ciência e Tecnologia Baiano, Km 2, Rodovia Itapetinga/Itororó, CEP 45700-000, Itapetinga-BA Universidade Federal Do Maranhão Centro de Ciências Agrárias e Ambientais, BR 222, Km 4, Boa Vista, CEP 65500-000, Chapadinha-MA Bolsista de Produtividade em Pesquisa Do CNPq Universidade Estadual Paulista Júlio de Mesquita Filho, Rua José Barbosa de Barros,1780, Fazenda Lageado, CEP 18603-307, Botucatu-SP

CT3 ; EnjS 4 ; avec travaux de conception d'ingénierie : oui : outil pour simuler des systèmes de culture (successions de cultures et ITK) sur un bassin versant; 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 Fremeur 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.

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 %).

International audience; A research procedure is proposed which aims to analyse the agricultural spatial dynamics during the last thirty years using two levels of organisation of farming activity: the agricultural production system and the cropping system. Based on methods of statistical mapping and data mining, this procedure involves modelling the diversity of production systems and cropping systems (crop successions and sequences of cultural practices for each crop) in the form of classes independently of their localisation within the basin. It identifies homogeneous regions made up of groups of contiguous agricultural districts which exhibit similar combinations of production systems, crop successions or cultural practices during a given period of time. The results show a major increase in arable farms since 1970 at the expense of dairy farms and mixed cropping/livestock. This trend however appeared to be greatly spatially differentiated according to the agricultural districts, since livestock remained important on the edges of the basin, whereas it practically disappeared in its centre. The crop successions practiced in the basin and the cultural practices used on them also appear to be spatially differentiated, although the link to the production systems is not always clear. Thus it appears pertinent to combine the analysis of the two levels of organisation of the agriculture (methods of land use described by the concept of cropping system, and also the production systems into which the cropping systems fit) in the context of an environmental problem.

O objetivo do presente trabalho foi avaliar sistemas de manejo de solo e de rotação de culturas sobre o rendimento de grãos e componentes do rendimento de soja durante seis anos. Foram comparados quatro sistemas de manejo de solo - 1) plantio direto, 2) cultivo mínimo, no inverno e semeadura direta, no verão, 3) preparo convencional de solo com arado de discos, no inverno e semeadura direta, no verão e 4) preparo convencional de solo com arado de aivecas, no inverno e semeadura direta, no verão - e três sistemas de rotação de culturas: sistema I (trigo/soja), sistema II (trigo/soja e ervilhaca/milho ou sorgo) e sistema III (trigo/soja, ervilhaca/milho ou sorgo e aveia branca/soja). O delineamento experimental foi de blocos ao acaso, com parcelas subdivididas e três repetições. O rendimento de grãos e o peso de 1.000 grãos de soja cultivada sob plantio direto e sob cultivo mínimo foi superior ao de soja cultivada sob preparo convencional de solo com arado de discos e com arado de aivecas. A maior estatura de plantas de soja ocorreu no plantio direto. O rendimento de grãos de soja cultivada após trigo, no sistema II, foi superior ao de soja cultivada após aveia branca e após trigo, no sistema III, e após trigo, no sistema I. O menor rendimento de grãos, peso de grãos por planta de soja e peso de 1.000 grãos ocorreu quando em monocultura (trigo/soja). The objective of this six-year study was to assess the soil tillage systems and crop rotation systems on soybean grain and yield components were evaluated at Embrapa Trigo in Passo Fundo, RS, Brazil. Four soil tillage systems - 1) no-tillage, 2) minimum tillage in winter and no-tillage in summer, 3) conventional tillage with disk plow in winter and no-tillage in summer, and 4) tillage using a moldboard plow in winter and no-tillage in summer - and three crop rotation systems [system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean)]. An experimental randomized blocks design, with split-plots and three replications, was used. The yield and weight of 1,000 kernels of soybean grown under no-tillage and minimum tillage was higher than soybean grown conventional soil tillage with disk plow and a moldboard plow. Plant height showed higher in the no-tillage. The yield of soybean grown after wheat, in system II, was higher than soybean grown after white oats and after wheat, in system III, and after wheat, in system I. The lowest soybean yield, grain weight/plant, and weight of 1,000 kernels was obtained in monoculture (wheat/soybean).

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:18:06Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:38:38Z : No. of bitstreams: 1 2-s2.0-0030486916.pdf: 641880 bytes, checksum: 7b90824b7a78c87a5e2d7433bce96115 (MD5) Made available in DSpace on 2014-05-27T11:18:06Z (GMT). No. of bitstreams: 0 Previous issue date: 1996-08-01 O ensaio foi conduzido com a cultivar IAC Carioca, durante dois anos agrícolas (1990/91 e 1992/93), no período de inverno. Usou-se a área experimental da Fazenda de Ensino e Pesquisa, da Faculdade de Engenharia de Ilha Solteira, UNESP, localizada no município de Selvíria, MS, em solo originalmente sob vegetação de cerrado. O objetivo foi estudar o efeito da incorporação de mucuria-preta e dos restos culturais de milho, no desenvolvimento e produção da cultura do feijão de inverno. Concluiu-se que a incorporação de matéria seca de milho, de milho + mucuna-preta ou só de mucuna-preta não afeta as características químicas do solo, avaliadas cerca de 80 dias apos a incorporação, nem os componentes de produção, nem a produtividade do feijoeiro de inverno cultivado em sucessão. The experiments were conducted during two years (1990/91 and 1992/93), to study the effects of the incorporation of bengal velvetbean and of residues on the development and yield of the winter bean crops. The trial was developed in experimental field at the Faculdade de Engenharia de Ilha Solteira, UNESP, located in Selvíria, MS, Brazil, in dark red latosol covered by savanna vegetation. It was concluded that: the incorporation of residues of corn or corn + bengal velvetbean or only bengal velvetbean had no effects on soil chemical characteristics, evaluated 80 days after the residues incorporation; in yield and bean crop development, no statistical differences were observed among treatments. Dep. Fitot. Econ. e Sociol. Rural Fac. de Engen. de Ilha Solteira UNESP, CEP 15385-000 Ilha Solteira, SP Dep. de Cie. do Solo e Engen. Rural Fac. Engen. de Ilha Solteira UNESP Dep. Fitot. Econ. e Sociol. Rural Fac. de Engen. de Ilha Solteira UNESP, CEP 15385-000 Ilha Solteira, SP Dep. de Cie. do Solo e Engen. Rural Fac. Engen. de Ilha Solteira UNESP