Pasture Crops Research Articles

Discrimination of Nitrogen Sources in Karst Spring Contributing Areas Using a Bayesian Isotope Mixing Model and Wastewater Tracers (Florida, USA)

ABSTRACT Many springs in Florida have experienced a proliferation of nuisance algae and alteration of trophic structure in response to increases in nitrate concentration concurrent with rapid population growth and land use intensification beginning in the mid-20th century. While loading targets and remediation plans have been developed by state agencies to address excess nitrogen inputs, further confirmation of the relative contribution of nitrogen sources to groundwater is necessary to optimize the use of resources when implementing projects to reduce nitrogen loads. In the present study, stable isotopes of nitrate and wastewater indicators were used to discriminate sources of nitrogen in wells and springs in central Florida. Sampling was performed in 50 wells at 38 sites and at 10 springs with varying levels of agriculture and urban development. Nitrate isotope values were used to develop Bayesian mixing models to estimate the probability distribution of the contributions of nitrate sources in wells. Prior probabilities for the fractional contribution of each source were adjusted based on land use and density of septic tanks. Sucralose and the Cl:Br mass ratio were used as confirmatory indicators of wastewater sources. In residential areas, mixing model results indicated that fertilizer or mixed fertilizer and wastewater (septic tank effluent and reuse water) were the primary sources, with sucralose detections corresponding to wells with elevated contributions from wastewater. Sources of nitrogen in pasture and field crop areas were primarily fertilizer and manure; however, model posterior distributions of δ15N indicated that manure sources may have been overpredicted. The present study demonstrates the utility of a multi-tracer approach to build multiple lines of evidence to develop locally relevant remediation strategies for nitrogen sources in groundwater.

Income Generation of Non-wood Forest Products in an Innovative Integrated Crop-Livestock-Forestry System

The wide extension area occupied by babassu palm (Atallea speciosa Mart. Ex Spreng) is usually considered as an important obstacle for agricultural activities, such as crop production and pasture maintenance in Brazil. This study aimed to evaluate the non-wood forest product use and income generated in an Integrated Crop-Livestock-Forestry (ICLF) system using babassu palm as the main forestry component in a rural area of Pindaré-Mirim, a municipality of Maranhão state, in the Amazon Eastern Region, Brazil. In order to rise a well-balanced agroforestry system in numerous rural areas of the country, three main questions were addressed in this study: 1) What is the production of babassu fruits in the system? 2) Is the babassu extractivism income economically suitable for traditional communities of women babassu breakers? 3) Which commercialization scenario of NWFP could generate more income? Data on phenology and fruit production, processing of all fruit components, and commercialization of babassu products were collected in two 12-month seasons of palm production (2017/2018 and 2018/2019). The mean fruit production reached 2,345.49 kg ha-1 season-1, resulting in an estimate of income generation ranging from R$ 8,206.96 ha-1 season-1 to R$ 36,628.54 ha-1 season-1, depending on the commercialization scenario. These numbers were compared to the statewide monthly income per household of R$ 605.00 and to the per capita monthly income of 54% of the municipality of less than R$ 499.00. The real field data and the estimates for two seasons of using babassu palm, as the innovative forestry component in ICLF system, demonstrated that babassu NWFP could generate substantial income for the surrounding user communities. Such innovative agricultural system may contribute to change people understanding, diversifying agrarian production, improving the socioeconomic household welfare, and reducing the long-term conflicts between livestock activities and babassu palm existence in Brazil.

Phytophthora cactorum as a Pathogen Associated with Root Rot on Alfalfa (Medicago sativa) in China.

Alfalfa (Medicago sativa) is the largest grown pasture crop in China due to its economic and ecological importance. During the summer season from June to August in 2018, stunted plants was frequently observed in alfalfa fields that have been established for two years in Jinchang, Gansu Province. The disease incidence of root rot ranged from 40% to 50%. Taproots of stunted plants showed red-brown to dark brown discolorations, and lateral roots were poorly developed. Shoots wilted with rotted taproots and lateral roots in severely affected plants. Twenty symptomatic plants were collected and transported to the laboratory for pathogen isolations. Roots were washed under running tap water, cut into 2 to 3 mm pieces (40 pieces each plant), and then sterilized in 75% ethanol for 2 mins followed by three times washing with autoclaved distilled water. Surface dried pieces on autoclaved filter papers were put onto water agar and also a Phytophthora selective medium P5ARP(H) (Jeffers and Martin 1986). The plates were incubated at 22°C for 3 to 5 days and then the growing hypha were subcultured onto potato dextrose agar (PDA). Thirty-two Phytophthora-like isolates were obtained and showed similar morphologies on PDA. Five isolates picked randomly were purified by single-hyphal-tip and plugs (4 to 5 mm) from PDA cultures were incubated in petri dishes with autoclaved distilled water at 22°C for 5 days. Sporangia, chlamydospores and oospores were examined. Sporangia were usually ovoid and sometimes appeared ellipsoid, with the length of 30.5-39.1 μm and width of 23.4-27.8 μm. The diameter of chlamydospores was 29.6 to 42.5μm. Oospores had a diameter of 23.6 to 30.2 μm. The isolates were tentatively identified as P. cactorum based on these morphology characteristics (Montealegre et al. 2016). DNA of these isolates were extracted and PCR amplifications of the rDNA ITS region and cytochrome oxidase subunit I (Cox I) (Kroon et al. 2004) were conducted. Sequences of these isolates were then compared with reference sequences in GenBank using BLAST search. The 866-bp ITS sequences had a sequence identity of 99% to 100% with P. cactorum (e.g. accession nos. EU662221, KJ128036). In addition, the 663-bp CoxI sequences showed 100% sequence identity with three P. cactorum isolates (accession nos. AB688156, HQ708234, EU660851). The ITS and CoxI sequences of one representative isolate Phy.c2 have been deposited in GenBank with the accession no. MT280033 and MT344138, respectively. Pathogenicity of the five isolates (Phy.c1-Phy.c5) were determined on two-week-old alfalfa seedlings (cv. Longdong) grown from seeds. Inoculums were prepared by subculturing agar plugs from edges of PDA cultures into the flask with autoclaved millet seeds, and incubated at 22°C in darkness for two weeks and shaken by hand every two days to ensure uniform colonization. Seedlings were transplanted into pots (12 cm x 12 cm) filled with autoclaved potting mix infested with millet-seed inoculum of each isolate at a rate of 0.5% (w/w). Control seedlings for comparison were transplanted into pots with uninfested potting mix. There were five seedlings per pot and twelve replicate pots for both inoculated and noninoculated treatments, and pots were kept under controlled environment room (22°C, 12 h photoperiod and 65% relative humidity) that were watered every two days to free draining. 87%~92% of the inoculated plants showed stunted symptoms with poorly developed and brown-discoloured roots three weeks after inoculation while the control plants were healthy with no root disease symptoms. To fulfil Koch's postulates, re-isolated cultures from discoloured root tissues were confirmed as the inoculated isolates by morphological examination and ITS sequencing. The five-purified isolates were submitted to the Grassland Culture Collection Center, Lanzhou University, with the accession nos. LZU-MsR-Phy.c1-Phy.c5. To our knowledge, this is the first report of P. cactorum as a pathogen of root rot on alfalfa in China. Phytophthora spp. has been reported causing root rot on alfalfa in America, Australia and Canada, and other legumes such as chickpea, and many other crops worldwide (Musial et al. 2005; Tan and Tan 1986; Vandemark and Barker 2003), and P. cactorum was reported as a root rot pathogen on lavender in China (Chen et al. 2017). P. cactorum may be a significant pathogen associated with root rot in major commercial alfalfa-producing areas in China where are based on flood-irrigation during the growth season.

A Review Paper on the Role of Terrestrial Carbon Stocks for Climate Change Mitigation Mechanisms

Global warming is among the greatest terrible horrors of the modern times. The global carbon cycle is taking place in three main reservoirs (the oceans, the atmosphere, and terrestrial systems), which store carbon in different forms and varying amounts. The forest ecosystems have large potential to act as a temporary and long-term carbon (C) pool. Global forest vegetation stores 283 Gt of carbon in its biomass, 38 Gt in dead wood and 317 Gt in soils (top 30 cm) and litter. Globally, the litter C pool accounts for an estimated 5% (43 Pg) of all forest ecosystem C stocks. Agroforestry practices can reduce or remove significant amounts of GHGs through increased carbon storage in biomass above-ground and below-ground and in soil organic carbon. Roots are an important part of the C balance, because they transfer large amounts of C into the soil. Grasslands, including rangelands, shrublands, pastureland, and cropland sown with pasture and fodder crops, covered approximately 3.5 billion ha in 2000, representing 26 percent of the world land area and 70 percent of the world agricultural area, and containing about 20 percent of the world’s soil carbon stocks. Soils are the largest carbon reservoirs of the terrestrial carbon cycle 1500–1550 Gt of organic soil carbon and soil inorganic C approximate 750 Gt both to 1 m depth. On a global scale, carbon loss from soils is mainly associated with soil degradation, including accelerated erosion and mineralization, and land use change, and has amounted to 78+/- 12 Gt since 1850. The idea of Reducing Emissions from Deforestation and forest Degradation (REDD) was conceived by United Nations Framework Convention on Climate Change (UNFCCC) as the main carbon emission reduction mechanism by developing countries. The implementation of improved land management practices to build up carbon stocks in terrestrial ecosystems is a proven technology for reducing the concentration of carbon dioxide (CO2) in the atmosphere – offsetting emissions from other sources and drawing down atmospheric CO2. Keywords: Carbon sequestration, Terrestrial carbon, Global warming and Carbon stocks. DOI: 10.7176/JEES/10-8-04 Publication date: August 31 st 2020

Modeling of disk sowing apparatus operation process

As foreign and domestic experience in livestock breeding shows, cultivated pastures are highly efficient and are considered to be a reliable source of consistent provision of animals with green feed during the pasture period. Free feeding of animals on pastures is a natural way of feeding them, which is created by nature within the framework of a single ecosystem in which natural grassland vegetation grows. One of the most expensive items in animal breeding is feed production. To exemplify this, when keeping animals on cultural pastures, there is a decrease in the relevant share of expenses for feed production in the structure of aggregate expenses compared to their management in livestock buildings by 2 times (from 60 … 65% to 30%), and the expenses on purchasing fuels and lubricants by 6 … 7 times. It has been established that in the North Caucasus region three methods of creating cultural pastures are used: based on existing natural and artificial grasses through their surface improvement (by carrying out cultural work, regulating the water-air regime of the soil, combating weed and poisonous vegetation, sowing grass, fertilizing); radical improvement of natural fodder farmland, i.e. the creation of artificial cultural pastures; using pasture crops of perennial grasses cultivated on strongly eroded slope lands to reduce or eliminate erosion processes. As can be seen from the above, the problem of creating cultural pastures on sloping lands is of great current interest.

Ethical Acknowledgment of Soil Ecosystem Integrity amid Agricultural Production in Australia

AbstractThe growing adoption of no-till cropping and other minimal-impact farming practices in recent decades signals a shift in how soil is understood and valued. Eschewing vigorous disturbance, standard in the West (and beyond) since the Neolithic Revolution, farmers instead learn to intervene with the soil profile more sensitively. This article focuses on the concept of soil integrity and its significance for farmers’ ethical relationship to soils in everyday practice, using the case study of pasture cropping, an Australian form of agriculture that extends no-till methods to embrace ecological relationships within and beyond the soil. Prioritizing the integrity of soil ecosystems often requires reconceiving what soil is and should be. Soil can be difficult to see as ethically significant partly because it often appears as a granular bulk good, seemingly featureless and fungible. To counteract this, farmers who care for soil integrity use various heuristic and aesthetic strategies to render soil integrity more perceptible and intelligible. The author considers how a keener perception of soil integrity may enable greater attunement toward the soil condition, acknowledgement of soil distress, and thus ethical responsiveness. The article considers this through a broader discussion of phenomenological ethics.

Occurrence of Macrophomina phaseolina Causing Root and Crown Rot on Alfalfa (Medicago sativa) in China

Alfalfa (Medicago sativa) is the widest grown and most important sown pasture crop in China and worldwide. Root and crown rot disease severely threatens alfalfa production, causing estimated annual yield losses of up to 20 to 40% worldwide (Fang et al. 2019). Field surveys in major alfalfa-growing areas in northwest China during summer (June to August) in 2017 to 2019 showed root and crown rot was common in fields established for more than 2 years with disease incidence ranging from 30 to 80%. Diseased plants were usually stunted and wilted; taproots and crowns exhibited red-brown to dark-brown discoloration in the cortex and/or vascular tissues. Frequently, lateral roots and stem tissues showed similar symptoms. Whole roots and crowns were decayed, with shoots wilted in severely affected plants. A total of 250 symptomatic plants were sampled randomly in Gansu Province from five alfalfa fields surveyed in 2018. Isolations were conducted by plating discolored root and crown tissues (40 pieces for each plant) sterilized with 1.25% sodium hypochlorite onto water agar. The plates were incubated at 22°C for 3 days, and then growing hyphae were subcultured onto potato dextrose agar (PDA). Twenty-one isolates from the fields in Zhangye, Gansu Province, were primarily identified as Macrophomina phaseolina based on cultural and morphological characteristics on PDA (Kaur et al. 2012; Sanchez et al. 2013). Five isolates picked randomly were purified by single-sclerotial isolation and maintained on 1/5 strength PDA at 4°C for further study. DNA of these isolates was extracted (Cenis 1992), and PCR amplifications of the internal transcribed spacer (ITS) region of rDNA (ITS1, 5.8S rDNA, and ITS2) were performed using primers ITS1 and ITS4. Sequences were then compared with the reference sequences in GenBank using BLAST search, showing sequence identity with M. phaseolina and the best matches at 98.47% (e.g., accession nos. MK408587 and KR012878). The ITS sequence of a representative isolate (Mp3) has been deposited in GenBank (accession no. MT192442). Pathogenicity tests of two isolates (Mp3 and Mp5) were conducted on 2-week-old alfalfa seedlings (cv. Longdong) with three to four leaves grown from surface-sterilized seeds. Seedlings were transplanted into pots (12 × 12 cm) containing pasteurized potting mix infested with mycelial-colonized millet seed inoculum of either isolate at a rate of 0.5% (w/w). Control seedlings were similarly transplanted into pots but with uninfested potting mix. Four seedlings were planted in a pot with 12 replicate pots for each treatment, and pots were watered every 2 days to free draining under controlled environment conditions (28°C, 12-h photoperiod, and 65% relative humidity). Three weeks postinoculation, all inoculated plants showed stunting symptoms, with discolored roots and crowns with a disease incidence of 100%, whereas the control plants showed no disease symptoms. To confirm Koch’s postulates, both isolates were reisolated from discolored root and crown tissues and again confirmed by morphological similarities and ITS sequencing as the inoculated isolates. Five purified isolates have been submitted to the Grassland Culture Collection Center, Lanzhou University (accession nos. LZU-MsR-Mp1 to Mp5). To our knowledge, this is the first report of M. phaseolina causing root and crown rot on alfalfa in China. M. phaseolina has been reported to cause root and crown rot on alfalfa in America, and on other legumes such as white clover in America, mungbean in India, and many other important crops worldwide (Kaur et al. 2012; Pandey et al. 2020; Pratt et al. 1998). Due to its broad host range and potential to be a significant pathogen in alfalfa-growing areas in China, further study on disease epidemic development is recommended.

Impact of long-term recycled water irrigation on crop yield and soil chemical properties

The variably-saturated flow and multi-component transport module UNSATCHEM of HYDRUS-1D was used to evaluate the impact of the long-term (2018-2050) application of recycled water (RCW) for irrigating perennial horticulture (almonds, pistachios), viticulture (grapevines), annual horticulture (carrot, onion, and potato), and pasture crops in representative soils from the Northern Adelaide Plains (NAP), South Australia. The input parameters for soil hydraulic, soil solution, and cation exchange data were determined for 14 soil profiles from the NAP region. For a warm-up period from 1970 to 2017, the model used historical climate data and low-salinity irrigation water. In the subsequent period (2018-2050), irrigation continued with RCW and projected meteorological conditions were obtained by considering expected future climate change. The average soil water salinity (ECsw) at the end of the simulation period ranged from 2.9-10.5 dS/m across all soils and crops. Potential yields of salt-sensitive crops such as annual horticulture and almonds were reduced by 4-32% due to increased salinity in the soil. Similarly, the model predicted that the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) would increase above threshold values, typically considered as indicative of poor growing conditions for most crops. Relationships between SAR and ESP were developed for four representative soils, providing the threshold soil SAR that corresponds to a critical ESP (>6), which would lead to adverse soil health and crop growth impacts. Threshold SARs were derived for calcareous (SAR = 4), hard red-brown (SAR = 3.5), sand over clay (SAR = 6), and deep uniform to gradational (SAR = 3) soils. An increase in SAR and ESP in soils adversely affects soil structural stability and soil water movement, which can severely impact the sustainable crop production in the NAP region. Relationships such as those between SAR and ESP help in identifying critical soil constraints and assist in devising better guidelines for the sustainable use of recycled water for irrigated agriculture.

The ‘Palo a Pique’ Long-Term Research Platform: First 25 Years of a Crop–Livestock Experiment in Uruguay

Mixed crop–livestock long-term experiments (LTE) are critical to increase the understanding of sustainability in complex agroecosystems. One example is the ‘Palo a Pique’ LTE which has been running for 25 years in Uruguay (from 1995 to present), evaluating four pasture–crop rotations under livestock grazing with no-till technology in soils with severe limitations. The results demonstrate that cropping systems reduced soil organic carbon (SOC) compared with permanent pastures, and that perennial pastures rotating with crops were critical to mitigate SOC losses. Data from the ‘Palo a Pique’ LTE has contributed to the establishment of new national policies to secure the sustainability of agricultural-based systems. Although the original purpose of the LTE was oriented to crops and soils, a demand for sustainable livestock intensification has gathered momentum over recent years. As a result, the current approach of the ‘Palo a Pique’ LTE matches each pasture–crop rotation with the most suitable livestock strategy with the common goal of producing 400 kg liveweight/ha per year. General approaches to the pursuit of sustainable livestock intensification include shortening the cycle of production, diversifying animal categories, increasing liveweight gain and final animal liveweight, and strategic livestock supplementation. Prediction of trade-offs between environmental, economic, and production indicators can be addressed through monitoring and modeling, enabling the timely anticipation of adverse sustainability issues on commercial farms. The ‘Palo a Pique’ LTE serves as a framework to address contemporary and future questions dealing with the role of ruminants on climate change, competition for land, nutrient dynamics, and food security.

Corrigendum to: Fish in the matrix: effects of landscape on community-structure patterns of the ichthyofauna of streams in Cerrado

This study aims to identify species richness and composition patterns of the ichthyofauna in different landscape matrices (forest, pasture and eucalypt crops) and to evaluate the variation of species composition in different matrices, identifying possible indicator species. We selected 21 streams; 7 were surrounded by native vegetation, 9 surrounded by pasture and 5 by eucalypt crops. We tested whether there was difference in the composition and species richness. In addition, we used the indicator value (IndVal) to verify if there were species faithful and specific to some land use and land cover. Streams located in forest presented the highest estimated species richness, followed by streams in pasturelands and eucalypt matrices. There was no difference between the composition of fishes in different matrices, but we observed a relationship between Phenacorhamdia somnians (Mees, 1974) and pasture matrix. The results indicated that the change in land use may benefit some generalist species such as Phenacorhamdia somnians.

Soil‐test biological activity with short‐term and long‐term carbon contributions

AbstractSoil‐test biological activity (STBA) is a key indicator of soil health because of its relevance to ecosystem processing, broad applicability, and simple and rapid analysis. Short‐term and long‐term influences of carbon (C) availability on STBA were assessed. A short‐term factor was root‐derived C inputs from a sudangrass (Sorghum × drummondii) test crop grown under greenhouse conditions. Long‐term factors were from soil at two depths in three sections of a field varying in soil texture and exposed to 16 yr of different pasture–crop rotation management. Soil‐test biological activity was determined after 0, 14, 21, 31, and 45 d of greenhouse growth. Total variation in STBA was 7% from the short‐term factor and 81% from the long‐term factors. Soil depth was the primary long‐term factor influencing STBA (57%) and soil texture was intermediate (24%). Results indicate that short‐term changes in STBA are important but modest compared with variations due to soil depth and texture.

Environmental Sustainability of Open-Pit Coal Mining Practices at Baganuur, Mongolia

In this paper, we studied one of the largest coal mines in Mongolia, the Baganuur Coal Mine, in terms of environmental sustainability related to mining practices, with a focus on discharged water and waste sediments. The present quality and potential for future pollution were assessed. Based on World Health Organization and Mongolian guidelines, groundwater pumped from the mining operations could be used for drinking and domestic purposes. In addition, based on the Na absorption ratio, groundwater samples from GW-2 and GW-3 could be used as agriculture water supplies with salinity reduction, or used to grow halophytes as a measure for desertification control and pasture production. All waste soil samples appeared to have a desertification potential. Dust particles smaller than 150 μm comprised more than 80% of soil samples, which had arsenic levels higher than the Mongolian soil pollution standards. In addition, soil collected between coal seams (S-5) showed high sulphur content based on X-ray fluorescence (XRF) and scanning electron microscopy–energy dispersive X-ray (SEM-EDX) spectroscopy analyses, strong potential for producing acid mine drainage in the analysis of pH of net acid generation and net acid production potential, and potential for leaching of metals, such as Co. Therefore, the Baganuur Coal Mine requires soil pollution control measures to mitigate the risks of dust and desertification. In this perspective, mine groundwater could be used to reduce environmental stresses by supporting pasture crops such as halophytes on waste disposal sites, thereby preventing dust issues and desertification. Continuous efforts, including monitoring and enacting environmental management measures, are needed from both the mining company and the government to ensure sustainable mine development.

Effects of long-term grazed crop and pasture systems under no-till on organic matter fractions and selected quality parameters of soil in the Overberg, South Africa

There is limited soil research on semi-arid, grazed no-till crop and pasture systems. The long-term (10 years) effect of three grazed no-till dryland crop and pasture rotation systems, and perennial lucerne pasture were assessed on soil carbon (C) and nitrogen (N) stocks, soil organic matter functional pools and selected soil quality parameters in the Overberg, South Africa. The largest soil C and N stocks (0–30 cm) were found in crop–pasture systems containing wheat and medic/clover (70.2–74.9 Mg C ha−1 and 8.3–8.4 Mg N ha−1), compared with perennial lucerne pasture (63.4 Mg C ha−1 and 7.7 Mg N ha−1) or cropping-only systems (54.7–58.9 Mg C ha−1 and 6.3–6.7 Mg N ha−1). Significantly higher labile C and N (free particulate organic matter fraction) contents were observed in crop–pasture systems (1.37–1.74 g C kg−1 and 0.107–0.110 g N kg−1) than in continuous cropping systems (0.9–1.0 g C kg−1 and 0.042–0.045 g N kg−1), attributed to higher annual C and N inputs and lower extent of soil disturbance. Significant positive correlations were found between soil C and N functional pools and soil quality parameters (soil respiration, effective cation exchange capacity and aggregate stability) and wheat yields. The results show the importance of the medic/clover pasture and wheat rotations in enhancing soil quality in the Overberg region.

Cluster Analysis Referring to Rural Enterprises of Sugarcane Local Productive Arrangement (LPA) in Quirinópolis, Brazil

In Brazil in recent decades, the the dynamics of land use widened the agricultural frontier for sugarcane cultivation by modifying and replacing intensively traditional and pasture crops. It is proposed to examine the aggregating characteristics of rural enterprises that are part of the sugarcane agribusiness productive arrangement, evaluating their profiles, providing a more effective understanding of their socioeconomic sustainability. The quantitative approach was adopted applying statistical tests for variable selection and multivariate statistical techniques (cluster analysis) to evaluate rural enterprises. The results indicated two clusters with peculiar profiles, and the average distance between farm and agribusiness (± 22 km) and succession capacity (± 2.5 points) of both are similar. The other variables were discrepant (P <0.05), in cluster 1 the very negative rural exodus (-48%) and in cluster 2 positive (23%). Operating costs in relation to compensation for Cluster 1 was 61%, much higher than cluster 2 with 6% on average. It was concluded that through cluster analysis that the contract variables and the size of the establishment are the most significant factors directly influencing the rural exodus and production costs. These observations contribute to the creation of sectorial policies for the use of land and regional economic development, as such imply in a theoretical consolidation of precepts on the sugarcane expansion, as such also imply, under the perspective of the rural practice, in elements for the improvement in planning the agricultural enterprise.

Effect of seed coating on germination of Ciliate Medick [Medicago ciliaris (L.) All.] and Snail Medick [Medicago scutellata (L.) Mill.

A study was conducted in the Seed Technology Laboratory of Department of Field Crops, Pasture and Forage Crops Section, Faculty of Agriculture of Ege University, Turkey. Aim of the study was to remove the seed coat hardness by various treatments of Ciliate and Snail Medick to enhance germination which is significant in terms of agronomical handicaps of sowing small seeded legumes under field conditions. Pre-sowing seed treatments (Control, scarification by sandpaper, acid treatment with 95.0-98.0% H2SO4 for 5-10-15 minutes and soaking in water for 24-48 hours) were practiced on these small seeded legumes. All observations and tests were conducted following ISTA regulations and notifications. Germination of tested seeds highly increased by acid treatment for 10-15 minutes duration, while scarification treatment provided favorable germination rates.

Diversity of soil spiders in land use and management systems in Santa Catarina, Brazil

Abstract: The ability of spiders to spread over contiguous areas (Arachnida: Araneae) is directly related to soil management conditions. The objective of this work was to study the effect of land use system (LUS) on the abundance and diversity of soil spider families and their relationship with soil physical and chemical properties. The evaluated LUS were: native forest, eucalyptus reforestation, pasture, crop-livestock integration, and no-tillage crop. Samples were collected in three municipalities of Southern Plateau of Santa Catarina, considered as true replicates, during winter and summer. A total of 270 samples was taken in each area and season. The sampling points were arranged in a grid of 3 × 3 m, spaced by 30 m. We evaluated soil physical, chemical, and microbiological attributes and the abundance and diversity of spider families, collected by soil monolith and soil traps. A total of 448 spiders were captured, 152 in winter and 296 in summer, distributed in 24 families and 52 species/morphospecies. There was a seasonality effect related to the land use systems and the highest Shannon-Wiener diversity index was recorded in the native forest in both sampling periods. Most families of spiders have a direct dependence on soil physical and chemical properties, such as microporosity, exchangeable aluminum, calcium, magnesium, and potassium during the winter. Organic matter, nitrogen, pH in water, weighted average diameter, soil density, and microbial biomass carbon exhibited dependence during the summer. Vegetation type and soil management are the factors that seem to affect most the occurrence of spiders. The families Theridiidae and Nemesiidae are dependent on sites with low human intervention.

Análise Espaço-Temporal de Mudança de Uso e Cobertura da Terra na Região do Vale do Paraíba Paulista: Desenvolvimento de Cenários Futuros (Spatial and Temporal Changes in the Land Use and Cover of the Paraíba Valley in São Paulo, Brazil: Development of Future Scenarios)

O Vale do Paraíba paulista é marcado por grandes transformações vinculadas aos ciclos econômicos brasileiros que mudaram a região transformando-a em um grande mosaico de pastos, fragmentos florestais e área urbana. Estudos temporais de uso e cobertura permitem observar essas mudanças e avaliar os impactos gerados por elas. É notória a substituição de extensas áreas de Mata Atlântica para o monocultivo de eucaliptos que possui alto desenvolvimento e constante expansão no Vale. Tal conversão de uso traz consequências como a fragmentação florestal, perda de biodiversidade, da qualidade das águas e do solo. A possibilidade de desenvolver cenários de simulação de mudanças de uso e cobertura da terra é fundamental para uma gestão pública eficiente e sustentável. Visando essas questões o presente estudo busca projetar cenários futuros levando em consideração diferentes questões sociais, econômicas e ambientais, a partir de análises sobre a dinâmica de expansão da silvicultura no Vale do Paraíba paulista. Os cenários criados podem ser classificados como “Tendencial” que mantém os mesmos padrões de mudanças do período observado (2000-2005); “Otimista” que diminui as taxas de conversão para silvicultura e pastagem, aumentando as áreas vegetadas; e “Pessimista” que alavanca as taxas de desmatamento a partir do crescimento dos cultivos de eucaliptos e pastagem. O desenvolvimento de cenários futuros de 2010 a 2050 no DinamicaEgo se mostrou eficaz, apresentando tendências e pré-disposições de transições de uso do solo sendo possível a utilização dos resultados no planejamento ambiental visando à sustentabilidade e melhor gestão dos recursos naturais e desenvolvimento de atividades econômicas. A B S T R A C TThe Paraíba Valley in São Paulo, Brazil, is marked by great transformations. The Brazilian economic cycles changed this region and transformed it into a great mosaic of pastures, forest fragments, and urban areas. Temporal studies on land use and cover have given information on these changes and evaluated their impacts. The conversion of extensive areas of the Atlantic Forest into eucalyptus crops is noticeable; this monoculture developed greatly and is expanding steadily in this valley. This land-use conversion has consequences, such as forest fragmentation, and losses in biodiversity, and water and soil quality. Developing future scenarios (2010 to 2050) that simulate changes in land use and cover is essential for an efficient and sustainable public management. Thus, the objective of the present study was to develop future scenarios while considering different social, economic, and environmental issues, based on analyses of the dynamics of forestry expansion in the Paraíba Valley in São Paulo, Brazil. The scenarios developed were classified as Trend, maintaining the same change patterns of the observed period (2000 to 2005); Optimistic, decreasing conversion rates of natural vegetation into forestry and pasture areas; and Pessimist, increasing deforestation rates and increasing eucalyptus and pasture areas. Future scenarios for the period of 2010 to 2050 were developed in the Dinamica Ego software, and it proved to be effective, presenting trends and predispositions of changes in land use. These results can be used for environmental planning focused on sustainability, better management of natural resources, and development of economic activities.Keywords: Forestry, Silviculture, Dynamic Spatial Modeling, Atlantic Forest

Antifungal Activities of Isoflavonoids from Uromyces striatus Infected Alfalfa.

Fungal pathogens constitute a severe yield-limiting factor for the pasture crop alfalfa (Medicago sativa L.). Eleven phenolic compounds, including a new isoflavane, were isolated from the Uromyces striatus Schroet. infected alfalfa. The effect of infection with U. striatus Schroet. on the phytochemical profile of alfalfa was investigated using ultra-performance liquid chromatography (UPLC), and the antifungal properties of isolated compounds against a range of pathogens were tested. It was found that the contents of most of the isolated compounds in U. striatus infected alfalfa were higher than those in healthy alfalfa. Compounds 1-5 exhibited a moderate inhibitory activity against Curvularia lunata with 40.14±1.63 %, 48.03±1.22 %, 57.54±1.18 %, 50.10±1.56 %, and 61.54±2.14 % inhibition ratio at the concentration of 50 μg/mL. Compounds 3 and 5 showed a weak inhibitory activity against Fusarium graminearum with the EC50 values of 104.2±2.66 and 123.0±1.23 μg/mL, and a moderate inhibitory activity against Bipolaris sorokinianum with the EC50 values of 39.1±2.05 and 95.0±1.01 μg/mL, respectively. In pot experiments with wheat, compounds 1-5 possessed desirable protective efficacy of over 80 % and curative effectiveness of over 50 % against Puccinia striiformis f. sp. tritici at a concentration of 0.5 mg/mL.

Spatial Variability of Soil Fauna Under Different Land Use and Managements

Geostatistics allows the evaluation of the distribution pattern of data with high spatial variability in agricultural systems. This study aimed to evaluate the spatial variability of biological diversity indices of soil fauna under different land (agriculture and forest). Samples were collected in seven areas (millet, soybean, corn, eucalyptus, pasture crops, and preserved and disturbed Cerrado), in Maranhão state, Brazil. The soil fauna was caught trapped in pitfall traps, installed 3 m away from each other. In each area, 130 traps were maintained for seven days. After this period, they were removed and their content transferred to bottles and taken to the laboratory, where the insects were screened and identified at the level of orders and families. Eight indices were calculated, namely: individuals trap-1 day-1, Jackknife richness estimator, the Simpson, McIntosh, Shannon, and total diversity, and Simpson dominance, and Pielou equitability indices. The spatial variability was derived from the semivariograms fitted to Gaussian, spherical, and exponential geostatistical models. Statistical analysis showed medium values of the coefficient of variation for millet, except for the indices individuals trap-1 day-1 and McIntosh diversity, which were considered high. The values of the correlation matrix were negative for some indices, suggesting an inverse relationship. For millet, corn, eucalyptus, disturbed Cerrado, and pasture areas, the Shannon diversity index exhibited a pure nugget effect. For the areas of millet, corn, disturbed Cerrado and pasture, the total diversity index was adjusted to the Gaussian model. The degree of spatial dependence was considered high for the individuals trap-1 day-1 and Pielou equitability indices for millet. Only for soybean and pasture similarity in the scaled semivariograms was observed for the spatial variability of the indices, indicating similarity of performance. Soil management and land use affect the patterns of soil fauna abundance, richness, and diversity. The presence of groups such as Araneae, Diplura, and Poduromorpha are related to ecological equilibrium, quality, and sustainability of the agricultural systems studied.

Agricultural management practices impacted carbon and nutrient concentrations in soil aggregates, with minimal influence on aggregate stability and total carbon and nutrient stocks in contrasting soils

Agricultural management practices can affect soil structure and soil organic carbon (SOC) and nutrient stocks, which are important for sustainable agriculture. There is however limited understanding of the long-term impact of management practices on SOC and total nitrogen (N), sulphur (S) and phosphorus (P) concentrations in aggregates from different soils, and consequent effects on SOC and nutrient storage in agro-ecosystems. Soils from long-term (16–46 years) management systems in semi-arid (Luvisol, at Condobolin, NSW), Mediterranean (Luvisol, at Merredin, WA) and sub-tropical (Vertisol, at Hermitage, QLD) environments in Australia were collected from 0 to 10 cm, 10 to 20 cm and 20 to 30 cm depths. Dry- and wet-sieving techniques were used to fractionate the soils into mega-aggregates (>2 mm), macro-aggregates (2–0.25 mm), micro-aggregates (0.25–0.053 mm), and silt-plus-clay particles, including micro-structures (<0.053 mm) i.e. “silt-plus-clay fractions”. Management practices in the Luvisols comprised conventional (CT) and reduced tillage (RT) under mixed crop–pasture rotation, no-till (NT) under continuous cereal–cover crop rotation, and perennial pasture (PP) at Condobolin, and stubble either retained (SR) or burnt (SB) under direct-drilled continuous wheat–legume rotation at Merredin. The practices in the Vertisol comprised a factorial combination of CT, NT, SR, SB, with either 0 (0N) or 90 kg urea-N ha−1 (90N) under continuous wheat–wheat rotation.In the Luvisol at Condobolin, the PP and NT had significantly (p < 0.05) higher soil aggregate stability than the CT and RT, with no impacts of management on SOC and total N, S and P stocks at all depths. The practices in the Luvisol at Merredin and Vertisol at Hermitage had no impact on soil aggregate stability, or on SOC and nutrient stocks at all depths, except the NT-SR-90N at Hermitage showed higher SOC (p < 0.10) and nutrient (p < 0.05) stocks than the other treatments at 0–10 cm only. The SOC and N concentrations were higher (p < 0.05) in the wet-sieved silt-plus-clay fractions and mega-aggregates than macro- and micro-aggregates in the PP and NT at Condobolin, and SR at Merredin, but were similar across aggregates in the CT and RT at Condobolin and SB at Merredin at 0–10 cm depth. Further, at Hermitage, SOC and N concentrations were similar among the aggregate-sizes across different treatments and depths. The only exception was the NT-SR-90N treatment, where SOC and N concentrations were higher (p < 0.05) in the silt-plus-clay fractions or micro-aggregates than in mega- and macro-aggregates, obtained by either dry- or wet-sieving. Total S concentration was in the order of macro- ≥ micro- > mega-aggregates across all the treatments and was higher in the PP at Condobolin (0–10 cm depth), and in the SR at Merredin (all soil depths) than the other corresponding treatments. Further, at Merredin, both SR and SB had higher P concentration in macro- and micro- than mega-aggregates. Across all the practices, SOC and N concentrations were higher in the dry- and wet-sieved silt-plus-clay fractions or micro- than mega- and macro-aggregates in both Luvisols, with no differences in the Vertisol. In summary, although the PP, NT, and SR (compared with other corresponding treatments at each site) had minimal impact on total SOC and nutrient stocks in bulk soils, these practices increased aggregate stability in some systems (i.e. Condobolin), and SOC and nutrient concentrations in the silt-plus-clay fractions or micro-aggregates in both Luvisols. These findings suggest that reducing soil disturbance and enhancing crop residue input in farming systems are important for SOC and nutrient storage, particularly in finer aggregate fractions.