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Kenaf (Hibiscus cannabinus L.) is an annual herbaceous crop with a high biomass production. In this paper, and based on international bibliography, the authors outline an agro-climatic and agro-ecological zoning model to determine potential growing areas in Argentina for kenaf. The bioclimatic variables considered were: 150 frost-free days, isohyets of 500, 780 and 1200 mm corresponding to November–March (the growing period), a mean annual temperature of 11.5 °C and temperatures of 15 °C, 20 °C, 25 °C and 27 °C during the growing period. The agroclimatic indices, which determine different classes of suitability, were integrated in a Geographic Information System in order to create thermic and hydric regions. The maps were superimposed, and the overlapping regions delineated the agroclimatic zoning. Thornthwaite's Moisture Index = 0 was overlapped on the agroclimatic zoning map to guarantee that the lands to be occupied by the proposed energy crop would be located under dry-subhumid, semiarid or arid climate conditions. This last map was superimposed on another one that determined unsuitable soils for traditional agriculture. The overlapping regions defined the agro-ecological zoning for kenaf. This is an innovative work, made by the implementation of a geographic information system that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database. Furthermore, its focus is not merely local since the model described may be applied to any part of the world, using the agroclimatic limits presented in this paper. [ABSTRACT FROM AUTHOR]

Climate affects litter decomposition directly through temperature and moisture, determining the ecosystem potential decomposition, and indirectly through its effect on plant community composition and litter quality, determining litter potential decomposition. It would be expected that both the direct and indirect effects of climate on decomposition act in the same direction along gradients of actual evapotranspiration (AET). However, studies from semiarid ecosystems challenge this idea, suggesting that the climatic conditions that favour decomposition activity, and the consequent ecosystem potential decomposition, do not necessarily lead to litter being easier to decompose. We explored the decomposition patterns of four arid to subhumid native ecosystems with different AET in central-western Argentina and we analysed if ecosystem potential decomposition (climatic direct effect), nutrient availability and leaf litter potential decomposition (climatic indirect effect) all increased with AET. In general, the direct effect of climate (AET) on decomposition (i.e. ecosystem potential decomposition), showed a similar pattern to nutrient availability in soils (higher for xerophytic and mountain woodlands and lower for the other ecosystems), but different from the pattern of leaf litter potential decomposition. However, the range of variation in the ecosystem potential decomposition was much higher than the range of variation in litter potential decomposition, indicating that the direct effect of climate on decomposition was far stronger than the indirect effect through litter quality. Our results provide additional experimental evidence supporting the direct control of climate over decomposition, and therefore nutrient cycling. For the ecosystems considered, those with the highest AET are the ecosystems with the highest potential decomposition. But what is more interesting is that our results suggest that the indirect control of climate over decomposition through vegetation characteristics and decomposability does not follow the same trend as the direct effect of climate. This finding has important implications in the prediction of the effects of climate change on semiarid ecosystems. [ABSTRACT FROM AUTHOR]

The main argentine agricultural region is located in pampean flatlands of the provinces of Buenos Aires, Santa Fe, Córdoba, Entre Ríos, La Pampa and San Luis and has an area about 840,000 km². Wheat, corn, soybean, sunflower and pastures for cattle raising are the more important land uses of this region. Most of the regional crops grown in non-irrigated land and frequently the availability of soil moisture limits the yields. Differing phases of ENSO (El Niño and La Niña) have differing impacts on soil moisture conditions across the study area. This paper analyses the summer and autumn soil water moisture regime during ENSO events. [ABSTRACT FROM AUTHOR]

The distribution of cultivations in the world is restricted by the climatic limits, for defect or for excess of vital necessities for the individuals that conform the different biotypes. Since sow is made, plants are subjected to asynchronous variations of component elements of climate and it is the climate the main decisive factor of probability of success of cultivation. The objective of this paper was the delimitation of the Argentinean geographical area where it is possible the economic production of Jatropha curcas, Ricinus communis and Cynara cardúnculus without watering. Since extracted data of the Climatic Statistics published by the National Meteorological Service it was sketched the climatic indexes that define the agroclimatic zone of the specie for the period 1961-1990 for meteorological and agrometeorological stations distributed in the country. Then, all maps corresponding to each one of the climatic indexes were elaborated and the resulting map of the overlapping of all previous ones defined the agroclimatic zone of Jatropha curcas (physic nut, piñón manso, tempate), Ricinus communis (tártago, ricino) and Cynara cardunculus (cardo). [ABSTRACT FROM AUTHOR]

Information about the effects of crop residues on soil parameters in no-tillage systems is not abundant in Argentina because the relative recent adoption this practice. Moreover, most of the available research to date refers to the humid Pampa region. In contrast, information on the semi-arid region is very scarce, despite the fact that an increase in cover stubble is particularly useful in water-limited soils. In this paper we report a long-term evaluation (5 to 10 years) of no-tillage practices on: a) chemical (soil organic matter -SOM, total N and NO3-N) and biological (microbial biomass and activity) soil characteristics, and b) quantity and chemical quality of soybean residues in monoculture and soybean-corn rotation. Research was conducted at Manfredi INTA Experimental Station in semi-arid, central Argentina(31°49' S and 63°46' W). Soils under no-tillage system had higher SOM and total N content compared with control (conservation tillage with chisel plow) in soybean monoculture and soybean-corn rotations. The observed difference increased with time (10 and 20% at 5 and 10 years, respectively). Nitrate content, and microbial activity and biomass showed high variability in the measurement periods, depending on climatic condition at the sampling date. Stubble cover was greater in the corn-soybean rotation with corn as preceding crop (2473.9 g m-2) than in soybean monoculture (1035.7 g m-2)). The stubble non-identifiable fraction was very significant in all treatments (ranging between 2-10 t ha-1), which would favor new surface organic soil formation. The soybean-corn rotation with soybean as preceding crop showed the lowest values in all chemical parameters, particularly in soluble compounds (nitrate, ammonium and soluble carbon). Contrarily to what is usually assumed, our results suggest that nutrient release from long-term stubble may become a significant nutrient source for the crops. Therefore, this nutrient source should be considered when evaluating crop fertilization requirements. [ABSTRACT FROM AUTHOR]

Current farm systems rely on the use of Plant Protection Products (PPP) to secure high productivity and control threats to the quality of the crops. However, PPP use may have considerable impacts on human health and the environment. A study protocol is presented aiming to determine the occurrence and levels of PPP residues in plants (crops), animals (livestock), humans and other non-target species (ecosystem representatives) for exposure modelling and impact assessment. To achieve this, we designed a cross-sectional study to compare conventional and organic farm systems across Europe. Environmental and biological samples were/are being/will be collected during the 2021 growing season, at 10 case study sites in Europe covering a range of climate zones and crops. An additional study site in Argentina will inform the impact of PPP use on growing soybean which is an important European protein-source in animal feed. We will study the impact of PPP mixtures using an integrated risk assessment methodology. The fate of PPP in environmental media (soil, water and air) and in the homes of farmers will be monitored. This will be complemented by biomonitoring to estimate PPP uptake by humans and farm animals (cow, goat, sheep and chicken), and by collection of samples from non-target species (earthworms, fish, aquatic and terrestrial macroinvertebrates, bats, and farm cats). We will use data on PPP residues in environmental and biological matrices to estimate exposures by modelling. These exposure estimates together with health and toxicity data will be used to predict the impact of PPP use on environment, plant, animal and human health. The outcome of this study will then be integrated with socio-economic information leading to an overall assessment used to identify transition pathways towards more sustainable plant protection and inform decision makers, practitioners and other stakeholders regarding farming practices and land use policy. [ABSTRACT FROM AUTHOR]

A simple method of analysis was proposed to characterize the impact of climatic conditions of a wide region of Argentina (from 27°05′S to 35°48′S, from 61°5′W to 64°21′W) on potential maize ( Zea mays L.) grain yield, and the occurrence of various climatic constraints (low temperatures and low soil water content, frost, drought stress and heat stress) along the cycle. The analysis was based on previous studies of the eco-physiology of maize crops and the use of climatic records of six locations in the region under study. Results were analyzed using a probabilistic method, later organized as a checklist to consider when deciding on sowing date in a location of the region. Thus, for each production scenario (combination of location and sowing date), farmers would have a tool enabling them to pay particular attention to the restrictions more likely to occur, to include some cultural practices to avoid or mitigate the most severe climatic constraint to maize production. [ABSTRACT FROM AUTHOR]

A total of 147 samples of garlic ( Allium sativum) bulbs affected by blue mould were obtained from a variety of agroclimatic districts between December 1999 and February 2000. Penicillium species were identified using both morphological and chemotaxonomic characteristics. Penicillium allii was the predominant species isolated (81·8%) in this survey and the only species proven to be pathogenic on garlic. Other species were isolated much less frequently: P. chrysogenum (13·7%), P. brevicompactum (2·8%), P. phoeniceum (0·9%), P. aurantiogriseum (0·6%) and P. flavigenum (0·2%). Colonies of P. allii could be classified into four morphotypes and their distribution seemed to be influenced by seed trade and agricultural practices. Penicillium allii isolates were grouped into three aggressiveness phenotypes (low, medium and high) based on their ability to cause disease during field trials on susceptible (Fuego INTA) and less susceptible (Castaño INTA) garlic cultivars. The number of surviving plants at 191 days after planting and postharvest bulb weight contributed the most towards aggressiveness modelling. [ABSTRACT FROM AUTHOR]