Mariana Amato

Relationships between soil structure, root distribution and water uptake of chickpea (Cicer arietinum L.). Plant growth and water distribution

Abstract Root clustering as a consequence of soil compaction has been hypothesised as a cause of reduction in both water uptake and growth of plants. On the basis of such a hypothesis models of water uptake that take root spatial arrangement into account have been proposed. Data to validate such models are scarce, particularly for leguminosae. This research was conducted on chickpea with the aim of studying the spatial distribution of roots and water in growth media of different degrees of compaction. Chickpea var. Sultano was grown in pots containing silty-clay soil with aggregates of

A Novel Low-Cost Open-Hardware Platform for Monitoring Soil Water Content and Multiple Soil-Air-Vegetation Parameters

Monitoring soil water content at high spatio-temporal resolution and coupled to other sensor data is crucial for applications oriented towards water sustainability in agriculture, such as precision irrigation or phenotyping root traits for drought tolerance. The cost of instrumentation, however, limits measurement frequency and number of sensors. The objective of this work was to design a low cost “open hardware” platform for multi-sensor measurements including water content at different depths, air and soil temperatures. The system is based on an open-source ARDUINO microcontroller-board, programmed in a simple integrated development environment (IDE). Low cost high-frequency dielectric probes were used in the platform and lab tested on three non-saline soils (ECe1: 2.5 < 0.1 mS/cm). Empirical calibration curves were subjected to cross-validation (leave-one-out method), and normalized root mean square error (NRMSE) were respectively 0.09 for the overall model, 0.09 for the sandy soil, 0.07 for the clay loam and 0.08 for the sandy loam. The overall model (pooled soil data) fitted the data very well (R2 = 0.89) showing a high stability, being able to generate very similar RMSEs during training and validation (RMSEtraining = 2.63; RMSEvalidation = 2.61). Data recorded on the card were automatically sent to a remote server allowing repeated field-data quality checks. This work provides a framework for the replication and upgrading of a customized low cost platform, consistent with the open source approach whereby sharing information on equipment design and software facilitates the adoption and continuous improvement of existing technologies.

Nutritional quality of seeds and leaf metabolites of Chia (Salvia hispanica L.) from Southern Italy

Chia (Salvia hispanica L.) is an expanding functional food crop from Central America, but little is known about effects of new growing environments and agronomical treatments on seed quality. The quality of seeds produced in Europe has never been reported and there’s a lack of information on secondary metabolites of leaves, an emerging product of Chia. In this work, the nutritional quality and oxidative stability of Chia seeds produced in Southern Italy (Basilicata region) have been evaluated, taking into account also different nitrogen fertilization strategies. The quality of seeds produced in Basilicata has been also compared with that of commercially available seeds from traditional and new production areas. Oil extracted from Italian Chia seeds was not quantitatively significantly different, but more rich in chlorophyll, carotenoids and α-linolenic acid than in commercial seeds. Oxidative stability, polyphenols and antioxidant activity were also influenced by seed source. Fertilization system affected free acidity, chlorophyll and carotenoids, whereas it reduced p-Anisidine value, phenols and oxidative stability. Moreover, the metabolic profile of Chia leaves has been reported for the first time; in particular, several flavonoids and hydroxycinnamic acids, and the two uncommon flavonoids acetyl vitexin and acetyl orientin were found.

Using an Automatic Resistivity Profiler Soil Sensor On-The-Go in Precision Viticulture

Spatial information on vineyard soil properties can be useful in precision viticulture. In this paper a combination of high resolution soil spatial information of soil electrical resistivity (ER) and ancillary topographic attributes, such as elevation and slope, were integrated to assess the spatial variability patterns of vegetative growth and yield of a commercial vineyard (Vitis vinifera L. cv. Tempranillo) located in the wine-producing region of La Rioja, Spain. High resolution continuous geoelectrical mapping was accomplished by an Automatic Resistivity Profiler (ARP) on-the-go sensor with an on-board GPS system; rolling electrodes enabled ER to be measured for a depth of investigation approximately up to 0.5, 1 and 2 m. Regression analysis and cluster analysis algorithm were used to jointly process soil resistivity data, landscape attributes and grapevine variables. ER showed a structured variability that matched well with trunk circumference spatial pattern and yield. Based on resistivity and a simple terrain attribute uniform management units were delineated. Once a spatial relationship to target variables is found, the integration of point measurement with continuous soil resistivity mapping is a useful technique to identify within-plots areas of vineyard with similar status.

Chia seeds products: an overview

Chia, Salvia hispanica L., is a medicinal and dietary plant species used since ancient times by Mayan and Aztec. Its product is a dry indehiscent fruit which is commonly called seed. In recent times, there was an increasing attention and diffusion of the seeds of the plant for their health benefits and uses in cooking. In fact, seeds are a rich source of nutrients first of all the polyunsaturated omega-3 fatty acids that protect from inflammation, enhance cognitive performance and reduce the level of cholesterol. Seeds are also rich in polyphenols derived from caffeic acid that are antioxidant compounds protecting the body from free radicals, aging and cancer. In addition, carbohydrate based fibers, present at high concentration levels, are associated with reducing inflammation, lowering cholesterol and regulating bowel function. This review summarizes the current knowledge on the phytochemistry and pharmacological properties of the seeds of this plant, with special emphasis on the nutritional, and phytochemical analysis of the plant, including the recently developed metabolomic studies.

Innovative Crop Productions for Healthy Food: The Case of Chia (Salvia hispanica L.)

Chia (Salvia hispanica L.) is an ancient crop from Central America which has been recently rediscovered as a source of ω-3 and nutraceuticals in seeds. Besides traditional seed consumption, innovative uses of the plant seeds and leaves have been proposed based on the high protein content and the production of mucilage which lends itself to a range of applications. This chapter reviews research on the plant’s genetics and breeding, quality, and uses. Agronomic studies which have only recently started worldwide are also presented along with results from case studies in Basilicata.

Photosynthetic response to water stress of pigweed (Amaranthus retroflexus) in a Southern-Mediterranean area.

Abstract Pigweed is an increasingly aggressive weed in semiarid environments such as Mediterranean areas, and in general the control of all Amaranthus species is becoming more and more difficult. Increasing pigweed aggressiveness could be a result of its ability to keep a high water use efficiency under drought conditions. An experiment was conducted to study the effect of water stress on the photosynthetic capacity, growth, and leaf water potential of pigweed at the field level and assess if this species, as a model for C4 weeds, is CO2-saturated at the current level of atmospheric CO2 in a Mediterranean area. Pigweed was studied within a naturally occurring weed population in a bell pepper field in southern Italy where a rain-fed treatment (V0) was compared to a fully irrigated one (V100) corresponding to the restoration of 100% of the maximum crop water evapotranspiration. Soil water content was measured periodically, and net assimilation rate, stomatal conductance, transpiration rate, and intercellular CO2 concentration were determined on pigweed leaves. Photosynthetic rates of 37.6 µmol m−2 s−1 in V100 and 13.9 µmol m−2 s−1 in V0 were recorded, with higher transpiration rates in V100; consequently stomatal conductance was significantly lower in rain-fed conditions (0.08 mol m−2 s−1)) compared to the irrigated treatment (0.30 mol m−2 s−1). Photosynthesis in pigweed is not completely CO2-saturated at the current atmospheric CO2 level in the Mediterranean area and this could affect competition and increase of aggressiveness toward crops at the actual CO2 atmospheric concentration in agro-ecosystems. This occurs because unlike other C4 crops already saturated for CO2, weeds that are not CO2-saturated will remain CO2-sensitive to higher ambient CO2 levels. Thus, when they are grown in mixed stands where competition occurs, they can still suppress the slower-growing species. Nomenclature: Redroot pigweed, Amaranthus retroflexus L. AMARE, bell pepper, Capsicum annuum L. ‘Peppone’

Field Plots and Crop Yields Under Innovative Methods of Carbon Sequestration in Soil

This chapter reviews the issues related to the responses of crops and soil fertility to management strategies aimed to conserve soil carbon, especially for Mediterranean-Temperate conditions. It reports the main results from field experiments conducted in three different Italian sites in order to compare traditional and innovative soil treatments for carbon sequestration. Field agronomic treatments included traditional and minimum tillage, green manuring, two rates of mature compost application, and spreading of water-soluble Fe–porphyrin. Their effects were tested in different sites representing distinct pedo-climatic conditions.

Multi-electrode Resistivity Imaging

Multi-electrode soil imaging is a promising way to investigate root systems by visualizing the distribution of soil volumes with different root densities, based on relationships between root biomass (RD) and electrical resistivity (ρ) of soils. Its most distinctive features are spatial coverage, rapidity, and minimum disturbance. Spatial patterns and frequency of ρ match those of RD, but calibration is needed and small RD values may not be clearly discriminated in soils with large ρ or variability in other features. Therefore it has been envisaged as: A nondestructive method for spatial quantification in two and three-dimensions A basis for spatially sound sampling A support for differential soil management Available data indicate that a definite response is not found for roots <2 mm and data sets are positively skewed. Statistical procedures to handle deviations from normality with the advantage of simplicity are discussed, as well as field of application, advantages, drawbacks, and future needs.

Plant architecture, auxin homeostasis and phenol content in Arabidopsis thaliana grown in cadmium- and zinc-enriched media

A screening strategy using micropropagation glass tubes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium (Cd) and zinc (Zn) at the concentration of 10-20μM and 100-200μM, respectively. Metal concentrations in plant shoots and roots were measured by quadrupole inductively coupled plasma mass spectrometry. After 21days from germination, all plants in the tubes were scanned at high resolution and the root systems analyzed. The localization of indole-3-acetic acid (IAA) in the primary root and lateral root apices was monitored using DR5:GUS, LAX3:GUS and AUX1:GUS Arabidopsis transgenic lines. Total phenol content in leaves was measured spectrophotometrically. Shoot and root dry weight and leaf area did not change in Zn-exposed plants and significantly decreased in Cd-exposed plants, compared to control plants. Cadmium induced a reduction of root length, of mean number of roots and of total root surface. Both Cd- and Zn-exposed plants showed a reduced specific root length. This morphological behavior, together with an observed increase in root diameter in metal-exposed plants could be interpreted as compensatory growth, and the observed thicker roots could act as a barrier to protect root from the metals. In comparison with the apical localization of the IAA signal in the control plants, Zn generally reinforced the intensity of IAA signal, without affecting its localization. In Cd-exposed plants, IAA localization remained apical but weaker compared to control plants. Total phenols decreased in plants exposed to Zn and Cd. Therefore, we propose that the remodelling of the root architecture and the production of some secondary metabolites, such as IAA and phenols could be two responses of plants subjected to metal stress. This knowledge can open the way to future phytoremediation strategies of contaminated sites.