Evapotranspiration models for a maize agro-ecosystem in irrigated and rainfed conditions

A high level of accuracy in the estimation of crop evapotranspiration (ET) may lead to significant savings of economic and water resources in irrigated agriculture. Although ET is a fundamental process in many applications, it cannot be directly measured but it has to be estimated by monitoring the exchange of energy/water above the vegetated surface (micrometeorological methods), or as a residual term of the hydrological balance (lysimeters, soil water budget). The techniques to be adopted are often complex, costly and require specific equipment. Thus, since the ‘50s, many researchers have devoted their activity to the development of models for its estimation. The available approaches can be classified in “direct” methods, based on the original Penman-Monteith (PM) equation, in which the canopy resistance rc is modelled, and “indirect” methods, based on the preliminary calculation of ET for a well-watered reference grass (ET0) with a constant rc, which is then multiplied by a crop coefficient Kc and, in case, by a stress coefficient Ks to obtain ET. Even if the latter approaches are more widely adopted for their practical simplicity, many authors show that the former often provide better ET estimates in absence of calibration of crop parameters. In this study the performances of different direct and indirect methods were evaluated in the case of a surface irrigated and of a rainfed maize grown in the Padana Plain (Northern Italy). The following models were considered: the “one-layer” original PM equation with three different models for rc (Monteith, Jarvis, Katerji-Perrier), the “two-layers” PM model proposed by Shuttleworth and Wallace, the “single” and “double” crop coefficient models illustrated in the Paper FAO-56. Latent heat fluxes measured in 2006 and 2011 in an experimental maize field by eddy-covariance were used to evaluate the models accuracy. Crop, soil and meteo data monitored contextually were used for the implementation of the different models. Results confirm that direct methods are more performing for both irrigated (2006) and rainfed (2011) conditions, with the SW model providing the best results and the FAO-56 models with generalized crop coefficients overestimating ET, especially during the middle growth stage

Towards a smart automated surface irrigation management in rice-growing areas in Italy

Italy is the leading rice producer in Europe, accounting for more than half of the total high-quality production of this crop. Rice is traditionally grown in fields that remain flooded starting with crop establishment until close to harvest, and this traditional irrigation technique (i.e., continuous submergence) is recognised as an important water resource sink (almost 40% of the irrigation water available worldwide is used for paddy areas). Meanwhile, the water management in rice areas requires a high level of labour because it is based on maintaining a predetermined water height in paddy fields and because the regulation of input and output flow is typically operated manually by the farmer. This study reveals the hardware and software characteristics of an automated and remote controlled technology tested for the first time in a rice farm near Pavia (Italy), during the 2016 growing season, aiming at a more efficient and less burdensome irrigation management system for rice fields. A water level sensor in the field provides the data required to govern the inflow regulation gate in real-time, according to the precise time to cut off the flow rate. Using a dedicated web page, the farmer can control flows, volumes and water levels in the fields by operating directly on the gate if necessary or setting the irrigation program according to his agronomic practices

COMPARING OPTICALAND DIRECT METHODS FOR LEAFAREA INDEX DETERMINATION IN A MAIZE CROP

Leaf area index (LAI) is a crucial variable in the modelling of many hydrological processes. Destructive sampling of LAI is extremely time-consuming, thus not suitable for monitoring temporal/spatial variations of the variable. In the last fifty years optical instruments retrieving LAI from more easily measurable variables (i.e. transmitted radiation through canopies) have been developed. Several instruments are available on the market, but very few are the studies comparing LAI estimates in agricultural crops. In this paper three optical instruments are compared with destructive sampling for a maize crop located in Northern Italy. Determinations were carried out on three plots (replicates) before and after successive thinning of plant populations. Destructively sampled LAI ranged from 4.9 m2m-2 (no thinning) to 1.2 m2m- 2 (maximum thinning). Correlation analysis showed that estimates by the AccuPAR-80, the hemispherical camera ("effective" and "true" LAI) and the LAI- 2000 (in the standard configuration, i.e. five zenithal rings, and excluding the fifth ring) were well correlated with destructive measurements (R2≥0.95). Anyway, if for the AccuPAR-80 the regression line was close to the 1:1 line, the "true LAI" by hemispherical photography tended to overestimate destructively sampled LAI for low values while the "effective LAI" and the LAI-2000 to underestimate it for high values (in a minor way for the LAI-2000 when the fifth ring was removed). Results from the ANOVA and the Tukey T test for two-factor experiments with replicates showed that only the "effective LAI" retrieved by hemispherical photographs and the estimates provided by the LAI-2000 in the standard configuration (five rings) were statistically different from destructive measurements

Monitoring water fluxes in rice plots under three different cultivation methods

Italy is the leading producer of rice in Europe with over half of total production, almost totally concentrated in a large traditional paddy rice area between the Lombardy and Piedmont regions, in the north-western part of the country. In this area irrigation of rice has been traditionally carried out by flooding. The introduction of new combined irrigation and agronomic management practices (dry seeding followed by field flooding and in a full aerobic cultivation with intermittent irrigations), aiming to reduce the water consumption, can determine considerable effect on the landscape and the water cycle. With the aim to study in depth the water fluxes during the whole crop season, three experimental plots at the Ente Nazionale Risi-Rice Research Centre’s Experimental Station of Castello d’Agogna (PV) were instrumented. In each plot the following instruments have been installed: 1) a long throated flume and a double shaped (V-notch and rectangular) thin plate for superficial inputs and outputs, 3) a set of piezometers for groundwater levels, 4) one stage level gauge in each submerged field, 5) four tensiometers and moisture sensors clusters, 6) one eddy covariance station for vapour fluxes estimation. Most of the instruments were equipped with electrical sensors connected by cables to a wireless data logger that, in turn, send the data to a PC placed within ENR offices and web-connected by a LAN. In this way, besides the automatic download of data, it was possible to remotely control the devices, to quickly fix troubles, and to better plan the field trips. The management of the whole framework was done by a specifically developed software. In this paper the whole system, which presents some degree of innovation, is described in detail

Prospects for improving gravity-fed surface irrigation systems in Mediterranean European contexts

Traditionally, most irrigation practices in Southern Europe have been based on gravity-fed surface irrigation systems. Currently, these systems remain a relevant typology in the European Union (EU) member states of the Mediterranean areas, where it is often the only sustainable method for farmers due to the small size of agricultural holdings, their reduced capacity and readiness to invest and the low ratio between yield profits and irrigation costs. In the last several years, in response to European and national directives, surface irrigation has garnered increasing attention at the political and bureaucratic levels due to frequent criticisms of its postulated low efficiency and high water wastage. However, these systems commonly provide a number of ecosystem services and nature-based solutions that increase the positive externalities in different rural socio-ecological contexts and often have the potential to extend these services and provide solutions that are compatible with economical sustainability. This study aims to discuss the prospects for new practices and for the rehabilitation and modernization of the gravity-fed surface irrigation systems in EU Mediterranean areas to enhance water efficiency, thus gaining both economic advantages and environmental benefits. The difficulties, stimuli for improvements and peculiarities of the irrigation water management of four rural environments located in Italy, Spain and Portugal were analyzed and compared to the current state of the gravity-fed surface irrigation systems with hypothetical future improvements achievable by innovative technologies and practices. In these different case studies, the current gravity-fed surface irrigation systems have an obsolete regulatory structure; water-use efficiency is not a driving criterion for the management of the conveyance and distribution canal network, and farmers are not yet adequately encouraged to adopt more efficient gravity-fed irrigation practices. A continuous knowledge exchange is thus necessary for the interaction of all irrigation water managers and farmers to improve their eco-efficiency and to preserve and promote their cultural heritage across the entire water supply and delivery chains. We argue that the best way forward will require precisely targeted rehabilitation measures of gravity-fed surface irrigation systems based on the integrated use of decision support services, gate automation, remote and feedback controls and real-time flow optimization

Prevalence and Correlates of Vitamin D Deficiency in a Sample of 290 Inpatients With Mental Illness

Introduction: Vitamin D inadequacy or deficiency (VDID) has been reported in a high percentage of otherwise healthy individuals. Factors that may contribute to the high prevalence of VDID in people with mental disorders include diet low in vitamin D, poor sunlight exposure, decrease in cutaneous vitamin D synthesis, intake of certain medications, poor mobility, excessive alcohol intake, and tobacco smoking. VDID has been correlated to a host of adverse conditions, including rickets, osteoporosis, osteomalacia, muscle diseases, depression, cognitive dysfunction, and even certain cancers.Objectives: The purpose of this study was to report the prevalence and correlates of vitamin D inadequacy in a sample of 290 psychiatric patients admitted to inpatient or day hospital treatment at the University of Siena Medical Center.Methods: We retrospectively evaluated the prevalence of VDID in 290 psychiatric inpatients' medical records during the year 2017 and evaluated the correlates of VDID in patients with mental illness.Results: Two hundred and seventy two out of two hundred and ninety patients (94%) showed VDID. Physical activity and regular diet were positively correlated with vitamin D levels whereas age, tobacco smoking, PTH, alkaline phosphatase levels were negatively correlated. Statistically significant differences were found among smokers and non-smokers in all study groups.Conclusions: VDID was highly prevalent in our sample. In addition to vitamin D supplementation, psychosocial intervention able to promote and help sustain physical activity, appropriate diet, quitting smoking and sensible sun exposure to prevent and treat VDID in patients with mental health should be implemented, tested, and introduced in our clinical practice

Feasibility, Adherence and Efficacy of Liraglutide Treatment in a Sample of Individuals With Mood Disorders and Obesity

Background: Liraglutide is a once-daily injectable medication approved for the treatment of obesity. Hereby we report the feasibility, adherence and efficacy of liraglutide treatment in a sample of individuals with mood disorders and obesity.Methods and Sample: Twenty-nine patients with Bipolar or Major Depressive Disorder received liraglutide once daily subcutaneously at a dose gradually titrated from 0.6 to 3 mg. All patients were obese and had previously failed multiple healthy lifestyle interventions, including exercise and diet programs. Patients' weight was recorded before liraglutide treatment (T0) and then 1 (T1), 3 (T3), and 6 months (T6) following T0.Results: Mean baseline (T0) weight was 110.54 Kg (±24.95). Compared to baseline, the percentage of weight loss was 3.37% at T1, 7.85% at T3, and 10.20% at T6. Thirty-one percent (n = 9) of patients had no side effects, 34.48% (n = 10) had one, 24.14% (n = 7) had two, and 10.34% (n = 3) had three side effects. All 29 subjects were still on liraglutide at T1; 79.31 and 48.28% were on liraglutide at T3 and T6. No significant relationship was found between liraglutide dose and likelihood to continue the medication. No patient showed a worsening of the psychiatric condition due to liraglutide treatment. Acceptability and satisfaction with treatment were good for the 48% that completed the study.Conclusions: Liraglutide treatment was efficacious, accepted and tolerated by ~50% of our sample, followed up for a period of 180 days. Larger, longer, controlled, prospective studies are warranted

Methodologies for the Sustainability Assessment of Agricultural Production Systems, with a Focus on Rice: A Review

The intensification of agricultural production is connected to the increased use of fertilizers, pesticides, irrigation water, and energy. Among all cropping systems, rice cultivation is considered to be one of the most significant sources of environmental harm due to the flooding conditions in which rice normally grows; at the same time, rice has important economic and social implications, especially in areas where it is a staple food. In the last 20 years, sustainable development of agricultural production has become a priority for scientific research and policy programs. Several studies proposed methodological frameworks to assess the impacts of different management practices adopted in agro-ecosystems and to identify strategies to mitigate the negative effects of agricultural intensification. Such methodologies are based on the use of particular indicators, which are increasingly seen as crucial tools in impact assessment studies and for decision making. This paper aims to review and analyze the most significant methodological frameworks developed to assess the sustainability of agricultural production systems, with a particular focus on rice cultivation. The analysis includes highlighting which dimensions of sustainability (economic, environmental, social, and governance) are covered by each method and identifying which indicators are used to describe the different dimensions. The spatial scale of the application of the indicators, their typology, the data needed for their implementation, and the criteria for formulating the overall sustainability judgment were then examined. The analysis highlighted the scarce availability of clear operational data for the calculation of the indicators and the often-limited involvement of stakeholders in the development and implementation of the methodologies. The exceptions to these limitations are represented by a few methodologies developed under the umbrella of important international organizations to promote sustainability and research efficiency in specific agricultural production systems, such as the SRP (sustainable rice platform) for rice. Finally, the analysis shows that there is a need to develop methodologies that are applicable not only to an individual farm or group of farms, but also at larger spatial scales (district, watershed, region), which are often those of greatest interest to decision makers