Michele Rinaldi

Multitemporal C-band radar measurements on wheat fields

This paper investigates the relationship between C-band backscatter measurements and wheat biomass and the underlying soil moisture content. It aims to define strategies for retrieval algorithms with a view to using satellite C-band synthetic aperture radar (SAR) data to monitor wheat growth. The study is based on a ground-based scatterometer experiment conducted on a wheat field at the Matera site in Italy during the 2001 growing season. From March to June 2001, eight C-band scatterometer acquisitions at horizontal-horizontal and vertical-vertical polarization, with incidence angles ranging from 23/spl deg/ to 60/spl deg/, were taken. At the same time, soil moisture, wheat biomass, and canopy structure were collected. The paper describes the experiment and investigates the radar sensitivity to biophysical parameters at different polarizations and incidence angles, and at different wheat phenological stages. Based on the experimental results, the retrieval of wheat biomass and soil moisture content using Advanced Synthetic Aperture Radar data is discussed.

Durum wheat (Triticum durum Desf.) in rotation with faba bean (Vicia faba var. minor L.): long-term simulation case study

The aim of this work was to applythe CropSyst simulation model toevaluate theeffect of faba bean cultivation as a break crop in the continuous durum wheat cropping system in southern Italy. The model was previously calibrated and validated for durum wheat and faba bean on data derived from experiments carried out in southern Italy (for different years and treatments), comparing observed and simulated crop growth, yield, soil water, and nitrogen output variables. The validation showed good agreement between simulated and observed values for cumulative above-ground biomass, greenareaindex,andsoilwatercontentforbothcropsandgrainyieldfordurumwheat;anegativecorrelationforgrainyieldin fababeanwasobservedduetoareductioninharvestindexinthewell-wateredcrop,whichthemodeldoesnotsimulatewell. Subsequently, a long-term analysis was carried out to study the effects on durum wheat of introducing a legume crop in rotation with the cereal in 2 and 3-year sequences. Along-termsimulation,basedon53yearsofdailymeasuredweatherdata,showedthatfababean,duetoalowerlevelof transpiratedwater(onaverage247mmfordurumwheatand197mmforfababean),allowedforgreatersoilwateravailability atdurumwheatsowingforthecerealwheninrotationwithalegumecrop(onaverage,+84mm/mfordurumwheatfollowing thefababean),withpositiveeffectsfornitrogenuptake,above-groundbiomass,andgrainyieldofwheat.Theyieldincrease of wheat when following a faba bean crop was on average +12%, but this effect was amplified in drier years (up to 135%). Inconclusion,thecasestudyofferedthepotentialtoconfirmthepositiveresultspreviouslyobtainedinlong/medium-term field experiments on the introduction of faba bean in rotation with durum wheat, as well as reduction in the chemical application of nitrogen.

On the use of temporal series of L-and X-band SAR data for soil moisture retrieval. Capitanata plain case study

Abstract This paper investigates the use of time series of ALOS/PALSAR-1 and COSMO-SkyMed data for the soil moisture retrieval (mv) by means of the SMOSAR algorithm. The application context is the exploitation of mv maps at a moderate spatial and temporal resolution for improving flood/drought monitoring at regional scale. The SAR data were acquired over the Capitanata plain in Southern Italy, over which ground campaigns were carried out in 2007, 2010 and 2011. The analysis shows that the mv retrieval accuracy is 5%-7% m3/m3 at L-and X band, although the latter is restricted to a use over nearly bare soil only.

On the use of multi-temporal series of COSMO-SkyMed data for LANDcover classification and surface parameter retrieval over agricultural sites

The objective of this paper is to report on the activities carried out during the first year of the Italian project “Use of COSMO-SkyMed data for LANDcover classification and surface parameters retrieval over agricultural sites” (COSMOLAND), funded by the Italian Space Agency. The project intends to contribute to the COSMO-SkyMed mission objectives in the agriculture and hydrology application domains.

Radiation-use efficiency of irrigated biomass sorghum in a Mediterranean environment

Mathematicalcropsimulationmodelsareusefultoolsinpredictingthepotentialyieldof fieldcropsinaspecific environment. The main driving parameter used to estimate biomass accumulation in most of these models is radiation-use efficiency(RUE).Biomasssorghum(SorghumbicolorL.Moench)isacropthatcanbeusedforenergyproduction(thermal and bioethanol chains) and a knowledge of its RUE in different water supply conditions can help to improve model simulations and evaluate crop diffusion. A 3-year field experiment was carried out in Southern Italy where sorghum was submitted to four irrigated regimes based on actual crop evapotranspiration (ETc). In the first year ETc was measured with weighted lysimeters, while in the other 2 years it was estimated by means of estimated crop coefficient (Kc) and the reference evapotranspiration ET0. The RUE, calculated as the slope of the first-order equation between dry biomass and intercepted photosynthetically active radiation along a crop cycle, showed an average of 2.91 � 0.54gMJ -1 , even if the RUE proved to be closely correlatedwithcropwaterconsumption.Thelatterrangedbetween891and454mmandtheRUEincreased4.2mgMJ -1 per mm of water used. A high crop interception of solar radiation was observed in sorghum, reaching its maximum efficiency 40 days after sowing. To obtain high yielding yield biomass sorghum requires a large supply of water, as confirmed by the Kc calculated during the crop cycle, which resulted higher (especially in the development and middle stages) when compared with those reported in the FAO 56 Paper. The obtained RUE values also confirmed a high efficiency in biomass production of this crop, allowing for the introduction of biomass sorghum in the cropping systems of Mediterranean environments as an alternative crop for energy purposes, but with adequate irrigation water supply.

Assimilation of COSMO-SkyMed-derived LAI maps into the AQUATER crop growth simulation model. Capitanata (Southern Italy) case study

Abstract AQUATER is a Decision Support System (DSS) developed to drive crop management decisions at district level in a Mediterranean area; it integrates information from soil and climatic databases with a crop growth simulation model and provides estimates of crop yield at regional scale. AQUATER can assimilate LAI maps derived from Earth observation data in order to mitigate the risk of erroneous model predictions over large areas. In this study, time-series of LAI maps derived from COSMO-SkyMed SAR images, acquired over the Capitanata plain (Puglia region) in 2010 and 2011, have been assimilated by a forcing procedure in AQUATER and the improvements of its predictions have been assessed. Results indicate that the LAI assimilation leads to significant improvements in the yield forecast of sugar beet and tomato crops, whereas in the case of wheat the improvements are marginal.

Time series of COSMO-SkyMed data for landcover classification and surface parameter retrieval over agricultural sites

This paper reports on the results of an Italian project aimed at investigating the use of X-band COSMO-SkyMed (CSK) SAR data for applications in agriculture and hydrology. Existing classification and retrieval algorithms have been tailored to CSK data and time series of crop, leaf area index and soil moisture maps have been retrieved and assessed through the comparison with in situ data collected over three agricultural sites. In addition, the CSK-derived surface parameters have been integrated into crop growth and hydrologic models and the resulting improvements have been assessed. Results indicate that multi-temporal dual-polarized CSK data are very well-suited for agricultural crop classification and that the integration of maps of SAR-derived surface parameters into crop growth and/or hydrologic models, in general, leads to significant improvements in the model performances.

On the assimilation of C-band radar data into CERES-wheat model

Based on recent experimental studies which have found a strong correlation between a multitemporal series of C-band HH/W backscatter ratios acquired at 40deg incidence angle and wheat biomass, this work investigates the effect of the assimilation of the radar retrieved information into CERES-Wheat crop model. A sensitivity analysis has shown that an inaccurate knowledge of some model inputs, concerning soil properties and crop management, can lead to erroneous predictions. However adopting a reinitialisation assimilation strategy, significant improvements in the model estimations have been obtained

A ground network for SAR-derived soil moisture product calibration, validation and exploitation in Southern Italy

A ground network of 12 stations continuously monitoring soil moisture and temperature at various depths has been recently set up over an experimental site of 4km2 in the Capitanata plain (Southern Italy). The calibration of the instrumentation is in progress. The long-term high resolution ground observations will be well-suited for SAR-derived soil moisture product validation. Moreover, the ground network will be also associated with hydrologic and agricultural model activities, with the aim of combining land process models with Earth Observation for improving land applications, such as flood/drought and crop yield monitoring and forecast. Indeed, the Capitanata plain is a crucial area in the Mediterranean basin for studying the impact of climate changes and anthropogenic pressure on water availability/demand and wheat production.

Decision Support Systems To Manage Water Resources At Irrigation District Level In Southern Italy Using Remote Sensing Information. An Integrated Project (AQUATER)

An efficient management of water resources is crucial point for Italy and in particular for southern areas characterized by Mediterranean climate in order to improve the economical and environmental sustainability of the agricultural activity.A three‐year Project (2005–2008) has been funded by the Italian Ministry of Agriculture and Forestry Policies; it involves four Italian research institutions: the Agricultural Research Council (ISA, Bari), the National Research Council (ISSIA, Bari) and two Universities (Federico II‐Naples and Milan). It is focused on the remote sensing, the plant and the climate and, for interdisciplinary relationships, the project working group consists of agronomists, engineers and physicists.The aims of the Project are:a) to produce a Decision Support System (DSS) combining remote sensing information, spatial data and simulation models to manage water resources in irrigation districts;b) to simulate irrigation scenarios to evaluate the effects of water stress on crop yield using ...