28 research outputs found
Agricoltura, ambiente e paesaggio - I complessi rapporti che intercorrono fra l'attività più antica dell'uomo e l'ambiente terrestre
No full textVengono esaminati i rapporti che si creano fra l'agricoltura, l'ambiente e il paesaggio man mano che il progresso e le nuove tecnologie irrompono nella scena mondiale. Un uso sconsiderato dei nuovi mezzi a disposizione può produrre danni gravissimi all'intero ecosistema terrestre sino ad arrivare alla catastrofe climatica finale. Ma esiste una scappatoia: un nuovo modello di sviluppo agricolo e alimentare in grado di soddisfare le esigenze di una popolazione in aumento e allo stesso tempo rispettoso dell'ambiente e produttore esso stesso di paesaggio
Tecnologie attive di condizionamento contro lo stress da caldo per le vacche da latte negli ambienti temperato-caldi (stato dell'arte)
No full textSi esaminano le tecniche di controllo del clima nelle stalle per vacche da latte messe a punto da vari studiosi negli ultimi anni. Viene dato particolare risalto al cooling by surface, ossia alla bagnatura dei soggetti mediante docce e alla successiva ventilazione
Portability of leaf chlorophyll empirical estimators obtained at Sentinel-2 spectral resolution
No full textFuture ESA Sentinel-2 (S2) constellation is expected to represent a breakthrough for the exploitation of earth observation data in precision agriculture applications. The present work addresses the comparison of the sensitivity of leaf chlorophyll estimators vegetation indices (VI), obtainable from Sentinel-2 spectral bands, and of their portability with different crops/soil/illumination conditions. The comparison is addressed by the analysis of a large synthetic dataset, obtained using the PROSPECT-SAILH model in the direct mode, considering different crops canopies in the 1-4 LAI (Leaf Area Index) range with different soil backgrounds and different illumination geometry. Considered broad-band indices (i.e. indices obtained only from visible and NIR bands) included the classical NDVI index and some indices incorporating green reflectance proposed al leaf chlorophyll density estimators (Green NDVI, Green SR or CI and CVI), whereas narrow-band indices (i.e. indices requiring narrow bands in the red-edge) included VI specifically proposed as leaf chlorophyll estimators at the canopy scale (i.e. TCI/OSAVI, REP and MTCI). Results indicate that the MTCI and TCI/OSAVI indices, obtainable at 20 m spatial resolution from future S2 data, are the best leaf chlorophyll estimators respectively for planophile and erectophile crops canopies and that the CVI index, obtainable at 10 m, is the second best estimator for both planophile and erectophile crops canopies
Cooling systems of the resting area in free stall dairy barn
No full textA study during the summer season evaluated the effect of different cooling systems on behavioral and productive responses of Italian Friesian dairy cows kept in an experimental-free stall barn located in the Po Valley in Italy. The study involved 30 lactating dairy cows subdivided into two groups kept in two pens with external hard court paddock in each free stall. The same cooling system was applied in the feeding area in both pens. A different cooling system in the resting area was applied to the two pens: in the pen SW, the resting area was equipped with fans and misters; in the other, there was simple ventilation (SV). Breathing rate, rectal temperature, milk yield, and milk characteristics (fat, protein, and somatic cell count) were measured. Behavioral activities (standing and lying cows in the different areas, as well as the animals in the feed bunk) were recorded. Mild to moderate heat waves during the trial were observed. On average, the breathing rate was numerically greater in SV compared with SW cows (60.2 and 55.8 breath/min, respectively), and mean rectal temperature remained below 39 °C in both groups during the trial (on average 38.7 and 38.8 °C in SV and SW, respectively. During the hotter periods of the trial, the time spent lying indoor in the free stall was greater in SW (11.8 h/day) than SV (10.7 h/day). Conversely, the time spent standing indoor without feeding was greater in SV (4.3 h/day) than SW (3.8 h/day). Milk yield was slightly better maintained during hotter period in SW compared with SV and somatic cell count was also slightly greater in the former. In conclusion, the adoption of the cooling system by means of evaporative cooling also in the resting area reduces the alteration of time budget caused by heat stres
Fan cooling of the resting area in a free stalls dairy barn
No full textThis summer study evaluated the effect of providing additional fans (cooling) in the resting area within a free-stall dairy barn that had fans and sprinklers in the feeding area and paddock availability. Thirty cows were divided into two homogenous groups and kept in two pens: one had the resting area equipped with two fans (FAN) while no fans were added to the other resting area (CON). Microclimatic parameters, rectal temperature (RT), breathing rate (BR), milk yield, and milk pH traits were recorded. Time budgeting and the behaviour of the cows (time spent in the feeding area, standing and lying in other areas) were also recorded using digital video technology. Two slight-to-moderate heat waves were observed. During the hottest period the daily maximum temperature recorded was 33.5 °C and the daily maximum THI was 81.6. During this period, the BR and RT increased only slightly in both groups, with lower BR (n.s.) in FAN compared with CON. Milk yield was better maintained (n.s.) in FAN compared with CON during the hottest period. The FAN cows showed a greater (P < 0.05) lying time in the free stalls (9.5 and 8.6 h/day in FAN and CON, respectively), whereas CON cows made greater (P < 0.05) use of the paddock during evening and late evening hours. Consequently, the total daily lying time was 13.5 h/day in both groups. In conclusion, the results suggest that using fans in the resting area improves cow comfort, which increases use of the resting area. The lying time results also suggest that the benefits of providing ventilation in the resting area might be more evident in barns where there is no paddock
Misting and fan cooling of the rest area in a dairy barn
No full textThis summer study aimed to evaluate the effect on dairy cows, kept in a free stall barn equipped with fans
and sprinklers in the feeding area, of the delivery rate of
misters in a cooling system in rest areas with different
bedding materials. Thirty cows were divided into two
homogenous groups according to milk yield and kept in
two pens: one had beds with sand (SAMM) while the other
had straw (STLM). Each pen was equipped with 2 fans (Ø
70 cm, 0.50 kW) and 2 misters (delivery rate of 11.2 and
22.5 L/h in STLM and SAMM, respectively) in the rest
area. Microclimatic parameters, rectal temperature (RT),
breathing rate (BR), milk yield, and some milk traits were
recorded. Behavioural routines of the cows (standing and
lying) were also continuously recorded during the hotter
days. During the trial, two mild–moderate heat waves were
observed. During these hotter periods, the daily maximum
temperature recorded in the rest areas was 28.9 in SAMM
and 31.2 in STLM, and the daily maximum THI was 78.2
in SAMM and 81.5 in STLM. In these periods, the cows in
SAMM compared with those in STLM showed lower BR
(P<0.05) and greater rest time (10.2 and 7.8 h/day in
SAMM and STLM, respectively). The RT did not differ
(38.89±0.29 and 38.88±0.33°C in STLM and SAMM r,
espectively). In conclusion, our research suggests that the
cooling system using fans plus misters with mild wetting in
rest areas with sand as bedding materials reduces heat stress
and improves cow comfort
Empirical Estimation of Leaf Chlorophyll Density in Winter Wheat Canopies Using Sentinel-2 Spectral Resolution
No full textA comparison between the sensitivities to leaf chlorophyll density at the canopy scale of several vegetation indices (VIs) obtained at different spectral resolutions was carried out using spectral reflectance collected in winter wheat field trials with different nitrogen fertilization levels. A total of 350 spectra were collected from experimental plots at Feekes growth stages 5, 6, and 9 using a portable spectroradiometer (ASD FieldSpec HH), along with Minolta SPAD measurements of leaf optical thickness as a proxy for leaf chlorophyll density. Indices based on visible and near-infrared (NIR) bands were obtained from average reflectance in spectral ranges corresponding to SPOT HRG and Sentinel-2 (S2) bands. Indices requiring a red-edge band were obtained from reflectance at the originally proposed VI wavelengths using the 1.6-nm nominal spectral resolution bandwidth of the spectroradiometer and from average reflectance in the S2 red-edge bands with the closest spectral position to VI originally proposed wavelengths. Among VIs obtained from Sentinel-2 bands MERIS terrestrial chlorophyll index, red-edge position and triangular chlorophyll index/optimized soil adjusted VI ratio (TCI/OSAVI) indices, obtainable at 20-m spatial resolution from future S2 red-edge bands, and chlorophyll VI (CVI), obtainable at 10 m from visible and NIR bands, were the best estimators of winter wheat leaf chlorophyll density. The sensitivity of the best-performing indices obtained from S2 bands to winter wheat with other conditions was addressed by the analysis of a large synthetic data set obtained using the PROSPECT-SAILH model in the direct mode. Analysis of the synthetic data set using Sentinel-2 spectral resolution indicates that the two leaf area index normalized (TCI/OSAVI and CVI) indices are better leaf chlorophyll estimator
Sensitivity of Sentinel-2 Red-Edge Bands to Leaf Chlorophyll Concentration in Winter Wheat.
No full textThe present work addresses the comparison between the sensitivity of several narrow-band and broad-band vegetation indices (VI) to leaf chlorophyll concentration at the canopy scale in winter wheat field trials with different nitrogen fertilization levels. Spectral signatures were collected on three dates (Feekes growth stages 5-6-9) over experimental plots with a portable spectroradiometer (ASD FieldSpec HH), along with Minolta SPAD measures of leaf optical thickness as a proxy of leaf chlorophyll concentration. Considered broad-band indices included classical slope-based VI (i.e.: NDVI, SR and OSAVI) and some indices incorporating green reflectance (i.e. Green NDVI, Green SR, CVI and MTVI), whereas narrow-band indices included VI specifically proposed as leaf chlorophyll estimators at the canopy scale (i.e. MCARI/OSAVI, TCARI/OSAVI, TCI/OSAVI, NOAC, REIP and MTCI). Broad-band VI were obtained from average reflectance in spectral ranges corresponding to SPOT HRG bands and from average reflectance in Sentinel-2 visible and NIR bands whereas narrow-band VI were obtained from reflectance at the original spectral resolution of the spectroradiometer and from average reflectance in Sentinel-2 Red-Edge bands. Among VI obtained from Sentinel-2 bands REIP and MTCI indices were the best narrow-band estimators of winter wheat leaf chlorophyll concentration, whereas CVI was the best estimator among broad-band VI
