scholarly journals Lettuce Production under Mini-PV Modules Arranged in Patterned Designs

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2554
Author(s):  
Angel Carreño-Ortega ◽  
Teresa A. do Paço ◽  
Manuel Díaz-Pérez ◽  
Marta Gómez-Galán

The growing need for clean energy and food production are favoring the use of underused spaces, such as rooftops. This study aims to demonstrate the compatibility of the use of rooftops both for the production of photovoltaic energy and for the production of food, despite the fact that both compete for the same resource, sunlight (rooftop agrivoltaic). In the experiment reported in this study, which was carried out in Almería (Spain) during the spring and summer of 2021, three shade treatments were tested for a lettuce crop, produced by photovoltaic modules with different arrangements: concentrated shade (CS), scattered shade (SS) and full sun (FS). This experiment was repeated in two seasons with high radiation levels and temperature. The results show that in these environmental conditions, the cultivation of plants that demand little sunlight, such as lettuce, is compatible with the shading produced by photovoltaic panels. In addition, it is shown that the same percentage of the area covered with shade (22%), but using mini-PV modules arranged in patterns, improves the productivity (fresh weight, dry matter, number of leaves, maximum length and dry matter of roots) of lettuce cultivation, both in spring and summer.

Pastura ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Eny Fuskhah ◽  
Adriani Darmawati

The research aim is to use sea water as nutrient source of plant especially soybean, so it reduces amount of anorganic fertilizer usage. The research held in green house of Ecology and Plant Production Laboratory of Animal Husbandry and Agriculture Faculty, Diponegoro University Semarang. Sea water as sample was taken from Semarang Marina Beach. Soybean which choosen is local bean of Grobogan. The design arranged was completely randomized design with factorial design 4 x 2 in 4 replications. First factor was sea water salinity level, L0 = without sea water and without mulch, L1 = sea water EC 1 mmhos/cm and water hyacinth mulch of 8 tons/ha, L2 = sea water EC 2 mmhos/cm and water hyacinth mulch of 8 tons/ha, L3 = sea water EC 3 mmhos/cm and water hyacinth mulch of 8 tons/ha. The second factor was Rhizobium inoculation, R1 = without rhizobium inoculation, and R2 = with Rhizobium inoculation. The parameters were length plant, number of leaves, fresh weight production of shoot and dry matter production. Based on variant analysis, showed no influenced between sea water salinity level and rhizobium inoculation againt to length plant, number of leaves, fresh weight production of shoot and dry matter production. Sea water and rhizobium inoculation tended to increase growth and production of soybean.Key words : soybean, nutrient of sea water, rhizobium, growth, production.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 599e-599
Author(s):  
Hameed Jasim Aljuburi

The study was carried out at the Experimental Station of Agric. Sci. College at Al-oha region. Eight hundred seedlings (7 months old) were chosen for each following cultivars, Lulu, Boman, Barhee and Khalas. The seedings for each cultivars were irrigated weekly with 0, 6, 12, 18 g I.-1 Nacl solution. The results revealed fresh weight of stems, roots and number of leaves/plant of Lulul, Barhee and Khalas cultivars progressively reduced with increasing Nacl concentration in irrigation water, while dry matter percentage of stems and roots increased and increasing salinity in irrigation water. The results also declared that the seedlings of four date palm cultivars has similar behavior, when exposed to high Nacl concentration in irrigation water during long term.


2011 ◽  
Vol 367 ◽  
pp. 507-515
Author(s):  
Tajudeen H. Sikiru ◽  
Olorunfemi Ojo ◽  
Boyi Jimoh

Manufacturers usually specify photovoltaic (PV) modules at standard test conditions of and , which may not be attainable anywhere in the world. Therefore, to determine the performance of PV modules at naturally occurring irradiance and ambient temperature, this paper proposes a theoretical methodology. This method could be used to predict the performance of PV modules given the irradiance and the ambient temperature at the site of installation. A novel technique that is based on the current-voltage characteristic model is used, it accounts for the variability in the environmental parameters. The irradiance and the ambient temperature of Zaria, Nigeria were used as an illustrative example, which showed the effects of the environmental conditions on the performance of PV modules.


Author(s):  
Isaías P. Guimarães ◽  
Francisco de A. de Oliveira ◽  
Salvador B. Torres ◽  
Francisco E. C. B. Pereira ◽  
Francisco D. de França ◽  
...  

ABSTRACT Lettuce stands out as the main leafy vegetable consumed in Brazil, with divergence regarding adaptability to different environmental conditions, which include salinity. The objective of the work was to evaluate the response of lettuce cultivars to the use of saline wastewater from fish farming. The experiment was conducted in a completely randomized design with four replicates, in a factorial 7 x 4, corresponding to seven cultivars (Regiane, Vera, Isabela, Elisa, Amelia, Lavinia and Angelina) and four salt concentrations (1.2, 2.2, 3.2 and 4.2 dS m-1). The evaluated characteristics were: number of leaves, leaf area, crown diameter and shoot fresh and dry matter. Diluted wastewater from fish farming can be used in the preparation of solution for fertigation of lettuce. The cultivars Regiane and Elisa had higher production of leaves and leaf area, while Amélia and Angelina were the most productive in terms of biomass. The cultivars Vera, Isabela, Amélia and Angelina were more tolerant to the salinity of the fertigation solution.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wonwook Oh ◽  
Seongtak Kim ◽  
Soohyun Bae ◽  
Nochang Park ◽  
Sung-Il Chan ◽  
...  

We investigated the migration of Sn and Pb onto the Ag fingers of crystalline Si solar cells in photovoltaic modules aged in field for 6 years. Layers of Sn and Pb were found on the Ag fingers down to the edge of the solar cells. This phenomenon is not observed in a standard acceleration test condition for PV modules. In contrast to the acceleration test conditions, field aging subjects the PV modules to solar irradiation and moisture condensation at the interface between the solar cells and the encapsulant. The solder ribbon releases Sn and Pb via repeated galvanic corrosion and the Sn and Pb precipitate on Ag fingers due to the light-induced plating under solar irradiation.


2017 ◽  
Vol 9 (11) ◽  
pp. 283 ◽  
Author(s):  
Renata V. Menezes ◽  
André D. Azevedo Neto ◽  
Hans R. Gheyi ◽  
Alide M. W. Cova ◽  
Hewsley H. B. Silva

Basil (Ocimum basilicum L.) is a medicinal species of Lamiaceae family, popularly known for its multiple benefits and high levels of volatile compounds. The species is considered to be one of the most essential oil producing plants. Also cultivated in Brazil as a condiment plant in home gardens. The objective of this study was to evaluate the effect of salinity on the growth of basil in nutrient solution of Furlani and to identify variables related to the salinity tolerance in this species. The first assay was performed with variation of five saline levels (0 - control, 20, 40, 60 and 80 mM NaCl). In the second assay six genotypes were evaluated in two salinity levels 0 and 80 mM NaCl. The height, stem diameter, number of leaves, dry mass and inorganic solutes in different organs, photosynthetic pigments, absolute membrane integrity and relative water content were evaluated. All biometric variables in basil were significantly reduced by salinity. Dry matter yield and percentage of membrane integrity were the variables that best discriminated the characteristics of salinity tolerance among the studied basil genotypes. Basil genotypes showed a differentiated tolerance among the genotypes, the ‘Toscano folha de alface’ being considered as the most tolerant and ‘Gennaro de menta’ as the most sensitive, among the species studied.


2012 ◽  
Vol 10 (1) ◽  
pp. 16-22 ◽  
Author(s):  
M. Z. U. Kamal ◽  
M. N. Yousuf

The investigation was carried out to evaluate the effect of different organic manures on turmeric with reference to vegetative growth, biomass production, rhizome yield and its attributes of turmeric (Curcuma longa L.). Turmeric showed better response to the application of organic manures. Plant with neem cake application had the taller plant (79.30 cm), maximum number of tillers per plant (5.40), leaf number (5.40), leaf area (44.09) leaf area index (0.429), fresh weight of halum ( 190.05g), fresh weight of root (49.13 g), fresh weight of rhizome per plant (256.21 g) and dry weight of halum (15.21g), dry weight of root (7.32 g), dry weight of rhizome per plant (40.35 g), total dry matter yield (6.85 t ha-1) than those received other types of manures. Moreover, yield attributes such as number of mother rhizomes per plant-1 (1.75), more number of primary rhizomes per plant-1 (5.19), secondary rhizomes per plant-1 (18.03) and tertiary rhizomes per plant (7.69) were also highly accelerated by neem cake application. Similarly, the same treatment expressed the best in terms of size of mother rhizome (7.69 cm), primary rhizome (21.86 cm) and secondary rhizomes (7.05 cm).All these parameters in cumulative contributed to  produce the highest estimated fresh rhizomes yield & cured rhizomes yield (29.48 t ha-1, 5.59 t ha-1 respectively). The highest curing percentage (20.28) was observed in T3 treatment having mustard cake@ 2.0 t/ha. Thus, organic manure like neem cake was best fitted natural fertilizer for turmeric cultivation.DOI: http://dx.doi.org/10.3329/agric.v10i1.11060The Agriculturists 2012; 10(1): 16-22


2004 ◽  
Vol 55 (3) ◽  
pp. 253 ◽  
Author(s):  
John B. Gaughan ◽  
M. Shane Davis ◽  
Terry L. Mader

A controlled crossover experimental design was used to determine the effect of altered water sprinkling duration on heifers subjected to heat stress conditions. Heifers were subjected to 3 days of thermoneutral conditions followed by 3 days of hot conditions accompanied by water sprinkling between 1300 and 1500 h (HOT1–3). Then on the following 2 days (HOT4–5), environmental conditions remained similar, but 3 heifers were sprinkled between 1200 and 1600 h (WET) and 3 were not sprinkled (NONWET). This was followed by a 1-day period (HOT6) in which environmental conditions and sprinkling regimen were similar to HOT1–3. Rectal temperature (RT) was collected hourly, and respiration rate (RR) was monitored every 2 h on HOT Days 2, 4, 5, and 6. Dry matter intake and rate of eating were also determined. Sprinkling reduced RR and RT (P < 0.01) of all heifers during HOT1–3. During HOT4–5, WET heifers had lower (P < 0.05) RT than NONWET from 1300 to 700 h and lower RR from 1400 to 2000 h. Dry matter intake of NONWET heifers was reduced by 30.6% (P < 0.05) during HOT4–5 and by 51.2% on HOT6. On HOT4–5 the dry matter intakes of WET heifers were similar to intakes under thermoneutral conditions. During HOT6, RT was again reduced following sprinkling in all heifers. Comparison of RT and RR of NONWET and WET heifers on HOT1–3 v. HOT6 revealed that under similar environmental conditions, NONWET heifers had increased RT, partially due to carry-over from HOT4–5. However, NONWET heifers had 40% lower feed intake but tended to have lower RR on HOT6 v. HOT1–3. Only RR of WET heifers was greater on HOT6, possibly a result of switching from a 4-h back to a 2-h sprinkling period, while maintaining a 62% greater intake (5.80 v. 3.58 kg/day) than NONWET heifers during this time. Results suggest that inconsistent cooling regimens may increase the susceptibility of cattle to heat stress and elicit different physiological and metabolic responses.


1968 ◽  
Vol 48 (2) ◽  
pp. 129-137 ◽  
Author(s):  
A. R. Maurer ◽  
H. F. Fletcher ◽  
D. P. Ormrod

Pea plants growing in "weighing lysimeters" were subjected to five soil-water regimes to determine their response to varying conditions of soil water imposed at different stages of development. Plants subjected to a minimal water stress developed luxuriantly and continued to grow up to the harvest period. Pea yield and plant height were not reduced, but fresh weight and dry matter were less if irrigation was applied when soil water fell to 60% rather than 88% of that available. A severe water stress after blossom reduced pea yield, irrespective of soil-water conditions prior to blossom. Plants which had been given ample soil water before blossom wilted visibly when a severe stress was imposed in the post-blossom period, yet wilting did not occur in plants subjected to severe water stress both before and after blossom. Severe water stress prior to blossom did not cause a decrease in pea yield if ample soil moisture was made available after blossom.


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