Evaluation of drip and microasperation irrigation methods in spinach (Spinaca oleracea) and Swiss lettuce (Valerianella locusta) in walipinis
This study occurred at the Ventilla Ecologic farm, situated in the central Altiplano of the Murillo province, 26 km from La Paz. Its objectives were to evaluate two types of irrigation, by drip and by microasperation, in spinach and Swiss lettuce in Walipinis, and to conduct an economic analysis. Th...
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| Format: | Others |
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BYU ScholarsArchive
2004
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| Online Access: | https://scholarsarchive.byu.edu/etd/5389 https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=6388&context=etd |
| Summary: | This study occurred at the Ventilla Ecologic farm, situated in the central Altiplano of the Murillo province, 26 km from La Paz. Its objectives were to evaluate two types of irrigation, by drip and by microasperation, in spinach and Swiss lettuce in Walipinis, and to conduct an economic analysis. The genetic material used was spinach (viroflay variety) and Swiss lettuce (large-leaved variety). Chapin irrigation belts and nebulizers were used, and two tensiometers were used to determine the soil moisture. Manual planting occurred on September 1, 2002, in all experimental areas. Seeds were dispersed in a continual flow with Swiss lettuce at a density of 3.5g/m2 and three bobbins, and in spinach the density was 0.26 g/m2 in parallel, 20 cm rows with the irrigation belts on either side. The spinach harvest was spread out, while the Swiss lettuce harvest occurred all at once. A factorial arrangement was used in this study, with two factors: two levels of irrigation (drip and microasperation) and different crops (spinach and Swiss lettuce). The response variables regarding drip irrigation efficiency had a uniformity coefficient of 97%, and microasperation had 85%. The depth reached by the watered bulb after two hours of control was more than 20 cm, while the microasperation only reached 15 cm after two hours. Irrigation occurred at midday but in accordance with the readings that the tensiometers gave. The response variables studied in the crop were: percentage germination, number of leaves, plant size, leaf size, and yield. Yield showed significant differences between types of irrigation of crops. Drip irrigation was better than microasperation. The response variables that had the greatest effect on yield were number of leaves, plant size, and leaf size. The economic production analysis found negative net benefits for the first trial. In the second trial, drip irrigation netted Bs.3.54/m2 for spinach and Bs. 3.68/m2 for Swiss lettuce, recovering the investment from the first trial. In contrast, the yield from microasperation irrigation, even though the second trial had positive net results, did not recover the investment from the first trial. Finally, based on these data, drip irrigation is recommended because of its better yields and a lower installation cost. |
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