Altura da lâmina, tempo e volume de enchimento de um equipamento de irrigação por pavio e determinação da uniformidade de distribuição de água em substratos

Abstract

ResumoOs objetivos deste experimento foram realizar a avaliação da altura da lâmina de água, do tempo e volume de enchimento de um equipamento de irrigação por pavio usando calhas autocompensadoras e determinar a uniformidade de distribuição de água (UDA) nesse equipamento utilizando substratos orgânicos comerciais (casca de pinus/CP e fibra de coco/FC). Dois módulos experimentais foram montados em delineamento experimental inteiramente casualizado com cinco repetições. Verificou-se grande variação das medidas de altura da lâmina de água (1,6 a 4,0 cm), mesmo com o equipamento nivelado. O tempo médio de enchimento foi de 6h22min para o Módulo 1 com CP e de 3h45min para o Módulo 2 com FC. O volume de enchimento foi variável, observando-se que as calhas das extremidades (n.° 1 e 5) apresentaram os menores volumes no Módulo 1, e as calhas do início (n.° 1 e 2) no Módulo 2. No Módulo 1, a umidade volumétrica (Ɵ) variou de 42% a 94%, e no Módulo 2, de 24% a 72%, com pontos isolados de secamento e/ou encharcamento. A altura da lâmina de água, o tempo e o volume de enchimento das calhas foram desuniformes nos dois módulos experimentais e nas cinco calhas autocompensadoras, indicando imperfeições no equipamento. A distribuição de água foi variável nos substratos em razão de suas características físico-hídricas e também da altura da lâmina de água nas calhas, apresentando maior umidade e uniformidade de distribuição de água na casca de pinus do que na fibra de coco.Palavras-chave: capilaridade, casca de pinus, fibra de coco, subirrigação. Water depth, filling time and volume of wick irrigation equipment and determination of water distribution uniformity in substrates AbstractThe aims of this study were to evaluate the water depth, filling time and volume in a wick irrigation equipment using auto compensating gutters and to determine the water distribution uniformity (WDU) in these equipments filled with organic commercial substrates (pine bark/PB and coconut coir/CC). We assembled two experimental modules in a completely randomized design with five replications. There was variation in water depth measurements (1.6 to 4.0 cm), even with the equipment leveled. Average filling time was 6h22min for Module 1 with PB and 3h45min for Module 2 with CC. The filling volume was variable, showing that gutters in the extremities (No. 1 and 5) had lower volumes in Module 1 and in the beginning (No. 1 and 2) in Module 2. Volumetric soil moisture (Ɵ) ranged from 42 to 94% in Module 1 and from 24 to 72% in Module 2, with isolated points of desiccation and/or flooding. Water depth, filling time and volume were disuniform in all experimental modules and auto compensating gutters, indicating equipment imperfections. Water distribution was variable in both substrates due to their hydro-physical characteristics and also water depth in the gutters, with higher humidity and water distribution uniformity in pine bark than in coconut coir.

Subirrigation equipment for the production of citrus rootstocks: Design and hydraulic assessment

“…These systems apply excessive amounts of water and, combined with the leaf interception as the plant grows (umbrella effect), leads to the irregular distribution of water, thus reducing irrigation efficiency. This method also increases the risk of environmental pollution due to the disposal of residual solution from fertigation (SCHMAL et al, 2011;FERRAREZI et al, 2012). It is estimated that between 49% and 83% of water applied through canopy irrigation is lost in the process and fails to reach the inside of the containers (DUMROESE; DAVIS; JACOBS, 2011).…”

“…The subirrigation method, by which water moves vertically by capillary rise in the substrate until it reaches the root system of plants, and can operate in an open or closed system, can potentially be used in crop production in protected environments, enabling a reduction of environmental and financial costs through resource conservation (SCHMAL et al, 2011 VAN IERSEL, 2011;MELLANO, 2011;FERRAREZI et al, 2013;MELO JUNIOR;GERVÁSIO;ARMINDO, 2013) have shown that subirrigation systems provide a more uniform and efficient application of solution, eliminating water and nutrient loss. These systems are made possible by automation and recirculation of the nutrient solution, and lead to increased production with better uniformity across the unit area, as well as reduced growth time.…”