Soil water energetic status and cowpea beans irrigated with saline water

Abstract

using the cultivar IPA 206 in Fluvisol collected in the municipality of Pesqueira, PE, Brazil. Waters with six levels of electrical conductivity (0; 2.5; 5; 7.5; 10; 12.5 dS m -1 ) formulated with NaCl and a salt mixture were used. The experiment was conducted in randomized blocks in a 6 x 2 factorial arrangement with four replicates, forming 48 experimental plots. The matric, osmotic and total potential of water in the soil, the osmotic, and water potential in the plant and atmospheric potential were determined. Plant and soil osmotic potentials decreased with the increase in irrigation water electrical conductivity, which contributed to the decrease in plant water potential. There was no significant difference between the salts used in the composition of the irrigation water for the potentials evaluated in the soil and in the plant; there was no equilibrium between soil and plant water potentials at predawn.Estado energético da água do solo e feijão-caupi irrigado com água salina R E S U M O O estudo do estado energético da água sob condição de salinidade e seu impacto sobre o desenvolvimento do feijão-caupi são de extrema importância visto que esta cultura é, em grande parte do mundo, a base alimentar. Experimento em casa de vegetação foi desenvolvido de março a maio de 2014 utilizando-se a cultivar de feijão-caupi IPA 206 em Neossolo Flúvico coletado no município de Pesqueira, PE. Foram utilizadas águas com seis níveis de condutividade elétrica (0; 2,5; 5; 7,5; 10; 12,5 dS m -1 ) formuladas a partir de NaCl e de uma mistura de sais, semelhante à água de um poço do local de coleta do solo. O experimento foi conduzido em blocos ao acaso em arranjo fatorial 6 x 2 com 4 repetições totalizando 48 unidades experimentais. Determinaram-se os potenciais matricial, osmótico e total do solo; osmótico e hídrico da planta e o potencial da atmosfera. Os potenciais osmóticos na planta e no solo diminuíram com o aumento da condutividade elétrica da água o que contribuiu também para a redução do potencial total na planta. Não houve diferença significativa entre as fontes de água na composição da água de irrigação para os potenciais avaliados no solo e na planta; não ocorreu equilíbrio entre os potencias hídricos do solo nem da planta antes do amanhecer.

Comparison of water and osmotic potentials on Vigna unguiculata stress response

“…The plants treated with the highest tension had a decrease of 130 % compared to the control. Oliveira et al (2016) found a similar decrease (116 %) in plants of the same cultivar subjected to tension of 1.0 MPa when compared to the control. Comparing the evaluated tensions sources, all tensions higher than 0.265 MPa presented differences (Figure 1a).…”

“…This result denotes the importance of the turgor pressure for the plant water status. Oliveira et al (2016) evaluated this same cultivar under irrigation with salt waters (Ѱ w ≅ -1.0 MPa) throughout the growing cycle and found that the turgor pressure potential contributed with approximately 0.60 MPa.…”

“…Ten-liter pots were filled with 8 kg of soil to ensure sufficient soil for the whole crop cycle (Rivas et al, 2013;Oliveira et al, 2016). These pots were moistened until saturation and subjected to daily weighing to monitor the soil gravimetric moisture until it reaches the moisture of the control treatment (86 % of the field capacity) to uniform water distribution throughout the soil before sowing.…”

“…Leaf water potential is a measure of water energy inside the plant (Negrão et al, 2017). It can be used to evaluate the water status of plants (Oliveira et al, 2016), as a parameter for selection of cultivars (Nichols et al, 2015;Zegaoui et al, 2017), and as a tool to monitor plants under abiotic stresses (water and salt) in areas with a potentially stressful environment for plants (Medrano et al, 2015).…”