Productive and morphogenetic characteristics of sunflower irrigated with domestic treated wastewater on northeast semiarid area

Abstract

The present study aimed to evaluate the agronomic performance of the sunflower crop irrigated with treated domestic wastewater and normal water (well-water) in a inceptisol of Apodi, State of Rio Grande do Norte, Brazil. The experiment was conducted in a randomized block experimental design, consisting of five treatments and five replications, using the H-251 sunflower cultivar from Embrapa. The treatments consisted of the application of five proportions of wastewater/well-water (T1-100% wastewater; T2-75% wastewater and 25% well water, T3-50% wastewater and 50% well-water, T4-25% wastewater and 75% well-water and T5-100% well-water plus chemical fertilizer, control). The variables such as plant height, leaf number, diameter of stem and the head, yield, oil production, thousand-grain weight and head weight were evaluated. The combined use of wastewater and well-water is an alternative for the substitution of mineral fertilization with minimal damage to the productive potential and development of the sunflower crop. In general, the T4 treatment was the most adequate to improve agronomic performance of the sunflower.

Metal contents in soils irrigated with diluted treated produced water from oil

“…The highest Ni contents were found for T5 (only TOPW) in both soil layers, and the lowest was found for T1 (only underground water) in the soil surface layer ( Figure 2B). Costa (2018) found different results, with higher Ni contents in the soil surface layer when irrigated only with underground water (control). The mean Ni contents in both layers were below the limit of 30 mg dm -3 , which was established by the CONAMA (Resolution no.…”

“…The treatments followed the recommendations for wastewater dilution in underground water proposed by Costa et al (2018) to minimize risks of soil salinization and sodification.…”

Chemical characteristics of soil irrigated with produced water treatment and underground water

“…Treatments followed recommendations by [12] for wastewater dilution in underground water to minimize salinization and sodification risks in the soil. The following treatments were assessed: a) T1 -100% of underground water (UW), control; b) T2 -75% UW and % of produced water treatment (PW); c) T3 -50% UW and 50% PW; d) T4 -25% UW and 75% PW; e) T5 -100% PW.…”

“…Tested contrasts were a) treatment T5 vs other treatments (T1, T2, T3 and T4); b) treatment T4 vs treatments T1, T2 and T3; c) treatment T3 vs treatments T1 and T2; d) treatment T2 vs treatment T1. The combination of contrasts with treatment averages was expressed as follows, according to [12]. C1 = 12 m1 + 12 m2 + 8 m3 +10 m4 -42 m5 C2 = 30 m1 + 30 m2 + 20 m3 -80 m4 C3 = 6 m1 + 6 m2 -12 m3 C4 = 6 m1 -6 m2…”