Gas exchange in yellow passion fruit under irrigation water salinity and nitrogen fertilization

ABSTRACT The objective of this study was to evaluate the gas exchange of ‘Redondo Amarelo’ passion fruit seedlings under the mitigating action of nitrogen fertilization on the salinity of irrigation water. The experiment was carried out in a greenhouse of the Universidade Federal de Campina Grande (CCTA-UFCG), Campus of Pombal, PB, Brazil, The experimental design was in randomized blocks, split plots, comprising five irrigation water electrical conductivities (plot) (ECw) (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of nitrogen (subplot) (60; 80; 100; 120 and 140% of 300 mg of N dm-3), in five blocks. Plants were grown in pots (Citropote JKS®) with volume of 3.780 mL, filled with soil, bovine manure, wood shavings in a proportion of 2:1:0.5 (mass basis), respectively. Water with salinity levels was applied in the period from 40 to 85 days after sowing. The internal CO2 concentration, transpiration, stomatal conductance and photosynthesis were measured at 55 and 70 days after sowing. There was an attenuating effect of nitrogen doses at irrigation water electrical conductivities of 1.7 and 2.4 dS m-1 on photosynthesis at 55 DAS. Irrigation water salinity reduces most of the variables evaluated, especially at the highest level studied (3.1 dS m-1).

How Does Quinoa (Chenopodium quinoa Willd.) Respond to Phosphorus Fertilization and Irrigation Water Salinity?

Soil salinity is a major problem in arid and semi-arid regions, causing land degradation, desertification, and subsequently, food insecurity. Salt-affected soils and phosphorus (P) deficiency are the common problems in the sub-Sahara, including the Southern region of Morocco. Soil salinity limits plant growth by limiting water availability, causing a nutritional imbalance, and imparting osmotic stress in the plants. The objective of this study was to determine the positive effects of P on growth and productivity and understand the major leaf mineral nutrient content of quinoa (Chenopodium quinoa Willd.) cv. “ICBA Q5” irrigated with saline water. A field experiment applying three salinity (Electrical Conductivity, EC) levels of irrigation water (ECw = 5, 12, and 17 dS·m−1) and three P fertilizer rates (0, 60, and 70 kg of P2O5 ha−1) were evaluated in a split-plot design with three replications. The experiment was conducted in Foum El Oued, South of Morocco on sandy loam soil during the period of March–July 2020. The results showed that irrigation with saline water significantly reduced the final dry biomass, seed yield, harvest index, and crop water productivity of quinoa; however, P application under saline conditions minimized the effect of salinity and improved the yield. The application of 60 and 70 kg of P2O5 ha−1 increased (p < 0.05) the seed yield by 29 and 51% at low salinity (5 dS·m−1), by 16 and 2% at medium salinity (12 dS·m−1), and by 13 and 8% at high salinity (17 dS·m−1), respectively. The leaf Na+ and K+ content and Na+/K+ ratio increased with irrigation water salinity. However, the leaf content of Mg, Ca, Zn, and Fe decreased under high salinity. It was also found that increasing P fertilization improved the essential nutrient content and nutrient uptake. Our finding suggests that P application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy under saline conditions.

Surfactant and Friction Reducer Interaction in High Salinity Slickwater Fracturing

Slickwater fracturing has been phenomenally successful in unconventional shale formations due to their unique geomechanical properties. Nevertheless, these treatments consume large volumes of water. On average, hydraulic fracturing treatments use up to 13,000,000 gallons of water in unconventional wells. In an effort to reduce the use of freshwater, research has focused on developing friction reducers (FR) that can be used in high salinity brines such as seawater and produced water. However, commonly used friction reducers precipitate in high salinity brine, lose their friction reduction properties, and cause severe formation damage to the proppant pack. Consequently, this work proposes the use of common surfactants to aid the FR system and achieve salt tolerance at water salinity up to 230,000 ppm. This paper will (a) evaluate five surfactants for use in high salinity FR systems, (b) evaluate the rheological properties of these systems, and (c) evaluate the damage generated from using these systems. Four types of tests were conducted to analyze the performance of the new FR at high salinity brine. These are (a) rheology, (b) static proppant settling, (c) breakability, and (d) coreflood tests. Surfactants with ethylene oxide chain lengths ranging from 6 to 12 were incorporated in the tests. Rheology tests were done at temperatures up to 150°F to evaluate the FR at shear rates between 40-1000 s-1. Proppant settling tests were performed to investigate the proppant carrying capacity of the new FR system. Breakability and coreflood tests were conducted to study the potential damage caused by the proposed systems. Rheology tests showed that using surfactants with high ethylene oxide chain length (&gt;8) improved the performance of the FR at water salinity up to 230,000 ppm. Anionic surfactants performed better than cationic surfactants in improving FR performance. The ammonium persulfate was used as a breaker and showed effectiveness with the proposed formula. Finally, the retained permeability after 12 hours of injecting the FR was over 95%. This shows that after using this system, the productivity of the formation is minimally affected by the new FR system. This research provides the first guide on studying the impact of using different ethylene oxide chain lengths of surfactants in developing new FR systems that can perform well in a high salinity environment. Given the economic and environmental benefits of reusing produced water, this new system can save costs that were previously spent on water treatments.

Quick-Look Water Saturation Estimate with Density-Neutron Logs in Unknown or Mixed Salinity Environments: Case Studies in Middle East Oil-Bearing Carbonate Reservoirs

We have shown previously that while total porosity is the weighted sum of density and neutron porosities, hydrocarbon volume is the weighted difference of the two. Thus, their ratio yields hydrocarbon, or equivalently, water saturation (Sw). In LWD environments where negligible invasion takes place while drilling, we investigate whether Sw derived from LWD density-neutron logs could approach true Sw in unknown or mixed water salinity environments. In such environments, it is well known that Sw determined from standalone resistivity or capture sigma logs is uncertain due to large water resistivity (Rw) or capture sigma (Σw) changes with salinity. On the other hand, the water density (ρw) and hydrogen index (HIw) variations with salinity are much less (Table 1). Hence, the water point on the density neutron crossplot does not move with salinity as much as the water point on a sigma-porosity crossplot does. Similarly, the water point on a resistivity-porosity Pickett plot would move drastically with changes in Rw. Also, because the hydrocarbon effect on density-neutron logs is much less in oil than in gas, the weights in the density-neutron porosities can be conveniently set at midpoint in light oil-bearing reservoirs without compromising porosity and saturation results. Thus, a quicklook estimate of Sw from density-neutron logs is the normalized ratio of the difference over the sum of density and neutron porosities. The normalization factor is a function of the hydrocarbon density. We also build a graphical Sw overlay for petrophysical insights. We tested the LWD density-neutron derived Sw in two Middle East carbonate oil wells that have mixed salinity. The two wells were extensively studied in the past. In the first well, the reference Sw is given by the joint-inversion of resistivity-sigma logs, corroborated with Sw estimated from multi-measurements time-lapsed analysis, and validated with water analysis on water samples taken by formation testers. In the second well, comprehensive wireline measurements targeting mixed salinity such as dielectric and 3D NMR were acquired to derive Sw, and complemented by formation tester sampling, core measurements, and LWD resistivity-sigma Sw. In both wells, density-neutron quicklook Sw agrees surprisingly well with Sw from other techniques. It may lack the accuracy and precision and the continuous salinity output but is sufficient to pinpoint both flooded zones and bypassed oil zones. Since density-neutron is part of triple-combo data that are first available in well data acquisition, it is recommended to go beyond porosity application and compute water saturation (Sw) in unknown or mixed salinity environments. The computation is straightforward and can be useful to complement other established techniques for quick evaluation in unknown or mixed water salinity environments.

Assessing the impact of shallow subsurface pipe drainage on soil salinity and crop yield in arid zone

Purpose Soil salinization is one of the key problems of sustainable development of arid agricultural land. Exploring the use of shallow subsurface pipe drainage to improve soil salinization. Methods This study investigates the desalinization effect of shallow subsurface pipe drainage, in combination with drip irrigation under plastic mulch, in an arid region in China. Field data collection was conducted in 2010. Soil salinity at a range of soil depths, water EC and pH of subsurface pipe drainage and crop yield during crop growth stages in salinized farmlands were measured. Results and Conclusion The results show that soil salinity was reduced significantly on mildly (1–3 dS m−1) and moderately (3–6 dS m−1) salinized farmlands. The highest desalinization rate of mildly and moderately salinized soils was 51% and 91% respectively. The desalinization in upper soil layers, to a depth of 60 cm, was more significant than that in lower soil layers. Drainage water salinity was much higher than irrigation water salinity. Crop yield on mildly and moderately salinized land increased about 25% and 50%, respectively. This indicates that the combination of drip irrigation and shallow subsurface pipe drainage on farmlands is potential feasible to desalt farmlands and to improve crop yield. The study has led to a desalinization of 330 ha year−1 in Xinjiang.