The introduction of nanofertilizers (Nfs) in agriculture has allowed the development of new technologies that enhance the productivity of crops. Within the most studied Nfs we find metal oxides, especially ZnO; however, the results of various experiments provide contradictory data on the growth variables. Therefore, this study intended to evaluate the efficiency associated with the use of nanoparticles, sulfates, and zinc-chelates in Phaseolus vulgaris L. cv. Strike grown in acid soil, as well as to evaluate its production, total biomass, and nitrogen assimilation. Phaseolus vulgaris L. cv. Strike plants were sprouted and grown in polyethylene bags containing 3 kg of acid soil (pH 6.8) in an experimental greenhouse and were watered with a nutritious solution. A completely randomized design including ten treatments and five repetitions was used. Treatments consisted of applying different zinc sources (sulfate, DTPA chelate, and zinc oxide nanoparticles) to four different doses (0, 25, 50, and 100 ppm of zinc). Results obtained indicated that the doses best favoring an increase in biomass, production, and nitrogen assimilation were 50 ppm of ZnSO4, 100 ppm of DTPA-Zn, and 25 ppm of zinc oxide nanofertilizers (NfsOZn). Hence, the dose containing 25 ppm of NfsOZn was the most efficient dose, since at a lower dose it was able to equalize biomass accumulation, production, and nitrogen assimilation as compared to ZnSO4 and DTPA-Zn sources. However, further research is required, given that high-concentration doses were toxic for beans. Finally, it is worth highlighting that zinc oxide nanoparticles have a huge potential to be used as nanofertilizers if applied in optimal concentrations.

Objective: To evaluate if the application of calcium carbonate on the soil and to the leaf influences the weight and number of fruits in rocoto pepper grown under greenhouse conditions. Design/Methodology/Approach: The study was carried out in the greenhouse of the Facultad de Ciencias Agrotecnológicas, of the Universidad Autónoma de Chihuahua. The Taguchi method was used to develop the 13 treatments, with two factors, five levels per factor, and five repetitions per treatment, using 65 plants under study. Data was analyzed using the quadratic response surface technique, fitting the surface to determine factor levels for optimal response. Results: Reducing soil CaCO3 by 9% and increasing leaf CaCO3 by 100% was necessary to obtain the highest weight in the three harvests (234.8 g). Findings/Conclusions: A rise in the number of rocoto peppers (from 59 to 70, in the three harvest periods) required an increase in the soil and foliar CaCO3 by 8.5% and 100%, respectively.

Groundwater and domestic wastewater are often used in conjunction with surface water to irrigate crops in semiarid areas. A concern associated with this practice is the potential accumulation of arsenic (As) and heavy metals in soil and plants, especially in places where irrigation water contains geogenic As. Studies on arsenic uptake in cereal crops growing under dry and oxidizing conditions are scarce. A one-year field experiment was conducted to evaluate the uptake and translocation of As in barley and oats irrigated with either groundwater (GW) or treated domestic wastewater (TWW) in northern Mexico. The content of As, as well as toxic metals Cd and Pb, were determined in soil and 24 sets each of barley and oat plants. Metal(loid)s accumulated more in the roots and leaves, and less in the stems and grains. Barley grains contained 0.2 mg/kg of As under GW or TWW, whereas oat grains contained twice this amount. Bioconcentration (BCF) and translocation (TF) factors were < 1 for As and Cd in plants irrigated with both GW and TWW indicating that neither barley nor oats are As-accumulators, and their grain and leaves can be safely used for fodder. However, oats irrigated with TWW bioaccumulated Pb in leaves. Conscientious monitoring of As and associated metals in soil and crops irrigated with TWW and GW is recommended.

The use of treated wastewater (TWW) for irrigation has gained global attention since it reduces pressure on groundwater (GW) and surface water. This study aimed to evaluate the effect of TWW on agronomic, photosynthetic, stomatal, and nutritional characteristics of barley plants. The experiment with barley was established on two bands: one band was irrigated with GW and the other with TWW. The evaluation was performed 25, 40, 60, 90, and 115 days after sowing (DAS). Results showed that irrigation with TWW increased (p < 0.01) grain yield by 54.3% and forage yield by 39.4% compared to GW irrigation. In addition, it increased plant height (PH) (p = 0.013), chlorophyll concentration index (CCI) (p = 0.006), and leaf area index (LAI) (p = 0.002). TWW also produced a positive effect (p < 0.05) in all the photosynthetic efficiency parameters evaluated. Barley plants irrigated with TWW had lower stomatal density (SD) and area (SA) (p < 0.001) than plants irrigated with GW. Plants irrigated with TWW had a higher P concentration (p < 0.05) in stems and roots and K concentration in leaves than plants irrigated with GW. We concluded that the use of TWW induced important biochemical, physiological, and agronomic changes in barley plants. Hence, the use of TWW may be a sustainable alternative for barley production in arid and semi-arid regions. This study was part of a government project, which aimed to develop a new metropolitan irrigation district with TWW. This study may contribute to the sustainability of water resources and agricultural practices in northern Mexico.

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