Enhanced nutrient uptake in salt-stressed Mentha piperita using magnetically treated water.

The improvement of the growth and quality of medicinal plants under stress is of significance, worldwide. The hypothesis was to alleviate salinity stress in Mentha piperita by enhancing nutrient uptake using magnetically treated water, which to our knowledge has not been previously investigated. The objective was to test the effects of magnetized water (using alternating magnetic fields) (main plots, M1-M4 representing control, 100, 200, and 300 mT, respectively), salinity (subplots, S1-S4 representing control, 40, 80, and 120 mM NaCl, respectively), and growth medium (sub-subplots, X1-X4 representing coco peat, palm, coco peat + perlite, and palm + perlite, respectively) on M. piperita nutrient uptake in the greenhouse. The M treatments, especially the 100 and 200 mT levels, significantly increased plant N (1.08%, S3M4X1), P (0.89%, S3M3X1), K (3.23%, S3M3X1), Ca (53.6 mg/kg, S4M4X4), and Mg (39.63 mg/kg, S3M3X2) concentrations (compared with control at 0.71, 0.49, 2.4, 26.63, 1.63) even at the highest level of salinity. Magnetically treated water also significantly enhanced plant Fe and Zn concentration to a maximum of 750 µg/kg (M4S3X1) and 94.67 µg/kg (S4M4X3), under salinity stress, respectively. The single and the combined use of organic and mineral media significantly affected plant nutrient uptake, especially when used with the proper rate of M treatment. If combined with the proper growth medium, the magnetized water may be more effective on the alleviation of salt stress in Mentha piperita by enhancing nutrient uptake.

Pepermint (Mentha piperita L.) growth and biochemical properties affected by magnetized saline water.

Due to the limitation of suitable water for crop production in the world, recycling water is among the most proper methods enhancing water efficiency and availability. One modern method, which is of economic, health, and environmental significance, and may improve water properties for plant use is water magnetization. Medicinal plants are of nutritional, economic and medical values and their growth decreases under salinity stresses. This research was hypothesized and conducted because there is not any data, to our knowledge, on the use of magnetized salty water affecting the growth and biochemical properties of peppermint (Mentha piperita L.). The experiment was a split plot design with three replicates. The main plots consisted of magnetic fields at control (M1), 100 mT (M2), 200 mT (M3), and 300 mT (M4), the sub-plots consisted of salinity treatments (NaCl) at control (S1), 4 dS/m (S2), 8 dS/m (S3), and 12 dS/m (S4), and the growth media including cocopeat (X1), palm (X2), cocopeat + perlite (V/V = 50, X3) and palm + perlite (V/V = 50, X4) were located in the sub-sub-plots. Different plant growth and biochemical properties including plant fresh and dry weight, plant menthol, menthone, chlorophyll and proline contents were determined. Analysis of variance indicated the significant effects of experimental treatments and their interactions on the growth and biochemistry of peppermint. Different magnetic fields significantly increased plant growth, and interestingly with increasing the salinity level the alleviating effects of magnetic field on salinity stress became more clear (significant interaction between salinity and magnetic field treatments). Cocopeat was the most efficient growth medium. At the third level of salinity (8 dS/m) just the two levels of 100 and 200 mT increased plant menthol concentration. Treatments M3S2X4 and M1S1X1 resulted in the highest (38%) and the least menthol percentage (13%), respectively. Treatments S2 and M2 and M3 significantly increased plant menthone concentration, especially in the growth media of X1 and X3. However, at the third level of salinity, M3 and M4 were the most effective treatments. The highest (25.8%) and the least (1.2%) concentrations of menthone were related to treatments M3S2X4 and M2S4X1, respectively. The results indicated that it is possible to alleviate the stress of salinity on peppermint growth and improve its biochemical (medicinal) properties using magnetized salty water, although proline concentration was not much affected by the magnetic field.

The quantity/intensity relation is affected by chemical and organic P fertilization in calcareous soils.

The use of organic fertilization increases the availability of phosphorus (P) in calcareous soils by affecting the colloidal properties of soils. Accordingly, it was hypothesized that chemical and organic fertilizers affect P availability in calcareous soils by influencing P sorption and buffering capacity. The objective was to investigate the quantity/intensity (Q/I) relation in calcareous soils as affected by chemical and organic P fertilization. Three different soil types with different Olsen-P values including Qazvin1 (very low P, VLP), Qazvin2 (low P, LP) and Dizan (medium P, MP) were fertilized with 50 mg P kg-1 soil using triple superphosphate (TSP), sheep manure (SM), and municipal solid waste compost (MSWC). The treated experimental soils were incubated for 90 days, and P sorption and buffering capacity indexes were determined using calcium chloride solutions in a range of 0-100 mg P L-1. A greenhouse experiment was conducted to determine wheat (Triticum aestivum L.) response to the experimental treatments. Wheat P content at tillering (60 days after planting) was determined. The SM and TSP treatments were the most efficient sources of P for plant use in the greenhouse, as they resulted in the highest wheat growth and P content. The incubation data were fitted to Langmuir, Freundlich, Temkin and surface sorption isotherm models. Langmuir model, as the best fitted one, indicated the highest P sorption (A) was resulted by the SM treatment for VLP and LP soils, compared to the other treatments. According to the model, the SM and MSWC treatments resulted in the least (0.04) and the highest (1.11) sorption energy (K) by the VLP soil, respectively. In the VLP soil the SM and MSWC treatments, and in the LP soil the MSWC treatment decreased P sorption, at the final concentration of P (100 mg L-1), compared to the control treatment. Organic fertilizers decreased buffering index, phosphorous buffering capacity, and K1 indexes in the VLP soil, compared to the control treatment. The corresponding reductions for SM were equal to 35.99, 2.7, 1.19 mL P g-1 and for MSWC were equal to 12.33, 36.2 and 1.19 mL P g-1. In the VLP and MP soils, (compared with control), the SM treatment decreased the rates of maximum buffering capacity at 0.38 and 0.52 mL P g-1, respectively. There were high and significant correlations among the soil P buffering indexes with soil and wheat P content. Fertilization affected soil P availability by affecting the Q/I relation and the buffering capacity indexes. It is possible to predict plant response to available P using the tested fitting models.