Among the essential micronutrients, zinc (Zn) affects vital functions in crop plants. The influences of foliar nourishing with certain Zn-containing forms on the growth, productivity, and physiology of carrot plants (cv. Fire wedge F1) and their nutritional contents when grown in Zn-deficient soil were examined in both 2019/2020 and 2020/2021 field trials. Two doses of zinc oxide nanoparticles (ZnO-NPs(1) = 20 and ZnO-NPs(2) = 40 mg L⁻¹), zinc–EDTA (Zn–EDTA(1) = 1 and Zn–EDTA(2) = 2 g L⁻¹), or bulk zinc oxide (ZnO-B(1) = 200 and ZnO-B(2) = 400 mg L⁻¹) were applied three times. The data outputted indicated, in general, that ZnO-NPs(2) were the best treatment that conferred more acceptable plant growth (measured as shoot length and fresh and dry weights), physiology (measured as cell membrane stability index, SPAD readings, and nutrient uptake), and nutritional homeostasis (e.g., P, Ca, Fe, Mn, Zn, and Cu contents). All these positive attributes were reflected in the highest yield, which was measured as fresh weight, dry matter, length, diameter, volume, and total yield of carrot roots. However, there were some exceptions, including the highest membrane stability index in both seasons, the highest Cu uptake and Mn content in the first season, and root fresh weight in both seasons obtained with ZnO-NPs(1). Moreover, the maximum P uptake and root dry matter were obtained with ZnO-B(1) and the highest content of root P was obtained by ZnO-B(2). Based on the above data, foliar nourishing with ZnO-NPs(2) can be recommended for the sustainability of carrot cultivation in Zn-deficient soils.

The present work aims to modify Fredlund and Xeng (FX) model to simulate soil water characteristic curve (SWCC) in order to be applicable in the field of soil physics and agriculture. Laboratory measurements of the SWCC of clay soil, representing the soil type close to river Nile in Egypt, were carried out using a pressure plate extractor. The measured points of the curve include saturation, field capacity (FC), and permanent wilting point (PWP). The estimation of the regression equations and unknown parameter were performed using non-linear estimation in the STATISTICA program through user-specified regression. The flexibility and capability of the proposed equation (PE) for a wide range of soil suction (ψ) values and soil types were also determined. The SWCC of the experimental soil and statistical tools indicated that PE showed a very good fit to the measured data. The three compared models accurately simulated the entire range of SWCCs for different soil textures. The statistical analysis and fitting curves revealed that the PE precisely simulated the SWCCs for the entire range of ψ values for different soil types and performed better than MVG and FX. Furthermore, only PE was able to simulate SWCCs using different forms of soil moisture, distinct from MVG and FX. The study hence recommends the use of the PE in simulating SWCCs.