The behavior of phosphorus (P) fertilizers in soil is governed not only by fertilizer solubility, but also by P mobility and vertical redistribution within the soil profile under contrasting water regime. This study aimed to investigate the combined effects of water regime, fertilizer type, and soil properties on the vertical redistribution of ammonium acetate–lactate extractable phosphorus (P-AL) in the surface soil layer under controlled pot conditions. Experiments were conducted using three soils with contrasting chemical properties: AC-LO (acidic loam, pH 5.9), NE-CL (neutral clay loam, pH 6.8), and AL-SL (alkaline sandy loam, pH 8.0). Four simulated rainfall regimes were applied at a constant rate of 25 mm day⁻¹, corresponding to cumulative water inputs of 0 mm (W0), 50 mm (W50), 100 mm (W100), and 150 mm (W150). Fertilizer treatments included an unfertilized control (NF), a liquid NP 4–18 fertilizer applied at a low dose (L1), a liquid NP 4–18 fertilizer applied at a high dose (L2), and a solid NPK 15–15–15 fertilizer (S). Water regime exerted the strongest control on P mobility, with P-AL increasing by approximately 40–60% from W0 to W150, depending on soil type. In AC-LO, strong P fixation under low moisture minimized differences among fertilizer treatments, whereas under higher moisture (W100–W150), liquid fertilizers—particularly L2—resulted in P-AL levels approximately 10–30% higher than those of the solid fertilizer. In NE-CL, P mobility was moderate and, under W100–W150, L2 produced P-AL values approximately 10–15% higher than the solid fertilizer, promoting a more uniform P redistribution within the 2–8 cm layer. In AL-SL, the response under wet conditions depended on the water regime: at W100, L2 generated P-AL values comparable to the solid fertilizer, whereas at W150, L2 increased P-AL by approximately 11% relative to the solid form. Overall, the results indicate that soil chemical properties primarily regulate the extent of phosphorus redistribution, while water regime controls its intensity and fertilizer form influences the initial spatial configuration of P within the surface soil layer. The findings provide mechanistic insight into short-range phosphorus transport in soil, without allowing direct inferences regarding agronomic efficiency or crop response.

Research Journal of Agricultural Science

In Romania’s wild flora, several Iris species exhibit important ornamental characteristics, such as early spring flowering and resilience to abiotic stress. This study assessed the behavior to new ecological conditions, the ornamental potential, and the antioxidant capacity of the wild species of Iris brandzae using morpho-anatomical, physiological, and biochemical biomarkers. The study of phenotypic characteristics (number and size of leaves on sterile and fertile shoots, size of flowering stems, bracts protecting the flowers, and perianth-segments) aimed to confirm and supplement existing information in the literature, as well as to evaluate the ornamental potential of this species. Morphological analyses revealed clear differences between fertile and sterile shoots, while photosynthetic activity across phenophases showed values within normal parameters, with the maximum recorded during flowering and with the chlorophyll a/chlorophyll b ratio maintained at values close to 3:1, indicating favorable cultivation conditions. Biochemical investigations (total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity) demonstrated that dried plant material, particularly roots, contained higher levels of phenolic and flavonoid compounds and exhibited stronger antioxidant activity compared to fresh material. By integrating morpho-anatomical, physiological, and biochemical data, this research provides the first comprehensive characterization of I. brandzae beyond taxonomic and ecological descriptions. Our findings emphasize the species behavior under cultivation conditions, its ornamental value, and its potential as a source of bioactive compounds relevant to pharmaceutical applications.

Raspberry (Rubus idaeus L.) fruits are highly appreciated by consumers due to the taste but also for the benefits it has on human health. In recent years, in Romania, the areas cultivated with raspberries have increased due to market demand but also due to the profitability of the crop. Raspberry fruit is rich in vitamins and fiber, which attracts consumers looking for healthy living [5]. In this study, were monitored the effects of the nitrogen fertilizers, in different doses, on the quality of the fruits. The results in correlation with the high temperatures of the harvest period. The mineral fertilizer, ammonium nitrate, was chosen according to the soil analysis and had been used in three doses: 30, 60 and 90 kg/ha N active substance. A number of 5 samples were extracted from the harvested fruits, Heritage and Meeker variety, and subjected to laboratory analysis to determine: soluble dry matter, titratable acidity, total dry matter, average fruit weight. The application of high doses of fertilizer led to an increase in raspberry production, bigger fruits, but lower dry matter 11.6%. The highest dry matter content was obtained in the case of the unfertilized variant 14.97%. Titratable acidity was not influenced by the application of fertilizers, but there was a decrease due to the high temperatures during the harvest period. The application of nitrogen fertilizers led to higher yields. The high temperatures during harvest period have substantially changed the fruit quality indices.

In alkaline soils rich in residual phosphorus, phosphorus availability to plants depends not only on the existing reserve, but also on the redistribution of the extractable fraction within the root-explored zone. This study evaluated the effects of water regime, fertilizer treatment, and wheat presence on the distribution of ammonium lactate-extractable phosphorus (P-AL) within the 2–8 cm layer of an alkaline calcareous Chernozem with high initial P availability (P-AL = 178.1 mg kg⁻¹). The pot experiment compared plant-free soil (S0) and wheat-planted soil (SP), four water regimes (H0–H150; 0–150 L m⁻²), and four fertilization treatments: an unfertilized control (F0), a solid NPK fertilizer (FS), and a liquid NP fertilizer applied at low and high rates (FL1 and FL2). These treatments represented practical fertilization options and were not equivalent in P input, supplying 51.8, 13.9, and 27.9 mg P pot⁻¹ for FS, FL1, and FL2, respectively. Soil and plant samples were collected at BBCH 21–22, 20 days after fertilization. Water regime was a major factor shaping P-AL redistribution, significantly affecting P-AL at all three analyzed soil depths (p < 0.001), with its effect depending on vegetation condition and fertilization treatment. Wheat presence reduced P-AL relative to S0, and apparent P-AL depletion (ΔP-AL = S0 − SP) was greatest under H0, ranging from 83 to 99 mg kg⁻¹. FL2 produced the largest S0–SP contrasts under H0–H100, whereas under H150 the largest difference was associated with FS. Under high water input, the higher-input solid NPK treatment (FS), which supplied the largest P input and was the only treatment supplying K, was associated with the highest shoot biomass (16.7 g), root biomass (6.92 g), and root P accumulation (25.2 mg pot⁻¹). The results indicate that P fertilization in high-P alkaline soils should be adapted to water regime, fertilizer input and application method, without allowing for direct conclusions regarding phosphorus use efficiency, total plant P uptake, or leaching losses.