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Water and nutrient deficiencies in soil are becoming a serious threat to crop production. Therefore, usable water and nutrient recovery from wastewater, such as urine and grey water, should be considered. In this work, we showed the possibility of using grey water and urine after processing in an aerobic reactor with activated sludge in which the nitrification process takes place. The resulting liquid (nitrified urine and grey water, NUG) contains three potential factors that can adversely affect plant growth in a hydroponic system: anionic surfactants, nutrient deficits, and salinity. After dilution and supplementation with small amounts of macro- and micro-elements, NUG was suitable for cucumber cultivation. Plant growth on this modified medium (enriched nitrified urine and grey water, NUGE) was similar to that of plants cultivated on Hoagland solution (HS) and reference commercial fertilizer (RCF). The modified medium (NUGE) contained a significant amount of sodium (Na) ions. Therefore, typical effects of salt stress were observed in cucumber plants, including reduced chlorophyll levels, slightly weaker photosynthesis parameters, increased H2O2 levels, lipid peroxidation, ascorbate peroxidase (APX) activity, and proline content in the leaves. In addition, reduced protein levels were observed in plants treated with recycled medium. At the same time, lower nitrate content in tissues was found, which may have resulted from their intensive use by nitrate reductase (NR), the activity of which significantly increased. Although cucumber is a glycophyte, it grew very well in this recycled medium. Interestingly, salt stress and possibly anionic surfactants promoted flower formation, which in turn could positively affect plant yield.

In the experiment, the impact of magnetisation on cucumber seeds is examined with the use of Bitter magnets with a constant magnetic field. The magnetisation process is performed in three magnetic fields: low—200 mT, medium—1 T, and high—9 T for 15 and 60 min. After germination, the biometric parameters are determined. The results of this research show that cucumber after pre-treatment in a magnetic field of 1 T for 60 min has a similar germination capacity and root length as the control sample. However, cucumber seeds magnetised in a 1 T field for 60 min have a significantly higher dry weight than the control sample (5.50 ± 0.32 mg vs. 3.01 ± 0.18 mg). The magnetisation in 9 T for both 15 and 60 min shows that these samples have a significantly lower germination capacity (86.8 ± 4.4% and 81.4 ± 7.3% vs. 91.8 a ± 3.2%) and root length (1.78 ± 0.02 cm and 4.42 ± 0.83 cm vs. 8.21 ± 0.34 cm) compared to the control sample. The cucumber seeds pre-treated at 9 T have a significantly greater dry weight than the control sample. Additionally, our research shows that some magnetic field intensities and magnetisation durations inhibit root growth and limit germination. These results are also important as they indicate which values of magnetic fields should be avoided.

Struvite is regarded as a promising phosphorus (P) fertilizer compared to commercial pristine mineral phosphorus fertilizers. The aim of this study was to determine the effect of Phosgreen fertilizer, with struvite as its phosphorus source, on the chlorophyll, potassium (K), and calcium (Ca) contents in lettuce grown in peat compared to superphosphate. The study was carried out as a pot experiment with different doses of P fertilization. The study presents the chlorophyll a, b, total (a + b) chlorophyll, and carotenoid contents of the lettuce plants. Significant differences in the chlorophyll a and b contents were observed between the different phosphorus applications, and this can have a direct impact on the crop yields. Significantly higher contents of both chlorophyll contents were observed under Phosgreen fertilization as well as the chlorophyll a + b content *. The results of the study on lettuce indicate a dependence of vitamin C content on phosphorus fertilizer, but with no significant increase under Phosgreen fertilization; the contents of K and Ca were not significantly dependent on the type of phosphorus fertilizer. Due to the favorable composition of Phosgreen, it may be recommended for use as a phosphorus fertilizer in the agriculture and horticulture sectors.

This study aimed to examine the influence of long-lasting moderate (45% field water capacity—FWC) and severe (30% FWC) water stress and application of sulphur (elemental sulphur or sulphate) on the growth, yield and mineral composition of wheat and maize. Concentrations of macro- and micronutrients were determined in the aboveground parts of the plants. Drought stress caused a marked decrease in the growth parameters of both plants. Under both optimal water conditions (60% FWC) and moderate water stress (45% FWC), grain yields of wheat grown without sulphur application were not significantly different. Applying elemental sulphur caused an increase in grain yield under moderate stress, whereas sulphate was more effective in wheat grown under adequate water supply. Severe water stress significantly lowered wheat yield, regardless of sulphur fertilisation. Increasing water stress resulted in a greater reduction in maize growth, with an average 50% decrease in dry mass under severe water stress. Both crops maintained relatively high levels of macro- (N, P, K, Mg, Ca, S) and microelements (Mn, Fe, Cu, Zn) and did not suffer noticeably from deficiencies in such. Sulphur application did not modify these relationships. In conclusion, sulphur fertilisation may be recommended in wheat cultivation when plants are exposed to moderate water stress.

Water absorbing geocomposite (GC) consisting of SAP, geotextile and internal skeleton is a novel method of superabsorbent polymer (SAP) and fertilizer application. Roots can overgrow the geotextile and thus obtain access to water. The objective of the experiment was to determine the effect of the geocomposite on the growth of container-grown Brunnera macrophylla. The geocomposite was used as a multi-compound fertilizer (Insol® U) carrier and compared with soluble fertilizer (SF) and controlled-release fertilizer (CRF). The doses of fertilizers were calculated to cover the equal N supply: 0.36 and 0.72 g plant−1. The geocomposite positively influenced the plant traits after 8 and 16 weeks of cultivation. The number of leaves increased by 42% and 60% and the biomass of the above-ground parts of plants increased by 260% and 340% in comparison to plants treated with other fertilizers. The effect of the fertilization rate on plants was weakly pronounced, but a positive influence of a higher dose and the GC combined on all the examined traits of Siberian bugloss plants was detected.

The aim of the study was to determine the effect of the geocomposite (GC) on macronutrient uptake of container-grown Brunnera macrophylla and substrate properties. The GC consists of super-absorbent polymer (SAP), internal skeleton and non-woven geotextile. It was designed to retain water in the soil in a form available for plants, by roots overgrowing the geotextile to access water. The GC was soaked in a multi-compound fertilizer (Insol® U) and compared with soluble fertilizer (SF) and controlled-release fertilizer (CRF). The fertilizer rates were calculated to cover the equal N supply: 0.36 and 0.72 g N plant−1. Nitrogen uptake of Brunnera cultivated with the geocomposite was approximately twice and three times as high as that of plants fertilized with SF and CRF, respectively. Exceptionally high N content was observed in plants cultivated with the GC-0.72 g N plant−1. The use of the GC also enhanced the accumulation of K and P, while CRF strongly reduced their content in plants. Distinct relations could be observed in the case of Ca accumulation. GC-0.72 g N plant−1 increased EC and water content in the medium without direct contact between SAP and substrate.

Geocomposite (GC) with hydrophilic polymer is an innovative method of su-perabsorbent application. The aim of the conducted research was to assess the usefulness of the geocomposite for the fertilization of Hosta with liquid fertilizer in comparison with soluble fertilizer (SF) and controlled release fertilizer (CRF). Plants were grown in con-tainers filled with peat substrate, in a plastic tunnel and regularly feed with two doses of the fertilizers (according to N supply: 0.36 or 0.72 g·plant-1). Hostas responded positively to GC application: plants were higher and wider and their fresh weight increased respec-tively by 15 and 22% in comparison with SF and CRF application. The yield of dry matter was also higher. Plant nutrient status was better in case of P, K and Mg, but the N leaf content was lower. Lower electrical conductivity of the substrate at the end of cultivation with GC, alongside with intensive growth of plants proved high utilization of nutrients. The experiment confirmed usefulness of geocomposite for ornamental plant fertilization.

Small size of cabbage heads around 2.0 kg, preferred by the fresh market, may be attained by the choice of cultivar suitable for such purpose of production as well as culture practice, including reasonable rate of fertilization. The aim of the study was to evaluate the impact of increasing plant population combined with differentiated dose of nitrogen on yield of cabbage, its structure and plant composition. White head cabbage ‘Kalorama F1’ cv. was planted in rows 45 cm apart and 50, 40, 35 or 30 cm within rows, which assured 44 000, 55 000, 63 000 and 74 000 plants per 1 ha, respectively. Nitrogen at the rates of 150 or 300 kg ha-1 was used in 3 equal doses supplied as preplant and top dressing fertilization. Data obtained in the trial indicate that the dose of 150 kg N ha-1 was a limiting factor for the increment of crop yield in higher than 44 000 plant population per 1 ha. In the case of application the dose of 300 kg N ha-1 plants grown in population 63 000 and 74 000 per hectare produced significantly higher yield of heads if compared to the treatment with 44 000 plants. Taking into account the yield size and its structure it can be assumed that spacing 45 cm between plant rows and 40 cm distance in the row, which assure 55 000 plants per 1 ha is the optimum for production of cabbage heads weighted 1.0–2.0 kg, that meet the consumers expectation in the fresh market. Close plant spacing appeared to be beneficial for dry matter, vitamin C and total sugars contents and for decrease of nitrates accumulation. The enhancement of N dose to 300 kg N ha-1 was beneficial for total yield of heads as well those weighted > 1.0 kg. The only change in plant composition under influence of heavy N fertilization was the increment of nitrates accumulation and decrease of Ca content in cabbage heads.

In two field experiments carried out in 2006–2008, with two radish cultivars Treto F1 and Wernar F1 the effect of differentiated nitrogen fertilization on yield and biological value of radish grown for autumn harvest was examined. Mineral N content in the soil before seeds sowing was raised up to the level of: 50, 100 and 150 mg N·dm-3 by using: ammonium nitrate 34% N – [NH4NO3], calcium nitrate 15.5% N – [Ca(NO3)2·H2O], ammonium sulphate 20.0% N – [(NH4)2SO4], and ENTEC 26% N – [NH4NO3+(NH4)2SO4 + 0.8% DNPP]. The highest marketable yield of radish Treto F1 cv. was achieved in the case of ammonium nitrate use. In the case of Wernar F1 cv. kind of fertilizer didn’t affect the yield. Irrespective of the kind of fertilizer, increment of nitrogen content in the soil from 50 to 100 mg N·dm-3 caused the significant enhancement of radish yield. The similar yielding was recorded at nitrogen concentration equal to 150 mg N·dm-3 and 100 mg N·dm-3. Increasing mineral nitrogen concentration in the soil resulted in increment of nitrates content in radish roots, however their amounts not exceed permissible level. Plants fertilized with ammonium sulphate and ENTEC 26 contained lower amount of nitrates in edible parts in comparison to those supplied with ammonium nitrate and calcium nitrate.

In the field experiment with cabbage cv. ‘Menza F1’ fertilized with 150 and 250 kg N·ha-1, the first weeding started 3, 6, 9, 12 weeks after transplanting, including unweeded control. Higher dose of nitrogen especially in treatments with delayed weed control affected in significant increase of marketable yield, as well as the mean weight of cabbage heads in comparison to the dose of 150 N·ha-1. The highest yielding was recorded in treatment where the first weeding was conducted 3 weeks after transplanting. The delay of this operation to 6, 9, and 12 weeks after transplanting caused the decrease in marketable yield by 16.0%, 33.1% and 48.4%, respectively. The dose of 250 N·ha-1 contributed to the slight decrease of dry matter, total and reducing sugar contents, and higher accumulation of nitrates in edible parts of cabbage heads. Late start of weed removal was disadvantageous for dry matter and sugars content and caused higher nitrates accumulation in cabbage.

The effect of inert media and fertilization levels on nutrition status of green house tomato cv. ‘Maeva F1 ’ was investigated. Mean microelement content was: 118.5 mg Fe, 51.7 mg Zn, 269.0 mg Mn and 11.43 mg Cu kg -1 of dry mass of the index parts of the tomato (9–10 leaf form the top). No significant effect of rockwool, expanded clay and polyurethane foam on microelement contents was found in the index parts of the greenhouse tomato, except for zinc whose content was significantly higher in the leaves of the plants grown in rockwool and polyurethane foam than in expanded clay. Fertilization levels did not affect significantly the content of iron, manganese and copper in the index parts, except for zinc whose content lowered at higher fertilization level. High tolerance of the tomato plants to zinc and manganese content in feeding solutions was indicated. No phytotoxicity of zinc nor manganese was found at the content of 2.01 mg Zn and 1.78 mg Mn dm -3 of water or feeding solution.