Phosphorus (P) is a limited yet essential resource. P cannot be replaced, but it can be recovered from waste. We proposed the TRIZ approach (Teoria reszenija izobretatielskich zadacz - Rus., Theory of Inventive Problem Solving - Eng.) to identify a feasible solution. We aimed at minimizing the environmental impact and, by eliminating contradictions, proposed viable technical solutions. P recovery can be more sustainable based on circular economy and 4Rs (reduction, recovery, reuse, and recycling). The TRIZ approach identified sewage sludge (SS) as waste with a large potential for P recovery (up to 90%). Successful selection and application of SS management and P recovery require a transdisciplinary approach to overcome the various socio-economic, environmental, technical, and legal aspects. The review provides an understanding of principles that must be taken to improve understanding of the whole process of P recovery from wastewater while building on the last two decades of research.

The wastewater treatment process generates large amounts of P-rich organic waste (sewage sludge (SS)). The direct application of SS in agriculture, being controversial, is gradually being replaced by incineration, leading to the concentration of both P and heavy metals in the solid residual-sewage sludge ash (SSA). The novel closed-loop, cradle-to-cradle (C2C) approach leads to maintaining P production at current levels and counteracts its depletion in the future. The aim of this review is the presentation of the implementation of the C2C approach for P recovery. The paper focuses on steps that comprise P C2C, starting from the SS properties, being a derivative of wastewater type and treatment processes, to SS pre-treatment and finally leading to certified P-fertilizers production from SSA by application thermochemical or wet chemical extraction technologies. Examples of SSA treatment technologies and the final products are provided. It has been summarized that future research should focus on the production of SSA-based fertilizers aligning with the C2C concept and determining its effect on the various agriculture and horticulture crops.

In 2015–2017, field experiments were conducted, in two facilities of the Wroclaw University of Environmental and Life Sciences: at the Research and Didactic Station in Psary (51°19′08” N, 17°03′37” E) and in the plots of the Department of Crop Production in Pawlowice (51°17′32” N, 17°11′72” E). The research aimed to evaluate fresh biomass yield and selected quality parameters of quinoa grown as a green leafy vegetable. The study was conducted on two soils: medium (clay soil texture) and light (sand soil texture), sowing quinoa in spring and summer periods. On both soils, quinoa was harvested 5 times at each sowing date. The yields of fresh plant biomass, basic morphological characteristics and certain quality traits were compared. All experimental factors had a significant effect on quinoa fresh biomass yield. On light soil, quinoa yielded 4 times lower than on medium soil, and its cultivation posed a high risk, especially at the summer sowing date. The experimental factors used had the greatest effect on macronutrient content. Growing quinoa on medium soil yielded biomass with higher K, Mg, Ca and N-NO₃ concentration, while spring sown plants had higher K and N-NO₃ concentration. Harvesting date had the greatest effect on the change in nutritional values. Potassium content decreased as the harvest date was delayed, and N-NO₃ content decreased gradually until the fourth harvest date. The results showed that quinoa should be harvested as a green leafy vegetable when it reaches a height of 20–30 cm; biomass production is then at 500–1000 g per m², potassium content is less than 10 g per 100 g dry matter and N-NO₃ content is less than 100 mg 100⁻¹ f.m.

Soybean is a thermophilic and photophilic plant very sensitive to weather course during the vegetation period. This trait limits soybean cultivation in higher latitude countries. This field study aimed to evaluate the effects of three sowing dates on the development, the duration of vegetative and generative stages, and the yield of two soybean cultivars (Lissabon and Merlin) under conditions in south-western Poland in the years 2016–2019. The sowing date determines the temperature and the day length available for soybean plants, influencing development and yield. Delaying the sowing date by 20 days in relation to the earliest (16–21.04) resulted in the shortening of the length of the vegetative development by 12 days and the shortening of the entire vegetation period by 14 days. The delayed sowing date (06–19.05) under the conditions of south-western Poland (Lower Silesia) contributed to a significant decrease in yield. Lissabon produced greater soybean yield than Merlin. Special attention should be paid to proper seed sowing dates in soybean agriculture practice. It is necessary to breed soybean genotypes adapted to day length and thermal conditions of the cultivation area to achieve the maximum seed yield.

This study aimed to investigate whether different doses of specific phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid), alone or in combination, can inhibit the early growth of the common ragweed (Ambrosia artemisiifolia L., Asterales: Asteraceae). A seed bioassay was performed in Petri dishes and placed in a climate chamber to assess the effects of five dose levels of phenolic acids to radicle and shoot length, as well seedling biomass of A. artemisiifolia. The lowest dose of phenolic acid corresponded to the natural phenolic acid concentration previously reported in dry plant tissue samples from Brassicaceae cover crop plants. Results show that the inhibition of the early growth of A. artemisiifolia depends strongly on phenolic acid. Across different treatments, high doses of phenolic acids significantly shortened shoots and radicles, as well as reduced seedling biomass. Treating seeds with ferulic acid alone, vanillic acid alone, p-hydroxybenzoic acid alone, or a mixture of all phenolic acids significantly reduced all early growth parameters. The estimated effective dose for the 50% inhibition (ED₅₀) of radicle growth in A. artemisiifolia seedlings was 368.39 ± 59.85 × 10⁻⁸ mol with ferulic acid, 135.41 ± 17.65 × 10⁻⁸ mol with p-coumaric acid, 810.36 ± 134.15 × 10⁻⁸ mol with p-hydroxybenzoic acid, and 160.11 ± 12.30 × 10⁻⁸ mol with the combination of all phenolic acids.

This study aims to determine the effects of differences in variety and irrigations levels on potato yield (appropriate humidity, temperature, shading the plants from the sun if necessary) on potato yield in greenhouse conditions. Functions of potato production with respect to water use were developed for five dates of measurements of plant growth, in relation to the various vegetation phases. On the basis of potato vegetation phases, the potato water demand was determined. An experiment was conducted using the randomized sub-block method. The first order factor were the two varieties of potato that were grown under drip irrigation with three water regimes as a second factor experiment: level 1 (pF 2.7), level 2 (pF 2.5) and level 3 (pF 2.2). The variety had a significant effect on the weight of potato tubers. The irrigation level had only a significant effect on the total potato biomass. The potato harvest date had a significant effect on both of the examined treatments. The growth dynamics of the aboveground part and potato tubers were the highest in conditions of constant level 1. Regardless of the variety studied, on level 3 caused a reduction in potato biomass production.The highest water consumption was observed during the tuber potato growth period to flowering. The values were varied from 0.39 l/pot day level 1 (in both investigated cultivars) to 0.99 l/ pot/day (humidity level 3 for Julinka cultivar) in July. The most intensive increase in water consumption was observed at the level 3. The average W index of the average daily water dose calculated for Denar cultivar amounted 0.40 l day⁻¹ in the first period (O1) to 0.79 l day⁻¹ in the fifth period (O5) and for Julinka cultivar 0.49 l day⁻¹ (O1) to 0.92 l day⁻¹ (O5). Stress due to water shortage and/or excessive levels of water in the soil negatively influenced the yield of potato tuber. Potato varieties reacted differently to soil water content.