Courgette is considered as a low-calorie vegetable with health-promoting properties. However, scientific publications focused on the profile and content of bioactive compounds in courgette, as well as the potential fruit quality modulating factors, are rare. Due to the high adaptability of courgette to weather and agronomic conditions, it is produced on a global scale. The aim of this study was to analyse the impact of organic versus conventional agronomic practices on the concentration of selected antioxidants in courgette fruits. Fruits of two courgette varieties (Astra Polka and Nimba) produced in an organic and conventional system were tested by high performance liquid chromatography (HPLC) to determine the content of polyphenols (flavonoids and phenolic acids), carotenoids, chlorophylls, and vitamin C. Organic courgette fruits were characterised by their significantly higher content of phenolic acids and flavonoids when compared to the conventionally grown fruit. The organic cultivation might be a good method to increase concentration of bioactive compounds with antioxidant properties in courgette fruits. Nevertheless, the identified trends should be further confirmed, with attention paid to other courgette varieties, as well as to the potential interactions between the plant genotype, agronomic system and the location-specific growing conditions.

Organic agriculture is considered one of the elements of sustainable food production and consumption, mainly due to its limited impact on the natural environment. At the same time, the quality features of organically produced foods, especially sensory attributes and health promoting values, are important factors determining consumers’ interest, and therefore play a key role in the organic sector’s development. The aim of this study was to investigate the sensory characteristics and concentrations of sugars and selected health-promoting bioactive compounds of organic courgette compared to conventionally grown courgette. In addition, untargeted metabolomic analysis of the courgette fruits was performed. The results of this study did not show a significant effect of the horticultural system (organic vs. conventional) on the concentrations of vitamin C, carotenoids, and chlorophylls in the courgette fruits. However, the fruits from the organic systems were significantly richer in sugars when compared to the conventionally cultivated ones (p = 0.038). Moreover, the organic fruits fertilized with manure contained significantly higher amounts of polyphenols, including gallic acid (p = 0.016), chlorogenic acid (p = 0.012), ferulic acid (p = 0.019), and quercetin-3-O-rutinoside (p = 0.020) compared to the conventional fruits. The untargeted analysis detected features significantly differentiating courgette fruits depending on the cultivar and horticultural system. Some significant differences in sensory values were also identified between fruits representing the two cultivars and coming from the horticultural systems compared in the study. Conventional courgettes were characterized by the most intensive peel color and aquosity, but at the same time were the least hard and firm compared to the fruits from the two organic systems. There was also a trend towards higher overall quality of the organically grown fruits. The presented study shows that the organic and conventional courgette fruits differ in a number of quality features which can influence consumers’ health and purchasing choices.

To improve sward efficiency and maintain high feed quality in organic farming—as well as compensate for yield losses under anticipated drought periods—alternative fertilization practices should be considered. In this context, this study aimed to assess the response to summer drought of grass–clover sward in organic cultivation under various conditions of foliar fertilization with silicon (Si) (without Si, Si applied with multicomponent fertilizer Herbagreen, Si applied with growth stimulator Optysil). The research was conducted at the certified organic field in the 3rd, 4th and 5th year of mowing utilization (from 2015 to 2017). The studies demonstrated a beneficial effect of Si application on the yield of the grass–clover sward, especially under multicomponent fertilizer. Both fertilizers increased roots mass, but growth stimulator (containing mainly Si) had a stronger impact, especially with rainfall scarcity. In such conditions the application of Si decreased flavones concentration in plants and increased values of chlorophyll index. This study also indicated the potential for applying Si fertilizers to improve content of nutrients (crude protein, organic matter digestibility, potassium and phosphorus) in the sward. The results of presented studies may be used in fertilization practice of organic crop for enhancing sward productivity and to compensate for yield losses under condition of rainfall deficiency.

Open Access Agricultural Journals published by Institute of Agricultural Economics and Information

The aim of this study was to compare the long-term effects of conventional tillage (CT) and no-till (NT) systems on the main soil properties that determine soil health. The research was conducted in a field experiment established in 1975 in Chylice, central Poland, at the WULS-SGGW Experimental Station Skierniewice. Soil samples collected from 0–10 and 10–20 cm of the mollic horizon of the Phaeozem were analysed for total organic carbon (TOC) content, fractional composition of SOM and spectroscopic properties of humin, soil structural stability, soil water retention characteristics and soil water repellency (SWR). The results showed that NT practice almost doubled the TOC in the 0–10 cm layer. However, optical parameters of humin indicated that NT management promoted the formation of humin with a lower molecular weight and lower degree of condensation of aromatic structures. In the NT 0–10 cm layer, a significant increase in the number of water-resistant macroaggregates was found. In the 0–10 cm layer, the water capacity increased by 9%, 18%, 22% and 26% compared to CT at (certain soil suction) pF values of 0.0, 2.0, 3.0 and 4.2, respectively. SWR occurs regardless of the cultivation method at a soil moisture equivalent to pF 4.2, and the greatest range of SWR was found in the NT 0–10 cm layer.

The aim of this study was to evaluate the effect of long-term crop rotation and fertilization treatments on the yield and yield component stability of spring barley and winter wheat on the basis of selected data over 30 years. The stability was measured using statistical methods (the Shukla stability index and linear mixed models). The long-term field experiments established in 1955 were conducted in central Poland (Chylice near Warsaw, 52°06′ N, 20°33′ E) and consisted of two crop rotations with the same fertilization regime. The first field experiment (A—NOR) is typical of the Norfolk rotation and consists of the following four crops: 1. sugar beet, 2. spring barley with undersown red clover, 3. red clover, and 4. winter wheat, while the second field experiment (B—NONleg) contains a sequence of crops without legumes: 1. sugar beet, 2. spring barley, 3. winter rapeseed, and 4. winter wheat. The following fertilization regimes are used in both experiments: a control without any fertilization (O), mineral fertilization (NPK), farmyard manure (FM), and mixed mineral and organic fertilization (½ NPK + ½ FM). The average yields of winter wheat and spring barley (in t*ha⁻¹) were 4.34 (a max of 5.48 in NONleg_NPK) and 4.27 (a max of 5.67 in NONleg_NPK) in the NONleg rotation treatment and 5.39 (a max of 6.12 in NOR_NPK) and 4.28 (a max of 5.22 in NOR_½ NPK + ½ FM), respectively, in the legume-based NOR rotation treatment. In the legume-free rotation treatment, the highest yield stability was found in the treatments fertilized only with manure (NONleg_FM) and in a mixed manner (NONleg_½NPK + ½FM), while in the Norfolk rotation treatment, the yield stability was the highest in the treatments with mixed fertilization (NOR_½NPK+½FM) and the treatments in which only mineral fertilizers were used (NOR_NPK).