Impact of Metal-Based Nanoparticles on Cambisol Microbial Functionality, Enzyme Activity, and Plant Growth

An increase in the penetration of metal-based nanoparticles (NPs) into the environment requires an assessment of their ecotoxicity as they impair the critical activity of plants, animals, bacteria, and enzymes. Therefore, the study aimed to observe the effects of metal-based NPs, including copper (Cu), nickel (Ni), and zinc (Zn), on the Cambisols, which cover a significant part of the earth's soil and play an important role in the biosphere. Metal-based NPs were introduced into the soil at concentrations of 100, 1,000, and 10,000 mg/kg. The biological properties of the soil are being investigated as the most sensitive to external contamination. The highest ecotoxicity of the studied pollutants introduced into the soil at the same concentrations was shown by Cu (up to 34%) and Zn (up to 30%) NPs, while Ni NPs showed less (up to 22%). Microbiological (total number of bacteria, Azotobacter sp. abundance) and phytotoxic properties (radish seed germination and length of roots) of Cambisols were more sensitive (22–53%) to pollution by NPs of Cu, Zn, and Ni, while enzymatic activity (catalase and dehydrogenases) showed less sensitivity (14–32%). The present results could be useful for biomonitoring the state of contaminated soils, especially by NPs.

Effect of macro- and microfertilizers on oil radish seed yield in the forest steppe conditions of the Central Federal district of Russia

We studied effect of macro- and micronutrient fertilizers on oil radish (Raphanus sativus var. oleifera Metzg.) seed yield in fields of the Lipetsk Research Institute of Rapeseed in 2019–2020. The research was conducted in the forest-steppe conditions of the Central Federal district of the Russian Federation. Field experiment variants were as following: control (without fertilizers), (NPK)40, (NPK)80 and N40 in autumn under plowing, (NPK)40 and N40 in spring under before-sowing cultivation, and as a part of the main (NPK)40 application, foliar application with Plantofola (20:20:20), Polydon Amino Start and Polydon Amino Mix. Soil of the experimental field was leached, heavy clay loam chernozem having the distinctive agrochemical characteristics. In general, the weather conditions for the oil radish growing season in 2019 were close to the average long-term norm, and in 2020 the weather conditions were distinguished by a significant lack of precipitation, which affected the formation of oil radish yield. The studies have shown that the effect patterns of the studied macro- and micronutrient fertilizers on oil radish yield in the years of the experiments did not practically differ. On the average in both 2019 and 2020 the yield increase has been noted. The application of nitrogen and complete mineral fertilizers for this crop under plowing in autumn and under before-sowing cultivation in spring significantly increased its yield, which reached the highest values (22.3 quintal per ha) in the experiment with (NPK)80 as the main fertilizer. At the same time, an equivalent oil radish seed yield was formed with less costly agricultural technologies, when with application of (NPK)40, in autumn under plowing foliar application with Plantofola (1.0 l per ha) was conducted in the phases of 5–7 true leaves and budding–beginning of flowering or Polydon Amino Start (1.0 l per ha) was used in the phase of 5–7 true leaves.

Interference of feral radish (Raphanus sativus) resistant to AHAS-inhibiting herbicides in oilseed rape, wheat and sunflower crops

Raphanus sativus (feral radish), a cosmopolitan weed, has developed resistance to acetohydroxyacid synthase (AHAS) inhibitor herbicides in several countries of South America. This study reports the effects of season-long interference of several feral radish densities on grain yield and yield components of oilseed rape, wheat and sunflower, and on feral radish traits under field conditions. Feral radish density treatments consisted of 0, 2, 4, 8 and 16 plants m−2 in oilseed rape, 0, 4 and 12 plants m−2 in wheat, and 0, 1.6, 4, 8 and 16 plants m−2 in sunflower. The number of inflorescences per area, seeds per inflorescence and the seed biomass of crops were reduced with increasing feral radish densities. The rectangular hyperbola model revealed yield losses by up to 100 %, 74.4 % and 12.2 % in oilseed rape, wheat and sunflower, respectively. Feral radish seed production ranged from 4,300 to 31,200, and 1000 to 4,700 seeds m−2 in winter crops and sunflower, respectively. Season-long feral radish interference can result in serious economic losses in oilseed rape, wheat and sunflower. The adverse impact of feral radish on the yield of winter and summer crops and the high feral radish seed and pods production suggests the need for the development and implementation of diverse and effective long-term weed management practices.