The effectiveness of herbicides is affected by the pH of the spray liquid. The use of adjuvants can mitigate the negative effect of pH, and it also allows for a reduction in herbicide doses while maintaining high efficiency. Greenhouse studies were performed to evaluate the efficacy of the herbicide sulcotrione (HRAC F2), against barnyardgrass, at full or reduced doses with adjuvants, and a modified pH of the solutions. The contact angle and surface tension of liquid spray drops, as well as the shear viscosity of individual solutions, were also tested. Results indicated that at a low pH of the spray liquid (4), the use of a reduced dose of sulcotrione with adjuvant based on methylated rapeseed oil can increase the effectiveness of barnyardgrass control to the same level as at the full dose of herbicide. The use of adjuvants contributed to the reduction in the contact angle and the surface tension of liquid spray droplets. No significant differences in shear viscosity were observed for individual solutions.

The field experiment was carried out in 2013 and 2014 as part of a long-term experiment to test the influence of different soil tillage systems (conventional, reduced, direct sowing) on (a) the yield of summer pea (Pisum sativum L.) and (b) the amount of biologically reduced atmospheric nitrogen (N), which was determined using the ¹⁵N dilution method (ID¹⁵N). Spring barley was used as a reference plant. Climatic conditions did not have a significant influence on the yield of pea seeds (mean value 4.56 t ha⁻¹), post-harvest residues (3.76 t ha⁻¹) and total biomass (8.33 t ha⁻¹). Soil tillage system was found to have a significant impact on all components of the pea yield in years of experiment, with the highest average seed yield values observed with the conventional system (5.19 t ha⁻¹) and significantly lower values observed with reduced tillage (4.34 t ha⁻¹) and direct sowing (4.17 t ha⁻¹). The content of total N was greatest in the pea biomass that was harvested in the conventional system (202 kg ha⁻¹) and lowest with direct sowing (155 kg ha⁻¹). Nitrogen accumulated in the pea seeds from three sources: atmosphere (mean value 35.2%), fertilizers (6.8%) and soil (57.9%), equating to 48.6, 9.9, and 85.4 kg ha⁻¹, respectively. Soil tillage system was found to have a significant impact on the amount of N that was fixed from the atmosphere by the peas: 17.7% in conventional tillage, 37.9 in reduced system and 50.2% in direct sowing, which equates to a harvested seed yield of 28.9, 52.0 and 64.4 kg ha⁻¹, respectively. In the post-harvest residues, the amount of N fixed from the atmosphere by the pea crop was also modified by the soil tillage system in range: 20.2% in conventional tillage and 32.6% in direct sowing (which equates to 7.4 and 8.5 kg N ha⁻¹, respectively), but the difference was not significant.

Agriculture is faced with the need to reduce mineral fertilizers in order to reduce costs but also to meet political goals. Resilience-enhancing climate change, especially in the face of increasingly frequent and prolonged droughts, has become another issue. The dynamically increasing production of insects for feed and food purposes has become one of the answers to this challenge. This study assesses the fertilizing efficacy effect of frass derived from Black Soldier Fly (Hermetia illucens) production on lettuce (Lactuca L.) growth, including aspects such as yield, photosynthesis activity, photosystem II performance (chlorophyll fluorescence), mineral profile, and antioxidant properties. Additionally, the properties of the soil were assessed by measuring the gas exchange between the soil and the atmosphere. The lettuce plants grew under two water regimes—optimal irrigation and induced drought. The efficiency of frass fertilization was compared with the control and traditional cattle manure. The results indicate that H. illucens frass (HI frass) used as a fertilizer increased the content of essential nutrients in plants—such as potassium and iron. As the dosage of frass increased, the content of vitamin B2 (riboflavin) doubled. The plants that were subjected to drought and properly fertilized showed greater resistance; therefore, a reduction in the synthesis of polyphenolic compounds was observed. Fertilizer had a positive effect on the efficiency of photosynthesis. This study underscores the promising impact of unconventional organic fertilizers, such as H. illucens frass, on enhancing plant performance, especially in challenging environmental conditions. Fertilizers obtained from insect production can be green chemicals in a sustainable food production model.

A field experiment was carried out in 2019–2021. The effect of an increased amount of iron in water and the addition of citric acid on the efficacy of herbicides applied in maize cultivation at various times was tested. In the pre-emergence treatment, thiencarbazone-methyl + isoxaflutole were applied, while in the post-emergence treatment, nicosulfuron + tritosulfuron + dicamba were applied once in a full dose or in low dose system at two times in half of the recommended dose with the addition of an adjuvant. In selected combinations, FeSO₄ × 7H₂O and citric acid were added to the composition of the spray solution. The species composition of weeds and the efficacy of the herbicides used were determined. Plant stress caused by competition from weeds was investigated by measuring the plant chlorophyll fluorescence. The height of the cultivated plants and their yield level were also determined. The lowest efficacy of weed control was observed when the post-emergence herbicides were applied once. Increasing the iron content in water reduced the efficacy of the herbicides, but the addition of citric acid made it possible to decrease this problem.

The pH of the spray liquid is one of the factors influencing the efficacy of herbicides. Adjusting the appropriate parameters of the spraying liquid may reduce the consumption of pesticides, which is in line with the currently introduced legal standards and society’s requirements. In the greenhouse experiment, the influence of herbicides containing mesotrione, nicosulfuron, rimsulfuron, bromoxynil, and a mixture of nicosulfuron, rimsulfuron, and mesotrione on the efficacy of oilseed rape control was investigated. Oilseed rape (Brassica napus L. ssp. oleifera), apart from being an important crop, can become a nuisance weed in many fields as form of volunteer plants. Visual assessment, reduction of fresh weight, and chlorophyll fluorescence were performed. Individual herbicides influenced the tested parameters to a different extent. The pH of the spray liquid influenced the efficacy of individual plant protection products. The highest herbicidal efficacy in relation to the tested plants was observed in the case of combinations in which mesotrione was applied at a reduced and increased pH, nicosulfuron applied in an acidic and alkaline environment, rimsulfuron without pH modification, and all treatments in which bromoxynil was applied. The herbicides containing mesotrione and bromoxynil had the greatest impact on the photosystem II activity.