Introduction Paris polyphylla var. chinensis (Franch.) Hara (P. polyphylla) is a perennial medicinal plant with a reputation for therapeutic properties. It is imperative to study the photochemical processes of P. polyphylla in order to determine the optimal levels of shading and moisture management for its cultivation in artificial environments.Methods In this study, six shading levels (no shading, 30%, 50%, 70%, 80% and 90% shading) and three soil water contents (20%, 40% and 60% of the soil water saturation capacity) were established to determine the appropriate shade intensity and soil moisture content for the growth of P. polyphylla.Results The results showed that only the low shade groups (no shade and 30% shade) showed irreversible damage to the daily photosynthetic dynamics of the plant over the course of a day. It is important to note that excessive light can damage not only the quantum yield for electron transport (phi Do) and PSII light quantum yield (Fv/Fm), but also various physiological mechanisms that can lead to overall plant damage and a decline in organic matter. A comparison of Fv/Fm during the midday period showed that the optimum shade intensity is between 50% and 70%. Low shading can significantly increase light use efficiency (LUE), but also reduces net photosynthetic rate (Pn) and transpiration (Tr), indicating the negative effect on P. polyphylla growth. Considering the balance between growth rate and damage incidence, 50% shade should be the optimal treatment for P. polyphylla, followed by 30% and 70% shade. It was also observed that treatment with low soil water content (20%) significantly reduced Pn and LUE, while increasing stomatal conductance (gs) and water use efficiency (WUE). This is associated with a decrease in the light response curve, indicating that low soil moisture inhibits the growth of P. polyphylla and increases the likelihood of irreversible light damage, so the optimum soil moisture content for P. polyphylla should be above 20%.Discussion Considering the economic benefits and the growth and health of P. polyphylla in artificial cultivation, it is recommended that shade be controlled at around 50% while maintaining soil moisture between 40% and 60% of water content.

Barley is an important cereal crop with versatile uses: barley grains are part of the human diet and are also used for animal feed, while the potential to use barley for ethanol production provides this grain with a promising bioenergy potential. As scientific research in the field of bioenergy progresses, barley may play an even greater role in meeting the world's future energy needs. The challenge facing today's barley growers, and one that will undoubtedly be addressed by future generations of grain farmers, is how to grow higher yields with lower costs while minimizing damage to the soil. One way to achieve this is by using simplified tillage methods, thereby avoiding soil compaction, structural degradation, and erosion. Moreover, studies have shown that when soil is cultivated using simplified methods, crop yields may actually increase. Our research was conducted in a long-term stationary field experiment, which was located at the Vytautas Magnus University Agriculture Academy Experimental Station. The aim of the investigation was to determine the effect of conservation tillage and deep plowing systems on soil water capacity and pore size distribution in spring barley cultivation. Comparing simplified tillage systems with deep plowing (DP), it can be concluded that the no-tillage (NT) technology most significantly improved the studied indicators, while the deep plowing (DP) technology exhibited the poorest results.

Agricultural practices that lead to soil carbon sequestration may be a win-win strategy for mitigating global warming and improving soil fertility and resource use efficiency. The mechanisms through which soil organic carbon (SOC) concentration affects crop yields are numerous but difficult to separate. The objective of this study was to disentangle these processes and estimate to what extent the yield response to SOC is mainly driven by changes in physical or biochemical properties and processes. This was achieved by analysing the response of yields in continuous maize to SOC concentrations during 20 years (2000-2019), which had evolved in 14 experimental treatments in a Swedish long-term field experiment at Ultuna since 1956, ranging from 0.94% to 3.65% in the topsoil (0-20 cm). Average maize yields during this period varied between 1.9 and 8.4 Mg dry mass per hectare in the different treatments. The treatments comprise applications of different mineral nitrogen (N) fertilizers and organic amendments and combinations thereof. Our analysis showed that maize yield in the treatments that were not severely limited by nitrogen supply or soil acidity increased by 16% for each percentage unit increase in SOC. We applied the widely used concept of critical N concentration in plant biomass to diagnose the N status in maize in the different treatments (N nutrition index [NNI]) and parameterized a response function between yield and pH (RpH). Dry soil bulk density (BD) was used as a proxy for soil physical properties. These three variables NNI, RpH and BD explained 95% of the variation in maize yields among treatments. Further analysis of the relationship between BD, SOC and plant available water capacity revealed that about two thirds of the yield increases in response to SOC change could be ascribed to associated changes in soil physical properties. Our analysis suggests that the extra storage capacity of water, which increased by up to 15 mm in the topsoil for each unit percentage increase in SOC, was the main driver for the observed yield responses. We conclude that measures for increasing SOC in soils most likely are an effective adaptation strategy for reducing the risk of crop damage during dry spells, which probably are becoming more frequent in the future due to climate change, even in relatively humid climates as in Sweden. After about six decades of different agricultural management, soil organic carbon (SOC) concentrations differed by up to a factor of four between the treatments in a Swedish field trial. Crop yields increased by 16% for each unit percentage of SOC increase in the high-N treatments and by 14% in the low-N treatments. image