Journal of Agronomy and Crop Science最新文献

This comprehensive review examined the intricate relationship between climate change and rye (Secale cereale L.) production, focusing on the multifaceted challenges and opportunities posed by changing environmental conditions. Rye is a versatile cereal crop cultivated in temperate regions and is known for its resilience and adaptability to adverse growing conditions. However, as global temperatures and atmospheric CO₂ concentrations rise, the effects of climate change on rye growth, yield and grain quality become increasingly apparent. In this review, we summarised the recent research findings on various aspects of rye production and quality under climate change, focusing on factors such as temperature (e.g., increasing temperature) resilience, and viability of rye production in the face of ongoing climate challenges, altered rainfall patterns (changing rainfall distributions with decreasing rainfall in the spring and early summer months as well as heavy rainfall events), biotic stress, agronomic practices and greenhouse gas emissions. Exploring the dynamic interplay among climate change, soil quality, biotic stressors and plant–microbe interactions reveals insights into the response of rye to environmental changes. These interactions shape the complex dynamics that influence the adaptation of rye to evolving environmental conditions. Implications for food security, agricultural sustainability and future research directions are also discussed, highlighting the urgent need for adaptive strategies to ensure the resilience and viability of rye production in the face of ongoing climate challenges.

Drought is one of the major yield-limiting factors under climatic adversaries. The positive role of silicon (Si) in drought tolerance of plants has unfolded a new avenue for enhancing crop productivity through better Si use efficiency. It is hence interesting to understand the mechanistic insights pertaining to its beneficial roles under drought stress conditions. Higher plants sense drought stress via roots which, regulate aboveground plant growth under stress. Cellular and molecular modulations occurring at the root and soil interphases influence the survival and growth of plants under drought stress; therefore, it is intriguing to know how Si influences the soil–root interphase and how this interaction augments overall plant growth under drought. In this review, we summarised the roles of Si in the root systems, rhizosphere and their interactions that could improve plant's growth and development under drought conditions. We have discussed the direct and indirect effects of Si-induced belowground changes on plant roots, soil physical, chemical and biological properties, and their mutual interactions in eliciting defence signalling, including hormone signalling pathways. A mechanistic model of Si-induced beneficial effects in water-limited environments is suggested, which could help improve the management of rainfed croplands through Si fertilisation.

The brown midrib bmr6 and bmr12 mutants of sorghum (Sorghum bicolor) have alterations to the phenylpropanoid pathway impairing the activity of cinnamyl alcohol dehydrogenase (CAD) and/or caffeate5/hydroxyferulate O-methyl transferase (COMT) enzymes, which inhibit lignin synthesis. Interestingly, these phenylpropanoids can also act as sunscreen compounds in plants and potentially attenuate ultraviolet radiation. We examined the effects of ultraviolet-B (UV-B; 280–320 nm) exclusion on growth, cell-wall constituents and UV-screening abilities of bmr6, bmr12, a double mutant (bmr6 bmr12; dm) and wild-type (WT) genotypes of S. bicolor. Plants were grown in a UV-transparent greenhouse under filters that either transmitted 2.8% (Mylar) or 90% (Aclar) of UV-B. The greenhouse experiment was a 2 × 4 (UV treatment × genotype) complete factorial design. Sorghum grown under reduced UV were 23% taller and had 22% fewer leaves. Among genotypes, the WT plants were 5%–12% taller than the bmr6, bmr12 and dm mutants. The near-ambient UV-B treatment group was more effective at UV screening and had a 16% higher UV-screening effectiveness than those under reduced UV-B. Sorghum plants with the bmr6 and dm genotypes had 8%–19% higher UV-shield than the bmr12 and WT. Plants grown under the reduced UV-B treatment had 5% less hemicellulose and 6% more cellulose in their cell walls. There were no overall treatment effects on bulk soluble phenolics, chlorophyll fluorescence (F_v/F_m) or lignin concentrations. These results are a possible indication that the bmr mutants of S. bicolor have a varied response to UV-B exclusion due to alterations in the phenylpropanoid pathway leading to redistribution of metabolites.

The carbon cycle of saline–alkali ecosystems will be affected to some extent in the context of future global warming. Therefore, we investigated the net ecosystem exchange (NEE) of three typical crops (wheat, maize and soybean) in the saline–alkaline land of the Yellow River Delta. To further investigate CO₂ fluxes, NEE was decomposed into gross primary productivity (GPP) and ecosystem respiration (Re). In terms of seasonal variation, wheat and soybean were carbon sources in the early and late growth periods, and carbon sinks in the rest of the period, whereas maize was a carbon sink in the majority of the period, and maize had good carbon sink potential. The cumulative NEE during the growth periods for wheat, maize, and soybean were 414.86, 258.24 and 228.92 g cm⁻², respectively, and the daily variation showed that the peak NEE values for the three crops preceded the peak values of both GPP and ecosystem respiration, occurring approximately at 12:00 a.m. In the correlation analysis, NEE and GPP of the three crops were well correlated with photosynthetic photon flux density and net radiation, whereas Re was significantly correlated with air temperature. Through a comparative analysis of CO₂ fluxes within various agricultural ecosystems, our findings indicated that wheat demonstrated moderate carbon sequestration capabilities, whereas maize and soybean exhibited strong carbon sink characteristics. Notably, saline–alkali crops exhibited lower Re, whereas GPP levels remained at a moderate range. Therefore, under the global warming trend, the respiration of saline crops and soils will be affected and may change the original carbon sink into a carbon source. Hence, implementing suitable measures targeting saline–alkali areas, such as the establishment of an effective crop rotation system and the enhance saline–alkali land conditions, can reduce emissions of greenhouse gases, thus reducing the pressure of global warming and maintaining a stable carbon cycle in saline–alkali land.

Soybean film mulching has shown promise in maintaining consistent and high yields in semi-arid regions. However, the specific impacts of full-film and semi-film mulching on soybean growth, root nodule traits and grain yield are poorly understood. This 2-year study (2021–2022) investigates the effects of full-film and semi-film mulching on soil moisture, soybean growth and yield. Our findings revealed that semi-film mulching increased soybean yield by 18.12% compared to full-film mulching, averaged across 2 years. Furthermore, the semi-film treatment significantly enhanced biological nitrogen fixation ability, increasing root nodule numbers by 24.81%–33.43%, compared to full-film mulching. This improvement also positively affected soybean quality, with crude protein content increasing by 5.89% in 2021 and 4.14% in 2022 compared to full-filming. Moreover, semi-film mulching helped maintain soil moisture and temperature during later soybean growth stages. There findings suggest that semi-film mulching is a viable agricultural strategy for soybean cultivation in semi-arid regions, improving soybean quality and efficiency while promoting environmental sustainability.

Rice–wheat rotation cropland is one of the most important agroecosystems in South China, the escalation of conflict between food demand augment and water supply shortage increased with climate change. Water use efficiency plays a more significant role in optimising water and carbon management. Thus, the diurnal and seasonal variations of water use efficiency were assessed by the 3-year eddy covariance observations in the Shouxian National Observatory, a typical rice–wheat rotation station. The results revealed a ‘U’-shaped diurnal pattern of water use efficiency for winter wheat (Triticum aestivum L.) and rice (Oryza sativa L.). Seasonal water use efficiency had two peaks with the highest in the winter wheat-growing season. The average water use efficiency for the rice–wheat rotation cropland was 2.85 g C kg⁻¹ H₂O over the whole year with 2.62 and 3.11 g C kg⁻¹ H₂O for winter wheat and rice, respectively. However, gross primary productivity and evapotranspiration of rice were higher than those of winter wheat. Temperature, photosynthetically active radiation were the principal impact factors of water use efficiency in the rice-growing season. Comparatively, soil water and vapour pressure deficit dominated the water use efficiency changes in the winter wheat-growing season. Our analyses can help understand the water use requirements for carbon assimilation on rice–wheat rotation cropland on the field scale.

Climate change is causing drastic reduction in crop yields around the globe due to increase in soil salinity, drought and heat stress. Quinoa (Chenopodium quinoa Willd) is regarded as a very significant food security crop considering the climate change scenario. Two quinoa genotypes (Puno and Titicaca) were cultivated on salt affected soil under drought stress with different sowing dates. Compared with early sowing, late sowing combined with salinity and drought stress caused drastic decline in plant growth and grain yield due to imposition of heat stress. Plant biomass and grain yield decreased by 26% and 39% in Puno, and by 34% and 49% in Titicaca under late sowing accompanied by salt and drought stress. Relative water contents and stomatal conductance of leaves declined in the same trend in both genotypes. Shoot Na⁺ concentration was the highest whereas K⁺ concentration was the lowest in both genotypes when drought and salt stress were combined under late sowing. Grain minerals (Ca, Mg, Fe, Zn, Cu, K, P, N and Mn) and dietary contents (protein, lipids, carbohydrates and fibre) were decreased more under the combination of salinity and drought for late sowing as compared to early sowing. When salinity and drought stress were combined under late sowing, the contents of H₂O₂ and TBARS were 1.9 and 2.2-fold higher in Puno and 2.4 and 2.6-fold higher in Titicaca, respectively. The oxidative stress was mitigated by enhanced activities of antioxidant enzymes (CAT, SOD and POD) more in Puno than Titicaca. Plant biomass and grain yield were higher in Puno with better grain quality than Titicaca. Hence, this genotype should be cultivated on salt affected soils facing drought and high temperatures.

A simulation study was conducted for assessing the climate change impact on wheat cultivars (HD2967 and PBW725) under RCP 4.5 and RCP 6.0 scenarios for four agroclimatic zones (AZ) of Punjab. The yield trend during 70 years (2025–95) using the CERES-Wheat model was assessed for different sowing windows (end October to end November). The maximum/minimum temperature and rainfall, respectively, during the season varied between 25–27°C/9–12°C and 27–103 mm (AZ II), 24–27°C/8–13°C and 37–105 mm (AZ III), 24–26°C/9–12°C and 20–80 mm (AZ IV) and 23–26°C/9–12°C and 30–71 mm (AZ V). The climatic conditions largely vary across the state, because of which only AZs II, III and V were found productive for wheat crop with most of the years lying in the high yield (>5000 kg/ha) category. The sowing of HD2967 during mid to end November would be suitable adaptation strategy for wheat growers in the state.