Journal of Agronomy and Crop Science最新文献

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.

CLE proteins are a class of signalling factors involved in plant growth and abiotic stress response. They play crucial roles in processes such as cell differentiation, chlorophyll synthesis and abscisic acid (ABA) signal transduction. However, the function of the CLE genes in Sorghum bicolor remains unclear. In this study, 42 sorghum CLE genes were identified, and their evolutionary relationship, gene structure, amino acid sequence and homologous genes were analysed. We also examined the expression levels of CLE genes under various treatment conditions. Transcriptome data showed that there were significant differences in the expression patterns of 42 CLE genes in different tissues and organs. It is worth noting that SbCLE39 is mainly highly expressed in sorghum roots. At the same time, the expression of SbCLE39 decreased significantly under salt and ABA treatment. Compared with wild-type yeast cells (EV), yeast cells with high expression of SbCLE39 had lower tolerance to salt stress. In addition, the excessive accumulation of ABA caused by external application of SbCLE39p reduced the salt tolerance of sorghum. These findings suggest that SbCLE39 negatively regulates the salt tolerance of sorghum. These results lay a foundation for revealing the mechanism of CLE genes regulating the salt tolerance of sorghum and are of great significance for the cultivation of salt-tolerant crops.

Soil waterlogging and high temperature (HT) are serious abiotic stresses that negatively affect cotton growth and yield. Yet effects of prewaterlogging to HT subsequently in cotton seedlings have not been obtained. To address this, two temperature conditions (30/20°C and 35/25°C) and two soil waterlogging levels (0 and 3 days) were established during the cotton seedling stage. Results showed that indexes of plant performance were decreased markedly under HT. Unexpectedly, plant performance for the treatment of HT combined with 3 days of soil waterlogging (HW) was better than HT treatment (specifically, increase of 7.9%, 9.0%, 10.2%, 5.4% and 4.6% in leaf area, plant height, belowground biomass, aboveground biomass and root-to-shoot ratio was detected). Decreases in MDA (malondialdehyde), H₂O₂ (hydrogen peroxide) contents and $��O_2^{-}�$ (superoxide radicals) generation rate under HW treatment were observed by 14.1%, 7.7% and 14.1%, respectively, compared with HT. Moreover, ASA (ascorbic acid) content and DHAR (dehydroascorbate reductase) activity were improved by 19.7% and 13.8% for HW treatment relative to HT, however, the opposite situation for activities of APX (ascorbate peroxidase) and GR (glutathione reductase). Besides, activities of SOD (superoxide dismutase), CAT (catalase) and POD (peroxidase) in HW treatment were increased by 16.7%, 8.3% and 18.4%, separately. Thus, we concluded that short-term soil waterlogging improved cotton cross-tolerance to the continued high-HT stress by enhanced SOD, CAT, POD and DHAR activities, increased ASA content in cotton seedlings. These results were expected to provide a theoretical basis for understanding cotton's cross-tolerance to abiotic stress.