Journal of Agronomy and Crop Science最新文献

The sustainability of global agriculture at higher productivity level is a concern owing to climate change, serious environmental footprints, dipping factor productivity and shrinking availability of natural resources, especially. The situation is worsening in the ‘Food Bowl of India’—Indo-Gangetic plains (IGP) by several amalgamated factors, such as declining groundwater, unpredictable precipitation owing to climate change and cultivation of heavy water duty crops. To neutralise these issues, a field experiment was executed for the period 2019–2021 to assess the efficacy of indigenous hydrogels (P-hydrogel and Superabsorbent polymer hydrogel-1118) and their application methods viz., seed treatment, slurry application and soil application on crop yield and water productivity, soil moisture dynamics and profitability in a soybean–wheat cropping system under irrigation and rainfed conditions. In both study years (2019–2020 and 2020–2021), due to higher seed germination percentage, irrigation application together with seed treatment and slurry application of superabsorbent polymer hydrogel-1118 improved system productivity by 8.1%–26.7% and system water productivity by 17.6%–33.8% over control. Wheat grain yield was enhanced by 8.0% (2019–2020) to 32.2% (2020–2021) due to superabsorbent polymer hydrogel-1118 hydrogel with 10 cm lesser use of irrigation water compared with control (no-hydrogel). Soil moisture content in 0–15 cm soil layer was also found higher by 1.8%–2.4% in superabsorbent polymer hydrogel-1118 and P-hydrogel slurry-applied plots. Therefore, higher gross profitability (31.8%), net profitability (89.8%) and B:C (26.9%) in wheat could be attributed to increased crop yields when seeds were treated with superabsorbent polymer hydrogel-1118. Therefore, the utilisation of modified hydrogel application, in the form of seed treatment (seed coating) and slurry application has demonstrated improvement in seed germination, crop yield and water productivity and made soybean–wheat cultivation more economical. This approach presents a feasible solution to achieving a viable production system of soybean and wheat crops by reducing irrigation amounts in the IGP of India, as well as other comparable ecological places worldwide.

There is a need for increasing cropping intensity in South Asia including India to ensure food security of burgeoning population. Accordingly, increasing cropping intensity in rainfed rice fallows can be a futuristic strategy. Identification of suitable cultivar and exploration of genetic variability of specific crops/traits are imperative for genetic improvement, drought resistance and yield gain in rice fallows. We evaluated the morphophysiological, yield traits and stability of 15 chickpea genotypes in randomised complete block design for three consecutive years on a drought-prone rainfed condition of Fluvisol in Kanpur, India. Among genotypes, ‘IPC 2014-55’, ‘IPC 2015-44’ and ‘IPC 2011-92’ had 2%–10% higher relative water content (RWC) over ‘ICC-92944’ (check cultivar). These genotypes did not differ for total chlorophyll content, root dry weight and nodule dry weight with ‘ICC-92944’ and ‘KWR 108’ (wider adaptable cultivar of the region). The nitrogen balance index was higher in ‘IPC 2011-92’, ‘IPC 2014-88’ and ‘IPC 2014-55’ by 5%–44% over check cultivar (p < 0.05). The membrane stability index was higher for ‘IPC 2014-55’ (30%, p < 0.05) and ‘IPC 2011-92’ (17%, p < 0.05) than ‘ICC-92944’. ‘IPC 2011-92’, ‘IPC 2014-88’ and ‘IPC 2014-55’ (3 years mean) had 3%–24% higher plant dry weight than ‘ICC-92944’. Notably, ‘IPC 2014-55’, ‘IPC 2015-44’, ‘IPC 2014-88’ and ‘IPC 2011-92’ had higher yield attributes such as pods plant⁻¹ by 9%, grain weight plant⁻¹ by 13% and 100-seed weight by 3% than ‘ICC-92944’ and ‘KWR 108’ (mean of years). These genotypes had higher mean seed yield than ‘ICC-92944’ by 23%–42% and ‘KWR 108’ by 7%–23% (p < 0.05). The yield of ‘IPC 2014-55’, ‘IPC 2015-44’, ‘IPC 2014-88’ and ‘IPC 2011-92’ were stable over years across variable soil and environmental condition as indicated by the genotype × year biplot. Membrane stability index, pods plant⁻¹ and 100-seed weight were the determinants for increased seed yield of chickpea under drought-prone condition. Evidently, genotype ‘IPC 2014-55’, ‘IPC 2015-44’, ‘IPC 2014-88’ and ‘IPC 2011-92’ were better under rainfed rice fallows. These genotypes could be tested under specific drought condition for developing varieties and promoted in rice fallows of South Asia for yield advantage and drought resistance.

In the eastern Indo-Gangetic plains, chickpea is grown postrice cultivation mostly under rainfed condition with residual soil moisture which adversely affects branching as well as pod and seed development, ultimately resulting in substantial yield losses. The current study analysed the moisture stress response of 12 chickpea genotypes with control for different morpho-physiological traits in two sets of field experiments carried out during the year 2017–18 and 2018–19. The current study observed varying response of chickpea genotypes under moisture stress condition with average yield reduction from 11.79% to 24.77%. Mean yield of genotypes under stress condition showed a strong positive association with yield index (1.00**) and stress tolerance index (0.915**). The biplot principal component analysis revealed maximum potential of three chickpea genotypes (DBGC 1, Pusa 256 and DBGC 2) for grain yield and biological yield under moisture stress condition. The correlation analysis showed a significant association of yield with physiological parameters such as photosynthetic rate (0.363**), stomatal conductance (0.364**) and transpiration rate (0.292*). The three higher yielding genotypes relatively maintained biological yield, yield plant⁻¹, 100 seed weight and photosynthesis rate and showed reduced rates of stomatal conductance and transpiration under moisture stress condition. The study found variable genotypic response to moisture stress and showed that yield index as well as stress tolerance index was more effective to identify superior genotypes for moisture stress condition. The superior genotypes identified in the present study may be considered for rainfed areas of eastern Indo-Gangetic plains and can be used in future chickpea breeding programs for drought tolerance.

Accelerated senescence under elevated CO₂ (eCO₂) has not received sufficient attention, and its impact on the effect of CO₂-fertilization is unclear. To investigate the relationship between plant senescence and CO₂ concentration, a pot experiment was conducted in four potato genotypes under low CO₂ (LC), medium CO₂ (MC) and high CO₂ (HC) conditions. Nitrogen (N) uptake and cumulative transpiration were analysed to clarify whether eCO₂-induced senescence could be explained by low N uptake due to reduced transpiration. Compared to LC, the lifespan of potato plants under MC and HC was reduced by 3%–6% and 12%–32%, respectively, depending on the genotype. Biomass accumulation at full senescence was reduced when lifespan was shortened by approximately 5% and 10% under MC and HC, respectively. Cumulative transpiration was less affected by eCO₂ during early developmental stages but decreased under eCO₂ as plants aged. Plant water use decreased with a shortened lifespan under eCO₂, but there was no reduction in N uptake, which was attributed to the high N uptake per unit of water used. The results of this study indicate that senescence in potato genotypes is non-linearly related to CO₂ concentration and cannot be explained by reduced N acquisition via reduced transpiration. The positive effect of CO₂ fertilization can be reversed by accelerated senescence under eCO₂.

Soil salinisation poses a significant threat to global agricultural production and food security. China is among the countries most severely impacted by soil salinisation. To investigate the improvement technology for saline–alkali stress in buckwheat, a typical multigrain crop in northwest China, a coupling regulation study using desulfurisation gypsum and polyacrylamide (PAM) was conducted in 2019 and 2020. Desulfurisation gypsum was applied at 0, 5.5, 11, 16.5 and 22 kg·ha⁻¹, while PAM was applied at 0, 15, 30, 45 and 60 kg·ha⁻¹. The results demonstrated that applying 11 t·ha⁻¹ desulfurisation gypsum and 30 kg·ha⁻¹ PAM effectively reduces soil salinity and pH, averaging 81.79% and 6.07%, respectively. Furthermore, it did not cause soil heavy metal pollution and created the best soil environment for buckwheat growth. Among the models tested, the nonrectangular hyperbolic model was the most accurate in describing buckwheat's photosynthetic light response. The optimal treatment for achieving the best photosynthetic performance—measured by apparent quantum efficiency, maximum net photosynthetic rate, light compensation point, light saturation point, dark respiration rate, stomatal conductance, intercellular CO₂ concentration, transpiration rate, leaf water use efficiency and yield—was achieved through applying 11 t·ha⁻¹ desulfurisation gypsum and 30 kg·ha⁻¹ PAM. Therefore, desulfurised gypsum and PAM should be applied at 11 t·ha⁻¹ and 30 kg·ha⁻¹, respectively, to improve buckwheat's adaptability to different light intensities while promoting its photosynthetic response in saline–alkali soils. This study provides an effective technical scheme for reducing salt and promoting the growth of crops under salinity stress, which is of great significance for improving salinity land in arid areas.

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.