Increased Leaf Area Research Articles

Empirical evidence and theoretical understanding of ecosystem carbon and nitrogen cycle interactions.

Interactions between carbon (C) and nitrogen (N) cycles in terrestrial ecosystems are simulated in advanced vegetation models, yet methodologies vary widely, leading to divergent simulations of past land C balance trends. This underscores the need to reassess our understanding of ecosystem processes, given recent theoretical advancements and empirical data. We review current knowledge, emphasising evidence from experiments and trait data compilations for vegetation responses to CO2 and N input, alongside theoretical and ecological principles for modelling. N fertilisation increases leaf N content but inconsistently enhances leaf-level photosynthetic capacity. Whole-plant responses include increased leaf area and biomass, with reduced root allocation and increased aboveground biomass. Elevated atmospheric CO2 also boosts leaf area and biomass but intensifies belowground allocation, depleting soil N and likely reducing N losses. Global leaf traits data confirm these findings, indicating that soil N availability influences leaf N content more than photosynthetic capacity. A demonstration model based on the functional balance hypothesis accurately predicts responses to N and CO2 fertilisation on tissue allocation, growth and biomass, offering a path to reduce uncertainty in global C cycle projections.

Enhancing the medicinal properties and phytochemical content of bitter melon (Momordica charantia L.) through elicitation with brassinosteroid, ethrel, and carrageenan

Bitter melon (Momordica charantia L.) is well-known for its high protein, steroid, alkaloid, mineral, lipid, triterpene, and phenolic compound content, as well as its medicinal properties, particularly its anti-diabetic effects. To investigate the impact of elicitors on the morphology and phytochemical characteristics of bitter melon (Jounpouri cultivar) over two consecutive years (2018 and 2019), we conducted a field experiment. The study aimed to determine the effects of Ethrel, brassinosteroids (BRs), and k-carrageenan on yield and the production of anti-diabetic agents in M. charantia farm crops. The elicitors included ten levels, ranging from a control group to Ethrel (100, 300, and 600 mg l− 1), brassinosteroids (BRs) (0.1, 0.5, and 1 mg l− 1), and k-carrageenan (200, 400, and 600 mg l− 1). These characteristics included leaf area, leaf length, leaf width, fruit parameters, carbohydrate content, total phenols and flavonoid accumulation, antioxidant activity, total acid, ascorbic acid, momordicine, and charantin. Across both years, we observed the highest flavonoid accumulation and antioxidant activity in the Ethrel treatment group. Specifically, applying 0.5 mg l− 1 BRs and 300 mg l− 1 Ethrel led to an 18.8% and 14.8% increase in momordicine content, respectively. All elicitor treatments, particularly at 0.1 mg l− 1 BRs, significantly increased leaf area, leaf length, and leaf width compared to the control group in both cropping years. Additionally, the application of all elicitors resulted in increased fruit weight, dimensions, and yield over the two consecutive years. Notably, in 2018, 600 mg l− 1 Ethrel contributed to enhanced fruit weight and yield, while in 2019, 0.5 mg l− 1 BRs exhibited the same effect. Metabolic and physiological changes in bitter squash induced by employed elicitors over two different years (2018–2019) are strongly dependent on a variety of environmental factors such as temperature and rainfall. In conclusion, using BRs as an elicitor has the potential to optimize the health benefits of bitter melon by increasing the content of two bioactive molecules, momordicine and charantin.

Assessment of Meteorological Drought in a Changing Environment: An Example in the Upper Yangtze River

AbstractRecent studies have suggested that drought projections using Palmer drought severity index (PDSI) and standardized evapotranspiration precipitation index (SPEI) may overestimate drought severity. This overestimation occurs because the potential evapotranspiration (PET) calculations fail to consider the interactive effects of vegetation responses such as increased leaf area index (LAI) and constrained stomatal conductance, which are influenced by elevated atmospheric CO2 concentrations ([CO2]). To address this issue, our study replaced the traditional Penman‐Monteith (PM) equation with a recently proposed PET equation that includes the effects of changing [CO2] and LAI to assess droughts at monthly scale in the Upper Yangtze River basin, which experiences the vegetation greening. The findings indicated a consistent increasing trend in drought conditions with minimal discrepancy between the two equations over the historical period (1986–2017). This consistency arises because the water‐saving effects of increased [CO2] and the greening effects of rising LAI largely counterbalance each other. However, for the future period (2018–2100), projections using PM equation predicted an intensification of drought conditions. In contrast, the improved SPEI indicated no significant drought variations, and the improved PDSI suggested a wetting trend. This divergence can be attributed to the water‐saving effects increasingly outweighing the greening effects, as PET shows a decreasing sensitivity to LAI with LAI increasing, but maintains a near‐constant sensitivity to elevated [CO2]. Consequently, the indices based on PM equation tend to overestimate future drought severity. Overall, this study demonstrates that the new PET estimation method is more capable of responding to the changing environment.

Enhanced relationship between seasonal soil moisture droughts and vegetation under climate change over China

Climate change could intensify seasonal soil moisture droughts and subsequently degrade vegetation, but it can also facilitate vegetation growth with the rising temperature and CO2 concentrations. Therefore, the change of the vegetation-drought relationship under climate change remains elusive. Here, we investigate the effects of vegetation greening (i.e., increasing leaf area index (LAI)) on seasonal soil moisture drought trends by performing a set of land surface model simulations with the Conjunctive Surface-Subsurface Process model version 2 (CSSPv2), as well as the impact of seasonal soil moisture drought change on vegetation productivity via a statistical fitting model. Our results indicate that both the impact of increasing LAI on exacerbating seasonal droughts and the impact of increasing seasonal droughts on reducing vegetation productivity have been enhanced over China during 1961–2018. Specifically, increased LAI accounts for 48 % of the rising drought frequency through escalated evapotranspiration losses, with more pronounced effects in northern semiarid regions. The decrease in vegetation stomatal conductance caused by rising CO2 concentrations limits transpiration and alleviates 11 % of the increase in drought frequency, but it cannot fully offset the drought aggravation induced by increased vegetation water consumption under climate warming. Meanwhile, increased drought frequency and intensity have reduced the upward trend in vegetation productivity by 5 % over China, and by 8 % in water-limited northern regions. Our study shows the relationship between seasonal soil moisture droughts and vegetation over China has strengthened, indicating that vegetation greening will lead to increased water shortages and further impact vegetation growth and carbon sequestration. This challenges water resources management and environmental sustainability, especially in semiarid regions.

Licorice-root extract and potassium sorbate spray improved the yield and fruit quality and decreased heat stress of the 'osteen' mango cultivar.

Heat stress, low mango yields and inconsistent fruit quality are main challenges for growers. Recently, licorice-root extract (LRE) has been utilized to enhance vegetative growth, yield, and tolerance to abiotic stresses in fruit trees. Potassium sorbate (PS) also plays a significant role in various physiological and biochemical processes that are essential for mango growth, quality and abiotic stress tolerance. This work aimed to elucidate the effects of foliar sprays containing LRE and PS on the growth, yield, fruit quality, total chlorophyll content, and antioxidant enzymes of 'Osteen' mango trees. The mango trees were sprayed with LRE at 0, 2, 4 and 6 g/L and PS 0, 1, 2, and 3 mM. In mid-May, the mango trees were sprayed with a foliar solution, followed by monthly applications until 1 month before harvest. The results showed that trees with the highest concentration (6 g/L) of LRE exhibited the maximum leaf area, followed by those treated with the highest concentration (3 mM) of PS. Application of LRE and PS to Osteen mango trees significantly enhanced fruit weight, number of fruits per tree, yield (kg/tree), yield increasing%, and reduced number of sun-burned fruits compared to the control. LRE and PS foliar sprays to Osteen mango trees significantly enhanced fruit total soluble solids ˚Brix, TSS/acid ratio, and vitamin C content compared to the control. Meanwhile, total acidity percentage in 'Osteen' mango fruits significantly decreased after both LRE and PS foliar sprays. 'Osteen' mango trees showed a significant increase in leaf area, total chlorophyll content, total pigments, and leaf carotenoids. Our results suggest that foliar sprays containing LRE and PS significantly improved growth parameters, yield, fruit quality, antioxidant content, and total pigment concentration in 'Osteen' mango trees. Moreover, the most effective treatments were 3 mM PS and 6 g/L LRE. LRE and PS foliar spray caused a significant increase in yield percentage by 305.77%, and 232.44%, in the first season, and 242.55%, 232.44% in the second season, respectively.

Reducing red light proportion in full-spectrum LEDs enhances runner plant propagation by promoting the growth and development of mother plants in strawberry.

Full-spectrum light-emitting diodes (LEDs) have gradually replaced narrow-spectrum LEDs and are widely used in plant factories with artificial lighting (PFALs). However, the specific effect of LED light quality on dry mass allocation in runner plant propagation remains unclear. Hence, we cultivated "Akihime" strawberries as mother plants for 115 days to conduct runner plant propagation experiment under white LEDs (W100), white and red LEDs (W84R16 and W55R45), red and blue LEDs (RB100), and red, blue and green LEDs (RB80G20) in PFALs, and determined key factors affecting dry mass accumulation and allocation among mother plants and runner plants based on growth component analysis. The results showed that the net photosynthetic rate and total leaf area in mother plants in W100 increased by 11% and 31%, respectively, compared with W55R45. In comparison to W84R16 and W55R45, W100 increased the dry mass (23%-30%) of runner plants mainly by increasing the total dry mass (TDM) (23%) of strawberry plants, without significantly affecting the fraction of dry mass partitioning to runner plants. However, the number of runners in W55R45 was 5.1 per plant, representing only 78% of that in W100. Compared with RB100, RB80G20 significantly increased the number of runner plants and runner numbers by 16% and 19% to 13.0 per plant and 5.8 per plant, respectively. The partial replacement of blue light with green light in RB80G20 induced a shade avoidance response in runner plants, resulting in a 55% increase in the total leaf area of runner plants compared with RB100. Data from growth component analysis showed that compared with red and blue LEDs, white LEDs increased the TDM of runner plants by 83% by increasing the plant TDM accumulation (44%) and the fraction of dry mass partitioning to runner plants (37%). Additionally, the dry mass (g) of runner plants per mol and per kilowatt-hour under in W100 were 0.11 and 0.75, respectively, significantly higher than other treatments. Therefore, reducing red light proportion in full-spectrum LEDs is beneficial for strawberry runner plant propagation in PFALs.

A moving target: trade-offs between maximizing carbon and minimizing hydraulic stress for plants in a changing climate.

Observational evidence indicates that tree leaf area may acclimate in response to changes in water availability to alleviate hydraulic stress. However, the underlying mechanisms driving leaf area changes and consequences of different leaf area allocation strategies remain unknown. Here, we use a trait-based hydraulically enabled tree model with two endmember leaf area allocation strategies, aimed at either maximizing carbon gain or moderating hydraulic stress. We examined the impacts of these strategies on future plant stress and productivity. Allocating leaf area to maximize carbon gain increased productivity with high CO2, but systematically increased hydraulic stress. Following an allocation strategy to avoid increased future hydraulic stress missed out on 26% of the potential future net primary productivity in some geographies. Both endmember leaf area allocation strategies resulted in leaf area decreases under future climate scenarios, contrary to Earth system model (ESM) predictions. Leaf area acclimation to avoid increased hydraulic stress (and potentially the risk of accelerated mortality) was possible, but led to reduced carbon gain. Accounting for plant hydraulic effects on canopy acclimation in ESMs could limit or reverse current projections of future increases in leaf area, with consequences for the carbon and water cycles, and surface energy budgets.

Grass leaf structural and stomatal trait responses to climate gradients assessed over the 20th century and across the Great Plains, USA.

Abstract. Using herbarium specimens spanning 133 years and field-collected measurements, we assessed intraspecific trait (leaf structural and stomatal) variability from grass species in the Great Plains of North America. We focused on two widespread, closely related grasses from the tribe Paniceae: Dichanthelium oligosanthes subsp. scribnerianum (C3) and Panicum virgatum (C4). Thirty-one specimens per taxon were sampled from local herbaria from the years 1887 to 2013 to assess trait responses across time to changes in atmospheric [CO2] and growing season precipitation and temperature. In 2021 and 2022, the species were measured from eight grasslands sites to explore how traits vary spatially across natural continental precipitation and temperature gradients. Δ13C increased with atmospheric [CO2] for D. oligosanthes but decreased for P. virgatum, likely linked to increases in precipitation in the study region over the past century. Notably, this is the first record of decreasing Δ13C over time for a C4 species illustrating 13C linkages to climate. As atmospheric [CO2] increased, C:N increased and δ15N decreased for both species and %N decreased for D. oligosanthes. Across a large precipitation gradient, D. oligosanthes leaf traits were more responsive to changes in precipitation than those of P. virgatum. In contrast, only two traits of P. virgatum responded to increases in temperature across a gradient: specific leaf area (increase) and leaf dry matter content (decrease). The only shared significant trend between species was increased C:N with precipitation. Our work demonstrates that these closely related grass species with different photosynthetic pathways exhibited various trait responses across temporal and spatial scales, illustrating the key role of scale of inquiry for forecasting leaf trait responses to future environmental change.

IMPACT OF VARIED AMOUNTS OF NITROGENOUS FERTILIZERS ON GRAIN YIELD AND RELATED AGRO-PHYSIOLOGICAL TRAITS IN SPRING WHEAT (TRITICUM AESTIVUM L.)

The application of nitrogen (N) is a critical factor influencing grain yield and agro-physiological traits in spring wheat (Triticum aestivum L.). This study aimed to evaluate the impact of varied nitrogen levels on grain yield and associated traits under field conditions. The study was conducted in Chak No. 136 / 6.R Haroonabad, District Bahawalnagar under the supervision of the Institute of Soil Fertility (Field) during the crop year 2022-23. A randomized complete block design (RCBD) was used, with five N treatments (160, 145, 131, 117 and 103 kg ha⁻¹) applied across three replicates. Key parameters, including flag leaf area, thousand-grain weight, spikelets per spike, number of grains per spike, chlorophyll a, stomatal conductance, net photosynthetic rate, biological yield and gain yield, were measured. The results showed a significant increase in flag leaf area, thousand-grain weight, spikelets per spike, number of grains per spike, chlorophyll a, stomatal conductance, net photosynthetic rate, biological yield and gain yield with increasing nitrogen application, with the highest yield observed at 160 kg ha⁻¹. The results unveiled the presence of highly significant variations among nitrogen treatments in wheat variety based on the agro-physiological parameters including flag leaf area, thousand-grain weight, number of spikelets per spike, number of grains per spike, chlorophyll a, stomatal conductance, net photosynthetic rate, biological yield and gain yield. Furthermore, the results also unveiled that treatments with higher nitrogen dosage produce better results for almost all the study parameters including grain yield. The correlation coefficient analysis also confirmed the results and suggested that any wheat breeding program aimed at improving wheat yield must select its parental genotypes based on traits having the highest correlation with yield i.e., flag leaf area, thousand-grain weight, number of grains per spike, chlorophyll a, stomatal conductance and net photosynthetic rate except the number of spikelets per spike and biological yield for which the correlation was positive but non-significant. The results suggest that nitrogen in higher amounts up to a certain level is necessary for obtaining maximum output from wheat crops under semi-arid conditions.

Impact of fertilizer doses on soil properties, vegetative growth, fruit quality and biochemical compounds of strawberry (Fragaria × ananassa Duch)

Fertilizers are important for plant growth, yield enhancement, and achieving food security, but overdose can have negative effects. This study sought to determine the impact of different fertilizer doses on soil properties, vegetative growth, fruit quality, and biochemical compounds of strawberry (Fragaria × ananassa Duch) cv. ‘Camarosa’. During the years 2022-2023, strawberry seedlings were grown in pots in a greenhouse. Four increasing dosages of fertilizers were applied. The results showed that following treatment, electrical conductivity and soil organic matter rose to maximum values of 176.26 µS. cm-1 and 2.63%, respectively, with d2 treatment. However, the pH was initially high before dropping considerably to 7.34 with d4 dosage. Treatment d1 was highly suggested for enhanced fruit number (5.8) and total yield (729 g. plant-1). The treatment d2 produced the highest fruit weight (24.3 g), volume (27.71 cm3), length (5.55 cm), and width (5.15 cm). The medium dose d3 drastically increased leaf area (2652.76 cm2), total soluble solids (7.4 °Brix), total phenols (1,332.54 mg GAE· L-1) and antioxidant activity (89.53%), but not significantly. The maximum petiole length (12.66 cm), petiole number (29.4), chlorophyll content, runners number (6), roots length (22.33 cm), fresh root and shoot weight (73.11 and 96.41 g), root and shoot dry weight (10.84 and 30.64 g), were recorded at d4 treatment. In control plants, all of these measures were lower, despite having higher fruit pH (3.72), titratable acidity (0.87%), and flowers number (4.40). In conclusion, increasing fertilizer doses may affect soil and strawberry plant qualities, and farmers must use them appropriately.

Response of orange Saplings to spraying with brassinolide and add-ing organic fertilizer in some of vegetative and root growth charac-teristics

The experiment was carried out at the Horticulture station in the Al-Hindiya district / Karbala governorate during the 2023 growing season, using a Randomized Complete Block Design (RCBD) with three replications. The study aimed to investigate the response of two orange Cultivars (Blood and Navel) to spraying with the growth regulator brassinolide at three concentrations (0, 0.3 and 0.6 mg L-1) and the addition of organic fertilizer (Humzinc) to the soil at three concentrations (0, 0.5 and 1 g L-1). The results showed the superiority of the Blood Cultivar over the Navel Cultivar in stem length, stem diameter, Leaves number, root length, and root volume, while the Navel Cultivar excelled in leaf area. Treatment with brassinolide at a concentration of 0.6 mg L-1 or the addition of organic fertilizer at a concentration of 1 g L-1 resulted in the highest significant increase in stem length, stem diameter, Leaves number, leaf area, root length, and root volume. Regarding the interactions between study factors, the binary and ternary interactions had a significant effect on improving vegetative and root growth Traits. The ternary interaction treatment (Blood Cultivar + brassinolide 0.6 mg L-1 + 1 g L-1) outperformed by giving the highest average increase in stem length (35.98 cm), stem diameter (7.993 mm), average Leaves number (117.66 leaves seedling-1), root length (120.67 cm), and root volume (52.33 cm3), while the treatment (Navel Cultivar + brassinolide 0.6 mg L-1 + 1 g L-1) significantly excelled in leaf area (38.57 cm2).

Distinguishing High Daytime From Nighttime Temperature Effects During Early Vegetative Growth in Cotton

ABSTRACTHigh‐temperature limits early season vegetative growth of cotton, and the physiological response of cotton (Gossypium hirsutum L.) to high daytime or nighttime temperature needs to be explored. The objectives of the current study were to determine (1) plant growth response, (2) physiological contributors to variation in biomass production and (3) mechanisms driving variation in net photosynthetic rate (AN) in response to different combinations of high daytime and nighttime temperatures. Beginning at planting, cotton was exposed to four different growth temperature regimes: (1) optimum (30/20°C day/night), (2) high nighttime (30/30°C), (3) high daytime (40/20°C) and combined high daytime and nighttime (40/30°C) for 4 weeks. Relative to the 30/20°C treatment, plant growth was positively affected by high nighttime temperature and negatively affected by high daytime temperature and combined high day and night temperature. Increased leaf area mainly contributed to increased biomass production in high nighttime temperature; higher nighttime respiration (RN) drove reductions in biomass in combined high daytime and nighttime temperature; and decreased leaf area and AN and increased RN drove reductions in biomass under high daytime temperature alone. AN was not impacted by high nighttime temperature, while decreased under high daytime temperature and increased with combined high daytime and nighttime temperature. Adjustments in leaf traits contributed to increases in AN in combined high daytime and nighttime temperature, and increased photorespiration and respiration contributed to reductions in AN under high daytime temperature. Overall, early season vegetative growth of cotton exhibited differential responses to high daytime and nighttime temperatures.

Evaluating the impact of phyto-hormones on the morpho-biochemical traits of soybean through seed treatment and foliar application

Global climate variations, mainly extreme temperatures reduce crop production and contributed to global food insecurity. Plant growth regulators (PGRs) improve physiological efficiency, photosynthetic capacity, and assimilate partitioning in field crops. However, their influence on soybean (Glycine max L.) yield and seed quality is under-researched. This study investigates the synergistic effects of auxin (2,4-D) and gibberellin (GA3) at 60 and 90 mg L−1 concentrations. This study investigates the impact of phytohormones, specifically gibberellic acid (GA3) and 2,4-dichlorophenoxyacetic acid (2,4-D), on the morphological and biochemical traits of soybean (Glycine max L.) through seed treatment and foliar application. These Growth regulators were applied through seed treatment at the time of sowing and foliar application at the time of flowering initiation stage. The experiment was designed using a RCBD arrangement and each block replicated thrice time. Seed treatment with 2,4-D at 90 mg/L showed that maximum plant height (116.80 cm), first node height (8.04 cm), No. of branches per plant (18.67), root length (18.12 cm) stem diameter (0.05 cm), no. of pods per plant (32.60), seed yield (1532.30 kg ha−1), biological yield (4109.30 ha−1), and harvest index (39.36 %). The GA3 (seed treatment) at conc. of 90 and 60 mg L−1 resulted in a significantly increased no. of nodule fresh weight, nodules per plant, and dry weight respectively. But the no. of seeds per pod did not showed significant results throughout the study. However, the foliar applied of 2,4-D at 90 mg L−1 resulted in significantly increased leaf area index (LAI) compared to the seed treatment. PGRs had a significant influence on quality traits. Thus, the application notably improved the potential of soybean and successful oilseed crop. Therefore, it is showed that using PGRs are extremely helpful for attaining higher growth, yield production, and improved quality of soybean.

The role of sodium nitroprusside (SNP) in alleviating cadmium stress in maize plants.

Cadmium (Cd) is a heavy metal that is highly toxic to plants and animals and can accumulate in the environment as a result of industrial activities and agricultural application of some types of phosphate fertilizer. This study aimed to assess the role of sodium nitroprusside (SNP), as a source of nitric oxide (NO) in alleviating Cd stress in maize plants. Maize plants were kept in soil saturated with 40%-strength nutrient solution in a greenhouse, and cadmium nitrate, Cd(NO3)2, was applied at different concentrations, (0, 10, and 50µM). Sodium nitroprusside, [Fe(CN)5NO]·2H2O, at concentrations of 0.05, 0.1, and 0.2µM. Growth, leaf gas exchange, and leaf anatomy analyses were performed. The experimental design was completely randomized in a 3 × 3 factorial arrangement with five replicates. The highest concentrations of Cd and SNP reduced the total dry mass and leaf and stem dry mass but increased the allocation of biomass to the roots and stem, but the leaf allocation did not change. The application of Cd and SNP promoted an increase in gas exchange and leaf area, in addition to an increase in leaf tissue thickness and stomatal density. The presence of SNP at low concentrations reduces the toxicity of Cd, but at high concentrations, this compound can generate negative effects and even toxicity in maize plants.

Optimizing Fertilization Strategies to Promote Leaf-Use Ginkgo Productivity and Ecosystem Economic Benefits: An Integrated Evaluation of a Field Trial in Southern China

Field experiments were conducted on a four-year-old leaf-use ginkgo plantation in southern China to assess the impact of nine different fertilization strategies with varying N-P2O5-K2O rates at three growth phases (FBD: March for bud development; FLG: May for leaf growth; FLS: July for leaf strengthening) on leaf-use ginkgo (Ginkgo biloba L.) leaf productivity and ecological economic benefits (EEBs). The results indicated that regardless of timing and rate, fertilizer application led to an increase in leaf area and thickness, resulting in higher ginkgo leaf yield. The highest fresh (215.14 g tree−1) and dry (78.83 g tree−1) yields were observed with 3 g N + 2.5 g P2O5 + 1.5 g K2O tree−1 in FLG. FLS was found to mitigate the decline in SPAD values of leaves during late summer. Furthermore, fertilized ginkgo trees exhibited higher flavonoid concentrations in leaves, enhancing profitability. However, higher fertilizer rates were associated with elevated greenhouse gas emissions, nitrogen losses and ecological costs. Despite these drawbacks, all fertilization treatments resulted in increased net economic income. Specifically, compared to no fertilization, FBD, FLG and FLS treatments boosted net income by 3.5~26.6%, 11.6~60.5% and 5.8~35.4%, respectively. Using the entropy weight TOPSIS method, it was concluded that optimizing the N, P and K fertilization rate and timing (applying 3–2.5–1.5 g tree−1 of N-P2O5-K2O in May) is a beneficial approach to maximize EEBs and industrial benefits in leaf-use ginkgo plantations in southern China. This study provides valuable insights into suitable fertilization patterns and management for leaf-use ginkgo plantations in southern China.

Improved water use efficiency of vegetation due to carbon fertilization not translating to increased soil moisture in India

Soil moisture (SM) plays a critical role in land–atmosphere interaction. Literature shows that the CO2 fertilization effect (CFE) governs vegetation dynamics and its interactions with the atmosphere. However, the impacts of changing vegetation properties due to CFE, on SM, specifically in India, remains unexplored. Comparing Land-hist (observed CO2 concentration) and Land-cCO2 (constant preindustrial CO2 concentration) simulations with the same meteorological forcings from the Land Use Model Inter-comparison Project (LUMIP), we found that changing vegetation due to CFE impacts SM following two pathways. Enhanced water use efficiency (WUE) due to CFE seeks to ameliorate SM by regulating transpiration. Conversely, elevated CO2 increases leaf area index and plant water use, ultimately leading to a decrease in SM due to the combined impacts of CFE in India. This reduction is most prominent in arid regions, where we observe a decline in SM particularly during dry periods. Our study highlights the need to consider plant physiology in land surface modeling under increased CO2 concentration.

Effects of intercropping with Fenlong tillage “145” mode on ratoon sugarcane photosynthesis, growth, and yield

AbstractSoil compaction and resource competition are bottlenecks in the improvement of sugarcane productivity in intercropping systems. Fenlong tillage improves crop yields by alleviating soil compaction and ensuring water supply. Wide‐narrow rows are an effective solution for light competition. An efficient intercropping system with Fenlong tillage technology as the core needs to be constructed. A two‐cycle field study was conducted to investigate the effects of planting methods [sole ratoon sugarcane (S) and ratoon sugarcane‐soybean intercropping (I)] combined with tillage [conventional rotary tillage (RT), Fenlong tillage “145” mode (FL145)] on soil physical characteristics, photosynthesis, and growth of ratoon sugarcane, as well as crop yields. For the ratoon sugarcane, compared to RT‐I, FL145‐I decreased bulk density and increased porosity in the 0–40 cm soil layer. Root growth parameters were improved under FL145‐I in the 0–20 cm soil layer. FL145‐I positively affected the stomatal conductance, causing increases in the net photosynthetic and transpiration rates. The increased leaf area index, chlorophyll relative content, and photosynthesis under FL145‐I caused higher dry matter accumulation. The increased single stalk weight under FL145‐I resulted in 17.13%–22.55% higher stalk yield with similar quality. Intercropping under the wide‐narrow row planting pattern had no negative effects on the growth and stalk yield of ratoon sugarcane. For the soybean, compared to RT‐I, the increased 100‐seed weight under FL145‐I resulted in 11.14% higher seed yield with similar quality. Therefore, FL145‐I presents a promising and novel management practice for sustainably increasing ratoon sugarcane productivity in China.

Influence of Plant Spacing and Bio-fertilizers on Yield and Yield Attributing Characters of Rain-fed Soybean at Damazin in Blue Nile State, Sudan

This study had the objective of evaluating the effect of biofertilizers on the performance of soybean plants under different planting spacing. It was conducted during the summer seasons of 2018 and 2019at one site at Demonstration Farm of Damazin Agricultural Research Station, Sudan. The different plant spacing designated as D1, D2, and D3 (5, 10, and 15 cm between plants) under three types of bio-fertilizers as Rhizobacteria (B1), Azotobacter (B2), Bacillus (B3) and control (B0). The experiment was laid out in Randomized Complete Block design (RCBD) with three replications as split-plots trail. The result revealed that the improvement due to the application of fertilizers with wider, spacing D3 stimulated plant growth and caused an increase in dry matter accumulation and high leaf area and gave the higher number of pods and seeds/pod, particularly at inoculation with B1 and B2 bacteria. While sowing seeds inoculated with B1or B2 under closer spacing resulted in higher seed yield per unit area. To achieve optimum results in soybean variety Sudan 1, the crop may be sown in plant spacing of 10cm with inoculation seeds with B1or B2 to achieve a high plant population per unit area to obtain higher seed yield.

Growth improvement of immature quinine by applying coffee husk compost and biofertilizer

The growth of immature Cinchona ledgeriana can be optimized by applying fertilizers to fill the nutritional needs of plants. Nutrients can be provided through the help of microorganisms derived from organic fertilizers and biofertilizers. This study aims to evaluate the effect of applying coffee husk compost and biofertilizer consortium on the growth of immature quinine plants. This research was conducted from November 2023 – January 2024 at Gambung Tea and Cinchona Research Center, Pasir Jambu District, Bandung Regency, West Java. The research used a randomized block design with four replications and six treatments, namely control (Urea 17 g.plant-1 + SP36 8 g.plant-1 + KCl 4 g.plant-1); solid coffee husk compost 3 kg.plant-1; liquid coffee husk compost 80 mL.L-1; biofertilizer 10 mL.L-1; solid coffee husk compost 3 kg.plants-1 + biofertilizer 10 mL.L-1; and liquid coffee husk compost 80 mL.L-1 + biofertilizer 10 mL.L-1. The results showed applying organic fertilizer from coffee husk waste and biofertilizer improved the growth of immature quinine plants. Combination of liquid organic fertilizer from coffee husk waste 80 mL.L-1 water + biofertilizer 10 mL.L-1 water produced a high increase in leaf area. Combination of solid organic fertilizer from coffee husk waste 3 kg. plants-1 + biofertilizer 10 mL.L-1 water showed the highest plant height increment. It implied the success of quinine improvement growth at the immature phase by applying coffee husk waste and biofertilizers.

Effects of atmospheric CO2 concentration on transpiration and leaf elongation responses to drought in Triticum aestivum, Lolium perenne and Festuca arundinacea.

Leaf elongation is vital for Poaceae species' productivity, influenced by atmospheric CO2 concentration ([CO2]) and climate-induced water availability changes. Although [CO2] mitigates the effects of drought on reducing transpiration per unit leaf area, it also increases total leaf area and water use. These complex interactions associated with leaf growth pose challenges in anticipating climate change effects. This study aims to assess [CO2] effects on leaf growth response to drought in perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea) and wheat (Triticum aestivum). Plants were cultivated in growth chambers with [CO2] at 200 or 800ppm. At leaf six to seven unfolding, half of the plants were subjected to severe drought treatment. Leaf elongation rate (LER) was measured daily, whereas plant transpiration was continuously recorded gravimetrically. Additionally, water-soluble carbohydrate (WSC) content along with water and osmotic potentials in the leaf growing zone were measured at drought onset, mid-drought and leaf growth cessation. Elevated [CO2] mitigated drought impacts on LER and delayed growth cessation across species. A positive correlation between LER and soil relative water content (SRWC) was observed. At the same SRWC, perennial grasses exhibited a higher LER with elevated [CO2], likely due to enhanced stomatal regulation. Despite stomatal closure and WSC accumulation, CO2 did not influence nighttime water potential or osmotic potential. The marked increase in leaf area across species resulted in similar (wheat and tall fescue) or higher (ryegrass) total water use by the experiment's end, under both watered and unwatered conditions. In conclusion, elevated [CO2] mitigates the adverse effects of drought on leaf elongation in three Poaceae species, due to its impact on plant transpiration. Overall, these findings provide valuable insights into CO2 and drought interactions that may help anticipate plant responses to climate change.