Increased Leaf Area Research Articles

Trait analysis in a population of the Greater Butterfly-orchid observed through a 16-year period.

A large English population of the temperate tuberous Greater Butterfly-orchid, Platanthera chlorantha, was monitored through a 16-year period. Each June the number of flowering plants was counted and 60 flowering plants were measured in situ for four morphological traits, selected for both ease of measurement and their contrasting contributions to the life history of the species. Trait data were tested annually in pairwise combinations for individual plants, before mean values throughout the study period were regressed and cross-correlated against each other and against local data for four meteorological parameters. Labellar spur length proved to be more constrained than either flower number or stem height, and rarely yielded statistically significant correlations with other traits, whereas the three remaining traits reliably showed modest but significant correlations. Mean values and coefficients of variation differed only modestly among years and showed few of any meaningful trends. Spring rainfall and insolation had no detectable effect on traits of plants flowering that June; instead, they impacted on trait expression during the following year, presumably as a result of differential resourcing of replacement tubers formed during the previous year. High spring rainfall in year t-1 increased leaf area and stem height in year t, whereas the widely fluctuating number of flowering plants was highest in years immediately following those characterised by relatively dry and/or sunny springs. The "decision" to flower is taken during the previous summer, though it may be modified through winter/spring abortion of above-ground organs. The proportion of the population electing to flower is the only measured parameter that impacts significantly on annual reproductive output, emphasising the under-rated difficulty of evolving through directional selection. Any attempt to predict the behaviour of plant species in response to climate change must integrate information on demography with that on life history, habitat preference and intimate symbioses.

Doubling Farmer Income through Cultivating Headed Broccoli (Brassica oleracea var. Itilica) under Different Irrigation Regimes and Water Saving Techniques

Doubling Farmer Income through application of precious irrigation and water saving techniques in vegetable crops may be possible under change in climatic and water scarcity conditions by proper inclusive adaptation of the results of present field experiment investigation. Significantly higher, net returns and benefit cost ratio Was observed in IR treatment I1.00. Total cost of cultivation and benefit cost ratio were significantly higher in IR treatment I0.75. The net returns and benefit cost ratio were significantly higher in WST treatment MK and benefit cost ratio were in MC. The treatment combination I1.00 x MK had given higher returns followed by followed by the treatment I0.75 x MBP among all the treatments. However, based on the IWM aspect to overcome the problem of irrigation water scarcity, adaptation and mitigation of changed climate as well as projected future climate change through precision farming, increasing leaf area, decreasing ambient temperature and economic profitability factor i.e. net returns from the cultivation of headed broccoli, the treatment combination I0.75 x MBP and I0.50 x MBP were observed significantly superior amongst all the treatments.

Interactions between endophytic fungus Pestalotiopsis sp. DO14 and Dendrobium catenatum: Deciphering plant polysaccharide and flavonoid accumulation and underlying mechanisms by comparative transcriptome and metabolome analyses

Dendrobium catenatum, which belongs to the Orchidaceae family, has been used as a traditional medicine and healthy food in China for over 2000 years, and is of enormous economic value. Polysaccharides and flavonoids are two major functional ingredients in D. catenatum stems that contribute to its health benefits. D. catenatum lives in close association with endophytic fungi, but the literature regarding the further relations between them, especially the fungal-induced accumulation of metabolites in the host plant, is sparse. Our previous study showed that Pestalotiopsis sp. DO14 isolated from D. catenatum improved the host plant growth and metabolite accumulation. This study was performed to investigate dynamic variations of the growth traits, key metabolites (polysaccharides and flavonoids), and expression of key genes of D. catenatum under conditions of the DO14 colonization. Colonization with DO14 promoted D. catenatum growth as indicated by increased leaf area, mid-stem thickness, and plant height. The content of polysaccharides, mannose, and sucrose increased even without DO14 entering the host cells or forming a mature symbiotic relationship concurrent with improved photosynthesis rate. Furthermore, DO14 induced upregulation of genes involved in sugar and flavonoid metabolism, especially phosphoenolpyruvate carboxykinase (PCKA), chalcone synthase (CHS) and UDP-glycose flavonoid glycosyltransferase (UFGT). These observations suggested that endophytic fungi induce the accumulation of polysaccharides and flavonoids by plants, increasing the efficiency of carbon assimilation and carbon turnover. The findings of this study provide insight into the mechanisms underlying Orchidaceae–endophyte interactions, and suggest potential novel applications of endophytic fungi in D. catenatum breeding to improved plant quality.

Effect of POLY4 Application on the Growth and Yield of Groundnut (Arachis hypogaea L.)

Aim: To evaluate the effect of POLY4 Application on the Growth and Yield of Groundnut.
 Study Design: Randomized Block Design.
 Place and Duration of Study: Gungal Research Farm, ICAR-Central Research Institute for Dry land Agriculture, Hyderabad, India between June 2022 and October 2022.
 Methodology: A field experiment was conducted at Gungal Research Farm, ICAR-Central Research Institute for Dry land Agriculture, Hyderabad, and Telangana during the Kharif season of 2022 to the evaluate the Impact of POLY4 Application on the Growth and Yield of Groundnut. The experiment was assigned in ten treatments, laid out in Randomized Block design with three replications. The treatments were T1-Recommended NPK (20:40:50 kg ha-1) + gypsum @ 500 kg ha-1, T2-Recommended NP only, T3-Recommended NPK, T4-Recommended NP + 50% K through MOP, T5-Recommended NP + 100% of rec. K through Poly4, T6-Recommended NP + 100% of rec. K through Poly4 + gypsum @ 310 kg ha-1, T7-Recommended NP + 50% of rec. K through Poly4, T8-Recommended NP + 50% of rec. K through Poly4 + gypsum @ 310 kg ha-1, T9-Recommended NP + gypsum @ 500 kg ha-1 and T10-Control.
 Results: The application of Recommended NP(20:40 kg ha-1) + 100% of rec. K(50 kg ha-1) through POLY4 (T5) treatment resulted in a significant increase in both plant height and leaf area at vegetative (18.1 cm and 320.4 cm2 plant-1), at flowering (31.9 cm and 554.7 cm2 plant-1),at pegging (39.5 cm and 785.3 cm2 plant-1), at pod formation (48.5 cm and 1088.5 cm2 plant-1), and at the harvest (54.4 cm and 359.5 cm2 plant-1) respectively compared to the control. Significantly higher pod yield (1556 kg ha-1) was recorded under Recommended NP (20:40 kg ha-1) + 100% K (50 kg ha-1) through POLY4 (T5). The lower yield (844 kg ha-1) was recorded in control (T10).
 Conclusion: Polyhalite, also known as POLY4, is a highly effective fertilizer that provides potassium (K), sulfur (S), magnesium (Mg), and calcium (Ca) in a more efficient manner compared to equivalent soluble salts. Based on the findings of the current study, it can be concluded that application of 100% K through polyhalite (POLY4) along with recommended doses of nitrogen and phosphorus (20:40 kg ha-1) in sandy loam soil was the best performing treatment.

The Effect of the Application of Mycorrhiza on Vegetative Growth, Mineral Element Intake, and Some Biochemical Characteristics of Strawberry Seedlings under Lime Stress

This study aims to determine the effects of vesicular–arbuscular mycorrhiza (VAM) applications on vegetative growth, mineral element intake, and some biochemical characteristics of strawberry seedlings grown under lime stress conditions. The experiment was conducted with frigo seeds of "Albion" strawberry cultivar in pots filled with 1% lime mixture and 1:1 ratio of peat and perlite. In the uprootings performed in three different stages (four leaved, blooming, and fruit stages) to examine the biochemical effects of mycorrhiza applications against the lime stress, vegetative growth criteria (leaf chlorophyll and anthocyanin content, area, crown diameter, fresh and dry plant weights) and mineral contents in the plant parts (leaf, crown, and root) were determined. The proline, total phenolic content, and malondialdehyde (MDA), end product of the lipid peroxidation, analyses were conducted on the leaf samples taken in these uprooting. In all three stages, an increase in crown diameter and leaf area was determined. In uprooting periods, proline and total phenolic amounts increased, and, on the other hand, MDA decreased. Microelement intake, which decreased with the lime application, was detected to be increased with mycorrhiza applications. At the end of the experiment, mycorrhiza application was observed to lessen the effect of lime stress on strawberry seedlings.

Tracking Moisture Sources of Precipitation Over China

AbstractMoisture of precipitation originates from terrestrial and oceanic evaporation through atmospheric transport. Understanding the contributions from different moisture sources to precipitation is essential for the hydrologic study. China is the world's third largest country in terms of land area and has contributed 25% of the global net increase in vegetation leaf area since 2000. Thus, it provides a good platform to understand the contributions from different moisture sources to precipitation and how increasing vegetation greenness affects precipitation trends. In this study, we investigated the moisture sources of precipitation and their changes in China during 1980–2018 based on the UTrack moisture recycling data set. We found that 47.3% of the moisture was from oceanic evaporation, and 52.7% was from terrestrial evapotranspiration (ET). For the moisture from terrestrial ET, 33.0% was from vegetation transpiration. The observed annual precipitation showed a significant increasing trend with 2.07 mm/year in China from 1980 to 2018. Increasing moisture from oceanic evaporation contributed the most to the increasing precipitation trend (0.98 mm/year), followed by the increasing moisture from vegetation transpiration (0.72 mm/year) and other terrestrial evaporation (0.37 mm/year). The increasing contribution of vegetation transpiration from China was comparable with that from neighboring countries (0.37 vs. 0.35 mm/year). The increasing moisture from vegetation transpiration could be due to the nationwide afforestation projects in China since 1999. The results provide a reference for understanding changes in precipitation and hydrologic processes.

Field-grown cotton shows genotypic variation in agronomic and physiological responses to waterlogging

ContextWaterlogging frequently occurs and causes serious damage to cotton. While genotypic variation in waterlogging tolerance has been reported in cotton, there is limited research on the difference in waterlogging tolerance among Chinese commercial cotton varieties, and whether waterlogging tolerance is related to their geographical origin remains unclear. MethodsTo this end, we conducted a comparative study to evaluate the waterlogging tolerance of commercial cotton varieties from three major cotton-growing regions in China. Field-grown cotton was subjected to seven days of waterlogging stress at early flowering. The effects of waterlogging on growth, seedcotton yield, yield reduction, and various physiological responses were assessed. ResultsThe losses of seedcotton yield and biological yield of cotton varieties from the Yangtze River valley were the lowest (7.6% and 4.7%), followed by those from the Yellow River valley (14.4% and 7.7%), while the losses of cotton varieties from the Northwest Inland were the greatest (21.8% and 15.5%). This indicated that cotton ecotypes from the Yangtze River valley and Yellow River valley, characterized by higher precipitation, exhibit greater tolerance to waterlogging than those from the Northwest Inland. The increases in H2O2, malondialdehyde (MDA), and abscisic acid (ABA) contents in the cotton variety from the Yangtze River valley (YZ1) were the lowest (10.8%, 18.6%, and 20.8%, respectively), followed by those from the Yellow River valley (YL1) (32.6%, 33.2%, and 79.9%, respectively), while the increases in cotton varieties from the Northwest Inland (NW1) were the greatest (37.9%, 42.8%, and 84.4%, respectively). The decreases in indole-3-acetic acid (IAA), nitric oxide (NO), and nitrogen (N) contents of YZ1 were the lowest (10.3%, 32.5%, and 25.6%, respectively), followed by those from YL1 (12.7%, 39.8%, and 30.2%, respectively), while the decreases of NW1 were the greatest (24.9%, 48.3%, and 45.1%, respectively). Quantitative real-time PCR analysis showed the highest expression of the NO (GhNIR) and IAA (GhYUC8) synthesis genes, but the lowest expression of the genes involved in H2O2 production (GhRBOHC), and ABA synthesis (GhNCED2) in YZ1, followed by those in YL1 and NW1, indicating that gene expression patterns aligned with the changes of NO, IAA, H2O2 and ABA contents. Ten days after waterlogging relief, waterlogged YZ1 exhibited the greatest increases in biomass, leaf area, and canopy photosynthesis (44.1%, 40.0%, and 46.4%, respectively), followed by YL1 (39.0%, 36.9% and 40.5%, respectively), while NW1 showed the lowest increases (36.3%, 32.6% and 35.4%, respectively), indicating stronger compensatory growth in the Yangtze River valley cotton variety. ConclusionsThe results suggest that cotton varieties from the Yangtze River valley were more tolerant to waterlogging as evidenced by the lower level of damage and stronger compensatory growth than those from other geographical origins. We propose that quiescence adaptation and compensatory growth are the two main strategies employed by cotton to cope with waterlogging stress. This study enhances our understanding of the damage caused by waterlogging and sheds light on the adaptive mechanisms of cotton. Furthermore, it provides valuable insights for the breeding waterlogging-tolerant cotton varieties and improving cultivation practices.

Growth, Yield, and Agronomic Use Efficiency of Delayed Sown Wheat under Slow-Release Nitrogen Fertilizer and Seeding Rate

Delayed sowing of wheat is a common problem in Punjab that exacerbates serious yield loss. However, individual or combined applications of seed rate and slow-release nitrogen fertilizer significantly impacted their efficacy in improving crop growth and productivity. In this regard, the present study explored the potential of slow-release nitrogen fertilizers (control (CK), simple urea (SU), neem-coated urea (NCU), and sulfur-coated urea (SCU)) to improve the growth, yield, and physiological and biochemical attributes of delayed sown wheat with three seed rate [(100 kg ha−1 (S1), 125 kg ha−1 (S2), and 150 kg ha−1 (S3)]. The study was carried out at the Postgraduate Agricultural Research Station of the University of Agriculture Faisalabad in 2018–19 and 2019–20. The study findings revealed that the sulfur-coated urea performed better under S3 seed rate. Combining SCU with S3 significantly increased leaf area index by 0.99 cm2 and plant height by 8.24% compared to simple urea, maximum spikelets, and spike length by 3.9 and 3.8 cm, respectively. The SCU with S3 treatment also increased the biological yield by 43% and 41% and the grain yield by 46% in 2018–2019 and 2019–2020, respectively, compared to CK. Similarly, higher N contents in straw and grain were recorded in the interaction of SCU with S3 treatment. Likewise, the SCU with S3 treatment enhanced the physiological attributes, i.e., chlorophyll contents and transpiration rate, by 18% and 25%, respectively, and decreased internal CO2 by 25.5%, compared to CK. In conclusion, applying sulfur-coated urea with a seed rate of 150 kg ha−1 could be considered a potential strategy for improving the growth and productivity of delayed sown wheat.

Effect of Nitrogen, Phosphorus and Fermented Poultry Waste on Pigments Balance and Lettuce Plant Growth

A field experiment was carried out in the season 2021–2022 in the Dora/Baghdad area on lettuce plants and included the treatment of soil with two levels of poultry waste (0,12) tons ha−1, phosphorus added at three levels (0, 100, 120) kg P ha−1 and nitrogen at three levels (0, 120, 180) kg N ha−1. The results showed a significant increase in leaf area and chlorophyll when adding fermented poultry waste, and the treatment of fertilization with poultry waste was superior to 670 Dcm2 and 40.60 for both leaf area and chlorophyll, respectively, and a significant increase was found when fertilizing with poultry waste. In urea phosphate levels, significant differences were recorded, while no significant differences were recorded in chlorophyll, and the fertilization with ammonium sulfate levels recorded significant differences for the two indicators, and the interaction treatment p1A3U3 recorded the highest values, which were 793 Dcm2 and 45.16 for each leaf area and chlorophyll, respectively, and there was a significant increase in the biological yield and economic yield of lettuce. When adding fermented poultry waste, the treatment of fertilization with poultry waste was recorded as 3237 gm plant−1 and 1678 gm plant−1 for both biological yield and economic yield, respectively. significant increase when fertilizing with urea phosphate levels and with significant differences, and the addition of ammonium sulfate showed significant increases for the two indicators, and the interaction treatment p1A3U3 recorded the highest values, and it was 4250 gm plant−1 and 2200 gm plant−1 for both biological yield and economic yield, respectively, and there was a significant increase in the proportion of protein and beta-carotene When adding fermented poultry waste, the treatment of fertilizing with poultry waste was superior to 1.35 gm of 100 g−1 and 1.330gm 100ml−1 juice for both protein and beta-carotene ratios, respectively. A significant increase was also found when fertilizing with urea phosphate levels with significant differences, and the addition of ammonium sulfate, which resulted in significant increases for the two indicators. And the interaction p1A3U3 treatment recorded the highest values, which were 1.50 g for 100 gm−1 and 1.853 gm for 100 ml−1 juice for each of the protein and beta-carotene ratios, respectively.

Effect of Foliar Spray of Nano Nitrogen and Bread Yeast on some Vegetative Growth of Pepper Plants

The College of Agriculture - Sumer University conducted a field experiment in 2019 to explore the effects of spraying pepper plants with nano-nitrogen and yeast extract on various vegetative features. Two variables’ effects were investigated in this experiment. Spraying pepper seedlings with three different concentrations of nano nitrogen (0, 2, 4 mlliter-1) and three different concentrations of yeast extract were the first two factors (0, 3, 6 g L-1). With three repetitions and nine experimental units per duplicate, the experiment was conducted in a fully randomized block design (RCBD). According to the findings, spraying with nano-nitrogen N2 resulted in a significant increase in the plant height and stem diameter, as well as an increase in leaf area and chlorophyll content in the leaves compared to the control treatment with N0. In contrast to spraying with yeast extract, the spraying treatment Y2 was more effective in terms of plant height and stem diameter, the number of leaves, leaf area, chlorophyll content in the leaves and percentages of N, P and K in the leaves than the control treatment Y0.

تقييم فعالية الفطر. Hirsutella sp ومبيد النيماتودا Verox لمقاومة النيماتودا تعقد الجذر Meloidogyne spp على شتلات التين

This study was conducted in the plastic house of the College of Agricultural Engineering Sciences at the University of Baghdad to evaluate the activity of Hirsutella sp. fungus and Nematode Verox against Meloidogyne spp. causative agent of root knots in Fig seedlings. Treatment of Meloidogyne spp. eggs with Hirsutella sp. at 20ml/L and with Verox at 2g/L caused significant inhibition in eggs hatching after 3,5 and 7 d. The number of non- hatching eggs were 96.70, 54.00and 29.30 eggs respectively in petri plates treated with Hirsutella sp., 106.70, 60.00and 46.00 eggs respectively in petri plates treated with Verox compared with 116.70, 111.00and96.00 eggs respectively in control. The treatment caused significant inhibition of juvenile-2 at the same periods. The number of juvenile-2 were 123.30, 114.00and 109.30 petri plates treated with Hirsutella sp at 20ml/L110.00, 63.00 and 26.70 in seedlings treated with Verox at 2g/L compared with 136.70, 132.00and120.00 in control after 3,5 and 7 d respectively. High significant reduction in root knots index and disease severity were observed in seedlings treated with Hirsutella sp. and Verox, 2.00 and 1.33% compared with 3.33 and 3.32% in control respectively. Significant increase in Phenylalanine Ammonia– Lyase and Chitinase activity induced in Fig seedling treated with Hirsutella sp. and Verox. PAL activity attained to 17.43and19.23 and 18.85 mg cinnamic acid/h/g fresh weight in seedlings treated with Hirsutella sp.16.76, 18.56and 18.05 mg cinnamic acid/ h /g fresh weight in seedlings treated with Verox compared with 15.30, 17.13and 15.74 mg cinnamic acid /h/g fresh weight in control after 3,5and 7 d respectively. The treatment induced significant increase in nitrogen and potassium in the leaves, Nitrogen and potassium percentage were attained to 7.619% and 2.120% in seedling treated with Hirsutella sp. 3.558%and 2.080% in seedlings treated with Verox compared with 2.858% and 1.820% in control respectively. Significant increase in leaf area and in seedlings height were observed in treated seedlings, 157.467 cm²and2.667 cm in seedling treated with Hirsutella sp, 134.687 cm2and 3.837 cm in seedlings treated with Verox compared with 105.883 cm2and 0.662 cm in control respectively. The treatment of Fig seedlings with Hirsutella sp and Verox induced significant increase in leaf chlorophyll content, foliage fresh weight, root fresh weight, foliage dry weight that attained to 37.17, 44.67, 60.63, 16.90 and 17.2ag respectively in Seedlings treated with Hirsutella sp, 35.83 , 44.33 , 52.50, 14.63 and 19.20g respectively in seedling treated with Verox, compared with 30.90, 28.57, 39.00 ,11.63 and 12.07g in control respectively.

차광재배에 따른 차나무 생육특성 및 말차의 품질변화

The term matcha means that tea leaves cultivated under shade are prepared by pulverizing the leaves with a grinding machine (such as a stone mill or a ball mill), turning the tea leaves into a fine powder. There is a great difference in quality depending on cultivation techniques such as the shading period and the type of shade. This study investigates the effect on growth and physiological changes of tea leaves for the production of high-quality green tea depending on the use of sequential double shading (SD-SD) and sequential single shading (S-SD). Leaf area, moisture content, photosynthetic capacity, and G-value increase based on the amount of shade in the following order: SD-SD > S-SD > no shade. Total phenolic compound and catechin content were highest in unshaded matcha. Antioxidant activity was highest in unshaded matcha, which also coincides with the highest phenolic compound content, such as catechins. Sugar content was highest from no shade, with leaves absorbing the most light energy, and the free amino acid content was highest under SD-SD. The results of taste analysis through an electronic tongue showed the highest sour taste and umami from S-SD, a salty taste from no shade, and sweet taste, bitter taste, astringent taste, and spicy taste from SD-SD. The overall physiological and growth status and beneficial ingredients showed that SD-SD increases the color of the tea leaves more than S-SD, and sequential double shading is effective in reducing stress on tea plants.

IMPACT OF THINNING AND FOLIAR-BORON-ZINC SPRAY ON SOME MORPHOLOGICAL AND PHYSIOLOGICAL INDICATORS IN APPLE TREE (MALUS DOMESTICA CV. GOLDEN DELICIOUS)-"TARTOUS GOVERNORATE"

The research was conducted in Tartous governorate on apple trees cv. Golden Delicious grafted on the rootstock “Malus domestica Borkh”, during two seasons 2019-2020 to study the impact of manual and chemical thinning using foliar boron /zinc spray separately or in combination on some morphological and physiological indicators. The results showed a significant increase in leaf area and its content of total chlorophyll and carotenoids in the second season (low fruit load) compared to the first season (heavy load) due to a rise in vegetative growth and a reduction in fruiting. During the heavy load season, a balance between vegetative and fruiting growth was noted when the manual and chemical thinning applied with no significant differences was found between the two seasons in leaf area, total chlorophyll and carotenoids content. On the other hand, the application of manual thinning, chemical thinning and foliar spraying with boron and zinc separately or together pointed out an increase in the branches content of carbohydrates and nitrogen and C/N ratio in the low load season compared to the control. Consequently, fruit thinning was more effective to obtain a balance between the seasons in term of leaf area, its pigments content, and C/N ratio in branches, which in turn mitigate the alternate bearing phenomenon.

Increased sensitivity of greening to afforestation in China over the recent 20 years

China has experienced extensive afforestation over the recent 20 years. The observed terrestrial vegetation greening in China, characterized by increasing leaf area index (LAI), is mainly associated with afforestation illustrated by increasing tree cover fraction. The increasing tree cover fraction not only contributed directly to greening but also impacted the vegetation growth conditions. Quantifying the combined direct and indirect effect of tree cover fraction change on vegetation greening is challenging and not yet conducted. Here we propose an index, namely the sensitivity of greening to afforestation (SGA=∂LAI∂TCF) to evaluate this effect. Comparing satellite-based land cover observations of 2003–2012 with 2010–2019, SGA in China increased by 1.03, 0.49, 3.3, and 2.46 (10−2 m2 m−2 %−1) for evergreen needleleaf, deciduous broadleaf, evergreen broadleaf, and mixed forests, respectively. This indicates greening (increasing LAI) becomes more sensitive to afforestation (increasing tree cover fraction), particularly in evergreen broadleaf forests. To explore possible eco-hydrothermal factors contributing to the observed SGA increase, a diagnostic framework synergizing atmospheric supply (precipitation and potential evaporation) and biological use (vegetation transpiration) of water and energy was constructed. The results suggest that an eased water-energy constraint mostly facilitates the observed SGA increase.

Beyond Electroculture: Modeling Possible Effect of Low Intensity Laser Pen to Improve Plant Growth

It is known that in many regions in this earth, there are growing concerns on rice and other crops supply stability, while the water supply for irrigation has become more scarce. Part of the problem is that farm lands have been reallocated to other purposes, including housing etc, and other reasons include the technology on farming was quite in stagnation for years. In this regard, studies have shown beneficial effects of laser technology to boost plant growth and especially during seed formation. In this small experiment, we take a look at modeling of such low intensity laser pen interacting with plant leaf, and then we tried to look at how low intensity laser pen actually can improve leaf textures, etc. Not necessarily increased leaf area is the only concern, as quality of leaf shall be more visible after low intensity laser pen treatment. It is our hope that this experiment can be useful in one or other ways especially in the spirit of Masanobu Fukuoka, the father of natural farming.

A physically-based potential evapotranspiration model for global water availability projections

When the projections from the hydrological models conflict with those from the fully-coupled climate model, the vegetation appears to be responsible for the divergence. In the presence of an elevated concentration of atmospheric CO2 (Ca), the leaf-level stomatal conductance (gsl) tends to decrease thereby reducing water demand, and such effects can be partly offset by the increased leaf area (generally represented by leaf area index, LAI) simultaneously. Nonetheless, the impacts of vegetation are rarely explicitly quantified in existing potential evapotranspiration (EP) models. In this study, we proposed a new EP equation that combines a well-established gsl model with a simple bulk upscale model. The new model allows us to investigate the effects of elevated Ca-induced physiological and structural changes in vegetation on EP estimations. The results show that, compared to conventional EP models (e.g., the Penman-Monteith reference crop model), the new EP equation performs better in capturing long-term EP changes. Furthermore, we embedded the new EP equation in a simple hydrologic model, the Budyko framework, to estimate the changes in long-term runoff. By accounting for both physiological and structural responses of vegetation, estimated runoff by the Budyko framework shows a significant increase of ∼ 30 mm/year in 2071–2100 compared to 2006–2035, consistent with projections from fully-coupled climate models. The increase in LAI offset ∼ 30% of the water-saving caused by stomatal closure on a global average. The newly developed EP model provides a fully transparent and easy-to-use way for describing the impacts of climate change-induced vegetation responses on EP and can be effectively employed to detect long-term hydrological changes.

Preparation and characterization of biochar and its effects on soil properties, rhizosphere bacterial and tobacco yield with reduced compound fertilizer application

Biochar is known to have soil-improving effects and has been applied in agricultural production. Continuous cropping of flue-cured tobacco is common due to limited land resources, which can lead to soil obstacles that negatively affect yield. This study aimed to use agricultural waste as raw material to prepare biochar, to improve soil and alleviate continuous cropping obstacles. A 7-year continuous cropping filed of flue-cured tobacco variety ‘yunyan 87′ in Luoshui Town was selected, with four treatments, compound fertilizer (T1) alone, and biochar with 100, 75 and 50% amount of compound fertilizer (T2, T3 and T4), respectively. The physicochemical properties of biochar were studied, its structure was observed under an electron microscope. Its effects with reduced compound fertilizer application on agronomic traits, tobacco yield, soil enzyme activity and rhizosphere bacteria communities were investigated. In the results, biochar increased the tobacco yield (by 10.84%) compared to the same amount of fertilizer without biochar. Biochar application with 75% compound fertilizer (T3) could increase leaf area and yield of flue-cured tobacco significantly. T3 treatment had little effect on the phenoloxidase activity in the rhizosphere soil, however it significantly enhanced the activities of peroxidase, protease and urease by 56.84%, 50% and 11.94% respectively, compared with the T1 treatment. The α-diversity was the highest Under the T1 treatment. Biochar application (T2–T4) increased the soil pH significantly. Under biochar application with the decrease of compound fertilizer, the relative abundance of Proteobacteria improved whereas the abundance of unidentified_Bacteria, Chloroflexi and Gemmatimonadetes decreased. Overall, the study provided evidence that the use of biochar with reduced amount of compound fertilizer could effectively improve the growth, soil quality and alleviate the negative effects of continuous cropping on tobacco. These findings provided a reference for the potential use of agricultural waste and promoting sustainable crop production.

Plant growth regulators affecting maize leaf senescence and area index impact yield under drought

Increasing leaf area duration (LAD, delaying leaf senescence) may be a suitable method to enhance maize (Zea mays L.) growth in drought stress conditions. Accordingly, it was hypothesized it is possible to enhance maize tolerance to drought stress conditions using plant growth regulators (PGR), which may increase leaf area index and delay leaf senescence. The experiments, conducted in two different sites in the province of Fars, Iran in 2018, were split plot on the basis of a complete randomized block design with four replications. Water stress (main factor) including control (S1) mild (S2), and sever stresses corresponding to irrigation after 80, 100- and 120-mm evaporation, respectively, and PGR (sub factor) including water spray (control), benzyl-adenine (45 mgL−1), proline (45% concentration), salicylic acid (45 mgL−1) superoxide dismutase (2.5 mgL−1), and their combination were tested. Drought stress significantly affected the measured parameters including leaf area index and durability, SPAD index, plant height, total dry weight, grain filling rate, peduncle length, number of grains per cob, biological and grain yields, and harvest index. However, the tested PGR, especially the combined one, were able to alleviate the stress by enhancing leaf indexes, and maize grain yield and its components in stress conditions. The tested PGR numerically increased LAD (delayed senescence) at S3 compared with S2. It is possible to alleviate the unfavorable effects of drought stress on maize growth and yield production, using the tested PGR, which may enhance leaf related parameters including LAI and LAD (delaying leaf senescence).

Land‐Use Intensity Reversed the Role of Cropland in Ecological Restoration Over the World's Most Severe Soil Erosion Region

AbstractLong‐term extending cultivation activities resulted in the world's worst soil erosion on the Chinese Loess Plateau (LP). By converting cropland into vegetated land, the Grain for Green Project (GfGP)—the world's largest investment revegetation project—effectively alleviates the soil erosion on the LP. However, during the GfGP implementation, the positive effect of cropland to the revegetation and soil erosion control has been underestimated to date, hindering a comprehensive evaluation to the effect of cropland on ecological restoration. Here, we evaluated the effect of the GfGP on soil erosion control across the LP, analyzed the dominant driver of the LP vegetation greening, and further identified the contributions of croplands to this world's largest revegetation project. We found that the vegetation of the LP was significantly improved and its leaf area increased by 1.23 × 105 km2 after the implementation of the GfGP, which contributed 42% to the decrease of the LP soil loss. Among them, our results show that cropland contributed 39.3% to the increased leaf areas of the LP, higher than grassland (36.3%) and forestland (14.3%). With the reduction of agricultural area, the contribution of cropland to the increased leaf areas in the LP was still the largest, which was mainly due to the increase in cropland utilization intensity. This study highlights the significance of the GfGP in soil erosion control and revises our understanding of the role of cropland in ecological restoration and society development.

Влияние сроков посева на фотосинтез тритикале в условиях Приамурья

Abstract. In the Amur region the share of soybean in the structure of sown areas has reached 73.7 % over the last decade, the phytosanitary condition of agrocenoses has deteriorated, pesticide load on fields has significantly increased, which causes new ecological risks. Some reduction of this load may be caused by increasing the proportion of grain crops, including triticale. The purpose of the study was to establish the effective sowing date of spring triticale varieties providing optimal photosynthetic activity of agrocenoses in the conditions of Amur region. The method of field experiment by B. A. Dospekhov and determination of photosynthetic activity of crops by A. A. Nichyparovich were used. Scientific novelty. The photosynthetic activity of spring triticale varieties at different sowing dates in years with different meteorological conditions has been evaluated. Results. The greatest area of leaf apparatus is formed at sowing in April, 29 reaching maximum values in a phase of flowering in sort Ukro – 37,2 thousand m2/ha, in sort Yarilo – 30,4 thousand m2/ha, in sort Karmen – 33,0 thousand m2/ha. The correlation analysis revealed direct and strong influence of sowing dates on formation of the assimilative apparatus of plants and yield of spring triticale rxy = 0,833. Statistically significant differences were obtained p = 0.016. In the regression equation with increasing leaf area by 1 m2/ha the grain yield of triticale is expected to increase by 0.056 t/ha. Photosynthetic potential of the varieties differed in the years of research and depended on the value of the assimilating surface and the duration of the leaves. A regular decrease in net photosynthetic productivity from early to late sowing was established. The highest value of net photosynthetic productivity was obtained at sowing 15.04 – 2.03 g/m2 per day. The constituent elements of photosynthesis resulted in grain yields of the variety Yarilo – 2.26 t/ha, Ukro – 2.61 t/ha and Karmen – 2.23 t/ha.