Physiological Efficiency Research Articles

The plyometric activity as a conditioning to enhance strength and precision of the finger movements in pianists

Stability of timing and force production in repetitive movements characterizes skillful motor behaviors such as surgery and playing musical instruments. However, even trained individuals such as musicians undergo further extensive training for the improvement of these skills. Previous studies that investigated the lower extremity movements such as jumping and sprinting demonstrated enhancement of the maximum force and rate of force development immediately after the plyometric exercises. However, it remains unknown whether the plyometric exercises enhance the stability of timing and force production of the dexterous finger movements in trained individuals. Here we address this issue by examining the effects of plyometric exercise specialized for finger movements on piano performance. We compared the training-related changes in the piano-key motion and several physiological features of the finger muscles (e.g., electromyography, rate of force development, and muscle temperature) by well-trained pianists. The conditioning demonstrated a decrease of the variation in timing and velocity of successive keystrokes, along with a concomitant increase in the rate of force development of the four fingers, but not the thumb, although there was no change in the finger muscular activities through the activity. By contrast, such a conditioning effect was not evident following a conventional repetitive piano practice. In addition, a significant increase in the forearm muscle temperature was observed specifically through performing the plyometric exercise with the fingers, implying its association with improved performance. These results indicate effectiveness of the plyometric exercises for improvement of strength, precision, and physiological efficiency of the finger movements even in expert pianists, which implicates that ways of practicing play a key role in enhancing experts’ expertise.

Physio-biochemical, agronomical, and gene expression analysis reveals different responsive approach to low nitrogen in contrasting rice cultivars for nitrogen use efficiency.

Nitrogen (N) is an essential macronutrient for plant growth and development as it is an essential constituent of biomolecules. Its availability directly impacts crop yield. Increased N application in crop fields has caused environmental and health problems, and decreasing nitrogen inputs are in demand to maintain crop production sustainability. Understanding the molecular mechanism of N utilization could play a crucial role in improving the nitrogen use efficiency (NUE) of crop plants. In the present study, the effect of low N supply on plant growth, physio-biochemical, chlorophyll fluorescence attributes, yield components, and gene expression analysis were measured at six developmental stages in rice cultivars. Two rice cultivars were grown with a supply of optimium (120kgha-1) and low N (60kgha-1). Cultivar Vikramarya excelled Aditya at low N supply, and exhibits enhanced plant growth, physiological efficiency, agronomic efficiency, and improved NUE due to higher N uptake and utilization at low N treatment. Moreover, plant biomass, leaf area, and photosynthetic rate were significantly higher in cv. Vikramarya than cv. Aditya at different growth stages, under low N treatment. In addition, enzymatic activities in cultivar Vikramarya were higher than cultivar Aditya under low nitrogen, indicating its greater potential for N metabolism. Gene expression analysis was carried out for the most important nitrogen assimilatory enzymes, such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT). Expression levels of these genes at different growth stages were significantly higher in cv. Vikramarya compared to cv. Aditya at low N supply. Our findings suggest that improving NUE needs specific revision in N metabolism and physiological assimilation. Overall differences in plant growth, physiological efficiency, biochemical activities, and expression levels of N metabolism genes in N-efficient and N-inefficient rice cultivars need a specific adaptation to N metabolism. Regulatory genes may separately or in conjunction, enhance the NUE. These results provide a platform for selecting crop cultivars for nitrogen utilization efficiency at low N treatment.

Nitrogen efficiency indices of potato in response to nitrogen doses estimated by algorithms and applied as top-dressing

The objective of this study was to evaluate the effect of N doses estimated by algorithms and applied as top-dressing on different nitrogen (N) efficiency indices in Asterix potatoes. Two experiments were installed in the field. The experiments were conducted in the randomized block design, in split-plot scheme, with four replicates, whose treatments, in the plots, were determined by five N doses in pre-planting and, in the subplots, by three criteria (algorithms evaluated) of top-dressing N. At 21 DAE (days after an emergency), the fourth fully developed potato leaf was evaluated with the SPAD (Soil Plant Analysis Development) chlorophyll meter. This reading was used as an indicator of the need for top dressing. In harvesting the tubers, the following variables were determined: N content in shoots and tubers, amounts of N absorbed by shoots, tubers and total N, harvest index, N use efficiency, N agronomic efficiency and physiological efficiency of N. The application criteria did not significantly influence the variables related to the content and amount of absorbed N, except for the N content of the tubers in the 2018 experiment. Of N absorbed by shoots, tubers and plants and the agronomic efficiency of N were significantly influenced by the N dose applied pre-planting. The agronomic efficiency was significantly influenced by the N dose estimated by the N cover recommendation criteria. The highest values obtained for the variables related to the content and amount of N absorbed were those under application of 200 to 300 kg ha−1 of N.

Sustainable Production of Soybean (Glycine max L.) Crop Through Chemical Fertilizers and Organic Manures Along with the Improvement in Soil Health

A field experiment was carried out on the black cotton soil in the years 2018 and 2019 in the district of Sangli, Maharashtra, India to evaluate the sustainable agricultural practices for improving the growth and yield of the soybean (Glycine max L.) variety JS-335 along with the soil improvement. Twelve treatments were evaluated in a randomized block design with three replications. The results revealed that combined applications of chemical fertilizer (RDF-30:80:20:40) and organic manures (FYM and VCM) improved the growth attributes and seed yield as compared to control and other treatments along with a significant improvement in the soil health parameters. This agricultural practice emerged as a promising method for sustainable cultivation of soybean (C.V. JS-335) which improved the economic yield (kg.ha-1), agronomic efficiency (kg.ha-1), physiological efficiency (kg.ha-1), partial factor productivity (kg.ha-1), apparent recovery efficiency (kg.ha-1) and sustainable yield index (0.80) with maximum return having cost: benefit ratio (1:3.8). The results found statistically significant and correlated having a positive relationship between yield and sustainability parameters.

Precise delivery of nitrogen at tillering stage enhances grain yield and nitrogen use efficiency in double rice cropping systems of South China

Nitrogen fertilizer management substantially affects the growth, productivity, and nitrogen use efficiency (NUE) of rice production systems. To assess the effects of precise application of nitrogen fertilizer at tillering stage as ‘tillering-fertilizer’ on grain yield and nitrogen use efficiency, field trials were conducted in the late season of 2019 and 2020, in addition to a radioisotope 15 N tracer experiment. The experiment was comprised of four N fertilizer treatments i.e., no fertilizer application as a control (T1), traditional surface broadcast fertilization (90 kg N/ha as basal fertilizer and 60 kg N/ha as tillering fertilizer, T2), deep placement of tillering fertilizer (surface broadcast at 90 kg N/ha as basal fertilizer and 45 kg N/ha as tillering fertilizer at 10 cm depth, T3), deep placement of tillering fertilizer (surface broadcast at 90 kg N/ha as basal fertilizer and 30 kg N/ha as tillering fertilizer at 10 cm depth, T4) and two rice cultivars i.e., Wufengyou 615 and Yuxiangyouzhan . Results showed that grain yield remained 18.8% and 12.4% higher owing to increase in productive panicles and grain filling, 42.2% and 38.9% higher nitrogen agronomic efficiency, 4.6% and 10.4% higher nitrogen recovery efficiency, and 10.2% and 7.8% higher nitrogen physiological efficiency in T3 than T2 for Wufengyou 615 and Yuxiangyouzhan , respectively. Moreover, nitrogen derived from fertilizer in T3 was increased by 8.0% and 4.4% compared to T2 for Wufengyou 615 and Yuxiangyouzhan , respectively whereas the residual rate of T3 was increased by 31.5%. In addition, the T3 treatment substantially enhanced the leaf area index and leaf chlorophyll content that led to improved photosynthesis and the activities of enzymes related to nitrogen metabolism. Overall, 45 kg N/ha as tillering fertilizer at 10 cm depth and surface broadcast at 90 kg N/ha as basal fertilizer can improve grain yield as well as nitrogen use efficiency in late season rice production system of South China. • Precise delivery of nitrogen (PDN) at tillering stage (TS) can enhance grain yield in rice. • PDN at TS can improve nitrogen use efficiency in rice. • PDN at TS can increase nitrogen residual rate in the soil and decrease nitrogen unaccounted rate.

Physiological Efficiency of Sage Tea (salvia officinalis L.)Administration on Fertility in Adult Female Rats

Salvia officinalis L. (common name sage) is one of this which has been used since ancient Egyptian times for increasing women's fertility;it has been used traditionally to increase fertility have been rather poorly understood.The present work was aimed to investigate the physiological role of sage tea drinking in fertility capacity by some female reproductive parameters of rat during the experiment for 28 day to includes reproductive hormones (follicular stimulating hormone (FSH), luteinizing hormone (LH), estrogen and progesterone hormones) and reproductive indexes (fertility, gestation, post-natal viability and weaning viability indexes). Thirty six female rats were divided at random into three main groups'one control group and two treatment groups as first experiment (received orally by gavage single (0.057 g/kg B.W.) and double (0.114 g/kg B.W.) traditional doses/daily of sage tea drinking for 28 day respectively). The second experiment was done to evaluate the reproductive indexes for female fertility. The results showed a higher significantly increase in serum FSH, LH, estrogen and progesterone hormones levels non dose dependent orally administration of sage tea. But, the reproductive indexes showed a single dose related orally administration of sage tea.Concludes from this present finding that sage tea drinking may be improves female fertility via of the hypothalamic-pituitary-ovarian axis in adult rats.

Optimizing nitrogen application and sowing date can improve environmental sustainability and economic benefit in wheat-rice rotation

CONTEXTIn wheat-rice rotation, late sowing and excessive nitrogen (N) application lead to low annual yield and additional fertilizer waste. A comprehensive assessment of yield sustainability, N use efficiency, N balancing mechanism, and economic benefit is urgent. OBJECTIVETo explore the feasibility of optimizing N application and sowing date to improve yield, N use efficiency, and economic benefit in wheat-rice rotation. METHODSA two-year experiment of wheat-rice rotation was conducted in China, involving four N application rates (0, 180, 240, and 300 kg ha−1), three sowing dates (normal, delayed, and late sowing), three planting density (1.2 × 104, 1.8 × 104, and 2.4 × 104 seeds ha−1) for wheat (Yangmai-23), and four N application rates (0, 135, 270, and 405 kg ha−1), three sowing dates (normal, delayed, and late sowing), and three varieties (Yongyou-2640, Wuyunjing-32, and Nanjing-9108) for rice. Treatments were imposed in a split-plot experiment design with three replications (except N0). Soil information, N uptake, and yield were obtained through field survey and sampling. In addition, N balance was studied based on measured data and Denitrification-Decomposition (DNDC) model. Reactive N emissions (NH3, N2O, and NO) simulated by DNDC were converted into environmental damage costs for annual economic analysis. RESULTS AND CONCLUSIONSDelaying sowing could reduce annual yield from 6.14% to 13.72%, while appropriate N application can mitigate this trend. However, delaying sowing promoted soil N accumulation and yield sustainability. N fertilizer addition and late sowing would reduce annual N physiologic efficiency by 45.98%, N recovery efficiency by 42.02%, and N agronomic efficiency by 68.10%, leading to N surplus. Applying more N not only increased annual yield (24.85%–39.44%) and profit (74.27%–162.16%) but also brought more reactive N damage cost (7.40%–25.14%). In this study, the appropriate N application rate for delayed sowing (WR-S2) and late sowing (WR-S3) were 510–705 kg N ha−1 and 315–510 kg N ha−1, respectively. SIGNIFICANCEOptimizing N fertilizer and sowing date is an easy-followed strategy for improving yield, N use efficiency, and economic benefit in wheat-rice rotation, which is highly-consistent with United Nations Sustainable Development Goals. This strategy is simple to implement for policy formulation on precision agriculture and highly-effective to manage.

Biomass production and nutrient use efficiency in white Guinea yam (Dioscorea rotundata Poir.) genotypes grown under contrasting soil mineral nutrient availability.

Yam (Dioscorea spp.) is of great importance to food security, especially in West Africa. However, the loss of soil fertility due to dwindling fallow lands with indigenous nutrient supply poses a challenge for yam cultivation. This study aimed to determine shoot and tuber biomass and nutrient use efficiency of white Guinea yam (Dioscorea rotundata) grown under low- and high-NPK conditions. Six white Guinea yam genotypes were used in field experiments conducted at Ibadan, Nigeria. Experiments were conducted with low soil NPK conditions with zero fertilizer input and high soil NPK conditions with mineral fertilizer input. Differences in response to soil NPK conditions, nutrient uptake, and nutrient use efficiency (apparent nutrient recovery efficiency) were observed among the tested genotypes. The genotypes TDr1499 and TDr1649, with high soil fertility susceptibility index (SFSI>1) and an increase in shoot and tuber biomass with fertilizer input, were recognized as susceptible to soil NPK conditions. There was a marked difference in apparent nutrient recovery efficiency; however, there was no varietal difference in physiological efficiency. Differences in apparent nutrient recovery efficiency among genotypes affected the fertilizer response (or susceptibility to soil NPK conditions) and the nutrient uptake. In contrast, the genotype TDr2029, with SFSI<1 and low reduction in shoot and tuber production between non-F and +F conditions, was recognized as a less susceptible genotype to soil NPK status. It was revealed that NPK fertilization did not reduce tuber dry matter content, regardless of genotype differences in susceptibility to soil NPK conditions. Hence, this could be helpful to farmers because it implies that yield can be increased without reducing tuber quality through a balanced application of soil nutrients. Our results highlight genotypic variation in sensitivity to the soil NPK availability, nutrient uptake, and nutrient use efficiency white Guinea yam. Differences in susceptibility to soil NPK conditions could be due to the genotypic variations in nutrient recovery efficiency white Guinea yam. Our findings could contribute to breeding programs for the development of improved white Guinea yam varieties that enhance productivity in low soil fertility conditions with low and high-input farming systems.

The Delayed Effect of Low-Energy Lignite Organic Matter on the Treatment Optimization of Zea mays L. Grown for Silage

The field experiment was conducted in the central-eastern Poland. The aim of the research was to determine the effect of low-energy lignite organic matter applied to the preceding crop in the form of an organomineral fertilizer on the treatment optimization of Zea mays L. maize grown for silage. Two factors were taken into account in the research: factor I—five fertilization plots control plot—without fertilization (1), NPKMgS (2), NPKMgS + N1(3), NPKMgS + N2 (4), NPKMgS + N3 (5); factor II—three varieties of Zea mays L. Nitrogen was applied as fertilizers 3, 4 and 5 at doses of N1-20, N2-40 and N3-60 kg per hectare. In the spring each year, selected plots were pre-sown with mineral fertilizers at doses of 100 kg·N, 35 kg·P, 125 kg·K, 12 kg·Mg and 14 kg·S per hectare. Organomineral fertilizer based on low-energy lignite was applied to the preceding crop (maize grown for silage) on two plots, in 1 and 5 t·ha−1 doses. Mineral fertilizers used in research significantly reduced the content of nitrogen, phosphorus, potassium, magnesium and sulphur in the dry matter of plants. The uptake of the nutrients reached the highest values for maize treated with NPKMgS + N1, NPKMgS + N2 and NPKMgS + N3. The agronomic efficiency (AE) of nitrogen, phosphorus, potassium, magnesium and sulphur, all of which were applied in the form of the polyfoska® fertilizer, M-MAKS (NPKMgS), potassium salt and urea, reached the highest values for plots treated with NPKMgS + N1 and NPKMgS + N2. In turn, the treatment of NPKMgS and NPKMgS + N3 with nitrogen, phosphorus, potassium, magnesium and sulphur resulted in the highest values of physiological efficiency (PE). Based on the three-year research carried out with the use of polyfoska® M-MAKS (NPKMgS), potassium salt and urea in the fertilization of maize grown for silage, it is possible to recommend the optimal dose of NPKMgS + N1 mineral fertilizers (100-35-125-12-14 pre-sowing, 20 kg top dressing N) and NPKMgS + N2 (pre-sowing 100-35-125-12-14, top dressing 40 kg·N). The low-energy lignite applied to the preceding crop in doses of 1 t and 5 t at the NPKMgS + N1 and NPKMgS + N2 plots contributed to the achievement of the analyzed parameters (uptake, AE and AE) at a high level.

Rice CO 53: A high yielding drought tolerant rice variety for drought prone districts of Tamil Nadu

Early duration drought tolerant rice culture CB 06803, a derivative of the cross PMK (R ) 3 x Norungan was released as Rice CO 53 during the year 2020 as an alternate variety for Anna(R)4, with 115 -120 days duration. It possesses desirable features like high yield, drought tolerance and better physiological efficiency. This culture with semi dwarf stature has efficient tillering capacity, long droopy panicles with a highly acceptable plant characters and is a replacement for the rice variety Anna (R) 4 due to its grain yield and pest and disease resistance. In the overall yield analysis, the culture CB06803 recorded an overall mean grain yield of 3718 kg/ha which was 12.19 per cent increase over TKM (R) 12 and 14.08 per cent over Anna (R) 4 under dry condition. Under semi dry condition, it recorded 3866 kg/ha with 18.40 per cent increase over TKM (R) 12 and 8.67 per cent over Anna (R) 4. It is moderately resistant to WBPH, leaf blast, neck blast, sheath rot, brown spot and RTD under artificial condition. It has white short bold rice with high milling percentage (69.6), head rice recovery (59.6%) and suitable for idly making. The culture, CB 06803 had better &nbsp;agronomic efficiency than TKM (R)12 and Anna (R) 4 by recording more number of productive tillers per plant and grain yield under control and drought. The culture CB 06803 had better physiological efficiency under drought than TKM (R) 12 and Anna (R) 4&nbsp; having higher RWC, total chlorophyll content, chlorophyll stability index, photosynthetic rate, stomatal conductance and photo chemical efficiency. The culture had higher proline content than TKM (R) 12 and was on par with Anna (R) 4. It had higher catalase activity than Anna (R) 4. CB 06803 had better physiological efficiency under drought by showing partial closure of stomata as that of Sahbagidhan. CO 53 with higher grain yield under drought, disease resistance and short bold grains and suitable for cultivation in drought prone districts of Tamil Nadu as direct seeded rainfed or semi dry rice ecosystem. Keywords: Rice CO 53, bold grain rice, short duration, drought tolerance

CO 54 (IET 24313) : An early maturing high yielding rice variety with marketable grain quality suitable for Tamil Nadu

The rice culture, CB 12588 evolved by crossing CB 04110 x CB 05501 was released as CO 54 during the year 2021 as an alternate variety to CO 51 and ADT 43 with 105-110 days duration. CO 54 is a medium tall variety with a profuse tillering habit, long erect leaves and droopy compact panicles possessing more number of filled grains per panicle. CB 12588&nbsp; recorded an overall mean grain yield of 6354 kg/ha in various yield trials which was 10.83 per cent improvement over CO 51 and 10.35 per cent over ADT 53.&nbsp; CO 54 has got high yielding potential due to its high agronomic and physiological efficiency and the maximum yield of 9259 was recorded in Bhavanisagar, Erode district under multi location trial. A High yield of more than 7000 kg/ha was realized in 16 locations in an adaptive research trial.&nbsp; Besides yield, the culture CB 12588 has got marketable grain type i.e. medium slender grains with high milling outturn and head rice recovery percentage. Desirable cooking quality parameters like good linear elongation ratio, high volume expansion, intermediate amylose, soft gel consistency and moderate gelatinization temperature along with highly productive plant traits make CO 54 a suitable alternate variety to CO 51 and ADT 53. The culture CB 12588 is moderately resistant to blast, sheath rot, sheath blight and BPH under artificial conditions. The rice culture CB 12588 was released as CO 54 with a higher yield, better pest and disease resistance and good cooking quality in comparison to the checks CO 51 and ADT 53. It is suitable for cultivation during Kar/ Kuruvai/Sornavari/Navarai and the seasons/tracts wherever early maturing rice varieties are cultivated throughout Tamil Nadu. &nbsp;Keywords: CO 54, Short duration, high yield, medium slender, cooking quality

Utilization of air-cooled ventilation to reduce heat stress in Nuami sheep in Saudi Arabia

Tropical and temperate countries experience significant economic losses in summer due to heat stress. It is possible to mitigate thermal stress through advances in environmental management, for instance, better accommodations, improved cooling systems, and improved feeding strategies. We examined the influence of ventilation on Nuami ewes in hot climates to determine their physiological efficiency and thermoregulation. Ten dry, non-cycling Nuami sheep were allocated to two treatments (n=5): The control (C) group was kept at ambient temperature, while the treatment (AC) group was kept at air-cooled temperature. Respiratory rate, rectal temperature, and infrared images of representative body regions were recorded weekly. There was a significant difference in climatic conditions between the two rooms. In comparison to the C group, AC sheep gained weight. Dry matter intake (kg/day) increased, water consumption (l/day) decreased, WI/DMI ratios fell, and respiratory rates fell 1.5 times in AC sheep compared to C sheep. AC group showed lower rectal, rump, and leg temperatures than the C group. Regardless of climate variations, the temperatures of the eyes and belly stayed pretty constant due to their physiological, anatomical, and coat characteristics. Therefore, cooled-air ventilation is the best method to reduce heat stress in livestock in the summer.

Silicon modifies C:N:P stoichiometry and improves the physiological efficiency and dry matter mass production of sorghum grown under nutritional sufficiency

Silicon (Si) may be involved in the modification of C:N:P stoichiometry and in physiological processes, increasing sorghum growth and grain production. The objective was to evaluate the effect of Si supply on C:N:P:Si stoichiometry, physiological response, growth, and grain production of sorghum. The experiment was carried out in pots with four concentrations of Si: 0; 1.2; 2.4; and 3.6 mmol L−1 in a completely randomized design, with six replicates. Physiological attributes and dark green color index were measured and grain and biomass production were determined. Posteriorly, the plant material was ground to determine silicon (Si), carbon (C), nitrogen (N), and phosphorus (P) contents in order to analyze C:N:P:Si stoichiometry. C:Si and C:N ratios decreased at all Si concentrations applied (1.2, 2.4, and 3.6 mmol L−1) and in all plant parts studied, being lower at 3.6 mmol L−1. The lowest C:P ratios of leaves and roots were observed at 3.6 mmol L−1 Si and the lowest C:P ratio of stems was observed at 1.2 mmol L−1 Si. Si concentrations were not significant for the N:P ratio of leaves. The highest N:P ratio of stems was observed at 3.6 mmol L−1, while the lowest N:P ratio of roots was observed at 2.4 and 3.6 mmol L−1. Regardless of photosynthetic parameters, the application of 1.2 mmol L−1 Si enhanced photosynthetic rate. The application of 2.4 and 3.6 mmol L−1 enhanced stomatal conductance and dark green color index. The mass of 1000 grains was not influenced by Si applications, while Si applications at all concentrations studied (1.2, 2.4, and 3.6 mmol L−1) enhanced shoot and total dry matter, not affecting root dry matter and grain production. In conclusion, Si supply modifies C:N:P:Si stoichiometry and increases physiologic parameters, growth, development, and grain production in sorghum.

Response of Growth and Production of Red and Green Okra Plants to Effect of Organic Fertilization

The effect of nitrogen on growth, and development of plants, metabolism, dry matter production has been well investigated. Extensive research has been conducted on organic fertilizers especially, i.e. the compost. This study investigated the effect of compost on okra pods yield, nitrogen agronomic use efficiency, supplied of nitrogen recovery efficiency and supplied nitrogen physiological efficiency in okra (Abelmoschus esculentus L. Moench). A completely randomized experimental design of 2x4 factorial patterns with three replications was used in this study. Factor (I) was the okra species (Green okra - Red okra) and factor (II) was the doses of compost (0, 50, 100 and 150 kg N ha−1). Kind of okra has different effects on the parameters observed. Results showed that green okra and red okra showed increased yield due to the increase in the nitrogen dose through compost. Agronomic use efficiency of green okra and red okra increased with increasing doses of compost. The nitrogen recovery efficiency of green okra and red okra also, increased with increasing doses of compost. Nitrogen physiological efficiency of green okra and red okra increased with increasing compost doses. An increase in compost doses resulted in increased nitrogen uptake, pods yield, Agronomic efficiency, nitrogen recovery efficiency and nitrogen physiological efficiency of both green and red okra. Increased compost doses resulted in decreased nitrogen use efficiency in green okra. Green okra is more efficient in using organic nitrogen from compost.

Efficiency of Nitrogen Use in Sunflower.

The large variation in the response of sunflower to nitrogen fertilization indicates the need for studies to better adjust the optimum levels of this nutrient for production conditions. Our objectives were to analyze the agronomic yield of sunflower cultivars as a function of nitrogen fertilization; indicate the cultivar with high nitrogen use efficiency; and measure the adequate N dose for sunflower through nutritional efficiency. The completely randomized block design with split plots was used to conduct the experiments. The treatments included five nitrogen rates being allocated in the plots and the four sunflower cultivars. To estimate the nutrient use efficiency in the sunflower, we measured agronomic efficiency (AE), physiological efficiency (PE), agrophysiological efficiency (APE), apparent recovery efficiency (ARE), and utilization efficiency (UE). The results indicate that all cultivars had a reduction in AE due to the increase in N doses in the first crop. For PE, the highest values were observed for Altis 99 during the 2016 harvest. In that same harvest, Altis 99 had the highest APE. The dose of 30 kg ha−1 provided greater ARE for all cultivars in both crops, with greater emphasis on BRS 122 and Altis 99. The cultivation of cultivars Altis 99 and Multissol at a dose of 30 kg ha−1 in is recommended semiarid regions.

Yield and Nitrogen Status of Maize (Zea mays L.) Fertilized with Solution of Urea—Ammonium Nitrate Enriched with P, Mg or S

UAN is a popular nitrogen fertilizer, broadly used in world agriculture. Research concerning the effects of this fertilizer is just as common. Contrarily, studies on the combined application of UAN with P, Mg or S are lacking. This fact has stimulated our study, undertaken in order to evaluate the effects of maize grown for grain and fertilized with UAN enriched with the macronutrients (P, Mg and S) on the crop’s yields and nitrogen metabolism. The following nitrogen fertilizers were applied: UAN 32%N, UAN + S—26% N + 3% S, UAN + P (Medium)—26% N and 11% P2O5, UAN + P (Starter)—21% N and 18% P2O5, UAN + Mg—20% N + 4% Mg. Based on the results of chemical analyses and yields of maize, the following indicators of nitrogen use efficiency (NUE) were calculated: agricultural efficiency (AE), physiological efficiency (PE), internal N utilization efficiency (IE), reciprocal internal N utilization efficiency (RIE), grain share in N accumulation (HIN), recovery of N from mineral fertilizers (RN) and partial nitrogen balance (PNB). The highest grain yields were harvested after the application of UAN + S/UAN + Mg, and after the pre-sowing and top-dressing application of UAN or UAN + P (Medium). Values of all calculated nitrogen use efficiency indicators were more strongly dependent on the weather conditions, which determined volumes of maize yields in a given year, than on the applied fertilization.

Yield, nitrogen-use efficiency, and distribution of nitrate-nitrogen in the soil profile as influenced by irrigation and fertilizer nitrogen levels under zero-till wheat in the eastern Indo-Gangetic plains of India

Due to the introduction of zero-till wheat in the Indo-Gangetic plains (IGP) in India, irrigation and fertilizer nitrogen (N) management needs to be modified from that followed under conventionally tilled fields. A field experiment was conducted to study the effect of irrigation and N levels on yield and N uptake by zero-till wheat, fertilizer N-use efficiency, and distribution of nitrate-N (NO3-N) in a soil profile under zero-till conditions in an acidic alluvial soil of the eastern IGP. The experiment was laid out in a split-plot design with four levels of irrigation as main plots (I0-no irrigation, rain-fed, I1-122 mm in one irrigation at 21 days after sowing (DAS), I2-263 mm in two irrigations at 21 and 42 DAS, and I3-386 mm in three irrigations at 21, 42, and 84 DAS) and 4 N levels [0 (N0), 60 (N1), 120 (N2), and 150 (N3) kg N ha−1] as subplots. Grain and straw yields were significantly higher at the irrigation level-I2 and 120 kg N ha−1-N2 over the control (I0 and N0) and were at par with the highest applied levels of irrigation and N (I3 and N3). The nitrogen uptake by wheat followed a trend similar to yield for irrigation levels; however, it increased significantly up to 150 kg N ha−1. After the harvest of wheat crop, more NO3-N was observed in the 60–90 cm subsurface soil layer than in the surface 0–15 cm and/or 15–30 cm and 30–60 cm subsurface soil layers. The highest NO3-N concentration was recorded in the treatment I2N2. Accumulation of NO3-N in the soil increased up to irrigation levels I2 and with increasing doses of fertilizer N application. Combined applications of irrigation and N had a positive and significant influence on agronomic efficiency (AE) and apparent N recovery (ANR) but had no significant effect on physiological efficiency (PE). This study suggests that an appropriate combination of irrigation and N levels in zero-till wheat can lead to not only high-yield levels and N-use efficiency but also adequately control NO3-N leaching under acidic alluvial soils in the eastern IGP.

Cocoa Clones Reveal Variation in Plant Biomass, Root Nitrogen Uptake, and Apparent Nitrogen Recovery at the Seedling Stage

We aimed to investigate variation in growth, biomass, macro-nutrient uptake, and nitrogen (N) use efficiency indices of cocoa (Theobroma cocoa L.) scion clones under two different nitrogen conditions. Ten clones were top-grafted onto 4-month-old rootstocks clone MCC 02. Each seedling received either 0 or 4.6 g of nitrogen applied as urea fertilizer. The design was arranged as a two-factor experiment with four replicates in a factorial randomized block design. We measured stem diameter, biomass, nutrient concentration, and calculated nutrient uptake, nitrogen use efficiency (NUE), agronomic efficiency (AE), apparent nitrogen recovery (ANR), and physiological efficiency (PE). We found that clones significantly affected stem diameter and shoot biomass of both rootstocks and scions. Clones differed in root magnesium (Mg) and shoot calcium (Ca) concentration, root N, and shoot Mg uptake. Furthermore, a significant clone effect was observed on ANR, with local clones showing higher ANR than introduced clones. Nitrogen application significantly improved stem diameter and biomass. Compared to unfertilized plants, a significantly higher N concentration was observed in roots, resulting in higher N uptake in both roots and shoots. Nitrogen application increased shoot Ca concentration and uptake but decreased shoot phosphorus (P) and Mg concentrations. Our results suggest genotypic variability in nitrogen uptake efficiency in clonal cocoa. Clones with high nitrogen uptake efficiency are valuable genetic resources for breeding cocoa clones that efficiently use available N and, therefore, grow better under N-deficient conditions.

Compositional and Metabolic Responses of Autotrophic Microbial Community to Salinity in Lacustrine Environments.

ABSTRACTThe compositional and physiological responses of autotrophic microbiotas to salinity in lakes remain unclear. In this study, the community composition and carbon fixation pathways of autotrophic microorganisms in lacustrine sediments with a salinity gradient (82.6 g/L to 0.54 g/L) were investigated by using metagenomic analysis. A total of 117 metagenome-assembled genomes (MAGs) with carbon fixation potentially belonging to 20 phyla were obtained. The abundance of these potential autotrophs increased significantly with decreasing salinity, and the variation of sediment autotrophic microbial communities was mainly affected by salinity, pH, and total organic carbon. Notably, along the decreasing salinity gradient, the dominant lineage shifted from Desulfobacterota to Proteobacteria. Meanwhile, the dominant carbon fixation pathway shifted from the Wood-Lungdahl pathway to the less-energy-efficient Calvin-Benson-Bassham cycle, with glycolysis shifting from the Embden-Meyerhof-Parnas pathway to the less-exergonic Entner-Doudoroff pathway. These results suggest that the physiological efficiency of autotrophic microorganisms decreased when the environmental salinity became lower. Metabolic inference of these MAGs revealed that carbon fixation may be coupled to the oxidation of reduced sulfur compounds and ferrous iron, dissimilatory nitrate reduction at low salinity, and dissimilatory sulfate reduction in hypersaline sediments. These results extend our understanding of metabolic versatility and niche diversity of autotrophic microorganisms in saline environments and shed light on the response of autotrophic microbiomes to salinity. These findings are of great significance for understanding the impact of desalination caused by climate warming on the carbon cycle of saline lake ecosystems.IMPORTANCE The Qinghai-Tibetan lakes are experiencing water increase and salinity decrease due to climate warming. However, little is known about how the salinity decrease will affect the composition of autotrophic microbial populations and their carbon fixation pathways. In this study, we used genome-resolved metagenomics to interpret the dynamic changes in the autotrophic microbial community and metabolic pathways along a salinity gradient. The results showed that desalination drove the shift of the dominant microbial lineage from Desulfobacterota to Proteobacteria, enriched autotrophs with lower physiological efficiency pathways, and enhanced coupling between the carbon cycle and other element cycles. These results can predict the future response of microbial communities to lake desalination and improve our understanding of the effect of climate warming on the carbon cycle in saline aquatic ecosystems.

Ameliorating drought stress in sugarcane (Saccharum spp.) using biostimulants

In India, abiotic stress, particularly drought, is known to affect sugarcane cultivation. Among various management strategies, application of biostimulants, especially those from seaweeds, offer promising results in containing yield loss due to drought stress. Here, we tested the efficacy of Sea6 liquid biostimulant formulation LBS6 in field condition along with conventional management practices for comparison purpose using two popular commercial varieties of sugarcane (Co 86032 and Co 0212). Drought stress imposed during formative phase of the crop and foliar application of sea6 liquid formulation was applied at 60, 90 and 120 days after planting (DAP). The effect of liquid formulation on mitigating drought stress was assessed by studying the growth, physiological, yield and yield traits at important pheno-phases of the crop. Results showed that, in Co 86032 shoot population of control was 100.5×103 ha-1 and drought was 85.1×103 ha-1 with mean reduction of 15.5% over control. Drought stress induced 11.4, 12.4, 9.8 and 5.0% reduction in plant height, leaf area index (LAI), chlorophyll content (SPAD value) and photochemical efficiency, respectively. In Co 0212, drought induced 10.15, 9.4, 10.5, 9.5 and 5.1% reduction in shoot population, plant height, LAI, SPAD value and photochemical efficiency, respectively. Under drought condition, in Co 86032, foliar application of KCl (2.5%) and seaweed extract LBS6(2 mL L-1) was observed comparatively higher cane yield of 92.9 t ha-1 and 89.5 t ha-1, with 18 and 16.5% yield improvement over untreated drought plot, respectively. In Co 0212, foliar application of KCl (2.5%) and seaweed extract LBS6 (2 mL L-1) recorded 99 and 93.5 t ha-1 with 18.5% and 15.2% yield improvement over untreated drought plot, respectively. Among the two varieties, Co 0212 performed better under drought situation with KCl (2.5%) spray demonstrating better physiological efficiency under stress, closely followed by of sea6 formulation LBS6 (2 mL L-1). Further, the drought management practices did not affect the juice quality parameters in both the tested varieties.