N2 Treatment Research Articles

Growth, Productivity and Profitability of Fodder Sorghum and Cluster Bean as Influenced by Mixed Cropping and Nutrient Management

Background: The year round green forage supply for better health and productivity of the animals can be ensured by mixed cropping of cereal and legume forages along with proper nutrient management. Keeping these facts in mind an experiment was carried out to analyse growth, productivity and profitability of fodder sorghum and clusterbean as influenced by mixed cropping and nutrient management. Methods: Experiment was laid out in factorial randomized complete block design with four seed rate combinations of sorghum and clusterbean (S1 - sole sorghum, S2 - sole clusterbean, S3 - 75% sorghum + 25% clusterbean and S4 - 60% sorghum + 40% clusterbean) along with six nutrient management treatments (N1 - 100% RDF, N2 - 100% RDF + PGPR, N3 - 100% RDF + seaweed extract, N4 - 75% RDF + PGPR, N5 - 75% RDF + seaweed extract and N6 – 50% RDF + PGPR + seaweed extract) in three replications. The growth of crops was evaluated in terms of plant height, leaf length, leaf width, number of leaves, leaf stem ratio and stem girth which all together contributed towards the fodder yield. Results: In sorghum crop the growth was not statistically different between the treatments S1 and S3 but in clusterbean sole crop recorded higher growth yet the influence was not significant on all parameters. Among nutrient management N1, N2 and N3 treatments recorded higher growth and thus yield in both crops which was not statistically different from N5 treatment. The correlation study indicated that cumulative influence of these growth parameters resulted in higher green and dry fodder yield under sole crop. Whereas in mixed cropping S3 treatment recorded significantly at par fodder yield to S1. The evidence presented above shows that 75% sorghum + 25% clusterbean mixed cropping treatment with 75% RDF + seaweed extract served its purpose of fodder yield enhancement.

Carbon use efficiency and microbial functional diversity in a temperate Luvisol and a tropical Nitisol after millet litter and N addition

Tropical soils often contain less soil organic C (SOC) and microbial biomass C (MBC) than temperate soils and, thus, exhibit lower soil fertility. The addition of plant residues and N fertilizers can improve soil fertility, which might be reflected by microbial C use efficiency (CUE) and functional diversity. A 42-day incubation study was carried out, adding leaf litter of the C4 plant finger millet (Eleusine coracana Gaertn.) and inorganic 15N fertilizer. The aim was to investigate amendment effects on CUE and functional diversity in a tropical Nitisol and a temperate Luvisol. At day 42, 28% of the millet litter-derived C (C4) added was mineralised to CO2C4 in the temperate Luvisol and only 18% in the tropical Nitisol, averaging all N treatments. In contrast, none of the different fractions used for calculating CUE values, i.e. CO2C4, MBC4, microbial residue C4, and particulate organic matter C4, differed between the soils in the N0 (no N addition) treatment. CUE values considering microbial residues varied around 0.63, regardless of soil type and sampling day, which needs further evaluation. Millet litter increased autochthonous SOC-derived CO2C3 production, but N addition did not. This priming effect was apparently not caused by N mining. The respiratory response to most substrates added by multi-substrate-induced respiration (MSIR) and, thus, functional diversity was higher in the Luvisol than in the Nitisol. Millet litter had positive and N addition negative effects on the functional diversity of Nitisol, indicating that MSIR is a useful tool for evaluating soil fertility.

How N fertilizer side-dressing timings mediates fertilizer N fates in maize grown in a Mollisol

ABSTRACT A field micro-plot experiment with nitrogen isotope (15 N) labelling was performed to study the impacts of the timing of aside-dressed Napplication on urea-15 N in amaize-soil system. The treatments comprised three application timings, each of which consisted of the identical total rate of N, i.e. 280kg ha−1. In all treatments, 40% of the Nwas used theday prior to sowing, and the rest was used either at the jointing stage (V6) (N1), at the bell stage (V12) (N2) or at the tasselling stage (VT) (N3). The results indicated that the grain yields increased in both the N1 and N2 treatments compared with the N3 treatment. Asplit application of Nat the bell stage significantly raised the percentage of Nderived from fertilizer N(Ndff) compared to the two other side-dressed Napplication timings. The 15 N recovery efficiencies for the N2 and N1 treatments were 10% greater than the N3 treatment. The possible Nlosses in the N2 treatment were lower than those in the other treatments. Therefore, Nside-dressing at the bell stage is an alternative and sustainable management strategy for maize production and NUE in spring maize cropping systems.

Optimizing the split of N fertilizer application over time increases grain yield of maize-pea intercropping in arid areas

Abstract Productive cropping systems like cereal-legume intercropping might contribute to feeding the ever-growing population. However, intercropping systems require adapted nitrogen (N) fertilizer management that better match temporal and spatial N supply with crop demand. On the basis of field experiment conducted in northwestern China from 2012 to 2014, the study evaluated three N management practices in maize (Zea mays L.)-pea (Pisum sativum L.) intercropping on yield performance. All three treatments (N1, N2, and N3) received the same amount of fertilizer N prior to planting and at the pre-tasseling stage of maize, while they received different ratios of fertilizer N at jointing (45, 90, and 135 kg N ha−1 for N1, N2 and N3, respectively) and at 15 d post-flowering (135, 90, and 45 kg N ha−1 for N1, N2 and N3, respectively). The N1 treatment was superior to other treatments as it achieved a mean N nutrition index (NNI) near 1 and extended the duration of N accumulation by 3.6 d for pea and 9.0 d for maize. This treatment also improved the nodulation advantage of intercropped pea, enhanced compensatory intensity of intercropped maize, and increased yield components of pea and maize, compared to N3 (current farmer practice). Consequently, grain yield of pea and maize in intercropping with N1 was increased by 6 and 14 %, respectively, compared to N3. The optimized NNI and improved grain yield allow us to conclude that the N1 treatment with jointing top-dress N at 45 kg N ha−1 and 15 d post-flowering top-dress N at 135 kg N ha−1 can be used as an efficient N management practice for maize-pea intercropping.

ITRAQ-based quantitative proteomic analysis reveals the metabolic pathways of grain chalkiness in response to nitrogen topdressing in rice

Grain chalkiness is a highly undesirable trait that adversely affects rice quality. This chalkiness is easily influenced by the application of chemical nitrogen (N) fertilizer at the late growth stage. However, on the molecular mechanism underlying grain chalkiness caused by late N fertilization is not fully clear. In this study, proteomic differences in expression were determined in developing grains exposed to N topdressing (108 kg N ha−1, N+) and a control (0 kg N ha−1, N0), using the rice variety OM052, which has a high level of chalkiness. A total of 198 differentially expressed proteins (DEPs) were detected between the N+ and N0 treatments, including 9 up-regulated proteins and 189 down-regulated proteins. Of these DEPs, approximately half were associated with carbohydrate metabolism (glycolysis, tricarboxylic acid cycle, pentose phosphate pathway, fermentation and starch metabolism) and N metabolism (protein synthesis, folding, degradation and storage, amino acid synthesis and catabolism). A detailed pathway dissection revealed that multiple metabolic pathways during the grain filling stage were involved in the N-induced grain chalkiness. Reduced abundances of proteins associated with respiratory metabolism and energy metabolism drastically impaired the biosynthesis and deposition of starch in the developmental endosperms, which might be a crucial trigger for the increase in grain chalkiness. The disturbed N metabolism and differential expression of storage proteins up-regulated during the grain filling stage are able to partially explain the occurrence of grain chalkiness in rice.

Effect of Different Forms and Levels of Urea Fertilizer on Rice (Oryza sativa L) and Mineral Nitrogen Status in Soil

Field experiment was conducted to determine the effect of prilled urea (PU) and urea super granule (USG) with their different nitrogen levels (N1 : 70, N2 : 100 and N3 : 130% of the recommended dose) on rice and NH4+-N/NO3- -N in post-harvest soil. Experiment was laid out in a randomized completely block design with three replications at Bangladesh Institute of Nuclear Agriculture (BINA) Farm, Mymensingh, Bangladesh during 2015-16. Higher yield attributing characters (plant height, effective tiller panicle-1, panicle length were achieved from USG × N2 treatment. USG, N2 (100% N) and USG × N2 produced the highest grain (3.60, 3.64, 3.78 t ha-1) and straw yield (3.55, 3.45, 3.70 t ha-1) respectively. Though USG × N3 treatment produced the highest effective tiller, panicle length and unfilled grain but USG × N2 treatment produced maximum grain yield of rice due to higher filled grain. In respect of mineral nitrogen, NH4+-N was decreased with the increase in soil depth but opposite result was found in NO3- -N in soil. Deep placement of USG fertilizer released NH4+-N slowly and steadily compared to prilled urea in soil. As a result, one time fertilizer application of USG is better than three times broadcast application of PU in terms of crop yield, nitrogen status in different depth of soil and labour cost. Future research needs to develop the effective USG fertilizer applicator for deep placement in soil during crop production.

Fortification of tomato with Ca and its effects on the fruit quality, calcium status and nutraceutical values of tomato in different NO3:NH4 ratios

ABSTRACT This study aimed to investigate the interaction between nitrogen source and calcium on tomato. A soilless culture experiment was accordingly carried out using four different ratios of NO3:NH4 (N1 = 1:0, N2 = 3:1, N3 = 1:1, N4 = 1:3) and three concentrations of Ca (2, 4, and 8 mmol/l) to grow the tomato fruits. The results showed that the Ca application increased the Ca levels in the fruits, yield, total amino acid, and auxin hormone of the fruits; however, Ca application decreased Pectin Methyl Esteras activity and the ABA hormone. The highest levels of nitrate and ammonium content were observed in the fruits exposed to N1 and N2 treatments, respectively. At the highest level of calcium, the fruits were more spherical, and the quality and yield of the tomato fruits were improved. The nutraceutical values of the tomato fruits, including amino acid content and composition, and the Ca level were increased, while nitrate accumulation was decreased in 8 mmol L−1 Ca and NO3: NH4 (100/0).

Soil microbial functional diversity and root growth responses to soil amendments contribute to CO2 emission in rainfed cropland

Carbon (C) losses induced by soil amendments have been shown to trigger soil conservation concerns. However, the mechanisms of fertilizer-induced CO2 emissions are still unclear. Here, we investigated the impact of soil nitrogen (N) amendments at an upland site on soil C stocks, CO2 emission, microbial functional diversity, and soil enzymatic activities during the stem elongation and harvest stages of rapeseed in 2016–2018. Five treatments were designed including non-N fertilizer (N0), conventional urea (U), monotypic CRU fertilization (CRU), co-application of U with CRU (CRC), and CRU plus organic fertilizer (CRO). The key finding is that the significant increases in CO2 emissions from CRO soils were ephemeral compared with the N0 treatment. Root biomass and root: shoot ratio partly explained the significant effect of N addition to CO2 production. Further, improved amylase activities and increasing consumptions of carboxylic acids, polymers and miscellaneous by soil microbes were mainly responsible for enhanced soil CO2 emissions in both growing seasons (P < 0.01). This suggests that fertilizer-induced CO2 emission could be regulated by soil C and N availability, which is attributed to the dynamic changes in soil carbon metabolism. During the stem elongation of 2016–2017, the consumption of carbohydrates, carboxylic acids, polymers, amines, and miscellaneous in CRO treatment during the first sampling phase was 21.65%, 41.36%, 17.98%, 27.61% and 49.52% higher than those in traditional urea fertilizer, respectively. Moreover, compared to the CRU, U, and N0 treatments, the CRO treatment significantly increased the McIntosh index during the stem elongation of both seasons. The results indicate that a sensitive and rapid indicator to finding a good soil N management is short-term alterations in the microbial functional diversity. Additionally, a broad spectrum of the utilization of substrates by soil bacteria was showed in CRO plots, irrespective of interannual variations of precipitation from 2016 to 2018. In contrast, non-N and conventional urea treatments produced a greater disparity in the utilization of carbon substrates from across all sampling times compared with CRU amended treatments, and both of them were less correlated with the most C-sources. Overall, single basal CRO fertilization, as a stable N source, can satisfy plant and soil microbial C and N demands, hence mitigating soil CO2 emission.

Competitive ability and plasticity of Wedelia trilobata (L.) under wetland hydrological variations

Growth behavior of different species under different habitats can be studied by comparing the production of biomass, plasticity index and relative competitive interaction. However, these functional traits of invasive species received rare consideration for determining the invasion success of invasive species at wetlands. Here, we examined the effect of water depth at 5 cm and 15 cm (static and fluctuated) with different nutrient concentrations (full-strength (n1), 1/4-strength (n2) and 1/8-strength (n3) Hoagland solution) on functional traits of invasive Wedelia trilobata and its congener native Wedelia chinensis under mono and mixed culture. Water depth of 5 cm with any of the nutrient treatments (n1, n2 and n3) significantly restrained the photosynthesis, leaf nitrogen and photosynthetic nitrogen use efficiency (PNUE) of both W. trilobata and W. chinensis. While, increase in the water depth to 15 cm with low nutrient treatment (n3) reduced more of biomass of W. chinensis under mixed culture. However, relative competition interaction (RCI) was recorded positive for W. trilobata and seemingly W. trilobata benefited more from RCI under high-fluctuated water depth at 15 cm in mixed culture. Therefore, higher PNUE, more competitive ability and higher plasticity may contribute to the invasiveness of W. trilobata in wetlands.

Effects of fertigation splits through center pivot on the nitrogen uptake, yield, and nitrogen use efficiency of winter wheat grown in the North China Plain

The number of fertigation splits through center pivot irrigation system is a major concern for implementing sprinkler fertigation due to the possible losses caused by drift and volatilization. Field experiments were conducted at two sites of the semi-arid regions in the North China Plain with different soil fertilities to investigate the influence of the number of fertigation splits and the nitrogen applied on the nitrogen content, yield, and nitrogen use efficiency of winter wheat in the 2018 and 2019 seasons. In the experiments, one (N1), two (N2), and three fertigation splits (N3) in season based on soil Nmin-method was used. A treatment without in season fertilization (CK1) and a treatment with local fertilizer management method (CK2) were applied as control. Similar amounts of basal fertilizers and irrigation schedules were applied for all treatments. In the two-year study, both the nitrogen applied and sprinkler fertigation splits had significant influence on nitrogen content in winter wheat grain, and these effects varied with the changes of soil fertility. At the Beijing site of low soil fertility, the significantly great yield was obtained in the in-season N management treatments and the yield increased with the increasing of fertigation splits. The average yield in N3 treatment in both seasons was 32.5% and 15.1% higher than that in CK1 and CK2 treatments, respectively. At the Hebei site where inherent soil fertility was higher than that at the Beijing site, there was no significant differences in yield among all treatments, and the maximum yield within in-season N management treatments was obtained in N3 and N2 treatment in the 2018 and 2019 season, respectively. In both sites and seasons, the maximum partial factor productivity from applied N (PFPN) was obtained in CK1 treatment. The average PFPN in in-season N management treatments was 29.5% and 71.7% higher than that in CK2 treatment at the Beijing and Hebei site, respectively. More frequent fertigation was recommended for soils with low inherent fertility level.

Study of electrical attributes of molybdenum ditelluride (MoTe2) FET using experimental and theoretical evidences

Two-dimensional (2D) semiconducting TMDCs materials have recently gained much attention and are considered as promising materials with a high surface-to-volume ratio for electronics. The performance of devices greatly affected by environmental factors. For attaining the high performance of the device, environmental issues must be addressed. Here, we have demonstrated an n-type doping effect from DUV + N2 treatment to overcome the environmental influences and to enhance the performance of MoTe2 FET. After the n-type doping effect from DUV + N2 treatment mobility, charge carrier density, and ION/IOFF ratio increased up to 62.4 cm2/Vs, 3 × 1012 cm−2 and 107 respectively. The negative shift of threshold voltage (Vth) and Raman peaks towards the lower wavenumber confirms the n-type doping effect in the MoTe2 FET from DUV + N2 treatment. By using this method, we can change and control the polarity of the MoTe2 FET by changing the doping time. First-principles calculation on the study of structural, electronic and optical properties have been performed using the density functional theory (DFT) where full-potential linearized augmented plane wave (FP-LAPW) was used a basis set with generalized gradient approximation plus Hubbard potential (GGA + U) respectively. Furthermore, investigation of electron charge density is done to analyze the mechanism of structural stability of nitrogen doped MoTe2. DUV + N2 treatment is an effective way to improve the performance of MoTe2 FET.

Combined Effect of some Nitrogen and Zinc Sources on some Quality Parameters of Spinach Grown on Salt Affected Soil التأثیر المشترک لبعض مصادر النیتروجین والزنک على بعض مقاییس الجودة للسبانخ النامی علی أرض متأثرة بالأملاح

Salinity is a major problem affecting vegetable production in Egypt. Thus, the purpose of this investigation was to evaluate the influence of foliar applications of different sources of zinc [(Z1): Zn-EDTA, (Z2): ZnSO4 and (Z3): without Zn (control)] with both (NH4)2 SO4 and Ca(NO3 )2 combined together with one level as 6 mixed ratios of Ca(NO3 )2 : (NH4)2 SO4 [N1100% Ca(NO3)2 : 0.0% (NH4)2 SO4, N2 75% Ca(NO3)2 : 25% (NH4)2 SO4, N3 50% Ca(NO3 )2 : 50% (NH4)2 SO4, N4 25% Ca(NO3 )2:75% (NH4)2 SO4, N5 0.0% Ca(NO3 )2 : 100% (NH4)2 SO4 and N6 control treatment (without nitrogen)] on some quality parameters and chemical composition of spinach plants grown on salt-affected soil during the winter season of 2018. The experiment was designed in a split-plot design with three replicates. As for most determined parameters at both growth stages (30 and 55 days sowing), the findings indicate that the highest values were recorded with N1 treatment and foliar application of Zn- EDTA (Z1),while the lowest values were recorded under a combination of N6 treatment (without N-fertilization) and Z3 treatment (untreated plants). It can be concluded that; foliar spraying with Zn-EDTA in combination with soil addition of calcium nitrate as a source of N-fertilization is considered the most suitable treatment for overcoming salinity stress in some Egyptian soils and releasing the highest safe yield of spinach plant.

Optimizing the nutritional quality and phosphorus use efficiency of alfalfa under drip irrigation with nitrogen and phosphorus fertilization

AbstractAppropriate fertilization is an important management practice for optimizing the nutritional quality and increasing the phosphorus use efficiency (PUE) of field‐grown alfalfa (Medicago sativa L.). A 2‐yr field experiment in 2017 and 2018 in Xinjiang, China, involving fertilization with different amounts of N (0, 105, and 210 kg ha−1, referred to as N0, N1, and N2, respectively) and P (0, 50, 100, and 150 kg ha−1, referred to as P0, P1, P2, and P3, respectively) was established and resulted in the production of high‐quality alfalfa under drip irrigation. The crude protein (CP) content in the N1 treatment was greater than that in the N2 treatment under the P0, P2, and P3 treatments. Compared with that in the N1P0 and N2P3 treatments, the relative feed value (RFV) in the N1P2 treatment increased by 9−21% and 8−18%, respectively. The annual total CP yield in the N1P2 treatment was the greatest. Compared with that in the N1P3 treatment, the total PUE in the N1P2 treatment increased by 76.69−99.69%. At each clipping, the CP yield and PUE of alfalfa were significantly different between the N and P treatments. Therefore, we conclude that when N was applied at 105 kg ha−1 and P was applied at 100 kg ha−1, alfalfa presented the greatest nutritional quality and PUE under drip irrigation.

0669 The Effects Of Continuous Positive Airway Pressure Therapy In Moderate To Severe Obstructive Sleep Apnea: A High-density EEG Study

Abstract Introduction A previous high-density electroencephalography (EEG) investigation in asymptomatic OSA showed regional deficits in sleep EEG power particularly slow wave activity (SWA) during NREM sleep in the parietal region. It is unclear whether treatment with CPAP can reverse local sleep EEG abnormalities in OSA, and whether any recovery is related to improvement in sleep-dependent memory consolidation. Methods Fifteen male participants (age 50.4±6.5yrs, AHI 51.7±23.5/h) with moderate-severe OSA (AHI&amp;gt;15/h) underwent overnight polysomnography with 256-channel high-density EEG at baseline and following 3 months of CPAP therapy. A word paired associates declarative memory task was administered before and after sleep. After artefact removal, spectral analysis was performed for all channels. Topographical power maps were calculated for standard frequency ranges for NREM sleep (164 channels within a 0.57 radius from the vertex). Maps were compared using both absolute and normalized power (z-scores computed for each subject) and differences between baseline and treatment were determined by statistical nonparametric mapping. Results In 11 CPAP compliant patients (intolerant of CPAP [n=3]/high-density EEG [n=1]), analysis of polysomnographic variables showed that total sleep time did not differ but N1 (baseline vs. treatment: 66.9 vs. 39.5 mins,p=0.008) and N2 (195.0 vs. 150.6 mins,p=0.002) sleep was lower and N3 (89.8 vs. 128.7 mins,p=0.003) was higher after CPAP. Topographic analysis of high-density EEG data revealed a regional increase in SWA (1-4.5Hz) EEG power during N3 sleep in a cluster of electrodes overlying the centro-parietal cortex (cluster mean t-value=2.87,p=0.02). The change in overnight declarative memory consolidation (% recognition) after CPAP was significantly correlated with the change in slow spindle frequency activity in frontal regions (cluster mean r=0.875,p=0.003). Conclusion CPAP treatment may enhance localised deficits in sleep EEG activity in OSA, and specific regional recovery may translate to memory improvements in the short-term. These data also highlight the potential for long-term therapeutic effects on cognitive outcomes in OSA. Support

Effect of Co-solution of Carbon Precursor and Activating Agent on the Textural Properties of Highly Porous Activated Carbon Obtained by Chemical Activation of Lignin With H3PO4

This work analyzes the effect of co-solution of carbon precursor and activating agent on the textural and surface chemistry properties of highly nanoporous activated carbons obtained by chemical activation of Alcell lignin with phosphoric acid. The success of this methodology highlights the possibility of directly using the liquors produced in organosolv process (Alcell) to prepare activated carbons by chemical activation with phosphoric acid. Co-solutions of lignin and phosphoric acid were submitted to a two steps thermal treatment, which consisted of a first oxidative treatment in air at 200 oC, followed by a thermal treatment in N2 at 400 oC, where activation of the oxidized lignin with phosphoric acid took place. A lignin-derived activated carbon with very high apparent surface area (2550 m2/g) and pore volume (1.30 cm3/g) was obtained with an initial phosphoric acid to lignin mass ratio of 2. Up to now, this is one of the highest values of apparent surface area reported not only for activated carbons prepared from lignin, but even for porous carbons prepared by chemical activation of other lignocellulosic materials with phosphoric acid. The use of lignin and phosphoric acid co-solution provided larger and more homogeneous effective interactions between the carbon precursor and the activating agent, by the formation of phosphate esters in the lignin matrix, which seems to be a key factor in the subsequent treatments: promoting crosslinking reactions in the carbonaceous matrix during the oxidative treatment in air at 200 oC and enhancing the development of a wide porosity during the following activation thermal treatment.

High radiation use efficiency improves yield in the recently developed elite hybrid rice Y-liangyou 900

Yield potential in super hybrid rice has continued to increase in recent decades through morphological improvements and the use of inter-subspecific heterosis. Radiation use efficiency (RUE) has been singled out as an important determinant of grain yield in cereal species. However, it is not known whether yield increases in super hybrid rice breeding programs have involved improvements in RUE. Three-year field experiments evaluated the effects of breeding on grain yield and its physiological determinants, including RUE, intercepted photosynthetically active radiation (IPAR), aboveground biomass production, and harvest index (HI), in three representative super hybrid rice varieties released between 1999 and 2015 and grown under three N regimes (N0: 0 kg ha–1, N1: 210 kg ha−1, N2: 300 kg ha–1). Grain yield in the recently developed super hybrid rice cultivar Y-liangyou 900 (YLY900) increased significantly, relative to Liangyoupeijiu (LYPJ) and Y-liangyou 2 (YLY2), reaching more than 11 t ha–1 in the N2 treatment each year. Yield improvements in YLY900 were primarily due to increased aboveground biomass production resulting from a higher RUE, being 10.6 % (biomass) and 12.1 % (RUE) higher than those in LYPJ and YLY2. Unlike YLY900, aboveground biomass accumulation in LYPJ and YLY2 mostly resulted from increased IPAR. Nitrogen supply significantly increased intercepted radiation and intercepted percentage but not RUE. The N treatments had no effect on HI, within or between varieties. Grain yield had a significant (P < 0.01) positive correlation with both intercepted radiation and RUE in all three cultivars. The multiple regression analysis showed that the higher grain yield in YLY900 was more closely related to RUE, while those in LYPJ and YLY2 were highly dependent on intercepted radiation. Considering that YLY900 had a significant yield advantage, we conclude that RUE plays a more prominent role than HI in yield progress in super hybrid rice. Crop breeders should focus on breeding for improved solar radiation properties as a sustainable means of increasing yields in super hybrid rice.

Sweet pepper and nitrogen supply in greenhouse production: Critical nitrogen curve, agronomic responses and risk of nitrogen loss

Intensive vegetable production in soil is often associated with large N losses to the environment. To contribute to improved N management of sweet pepper, this work developed a critical nitrogen curve (CNC). It also developed N recommendations and examined N use efficiency (NUE) and potential NO3− leaching loss in relation to increasing total available nitrogen (TAN). TAN is the sum of the soil mineral N at planting, N mineralized from soil organic material, and mineral N fertilizer. Three sweet pepper crops were grown in soil with autumn-winter cropping cycles in greenhouse conditions. Five different N concentrations in the nutrient solution were applied throughout the crop cycle: very N deficient (N1), N deficient (N2), conventional N management (N3), excessive N (N4) and very excessive N (N5). A critical N curve of %Nc=4.71×DMP-0.22 was determined for sweet pepper. Relative yield of the three crops had a strong linear-plateau relationship (R2 = 0.66) with integrated nitrogen nutrition index (NNIi). Maximum yield was associated with an NNIi of 0.86. In the three crops, total yield, dry matter production (DMP) and crop N uptake were generally strongly related to increasing TAN. An optimal TAN value (minimum TAN for maximum yield) of 425 kg N ha−1 was determined using a linear-plateau regression model. N uptake efficiency (NuptE) decreased exponentially with increasing TAN, from almost 0.90 kg kg−1 in the N1 treatment to 0.30 kg kg−1 in the N5 treatment. The sum of residual mineral N and leached NO3−–N was considered to be potential NO3− leaching loss. Potential NO3− leaching loss increased exponentially, with increasing TAN, to 686–1034 kg N ha−1 in the highest N treatments. For the optimal TAN value, NuptE was 0.63 kg kg−1 and the potential NO3− leaching was 125 kg N ha−1. The CNC and derived NNI values provide valuable information for N management of pepper. Consideration of TAN as the crop N supply enables maximum yield with less fertilizer N and less risk of N loss.

Effect of different NPK levels on growth and yield attributes of broccoli (Brassica oleracea L) under south Gujarat condition

A three years field experiment was conducted to study the effect of Nitrogen, Phosphorus and Potassium levels on yield and growth attributes of Broccoli under South Gujarat condition. There were different nineteen treatments including control. Out of them, eighteen treatments comprising of three nitrogen levels [ 80 kg N ha-1 (N1), 120 kg N ha-1 (N2) and 160 kg N ha-1 (N3)] combined with three phosphorus levels [40 kg P2O5 ha-1 (P1), 60 kg P2O5 ha-1 (P2) and 80 kg P2O5 ha-1 (P3)] along with two levels of potassium [control (K1) and 60 kg K2O (K2)]. In control, only biocompost is applied @ 5t/ha. The experiment was laid out in factorial RBD with three replications. P fertilizer was applied 100% while N and Kfertilizer were applied 50% at the time of transplanting. Need based control measures were taken for the pest and disease management. The results revealed that the higher dose of N (N3- 160 kg N /ha) recorded significantly higher values of number of leaves (18.53) and plant height (37.68 cm) per plant of broccoli. The combination P3N3 (40.34 cm) and P3K2 (36.98 cm) recorded significantly higher plant height. The interaction effect of all the factors (N x P x K) was also found significant on average head weight and the combination (P3N3K1) recorded significantly higher average head weight (211 g) and remained at par with P3N3K2 (192 g). The treatment N3 (10181, 9902 and 6159 kg/ha) recorded significantly the higher head yield of broccoli, respectively during all the three years. The treatment combinationN3P3K2 (160:80:60) recorded significantly higher values of av. head weight, polar diameter and equatorial diameter of head as well as significantly highest head yield (10120 kg/ha) than rest of the treatment combinations.

Soil water and nitrogen dynamics from interaction of irrigation and fertilization management practices in a greenhouse vegetable rotation

AbstractQuantifying the interactive effects of different irrigation and fertilization strategies on soil water and mineral N dynamics provides an important insight for developing more effective water and N use management practices. This experiment was carried out in a tomato (Solanum lycopersicum L.) (2016)–cucumber (Cucumis sativus L.) (2016)–tomato (2017) rotation, with 12 treatments in total combining two irrigation methods (drip and furrow), two irrigation levels (high and low), and three fertilizer types (control [N0], organic N [N1], and inorganic N [N2]). Soil water content (SWC) and soil mineral N concentration were measured for soil depth of 0–80 cm. Relative to furrow irrigation, drip irrigation led to lower temporal variation and smaller differences between soil depths and treatments in SWC and soil NO3−–N concentration. A high irrigation level led to higher SWC and soil NO3−–N concentration for N1 and N2 treatments under drip irrigation, whereas furrow irrigation had the opposite results. About 42.8% mineral N (over soil depth of −20 to 80 cm) was stored at the ridge under furrow irrigation. Relative to the start of the experiment, N2 fertilizer application increased the soil mineral N content by about 450 kg ha−1, whereas N0 and N1 application decreased soil mineral N content by about 200 kg ha−1 by the end of the rotation. Yield for N1 was similar or higher than that of inorganic N treatments, with drip irrigation–high irrigation–organic N having the highest soil mineral N and the greatest yield, indicating that a combination of organic N fertilizer with appropriate irrigation practices can achieve the balance of high yield and low environmental risks.

The Effect of Two Concentrations and Three Applications of Nitrobenzene on Growth and Yield of Bottle Gourd (Lagenaria siceraria L.)

The experiment was conducted in the Horticultural Farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh with aim to assess the influence of two concentrations and three applications of nitrobenzene in relation to control (C0) without nitrobenzene on the growth and yield of bottle gourd. Two concentrations of nitrobenzene applied were: @ 2 ml/L referred as C1 and 3 ml/L referred as C2 in relation to a control (C0) with water instead of nitrobenzene. Further, the above treatments were applied number of times, e.g. One spray (N1), Two spray (N2) and Three spray (N3). In case of different number of concentrations of nitrobenzene the maximum number of male flower (51.06), the maximum number of female flower (40.18), the highest number of fruit harvested per plant (10.95), the highest yield (55.69 t/ha) was found from C1 treatment, whereas the lowest from C0 treatment. For the number of sprays the highest number of flowers (male 49.02 and female 38.05), the maximum number of fruit per plant (10.32), the highest yield (52.94 t/ha) was recorded from N3 treatment, while the minimum from N1 treatment. Due to combined effect, the maximum number of flower (male 57.78 and female 47.12), the maximum number of fruit harvested per plant (12.55), the highest yield (63.38 t/ha) with net income (Tk. 587384.7) and BCR (2.23) was observed from C1N3 treatment combination, while the lowest from C0N1 treatment combination. So, the economic analysis revealed that the C1N3 treatment combination appeared to be the best for achieving the maximum growth, yield and economic benefit of bottle gourd.