MAIZE GROWTH, YIELD, WATER PRODUCTIVITY AND EVAPOTRANSPIRATION RESPONSE TO DIFFERENT IRRIGATION METHODS AND AMOUNTS AND DIFFERENT TIMING AND METHODS OF NITROGEN APPLICATIONS

Declining the quantity and quality of freshwater resources in many parts of the world, including Midwestern USA, especially in the light of rapidly growing world’s population and changing climate, imposes significant and, in some cases imminent, challenges for producers, policy- and decision-makers to produce more yield with less water and other inputs, particularly in water scarcity regions. There is not comprehensive previous research has quantified and evaluated coupled impacts of irrigation rates and nitrogen timing management strategies and their interactions on maize (Zea mays L.) productivity and its various attributed efficiency index metrics under different irrigation methods under the same environment conditions and under the same soil and crop management practices simultaneously. Extensive field experiments were conducted for maize during the 2016 and 2017 growing seasons in three large scale fields under center pivot (CP), subsurface drip irrigation (SDI) and furrow irrigation (FI) methods at full irrigation treatment (FIT), 80% FIT, 60% FIT and rainfed treatment (RFT) with three N application timing treatments. N application timing treatments that were imposed are: (i) traditional (NT); pre-plant application (TN) treatment, (ii) non-traditional-1 (NT-1); in-season three time N applications, and (iii) non-traditional-2 (NT-2); in-season four time N applications. The overall objectives of the study were to quantify and compare numerous maize plant physiological and biophysical properties, maize production, soil water dynamics, crop evapotranspiration (ETc), crop water productivity, yield response factor (Ky), N use efficiency indices, and developing new functions between nitrate-N vs. total water supply; seasonal irrigation water; and yield to account for nitrate-N driving factors. Main effects of N treatments, irrigation methods, and year were (pSDI \u3e FI across all treatments, both NT-1 and NT-2 were higher (p Results should provide invaluable data and information will improve synergy between nutrition and water, maximize maize and soil productivity, increase farmer’s profit, stakeholder awareness, and protect environmental quality for the study area

Maize response to irrigation and nitrogen under center pivot, subsurface drip and furrow irrigation: Water productivity, basal evapotranspiration and yield response factors

Information and data about quantification and comparison of crop water productivity indices for various irrigation levels and methods and nitrogen (N) application timings “simultaneously” under the same conditions do not exist. Unprecedented and extensive field experiments were conducted for maize (Zea mays L.) in 2016 and 2017 under center pivot (CP), subsurface drip irrigation (SDI) and furrow irrigation (FI) methods with full irrigation treatment (FIT), 80% FIT, 60% FIT and rainfed treatment (RFT) with three N application timings. N treatments were: (i) traditional (TN), (ii) non-traditional-1 (NT-1) and (iii) non-traditional-2 (NT-2). Irrigation yield production functions (IYPF); evapotranspiration-yield production functions (ETYPF), basal evapotranspiration (ETb), crop water productivity (CWP), irrigation water use efficiency (IWUE); evapotranspiration water use efficiency (ETWUE) and yield response factors (Ky) were quantified for each treatment and irrigation method. SDI method required the least seasonal irrigation amount in achieving maximum yield, followed by CP (\u3e~30 mm more than SDI) and FI (\u3e~55 mm more than SDI). Average crop water requirement for achieving maximum grain yield varied among the N treatments within and between the irrigation methods. Irrigation amounts for achieving maximum yields were about 160, 175 and 175 mm in TN, NT-1 and NT-2 nitrogen treatments, respectively, in the CP method; 130, 150 and 150 mm in TN, NT-1 and NT-2 nitrogen treatments, respectively, in the SDI method; and 184 mm in TN management in the FI method. The highest grain yield production per 25.4 mm of applied irrigation followed the order of CP-TN (2.07 Mg ha–1) \u3e SDI-NT-2 (1.91 Mg ha–1) \u3e FI-TN (1.22 Mg ha–1). Across all treatments for the given irrigation method, the highest averaged CWP of 3.00 kg m–3 (slope = 0.067 kg m–3) was observed in the SDI method (p \u3c 0.05) followed by 2.84 kg m–3 (slope = 0.052 kg m–3) in the CP method (p \u3c 0.05) and 2.51 kg m–3 (slope = 0.046 kg m–3) in the FI method. The lowest ETb was observed in FI-TN (169 mm), followed by CP-NT-2 (172 mm) and SDI-TN (255 mm). For two consecutive years, N treatments did not have significant (p \u3e 0.05) influence on IWUE in the CP or SDI methods. The highest IWUE, CWP and ETWUE were always obtained with limited irrigation treatments (60% FIT and/or 80% FIT) whereas the lowest with FIT. Maize under limited irrigation management had Ky \u3c 1 with CP, SDI and FI along with lower Ky values than the respective TN treatment in CP and SDI, suggesting that the yield reduction is impacted to a lesser degree from the magnitude of water stress. The overall conclusion disclosed that utilizing the combination of limited irrigation (80% FIT) with NT-1 fertigation under SDI and CP, while 80% FIT under FI can be viable management practices for achieving high grain yield and CWP in conditions similar to those presented in this research

Maize response to coupled irrigation and nitrogen fertilization under center pivot, subsurface drip and surface (furrow) irrigation: Soil-water dynamics and crop evapotranspiration

Determination of crop evapotranspiration (ETc) and root zone soil-water dynamics/distribution coupled with nitrogen (N) management strategies is important for effective management of agricultural fields for enhancing production efficiency. However, limited data and knowledge exist that sufficiently inform how soil-water dynamics and ETc response may vary with coupled irrigation levels and different N application timings under different irrigation methods. Extensive field experiments were conducted in 2016 and 2017 under center pivot (CP), subsurface drip irrigation (SDI), and furrow irrigation (FI) at full irrigation treatment (FIT), 80% FIT, 60% FIT, and rainfed treatment (RFT) with N application timing treatments of traditional N (TN), non-traditional-1 (NT-1), and non-traditional-2 (NT-2) to quantify and compare seasonal maize (Zea mays L.) grain yield, soilwater dynamics, ETc, and ETc vs. seasonal irrigation and total water supply relationships. Soil-water status and plant water extraction exhibited substantial differences between the irrigation levels and N management and with the irrigation methods. Irrigation method significantly (p \u3c 0.05) influenced ETc. CP had significantly higher ETc than SDI; and SDI had significantly higher ETc than FI. The NT-1 and NT-2 treatments had significantly higher ETc than TN. ETc was greatly influenced by the water availability more than N timing applications. The slope of maize ETc exhibited inter-annual and intra-annual variation between N treatments, irrigation methods, and years. CP had higher slope than FI and SDI and FI had higher slope than SDI under traditional and NT N management in both years (except NT-2 at SDI in 2017). These important findings can provide guidance to improve maize production efficiency by considering the coupled irrigation and N management strategies under different irrigation methods

Non-ST Elevation Myocardial Infarction: Diagnosis and Management

Cardiovascular disease is expected to be the main cause of death globally due to the rapidly increasing prevalence of obesity, hypertension and diabetes mellitus. Atherosclerotic lesions and plaque rupture are the most common cause of myocardial infarction. Resting 12-lead ECG is the first diagnostic test for patients with chest pain and should be performed and interpreted within the first 10 min of the patient’s admission to the emergency department. Cardiac biomarkers preferably, high-sensitivity cardiac troponin, is mandatory in all patients with suspected NSTEMI for the diagnosis, risk stratification and treatment. Rapid, efficient diagnosis and risk stratification of patients with chest pain will help to administer the appropriate medication and plan for the timing of invasive strategy and the choice of revascularization. This chapter helps to simply but elaborately discuss the diagnosis, risk stratification and the management of patients with non-ST elevation of myocardial infarction

Irrigation-Yield Production Functions and Irrigation Water Use Effciency Response of Drought-Tolerant and Non-Drought-Tolerant Maize Hybrids under Different Irrigation Levels, Population Densities, and Environments

Irrigation-yield production functions (IYPFs), irrigation water use effciency (IWUE), and grain production per unit of applied irrigation of non-drought-tolerant (NDT) and drought-tolerant (DT) maize (Zea mays L.) hybrids were quantified in four locations with different climates in Nebraska [Concord (sub-humid), Clay Center (transition zone between sub-humid and semi-arid); North Platte (semi-arid); and, Scottsbluff (semi-arid)] during three growing seasons (2010, 2011, and 2012) at three irrigation levels (fully-irrigated treatment (FIT), early cut-off (ECOT), and rainfed (RFT)) under two plant population densities (PPDs) (low-PPD; 59,300 plants ha-1; and, high-PPD, 84,000 plants ha-1). Overall, DT hybrids’ performance was superior to NDT hybrid at RFT, ECT, and FIT conditions, as confirmed by the yield response, IYPF and IWUE when all locations, years, and PPDs were averaged. The yield response to water was greater with the high-PPD than the low-PPD in most cases. The magnitude of the highest yields for DT hybrids ranged from 7.3 (low-PPD) to 8.5% (high-PPD) under RFT, 3.7 (low-PPD) to 9.6% (high-PPD) under ECOT, and 3.9% (high-PPD) under FIT higher than NDT hybrid. Relatively, DT hybrids can resist drought-stress conditions longer than NDT hybrid with fewer penalties in yield reduction and maintain comparable or even higher yield production at non-stress-water conditions

Simulation Study of Adrenaline Synthesis from Phenylalanine

          Simulation study of Adrenaline synthesis from Phenylalanine has been carried out using semi-empirical methods (PM3) and density functional theory (DFT) STO-3G level of theory . Geometrical properties and vibration mods have been calculated for all structures. Different probable products have been suggested for each reaction and the most probable products being selected depending upon the electronic properties to prove the pathway of reactions that’s needed to synthesis adrenaline in the human body.           The calculations show the most probable product than other structurs due its energetic values of total energy, energy barrier value, heat of formation, zero point energy, imaginary frequency and rate constant that’s equal to (5.554*1012, 5.572*1012, 7.857*1012, 1.331*1013,1.116*1013) respectively by s-1 units. Thermodynamic functions (∆H, ∆S, ∆G) have been calculated for five steps reactions of Adrenaline synthesis . In reaction 1 equal to (-69.468, 1.37*10-4, -66.610), reaction 2 (-46.453, 3.044*10-3, -64.710), reaction 3 (-63.734, 0.022, 138.900), reaction 4 (87.036, 8.631*10-3, -451.510) and reaction 5 (-6.722,-0.025, 346,800) respectively by kCal/mol, kCal/mol/deg, and kCal/mol respective units. The chemical reactivity or energy gap has been calculated for the most probable products in the pathway of adrenaline synthesis

Grain yield, crop and basal evapotranspiration, production functions and water productivity response of drought-tolerant and non-drought-tolerant maize hybrids under different irrigation levels, population densities and environments: Part II. In south-central and northeast Nebraska\u27s transition zone and sub-humid environments

Information and data on newer drought-tolerant maize hybrid response to water in different climates are extremely scarce. This research quantified the performance of non-drought-tolerant (NDT) (H1) and drought-tolerant (DT) (H2, H3, and H4) maize (Zea mays L.) hybrids response to grain yield, crop evapotranspiration (ETc), basal evapotranspiration (ETb), ETc-yield production functions (ETYPF), and crop water use efficiency (CWUE) at three irrigation levels and two plant population densities (PPDs) at two locations (transition zone between sub-humid and semiarid climates at Clay Center (SCAL), Nebraska, in 2010 and 2012; and in a sub-humid climate at Concord (HAL), Nebraska, in 2010, 2011, and 2012). Irrigation treatments were: fully irrigated (FIT), early cutoff (ECOT) (i.e., no irrigation after blister stage), and rainfed (RFT) under two PPDs of 59,300 plants ha-1 (low PPD), and 84,000 plants ha-1 (high PPD). Generally, DT hybrids performed superior to NDT hybrid consistently at both locations, treatments, and years. DT H3 and DT H4 had highest grain yield consistently at SCAL and HAL, respectively. DT H3 and H4 hybrids’ productivity was not only superior in the RFT, but also in FIT. The highest yield of 16.3, and 15.3 Mg ha-1 were achieved by DT H3 (high PPD) and DT H2 (high PPD), respectively, associated with 471 and 590 mm of ETc in the FIT in 2012 at SCAL, and HAL, respectively. In most cases, all hybrids had highest grain yield under low PPD than high PPD at the RFT. All hybrids exhibited a linear yield response to increasing ETc in all years at both locations with positive slopes in all cases. The individual ETYPF response for individual hybrids had inter-annual variation in slopes between the hybrids and for the same hybrids between the years and location for both low and high PPDs. The ETYPF slopes ranged from 0.004 to 0.102 Mg ha-1 mm-,1 including all treatments (i.e., irrigation and PPDs) at SCAL for 2010 and 2012; and they ranged from 0.008 to 0.057 Mg ha-1 mm-1 including all treatments at HAL for 2010, 2011, and 2012. The ETb values exhibited inter-annual variation for the same hybrid between the irrigation levels, PPDs, and locations and they also exhibited an inner-annual variation between the hybrids and treatments in a given year with DT hybrids having consistently lower ETb values than the NDT hybrid. The greatest CWUE values were found in DT hybrids consistently at both locations. The DT hybrids can significantly increase yield productivity as well as crop water productivity per unit of ETc with respect to conventional hybrids not only in dry conditions, but also in average or above average years in terms of precipitation

Dynamics of Crop Evapotranspiration of Four Major Crops on a Large Commercial Farm: Case of the Navajo Agricultural Products Industry, New Mexico, USA

Crop evapotranspiration (ETa) is the main source of water loss in farms and watersheds, and with its effects felt at a regional scale, it calls for irrigation professionals and water resource managers to accurately assess water requirements to meet crop water use. On a multi-crop commercial farm, different factors affect cropland allocation, among which crop evapotranspiration is one of the most important factors regarding the seasonally or annually available water resources for irrigation in combination with the in-season effective precipitation. The objective of the present study was to estimate crop evapotranspiration for four major crops grown on the Navajo Agricultural Products Industry (NAPI) farm for the 2016–2010 period to help crop management in crop plant allocation based on the different objectives of the NAPI. The monthly and seasonal satellite-based ETa of maize, potatoes, dry beans, and alfalfa were retrieved and compared using the analysis of variance and the least significant difference (LSD) at 5% of significance. Our results showed the highly significant effects of year, months, and crops. The year 2020 obtained the highest crop ETa, and July had the most evapotranspiration demand, followed by August, June, September, and May, and the pool of April, March, February, January, December, and November registered the lowest crop ETa. Maize monthly ETa varied from 17.5 to 201.7 mm with an average seasonal ETa of 703.8 mm. The monthly ETa of potatoes varied from 9.8 to 207.5 mm, and their seasonal ETa averaged 600.9 mm. The dry bean monthly ETa varied from 10.4 to 178.4 mm, and the seasonal ETa averaged 506.2 mm. The alfalfa annual ETa was the highest at 1015.4 mm, as it is a perennial crop. The alfalfa monthly ETa varied from 8.2 to 202.1 mm. The highest monthly crop ETa was obtained in July for all four crops. The results of this study are very critical for cropland allocation and irrigation management under limited available water across a large commercial farm with multiple crops and objectives

Maize nitrogen uptake, grain nitrogen concentration and root-zone residual nitrate nitrogen response under center pivot, subsurface drip and surface (furrow) irrigation

While the impact(s) of irrigation and nitrogen (N) levels on crop yields have been investigated separately, research lacks about how different irrigation methods coupled with different N application timing strategies under full and limited irrigation levels effect yield, soil nitrate nitrogen (NO3-N) residual and stover N uptake. Knowledge of these dynamics can help to establish effective water and N management guidelines for the same crop under different irrigation methods and irrigation levels. This research investigated maize (Zea mays L.) residual soil NO3-N concentration and stover and grain N uptake response to water under different irrigation methods [center pivot (CP), subsurface drip irrigation (SDI) and surface (furrow) irrigation (FI)] simultaneously. Three irrigation levels were imposed: (i) full irrigation treatment (FIT), (ii) limited irrigation (80% FIT and 60% FIT) and (iii) rainfed treatment (RFT). N treatments were: (i) traditional (TN) treatment in which seasonal N requirement was applied in spring as a pre-plant, (ii) non-traditional-1 (NT-1) in which 30% of the seasonal required N was applied as spring pre-plant, 40% and 30% as side-dress at V8 (8-leaf collar) and VT/VR (tasseling/ silking) stages, respectively, and (iii) non-traditional-2 (NT-2) in which 25% of the seasonal required N was applied as spring pre-plant, 25%, 30% and 20% as side-dress at V8, VT/VR and R3 (i.e., kernel, milk) stages, respectively. The highest NO3-N residual was observed in the topsoil and residual NO3-N was more pronounced in the RFT followed by limited irrigation levels. The highest average stover N concentration, regardless of N treatments, was in the order of FI (1.99%)\u3eSDI (1.94%)\u3eCP (1.73%). Overall, irrigation levels significantly influenced (p \u3c 0.05) seasonal stover N uptake in both growing seasons, regardless of N treatments and irrigation methods. In most cases, the highest seasonal stover N uptake was observed in the FIT and/or 80% FIT and the lowest values were observed with RFT. Grain N concentrations were higher in NT-1 and NT-2 than TN in SDI, whereas the CP seasonal grain N concentration had opposite trends with both NT-1 and NT-2 having higher seasonal grain N concentration than TN. The highest grain N uptake was observed in the SDI-NT-1, followed by CP-NT-2 and FI-TN under limited irrigation treatments. The coupled irrigation and N treatments of 80% FIT-NT- 2-CP, 60% FIT-NT-1-SDI and 80% FIT-NT-2-SDI had ≥ 5 mg kg-1 residual NO3-N in the 0.60 m soil layer in drier year in 2016. The trend was opposite in wetter year in 2017 and there was an increasing NO3-N content trend (≥5 mg kg-1) in the 0.60–1.20 m soil layer. The highest NO3-N concentrations were observed in the RFT, NT-1, and NT-2 across irrigation methods, indicating that the irrigation management and in-season N application treatments significantly (p \u3c 0.05) influenced the NO3-N magnitudes. Soil residual NO3-N had quadratic relationship with the seasonal total soil water supply; and soil residual NO3-N increased with decreasing total water supply. The quantitative analyses presented here can aid to improve N and water productivity and reduce unnecessary applied N in for maize under the conditions similar to those presented in this research

Maize response to coupled irrigation and nitrogen fertilization under center pivot, subsurface drip and surface (furrow) irrigation: Growth, development and productivity

Water availability and water quality problems negatively impact agricultural productivity due to improper nitrogen (N) and irrigation management, which can also negatively affect environmental services. Coupled irrigation and N management practices must be developed and practiced for alleviating these challenges. Investigating crop growth and development and yield response to coupled irrigation and N management under different irrigation methods can aid in developing optimum agronomic management practices to enhance crop production efficiency. Field experiments were conducted in 2016 and 2017 growing seasons to measure and compare maize (Zea mays L.) grain yield, leaf area index (LAI), plant height (and their relationships), and stem diameter under different N application timing treatments and traditional N application under different irrigation methods [center pivot (CP), subsurface drip irrigation (SDI), and furrow irrigation (FI)]. The irrigation levels were full irrigation treatment (FIT or 100%), 80% of FIT, 60% of FIT, and rainfed conditions (RFT) coupled with fertigation application timing treatments. The N treatments were: (i) traditional (TN) with spring pre-plant application, (ii) non-traditional-1 (NT-1) with three pre-season and in-season N applications, and (iii) nontraditional-2 (NT-2) with four pre- and in-season N applications. Grain yield, LAI, and plant height were significantly (p \u3c 0.05) altered by increasing irrigation levels for the traditional N and non-traditional N treatments for the given irrigation method as well between the irrigation methods for the same treatment. The irrigation method had a substantial influence on LAI, and both CP and SDI had 24% higher averaged LAI than FI across traditional N treatments. The highest grain yields were observed under NT-1 and NT-2 at FIT across the irrigation methods. The highest grain yields of 17.3, 16.8 and 15.2 Mg ha-1 were observed in 100% NT-1-CP, 100%-NT-1-SDI, and 100% T-FI in the 2016 growing season, respectively; and 17.8, 16.7 and 14 Mg ha-1 were observed in 100% NT-1-CP, 100%-NT-2-SDI, and 100% T-FI in the 2017 growing season, respectively. The traditional N treatment showed significantly (p \u3c 0.05) higher yield under CP than FI (8.1% and 25.5% higher under CP in 2016 and 2017, respectively). SDI had 8.1% and 23% higher yield than FI in 2016 and 2017 seasons, respectively. NT-1 and NT-2 treatments had significantly higher (p \u3c 0.05) grain yields than traditional N treatment under CP and SDI; and NT-1 and NT-2 yields were significantly higher (p \u3c 0.05) under CP than SDI. There was no significant difference (p \u3e 0.05) in yield between NT-1 and NT-2. However, the TN-1 yielded 4.3% higher under CP than in SDI method. NT-1 can be an effective N management practice coupled with 80% of FIT irrigation level under CP and SDI. Results and analyses presented here can provide guidance to growers and their advisors to assess maize productivity under different irrigation and N management strategies under different irrigation methods in the soil, climatic and management practices similar to those presented in this research