scholarly journals Assessment of DRAINMOD-NII Model for Prediction of Nitrogen Losses Through Subsurface Drained Sandy Clay Under Cultivation in South West Punjab, India

Author(s):  
MEHRAJ U DIN DAR ◽  
J.P. Singh

Abstract In the present study, DRAINMOD-NII model was calibrated for the years 2018-2019 and validated for the period 2019-2020 over the two cropping years. The model simulations were statistically evaluated by comparing the measured drain flows and nitrate-nitrogen (NO3-N) with the model simulated drain outflows and nitrate loss. The study results depicted closer agreement between the simulated and observed results for both the calibration and validation periods. The Root Mean Square Error (RMSE) of the drainage rate was 8.88 cm more than observed data,15.41, 0.53 and 0.57 cm were the values recorded for PBIAS, modelling efficiency (NSE) and R2. The similar parameter values for nitrogen load were recorded to be 0.14, 2.76 ,0.84 and 0.88 respectively during the calibration period for rice wheat system. The model was statistically tested during the validation period also, confirming DRAINMOD-NII has the capability to simulate nitrogen losses from the area subjected to subsurface drainage system.

1992 ◽  
Vol 32 (4) ◽  
pp. 473 ◽  
Author(s):  
G Gibson ◽  
BJ Radford ◽  
RGH Nielsen

The effects of tillage frequency (conventional, reduced and zero), primary tillage implement (disc, blade and chisel plough), stubble management (retention and removal), gypsum application, and paraplowing were examined with respect to soil water storage, soil nitrate accumulation, crop establishment, crop growth, grain yield and grain nitrogen content for 4 successive sorghum crops on a sodic, texture-contrast soil in south west Queensland. Retention of sorghum stubble (v. removal) produced an increase in mean yield of sorghum grain of 393 kg/ha, due to increased soil water extraction and increased water use efficiency by the following crop. The highest mean yield occurred after reduced blade tillage with stubble retained. Zero tillage with stubble removed gave the lowest mean grain yield. Zero tillage always had the lowest quantity of soil nitrate-nitrogen at sowing. In one fallow, increased aggressiveness of primary tillage (disc v. blade plough) increased the quantity of nitrate-nitrogen in the top 60 cm of soil at sowing. These effects on available soil nitrogen did not result in corresponding differences in grain nitrogen content. Results indicate that for optimum fallow management on this texture-contrast soil in south west Queensland, sorghum residues should be retained, tillage frequency should be reduced, but not to zero, blade ploughing should be preferred to discing, and gypsum application should not be practised.


1988 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
A. W. H. Turnpenny ◽  
C. H. Dempsey ◽  
M. H. Davis ◽  
J. M. Fleming

2018 ◽  
Vol 10 (4) ◽  
pp. 55 ◽  
Author(s):  
Chuki Sangalugeme ◽  
Philbert Luhunga ◽  
Agness Kijazi ◽  
Hamza Kabelwa

The WAVEWATCH III model is a third generation wave model and is commonly used for wave forecasting over different oceans. In this study, the performance of WAVEWATCH III to simulate Ocean wave characteristics (wavelengths, and wave heights (amplitudes)) over the western Indian Ocean in the Coast of East African countries was validated against satellite observation data. Simulated significant wave heights (SWH) and wavelengths over the South West Indian Ocean domain during the month of June 2014 was compared with satellite observation. Statistical measures of model performance that includes bias, Mean Error (ME), Root Mean Square Error (RMSE), Standard Deviation of error (SDE) and Correlation Coefficient (r) are used. It is found that in June 2014, when the WAVEWATCH III model was forced by wind data from the Global Forecasting System (GFS), simulated the wave heights over the Coast of East African countries with biases, Mean Error (ME), Root Mean Square Error (RMSE), Correlation Coefficient (r) and Standard Deviation of error (SDE) in the range of -0.25 to -0.39 m, 0.71 to 3.38 m, 0.84 to 1.84 m, 0.55 to 0.76 and 0.38 to 0.44 respectively. While, when the model was forced by wind data from the European Centre for Medium Range Weather Foresting (ECMWF) simulated wave height with biases, Mean Error (ME), Root Mean Square Error (RMSE), Correlation Coefficient (r) and Standard Deviation of error (SDE) in the range of -0.034 to 0.008 m, 0.0006 to 0.049 m, 0.026 to 0.22 m, 0.76 to 0.89 and 0.31 to 0.41 respectively. This implies that the WAVEWATCH III model performs better in simulating wave characteristics over the South West of Indian Ocean when forced by the boundary condition from ECMWF than from GFS.


2000 ◽  
Vol 29 (3) ◽  
pp. 817-825 ◽  
Author(s):  
S. L. Zhao ◽  
S. C. Gupta ◽  
D. R. Huggins ◽  
J. F. Moncrief

2005 ◽  
Author(s):  
Vinay Nangia ◽  
Prasanna H. Gowda ◽  
David J. Mulla ◽  
Gary R. Sands

2019 ◽  
Vol 11 (1-2) ◽  
pp. 73-81 ◽  
Author(s):  
MI Hossain ◽  
FH Shikha ◽  
AD Sharma

The study was carried out on the present status of shrimp processing plant’s waste management in Bangladesh. A detailed survey was conducted during February to May, 2013 in order to collect some basic information on the present status of shrimp waste management at shrimp processing plants through questionnaire interview on the various parameters. Information was collected from 52 plants of Khulna, Chittagong and Cox`s bazaar region. All collected information were accumulated, analyzed and are presented in graphs, figures and tables. The study had revealed that about 671.84MT of shrimp was purchased in 52 plants in a day and from which 248.8 MT of waste product was produced during processing. The study results showed that about 80% of the plants sell their waste products and rest of the plants discharged their wastes into river (63.50%) and 91.42% of the plants treated the waste water before discharge. Based on the obtained results from this study, it could be suggested that shrimp waste can be used further in different ecofriendly ways. J. Environ. Sci. & Natural Resources, 11(1-2): 73-81 2018


2018 ◽  
Vol 8 (1) ◽  
pp. 109
Author(s):  
Sophie E. Etomes ◽  
Ernest L. Molua

This study investigates strategies used by principals for enhancing the productivity of secondary school teachers in selected government secondary schools in Cameroon. Four major strategies were examined. These include motivation, conflict resolution, supervisory and communication strategies and the extent to which they influence teachers’ productivity. Four research questions and hypotheses guided the study. Questionnaire was used to collect data from 350 teachers selected from a population of 1400 teachers in government secondary schools in Fako Division of the South West Region of Cameroon. The multi-stage sampling technique was used to select teachers for the study. Results showed that, principals’ communication, conflict management, supervisory and motivation strategies influence the productivity of teachers in Government Secondary Schools. Of the four strategies examined, conflict management strategy was found to have more influence on the productivity of teachers. Principals’ strategies have a direct relationship with teachers’ productivity. Therefore, there is a possible correlation between principals’ leadership and management strategies, teachers’ productivity and school effectiveness. In addition, effective collaboration amongst teachers is necessary for teachers’ effectiveness. It is recommended that principals should put in strategies that will enhance effective communication, conflict management, motivation and supervision to improve on the productivity of teachers.


Sign in / Sign up

Export Citation Format

Share Document