scholarly journals The Application of a Modified Version of the SWAT Model at the Daily Temporal Scale and the Hydrological Response unit Spatial Scale: A Case Study Covering an Irrigation District in the Hei River Basin

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1064 ◽  
Author(s):  
Zheng Wei ◽  
Baozhong Zhang ◽  
Yu Liu ◽  
Di Xu

As a well-built, distributed hydrological model, the Soil and Water Assessment Tool (SWAT) has rarely been evaluated at small spatial and short temporal scales. This study evaluated crop growth (specifically, the leaf area index and shoot dry matter) and daily evapotranspiration at the hydrological response unit (HRU) scale, and SWAT2009 was modified to accurately simulate crop growth processes and major hydrological processes. The parameters of the modified SWAT2009 model were calibrated using data on maize for seed from 5 HRUs and validated using data from 7 HRUs. The results show that daily evapotranspiration, shoot dry matter and leaf area index estimates from the modified SWAT2009 model were satisfactory at the HRU level, and the RMSE values associated with daily evapotranspiration, shoot dry matter, and leaf area index were reduced by 17.0%, 1.6%, and 71.2%, compared with SWAT2009. Thus, the influences of various optimal management practices on the hydrology of agricultural watersheds can be effectively assessed using the modified model.

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016


2015 ◽  
Vol 40 (3) ◽  
pp. 333-345
Author(s):  
MSA Khan ◽  
MA Karim ◽  
MM Haque ◽  
AJMS Karim ◽  
MAK Mian

The experiment was conducted at the experimental site of Agronomy Department, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Salna, Gazipur during the period from January to June 2011 to evaluate twenty selected soybean genotypes in respect of growth, dry matter production and yield. Genotypic variations in plant height, leaf area index, dry matter and its distribution, crop growth rate and seed yield were observed. The plant height ranged from 40.33 to 63.17 cm, leaf area index varied from 3.01 to 8.13 at 75 days after emergence, total dry matter ranged from 12.25 to 24.71 g per plant at 90 days after emergence (DAE). The seed yield ranged from 1745 to 3640 kg per hectare. The genotypes BGM 02093, BD 2329, BD 2340, BD 2336, Galarsum, BD 2331 and G00015 yielded 3825, 3447, 3573, 3737, 3115, 3542 and 3762 kg per hectare, respectively and gave higher than others contributed by higher crop growth rate with maximum number of filled pods. Seed yield of soybean was positively related to total dry matter at 45 DAE (Y = 632.19 + 659.31X, R2= 0.46) and 60 DAE (Y= 95.335 + 405.53X, R2 = 0.48). The filled pods per plant had good relationship with seed yield (Y = 1397 + 41.85X, R2 = 0.41) than other components.Bangladesh J. Agril. Res. 40(3): 333-345, September 2015


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Kamal Ahmed Kazem ◽  
Wajeeha Abed Hassan

"To evaluate the performance of introduced varieties of maize under different sowing dates and locations, in addition to local variety, a field experiment was carried out in two locations;. The study compared five varieties of maize introduced from America, with a local synthetic variety (Ibba 5018) and tested it in two locations at three sowing dates (1, 15 July and 1 August). The Randomized Complete Block Design RCBD was used with four replications, with spilt plot arrangements, the main plots included three sowing dates, the secondary plots included, the varieties. The traits of the days number to tassling and days to silking, plant height, ear height, number of leaves, leaves area, leaf area index, number of ears plant-1 , ear length, the number of rows ear-1, number of grains row-1 , number of grains of the plant, weight of 100 grains, total dry matter weight, the number of days to Physiological maturity, crop growth rate, individual plant yield and yield (tons h-1 ) were studied. The results showed that the values of the standard error (SE) in the two trial locations were low for the studied traits and within the acceptable limit except leaf area which was high in the first and second dates for the Baghdad location and for the three dates of the Diyala incident, as well as the values of the coefficient of variation (CV) were also low and within statistically acceptable limits and for all the traits studied in the three dates and for the two locations. Genetic variations were higher than the = environmental variation for most of the studied traits and the phenotypic coefficient of variation is close to the coefficient of genetic variation for the two locations and the three sowing dates, and this indicates that the traits are genetically governed. The value of heritability in a broad sense was higher than 90% at Baghdad location for first of July for the traits leaves area and its index, weight of the dry matter, number of days to physiological maturity (96.6, 97.4, 93.4 and 94.4%, respectively) and for 15 July for the traits. Leaf area and its index, and number of days to physiological maturity (94.7, 94.7 and 93.4%), and for I Aug for 9 traits; number of days silking, the leaf area and leaf area index, number of ears dry matter, days to maturity, rate of crop growth and yield the plant and unit area ((95.7, 99.4, 99.4, 94, 98.4, 95.5, 98.6, 93.4, 93.5%) Sequentially. As for Diyala, the traits of leaf area, leaf area index, number of days to physiological maturity, yield of plants, and area unit in the three dates were superior to the highest heritability (92.3, 92.3, 98.7, 73.6, 73.6%), (90.2, 90.2, 98.8, 82.9, 82 .9%), (90.9, 90.9, 86.4, 80.7, 80.7% respectively)."


1982 ◽  
Vol 18 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. U. Remison ◽  
E. O. Lucas

SUMMARYTwo maize cvs, FARZ 23 and FARZ 25, were grown at three densities (37,000, 53,000 and 80,000 plants/ha) in 1979 and 1980. Leaf area index (LAI) increased with increase in plant population and was at a maximum at mid-silk. Grain yield was highest at 53,000 plants/ha. There was no relation between LAI and grain yield but there was a positive correlation between LAI and total dry matter yield.


1984 ◽  
Vol 20 (2) ◽  
pp. 161-170
Author(s):  
D. Boobathi Babu ◽  
S. P. Singh

SUMMARYThe effects of irrigation and spraying of transpiration suppressants on growth and nutrient uptake by spring sorghum (CSH 6) have been investigated. Crop growth, measured by plant-height, leaf area index and dry matter production, and uptake of N, P and K increased with more frequent irrigation and in response to the spraying of transpiration suppressants. Foliar applications of atrazine at 200 g ha−1 and CCC at 300 ml ha−1 proved to be the best in this NW Indian location.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 232
Author(s):  
Nangial Khan ◽  
Fangfang Xing ◽  
Lu Feng ◽  
Zhanbiao Wang ◽  
Minghua Xin ◽  
...  

The number of cotton plants grown per unit area has recently gained attention due to technology expense, high input, and seed cost. Yield consistency across a series of plant populations is an attractive cost-saving option. Field experiments were conducted to compare biomass accumulation, fiber quality, leaf area index, yield and yield components of cotton planted at various densities (D1, 1.5; D2, 3.3; D3, 5.1; D4, 6.9; D5, 8.7; and D6, 10.5 plants m−2). High planting density (D5) produced 21% and 28% more lint yield as compared to low planting density (D1) during both years, respectively. The highest seed cotton yield (4662 kg/ha) and lint yield (1763 kg/ha) were produced by high plant density (D5) while the further increase in the plant population (D6) decreased the yield. The increase in yield of D5 was due to more biomass accumulation in reproductive organs as compared to other treatments. The highest average (19.2 VA gm m−2 d−1) and maximum (21.8 VM gm m−2 d−1) rates of biomass were accumulated in reproductive structures. High boll load per leaf area and leaf area index were observed in high planting density as compared to low, while high dry matter partitioning was recorded in the lowest planting density as compared to other treatments. Plants with low density had 5% greater fiber length as compared to the highest plant density, while the fiber strength and micronaire value were 10% and 15% greater than the lowest plant density. Conclusively, plant density of 8.7 plants m−2 is a promising option for enhanced yield, biomass, and uniform fiber quality of cotton.


2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429


2020 ◽  
Vol 15 (1) ◽  
pp. 106-122
Author(s):  
J. Alam ◽  
R. K. Panda

 Any change in climate will have implications for climate-sensitive systems such as agriculture, forestry and some other natural resources. Changes in solar radiation, temperature and precipitation will produce changes in crop yields and hence economics of agriculture. It is possible to understand the phenomenon of climate change on crop production and to develop adaptation strategies for sustainability in food production, using a suitable crop simulation model. CERES-Maize model of DSSAT v4.0 was used to simulate the maize yield of the region under climate change scenarios using the historical weather data at Kharagpur (1977-2007), Damdam (1974-2003) and Purulia (1986-2000), West Bengal, India. The model was calibrated using the crop experimental data, climate data and soil data for two years (1996-1997) and was validated by using the data of the year 1998 at Kharagpur. The change in values of weather parameters due to climate change and its effects on the maize crop growth and yield was studied. It was observed that increase in mean temperature and leaf area index have negative impacts on maize yield. When the maximum leaf area index increased, the grain yield was found to be decreased. Increase in CO2 concentration with each degree incremental temperature decreased the grain yield but increase in CO2 concentration with fixed temperature increased the maize yield. Adjustments were made in the date of sowing to investigate suitable option for adaptation under the future climate change scenarios. Highest yield was obtained when the sowing date was advanced by a week at Kharagpur and Damdam whereas for Purulia, the experimental date of sowing was found to be beneficial.


2014 ◽  
Vol 6 (4) ◽  
pp. 178 ◽  
Author(s):  
J. T. Amodu ◽  
T. T. Akpensuen ◽  
D. D. Dung ◽  
R. J. Tanko ◽  
A. Musa ◽  
...  

An experiment was conducted to evaluate the yield of forage, silage and nutrients composition of two maize accessions: West Atlantic Seed Alliance 1 (WASA1) and an accession from Shika tagged (SHIMAZ). The maize seeds were planted in plots of 5 m x 5 m (25 m2) size with four replicates for each accession. The results showed that, there was no significant (P > 0.05) difference between the accessions for plant height and number of leaves at 4, 6, 8 and 10 weeks after sowing (WAS), but leaf area index (LAI) was significantly (P < 0.05) higher in SHIMAZ accession at 6 and 10 WAS. The number of leaves per plant, green leaves, leaf area and forage yield at 91, 105 and 119 days after sowing (DAS) were not significant (P > 0.05) in the two accessions of maize, but leaf area and LAI were significantly (P < 0.05) higher in WASA1 accession.. The percentage dry-matter (DM) content was significantly (P < 0.05) lower in WASA1, although leaf, and stem ratios were significantly (P < 0.01) higher at various stages of harvest. The crude protein (CP) and nitrogen free-extract (NFE) were significantly (P < 0.01) higher in WASA1 accession while crude fibre (CF) was significantly (P < 0.01) higher in SHIMAZ. The proximate components (ash, EE and CP) and NDF were significantly (P < 0.01) higher in WASA1 silage, but NFE and ADF were higher (P < 0.05) in SHIMAZ accession.


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