scholarly journals Determination of Crop Water Requirement and Crop Coefficient at Different Growth Stages of Green Gram Crop by Using Non-Weighing Lysimeter

Author(s):  
B. Srinivas ◽  
K.N. Tiwari
2021 ◽  
Vol 8 (2) ◽  
pp. 143-148
Author(s):  
RAVISH CHANDRA ◽  
SHABANAM KUMARI

This study is about estimation of crop water requirement for rice-wheat and rice-rabi maize cropping system for Pusa Region of Samastipur district of Bihar using CROPWAT model for year 2017-18.The effective rainfall was calculated using USDA S.C. Method. Reference crop evaporation was calculated using meteorological data viz temperature, relative humidity, wind speed and Sunshine using Penman Monteith equation. The meteorological data were collected from university observatory of R.P.C.A.U Pusa. Crop coefficient (Kc) value was taken according to crop growth stages. Effective rainfall and crop water requirement was used for determining net irrigation requirement. The annual crop water requirement of Rice- Wheat cropping system was found to be 904.1 mm whereas the crop-water requirement of Rice- Rabi Maize cropping system was 991.7 mm.


2020 ◽  
Vol 4 (3) ◽  
pp. 538-546
Author(s):  
A. Ahmed ◽  
M. A. Oyebode ◽  
H. E. Igbadun ◽  
Ezekiel Oiganji

This report presents a study of crop water requirement and crop coefficient (Kc) for Tomato crop cultivated under irrigation in Pampaida Millennium Village Cluster, Ikara Local Government Area of Kaduna State, Nigeria, during the 2009/2010 dry season. A total of 7 tomato farmers were selected out of 45 farmers for the assessment exercise. Water applied per irrigation and soil moisture contents before and after irrigation was monitored throughout the seasons, while Tomato bulbs were harvested at the end of season and weighed. Average  crop water use were estimated from the soil moisture content using the gypsum block, while daily reference Evapotranspiration (ETo) were computed from weather data using method Hargreaves equation. Crop coefficient values (Kc) were computed as the ratio of crop water use to ETo. The values of crop coefficients and seasonal crop water requirement per irrigation for different growth stages were determined, the computed *Kc values for different growth stage for the tomato crop grown in the study area was found to be between 0.77-1.15, the initial stage (*Kc =0.81; 20 mm/irrigation), crop development stage (*Kc = 1.09; 28 mm/irrigation), mid-season (*Kc = 1.15; 29 mm/ irrigation) and Late stage (*Kc = 0.77; 19 mm/irrigation), hence the mid-season gave the highest Kc value. However, the crop seasonal water requirement was found to be 386mm, which was within the recommended range. The crop coefficients and seasonal water requirement estimated in this study are reliable and could be used in irrigation design and scheduling for Tomato in the study area.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Songhao Shang

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop and reference evapotranspiration calculated from their values in growing stages. The proposed method was compared with two straightforward methods, that is, direct interpolation of crop evapotranspiration and crop coefficient by assuming that stage average values occurred in the middle of the stage. These methods were tested with a simulated daily crop evapotranspiration series. Results indicate that the proposed method is more reliable, showing that the downscaled crop evapotranspiration series is very close to the simulated ones.


2021 ◽  
Vol 23 (3) ◽  
pp. 306-309
Author(s):  
LAISHRAM KANTA SINGH ◽  
INGUDAM BHUPENCHANDRA ◽  
S. ROMA DEVI

The purpose of this study was to assess the evapotranspiration in field pea (Pisum sativum L.) in foothills valley areas of Manipur using the Hargreaves-Samani equation to predict the plant water demand. The crop coefficient (Kc) values ranged between 0.45 and 1.28 during the crop growth stages of field pea for the five crop seasons (2013-18). The average five-year effective rainfall was estimated to be 59.0 mm, with standard deviation (SD±) ranging between 4.4 to 35.1 mm. The average crop water requirement for field pea was estimated to be 221.0 mm and the average water demand for different crop growth stages of field pea was estimated to be 20.0 mm (initial stage), 52.0 mm (development stage), 100.0 mm (mid-season) and 49.0 mm (late season). Thus, the information generated may help in effective management of crop water requirements for sustainable crop production including field pea in the region.


In the world India is the highest producer and consumer of Arecanut. Also it is widely grown plantation crop in the coastal regions as well other parts of Karnataka. It has a great commercial value both in terms of export potential and revenue generation to the government. The crop sustains for a longer decades and demands huge amount of irrigation water throughout its life span. Assessment of exact amount of crop water requirement in different stages of the plant growth reduces the excessive irrigation. It increases crop yield thereby conserves both ground and surface water. The study targets to identify important wavelengths to predict age based crop water requirement. For this a small portion of the Channagiritaluk is considered for the study. The methodology adopted in this study uses the Hyperspectral data for age based classification of Arecanut crop to map its corresponding water requirement using NDVI based KC method. From the map pixel wise age based crop water requirement values were extractedand regressed with the corresponding spectral signatures from pre-processed satellite imagery. The PLSR model yielded a coefficient of determination of 0.98. The output of PLSR model results were used in VIP. Total of eight wavelengths, spanning across VNIR and SWIR regions were identified as significant in modeling the ACWR these were 1043, 1053, 1033, 1083, 1023, 1013, 1104, and 854nm. The identified wavelengths are useful to develop a model to estimate the water demand of the study area. The study helps for optimized planning of the water resources.


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