Crop Water Requirement and Water Use Efficiency

Author(s):  
Christian von Zabeltitz
Author(s):  
K. Ashok Kumar ◽  
M. Navaneetha ◽  
B. Aravind ◽  
T.M. Rajesh ◽  
M. Pravallika ◽  
...  

Background: The main challenge confronting both rainfed and irrigated agriculture is to improve water use efficiency (WUE) and sustainable water use for agriculture. A field experiment was conducted during early summer season of 2020 to study the effect of drip irrigation combined with organic mulching on soil moisture, growth, yield of tomato grown on alfisols at the college farm of College of Agricultural Engineering, Madakasira, Ananthapuramu district of Andhra Pradesh. Methods: The experiment was laid out in completely randomized block design (CRBD) with seven treatments comprising of various organic mulches. The treatments were T1 - Sawdust + Irrigation based on daily crop water requirement, T2 - Ragi straw + Irrigation based on daily crop water requirement, T3 - Groundnut shells + Irrigation based on daily crop water requirement, T4 - Groundnut shells + Irrigation once in every two days, T5 - Saw dust + Irrigation once in every two days, T6 - Ragi straw + Irrigation once in every two days and T7 - Control (without mulch) + Irrigation based on daily crop water requirement. All the treatments were replicated thrice. The plot size of each treatment was 4m × 2.5m. Result: The results revealed that throughout the crop growth period, T3 - Groundnut shells + Irrigation based on daily water requirement maintained soil higher moisture content to an extent of 132-146% as compared to control T7 (Control + Daily water requirement). The fruit yield obtained with T3 - Groundnut shells + Irrigation based on daily water requirement was significantly higher (8.8 t/ha) as compared to control T7 (Control + Daily water requirement) (7.6 t/ha). The highest water use efficiency (39.6 kg/ha/mm) was noted with T4 - Groundnut shells + Irrigation once in every two days), whereas T7 (Control + Daily water requirement) registered minimum WUE (16.3 kg/ha/mm). Weed dry matter and weed index was found to be higher (50% to 100%) in T7 (Control + Daily water requirement) throughout the crop growth period as compared to all the treatments applied with organic mulches. Our results indicated that T3 - (Groundnut shells + Irrigation based on daily crop water requirement) resulted in the highest plant height, number of fruits per plant and high water use efficiency as compared to without mulching. Further, under irrigation water constraints, groundnut shells mulch and drip irrigation once in two days was found to be effective in attaining higher WUE.


2021 ◽  
Vol 23 (4) ◽  
pp. 389-395
Author(s):  
VIKAS SHARMA ◽  
P.K. SINGH ◽  
S.R. BHAKAR ◽  
K.K. YADAV ◽  
S.S. LAKHAWAT ◽  
...  

The results of this study revealed that the pan evaporation and sensor based irrigation scheduling along with fertigation scheduling significantly affected the plant height, fruit weight, fruit length, crop water requirement, crop yield and water use efficiency of okra crop. The pan evaporation and crop evapotranspiration (ETc) values significantly vary over different stages of okra crop. The maximum and minimum average daily pan evaporation was recorded 8.4 mm day-1 and 4.5 mm day-1 at mid stage and late stage of okra crop respectively while, the maximum average daily ETc was recorded 7 mm day-1 at mid stage of okra crop. A approach of irrigation scheduling with 100 per cent field capacity, based on soil moisture sensor under automated drip irrigation system along with 100 per cent RDF through fertigation in equal splits at 4 day intervalor 80 % per cent of volume of crop water requirement based on pan evaporation under automated drip irrigation along with 100 per cent RDF through fertigation in equal splits at 2 day interval, can be used for irrigating okra crop with significant water saving, crop yield and water use efficiency under limited availability of daily weather datain climatic condition of Udaipur district of Rajasthan.


2021 ◽  
Author(s):  
Ceres Duarte Guedes Cabral de Almeida ◽  
Leandro Candido Gordin ◽  
Alexsandro Cláudio dos Santos Almeida ◽  
José Amilton Santos Júnior ◽  
Brivaldo Gomes de Almeida ◽  
...  

<p>Several methodologies and techniques are available for irrigation management in protected environments. Despite the cultivation of vegetables in the greenhouse is largely present in the northeastern region of Brazil, not many research has been aimed at supporting growers for accurate irrigation management.</p><p>The objective of this study is to evaluate yield and irrigation water use efficiency of Capsicum crop cultivated in a greenhouse under different methods to define the daily irrigation depth, based on the soil water status and the atmospheric evaporative demand. Moreover, two different strategies to apply the estimated irrigation depths (single or double daily application) were also examined.</p><p>The experiment was carried out in a greenhouse in the Federal Rural University of Pernambuco (UFRPE), northeastern of Brazil (8° 01’ 07” S and 34° 56’ 53” W, altitude 6.50 m). Based on a completely randomized design, the experimental units were distributed according to a 4 x 2 factorial scheme with eight replications, with a total of 64 experimental units. Four methods to estimate daily irrigation water requirement were evaluated: two based on soil sensors (soil water content sensors EC-5, SWS, and tensiometers, TS), whereas the other two were based on the atmospheric evaporative demand (weighing lysimeter, WL, and Piché evaporimeter, PE). Moreover, the daily irrigation depths were applied with a single watering (at 8:00 am) or split into two applications (the half at 8:00 am and the half at 4:30 pm). The commercial yield of the examined crop was calculated through the relationship between the weight of fresh fruit and the area occupied by the plant.</p><p>The statistical analysis showed that the water use efficiency, the total water volume applied and the commercial yield of capsicum were significantly influenced by the method used to estimate crop water requirement, as well as the irrigation strategies. The total irrigation depth applied during the entire crop cycle resulted in equal to 509 mm, 678 mm, 716 mm, and 790 mm for treatments with WL, PE, SWS, and TS, respectively. The seasonal applied irrigation depths corresponded to an average daily crop water requirement ranging, according to the treatments, from 5.4 to 8.3 mm day<sup>-1</sup>; these values are consistent for the examined crop cultivated under protected conditions. The highest yields of commercial fruits were obtained in the treatments in which the highest irrigation depth (SWS and TS) was applied. On the other hand, the highest values of water use efficiency were obtained in those treatments in which the irrigation depth was defined based on SWS and WL. Splitting the estimated daily irrigation depth in two applications promoted greater commercial productivity and water use efficiency (10.73 t ha<sup>-1</sup> and 1.60 kg m<sup>-3</sup>) compared to a single application (8.14 t ha<sup>-1</sup> and 1.22 kg m<sup>-3</sup>), with an increase of both variables of about 31%. These results evidenced that splitting the daily irrigation depth is a promising strategy to increase water use efficiency for vegetable crops in protected environments.</p>


1984 ◽  
Vol 11 (1) ◽  
pp. 4-6 ◽  
Author(s):  
D. K. Pahalwan ◽  
R. S. Tripathi

Abstract Field experiment was conducted during dry season of 1981 and 1982 to determine the optimal irrigation schedule for summer peanuts (Arachis hypogaea L.) in relation to evaporative demand and crop water requirement at different growth stages. It was observed that peanut crop requires a higher irrigation frequency schedule during pegging to pod formation stage followed by pod development to maturity and planting to flowering stages. The higher pod yield and water use efficiency was obtained when irrigations were scheduled at an irrigation water to the cumulative pan evaporation ratio of 0.5 during planting to flowering, 0.9 during pegging to pod formation and 0.7 during pod development to maturity stage. The profile water contribution to total crop water use was higher under less frequent irrigation schedules particularly when the irrigations were scheduled at 0.5 irrigation water to the cumulative pan evaporation ratio up to the pod formation stage.


2018 ◽  
Vol 10 (11) ◽  
pp. 1682 ◽  
Author(s):  
Kelly Thorp ◽  
Alison Thompson ◽  
Sara Harders ◽  
Andrew French ◽  
Richard Ward

Improvement of crop water use efficiency (CWUE), defined as crop yield per volume of water used, is an important goal for both crop management and breeding. While many technologies have been developed for measuring crop water use in crop management studies, rarely have these techniques been applied at the scale of breeding plots. The objective was to develop a high-throughput methodology for quantifying water use in a cotton breeding trial at Maricopa, AZ, USA in 2016 and 2017, using evapotranspiration (ET) measurements from a co-located irrigation management trial to evaluate the approach. Approximately weekly overflights with an unmanned aerial system provided multispectral imagery from which plot-level fractional vegetation cover ( f c ) was computed. The f c data were used to drive a daily ET-based soil water balance model for seasonal crop water use quantification. A mixed model statistical analysis demonstrated that differences in ET and CWUE could be discriminated among eight cotton varieties ( p < 0 . 05 ), which were sown at two planting dates and managed with four irrigation levels. The results permitted breeders to identify cotton varieties with more favorable water use characteristics and higher CWUE, indicating that the methodology could become a useful tool for breeding selection.


Sign in / Sign up

Export Citation Format

Share Document