scholarly journals Wheat water use and yield under different salinity of irrigation water

2017 ◽  
Vol 33 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Meysam Abedinpour

Abstract A field experiment was conducted for determination of crop coefficient (KC) and water stress coefficient (Ks) for wheat crop under different salinity levels, during 2015–2016. Complete randomized block design of five treatments were considered, i.e., 0.51 dS·m−1 (fresh water, FW) as a control treatment and other four saline water treatments (4, 6, 8 and 10 dS·m−1), for S1, S2, S3 and S4 with three replications. The results revealed that the water consumed by plants during the different crop growth stages follows the order of FW > S1 > S2 > S3 > S4 salinity levels. According to the obtained results, the calculated values of KC significantly differed from values released by FAO paper No 56 for the crops. The Ks values clearly differ from one stage to another because the salt accumulation in the root zone causes to reduction of total soil water potential (Ψt), therefore, the average values of water stress coefficient (Ks) follows this order; FW(1.0) = S1(1.0) > S2(1.0) > S3(0.93) > S4(0.82). Precise data of crop coefficient, which is required for regional scale irrigation management is lacking in developing countries. Thus, the estimated values of crop coefficient under different variables are essential to achieve the best management practice (BMP) in agriculture.

Author(s):  
Meysam Abedinpour

A field experiment was conducted for determination of crop coefficient (KC) and water stress coefficient (Ks) for wheat crop under different salinity levels, during 2015-16. Complete randomized block design of five treatments were considered, i.e., 0.51 dS/m (fresh water) as a control treatment and other four saline water treatments (4, 6, 8 and 10 dS/m), for S1, S2, S3 and S4 with three replications. The results revealed that the water consumed by plants during the different crop growth stages follows the order of FW>S1>S2>S3>S4 salinity levels. According to the obtained results, the calculated values of crop coefficients significantly differed from those suggested by FAO No.56 for the crops. The Ks values clearly differ from one stage to another because the salt stress causes both osmotic stress, due to a decrease in the soil water potential, and ionic stress which the average values of water stress coefficient (Ks) follows this order; FW(1.0)=S1(1.0)>S2(1.0)>S3(0.93)>S4(0.82). Overall, it was found the differences are attributed primarily to specific cultivar, the changes in local climatic conditions and seasonal differences in crop growth patterns. Thus, further studies are essential to determine the crop coefficient values under different variables, to make the best management practice (BMP) in agriculture.


Author(s):  
Élvis da S. Alves ◽  
Roberto Filgueiras ◽  
Lineu N. Rodrigues ◽  
Fernando F. da Cunha ◽  
Catariny C. Aleman

ABSTRACT In regions where the irrigated area is increasing and water availability is reduced, such as the West of the Bahia state, Brazil, the use of techniques that contribute to improving water use efficiency is paramount. One of the ways to improve irrigation is by improving the calculation of actual evapotranspiration (ETa), which among other factors is influenced by soil drying, so it is important to understand this relationship, which is usually accounted for in irrigation management models through the water stress coefficient (Ks). This study aimed to estimate the water stress coefficient (Ks) through information obtained via remote sensing, combined with field data. For this, a study was carried out in the municipality of São Desidério, an area located in western Bahia, using images of the Landsat-8 satellite. Ks was calculated by the relationship between crop evapotranspiration and ETa, calculated by the Simple Algorithm for Evapotranspiration Retrieving (SAFER). The Ks estimated by remote sensing showed, for the development and medium stages, average errors on the order of 5.50%. In the final stage of maize development, the errors obtained were of 23.2%.


2010 ◽  
Vol 56 (No. 2) ◽  
pp. 67-75 ◽  
Author(s):  
M.H. Biglouei ◽  
M.H. Assimi ◽  
A. Akbarzadeh

A field research was carried out in the years of 2005, 2006 and 2007 in order to determine the effect of irrigation and water stress imposed at different growth stages on quantity and quality traits of Virginia tobacco plants. A randomized complete block design with four treatments and three replications was applied at the Rasht tobacco research station. Treatments were: no irrigation (dryland farming) as the complete water stress (WS<sub>0</sub>), water stress till the end of flower bud forming stage (WS<sub>1</sub>), water stress till the end of flowering stage (WS<sub>2</sub>) and full irrigation (WS<sub>3</sub>) as control in each cropping season. The combined analysis of variance showed that the effect of water stress on all the traits related to yield, quality traits and all the traits related to yield components except number of leaves, was significant (<i>P</i> < 0.01). The interaction between year and water stress showed that the treatment of WS0 in all three experimental years significantly (<i>P</i> < 0.05) affected the fresh and dry leaf yield, plant height and sugar and nicotine percentage. The comparison of means of three years (average of three years) also revealed that the treatment of WS<sub>0</sub> significantly (<i>P</i> < 0.05) affected all of the traits which were related to tobacco quantity and quality except for the number of leaves. Moreover, the level of water productivity in recognition of each water volume unit for three experimental years for the treatments of WS<sub>1</sub>, WS<sub>2</sub> and WS<sub>3</sub> were 1.223, 0.873 and 0.594 kg/m<sup>3</sup>, respectively, in the case of average dry leaf yield. Consequently, the results indicate that with optimizing irrigation application we can reach the higher level of productivity.


2011 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
Nourali SAJEDI ◽  
Hamid MADANI ◽  
Ahmad NADERI

This study was carried out to investigate effects of microelements under water deficit stress at different growth stages on antioxidant enzyme alteration, chemical biomarker and grain yield of maize in the years 2007 and 2008. The experiment was conducted in a split plot factorial based on a randomized complete block design with four replications. There were three factors, water deficit stress at different stages of growth as main plot and combinations of selenium (with and without using) and microelements (with and without using) as sub plots. The result indicated that the activity of superoxide dismutase and malondialdehyde content under water deficit stress increased, but grain yield was reduced. The highest grain yield was obtained from optimum irrigation, while in the case of with water deficit stress at V8 stage it was non significant. Selenium spray increased activity of superoxide dismutase enzyme, malondialdehyde content of leaves in V8, R2 and R4 stages and also grain yield. Application of microelements increased the leaves superoxide dismutase enzyme activity and malondialdehyde content. Selenium and microelements spray under water deficit stress conditions during vegetative growth and dough stage increased grain yield in comparison to not spraying elements under water stress conditions. The present results also showed that by using selenium and microelements under water stress can obtain acceptable yield compared to not using these elements.


2013 ◽  
Vol 54 (2) ◽  
pp. 59-68
Author(s):  
Jadwiga Treder ◽  
Joanna Nowak

The response of osteospermum 'Denebola' and New Guinea impatiens 'Timor' grown on ebb-and-flow benches to different water potential of growing medium applied during whole growing period was investigated by measuring plant growth parameters and stomatal conductance (g<sub>S</sub>). After cutting establishment, four different irrigation treatments based on soil water potential were applied to osteospermum: at -0,5 , -3,0 , -10,0 , -20 kPa. In the case of impatiens the last water treatment was omitted. Plants were evaluated when they reach one ofthe three growth stages: lateral shoots development, visible flower buds (osteospermum) or beginning of flowering (impatiens) and at flowering. All plants produced with a moderate water deficit (irrigation at -3 and -10 kPa) were more compact than plants irrigated at -0,5 kPa but their flowering were not affected. Strong decrease in pIant growth and flowering was observed when plants were irrigated at the lowest water potential (-20 kPa). However, for impatiens the highest irrigation frequency was also not favorable. As a result of water stress the decrease in stomatal conductance (g~) in both plants was observed. Osteospermum was more resistant to water stress than impatiens.


Author(s):  
O. V. Zhuravlov ◽  
A. P. Shatkovskyi ◽  
V. V. Vasiuta

Based on the results of observations, it was specified that when decreasing soil moisture there is a disproportionate decrease in the average daily evapotranspiration (ET). Thus, in the range of soil moisture of 94-80% minimum moisture-holding capacity (MMHC) ET was 9,76 mm a day, and in the range of 70-62% MMHC - its value decreased by 3 times. When the soil moisture reached 58,5% MMHC, the value of ET did not exceed 0,5 mm a day, which is 20 times less than the initial one. It was determined that the decrease in soil moisture by 10% in the range of 90 - 70% MMHC occurs during 3 days, and from 70 to 60% MMHC and from 60 to 58% MMHC - during 8 days. When soil moisture is 70% MMHC and below, the actual evapotranspiration is less than ETo that proves the effect of water stress on soybeans ET. When calculating water stress coefficient (Ks), a mathematical model based on the dependence of Ks on soil moisture as a percentage of MMHC was obtained. The average absolute percentage error (MAPE) is 8,6%, which corresponds to the high accuracy of the obtained dependence. In the range of soil moisture from 58 to 80% MMHC, the water stress coefficient is calculated by the formula Ks =-0.0011·FC²+0.1925·FC-7,4541. When having soil moisture as 80% MMHC and above, Ks = 1. A comprehensive comparative assessment of existing methods for calculating waster stress coefficient Ks was taken and it was found out that the actual values of Ks when having soil moisture as 80-70 and 60-65% MMHC by 8-14 % and 72-32 %, respectively, less than Ks FAO 56, and by 35-40 % larger than those determined by Saxton method. It was proved the need of taking into account the reduction in evapotranspiration when calculating water balance under water stress of plants. The calculation of evapotranspiration (ETs) by the Penman-Monteith method, without taking into account the water stress coefficient, showed that the value of the actual and calculated water balance coincides only when soil moisture does not exceed 62% MMHC. With a further decrease in soil moisture, the estimated soil moisture was 20% less than the actual, which led to the errors in determining soil moisture after irrigation, because its actual value was almost 100% MMHC, and the estimated one was only 60% MMHC. It was proved that the determination of water balance by calculation methods without taking into account the water stress coefficient leads to significant errors.


2017 ◽  
Vol 3 (9) ◽  
pp. 110
Author(s):  
Aruna KT

The pot experiment was carried out during September 2015 to January 2016 at instructional farm, College of Agricultural Engineering, UAS Raichur under rain shelter to study the effect of different water regimes, (i.e. T1:100, T2:90, T3:80, T4:70, T5:60 and T6:50) per cent of water application with available moisture holding capacity on grain yield and water use efficiency. Completely Randomized block design with four replications was used in this study. The results showed that there was significant difference between the yield and (WUE) under different levels of irrigation. The total irrigation water applied were (i.e., 211.98, 243.02, 225.78, 155.09, 135.51 and 105.62 mm/plant) under different water regime treatments (100, 90, 80, 70, 60 and 50 %) of available moisture holding capacity (AMHC) respectively. Grain yield productions under different treatments were 106.25, 171.25, 127.50, 75, 55 and 40.75 g/plant/pot at 100, 90, 80, 70, 60 and 50 per cent of AMHC respectively. The results showed that water use efficiency (WUE) at different treatments were 0.50, 0.70, 0.56, 0.48, 0.41 and 0.39 g/mm for (100, 90, 80, 70, 60 and 50 %) per cent of AMHC respectively. Therefore, the 90 % of AMHC treatment (T2) is recommended for groundnut irrigation for water saving. The comparison of actual crop coefficient that obtained by water balance technic in experiment and crop coefficient (Kc) values of groundnut for different crop growth stages were selected based on the values suggested by FAO (Allen et al., 1998) are similar in the treatment of 90 % (T2) of the AMHC. Furthermore, the result showed that the treatment of 90 per cent of Available moisture holding capacity (T2) seemed to be better adapted to product a high crop yield with acceptable yield coupling with water use efficiency in this region.


1977 ◽  
Vol 57 (3) ◽  
pp. 925-927 ◽  
Author(s):  
A. R. SEPASKHAH

The effects of plant water stress at flower induction, flowering, podding and pod-filling stages on yield and yield components of soybean (Glycine max (L.) Merr.) were determined at three salinity levels in a greenhouse study. At all salinity levels, plant water stress was more critical in the pod-filling stage, and reduced seed yield and 100-seed weight.


Sign in / Sign up

Export Citation Format

Share Document