Effect of irrigation and defoliation on the herbage production and water use efficiency of four temperate pasture species

1973 ◽  
Vol 24 (6) ◽  
pp. 797 ◽  
Author(s):  
GG Johns ◽  
A Lazenby

Measurements were made over a 12-month period of the herbage production of both dryland and irrigated monoculture swards of four temperate pasture species under two defoliation regimes. By relating herbage production to the previously reported water use results for these swards, water use efficiencies (WUE) have been computed. Dryland clover produced 2000 kg/ha less herbage than did the dryland grasses, although it used a similar quantity of water. Consequently, the WUE of dryland clover was substantially less than that of the dryland grasses. Under dryland conditions, fescue not only produced more herbage, but also used water more efficiently than did the other species. Similar amounts of irrigation enabled the clover to yield an extra 6000 kg/ha of herbage compared with a mean grass response of 1760 kg/ha. The irrigated clover swards generally used water much more efficiently than the dryland clover swards. In contrast, the grasses generally used water with similar efficiency under both irrigated and dryland conditions. Under both irrigated and dryland conditions the frequently defoliated swards usually outyielded those cut infrequently as well as making more efficient use of water. The response of pastures to irrigation is discussed in terms of the effects of irrigation on the water status of the plants and the availability of nutrients in the rhizosphere.

1991 ◽  
Vol 71 (3) ◽  
pp. 695-702 ◽  
Author(s):  
J. M. Clarke ◽  
R. A. Richards ◽  
A. G. Condon

Increasing the water use efficiency (WUE) of wheat (Triticum spp.) has long been a goal in semiarid areas. Low rates of residual (cuticular) transpiration are thought to improve yield potential of wheat under dry conditions, although the linkage is tenuous. The objective of this work was to investigate the association of residual transpiration with water use, WUE, and leaf water status in hexaploid (T. aestivum L.) and tetraploid (T. turgidum L. var. durum) genotypes grown under two watering regimes in two glasshouse experiments. Single plants were grown in 0.1-m × 1-m (0.1-m × 0.5-m in exp. 2 low-stress treatment) PVC tubes filled with soil. The watering regimes consisted of weekly replenishment of water used (low stress), or addition of sufficient water to ensure plant survival (high stress). At anthesis, flag leaf residual transpiration (rate of water loss from excised leaves), stomatal conductance, relative water content (RWC), and osmotic potential (exp. 1 only) were measured. Water use was not correlated with residual transpiration rate in either experiment. Residual transpiration rate did not differ for the two stress treatments in exp. 1, but there were significant (P < 0.01) genotype by stress treatment interactions. Residual transpiration rate was not related to plant water status (leaf RWC or osmotic potential) as had been reported in other studies. Key words: Cuticular transpiration, water use efficiency, Triticum aestivum L., Triticum turgidum L. var. durum


Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 153 ◽  
Author(s):  
Katherine Sinacore ◽  
Heidi Asbjornsen ◽  
Virginia Hernandez-Santana ◽  
Jefferson S. Hall

Drought conditions may have differential impacts on growth, transpiration, and water use efficiency (WUE) in mixed species and monospecific planted forests. Understanding the resistance (i.e., the capacity to maintain processes unchanged) of different tree species to drought, and how resistance is affected by complementary interactions within species mixtures, is particularly important in the seasonally dry tropics where projected increases in the frequency and severity of drought threaten tree planting efforts and water resources. Complementary interactions between species may lead to more resistant stands if complementarity leads to greater buffering capacity during drought. We examined growth, transpiration, and WUE of mixtures and monocultures of Terminalia amazonia (J.F. Gmel.) Exell and Dalbergia retusa Hemsl. before and during a prolonged drought using intensive measurements of tree sap flow and growth. Tree sapwood area growth was highest for T. amazonia in mixtures during normal (6.78 ± 4.08 mm2 yr−1) and drought (7.12 ± 4.85 mm2 yr−1) conditions compared to the other treatments. However, stand sapwood area growth was greatest for T. amazonia monocultures, followed by mixtures, and finally, D. retusa monocultures. There was a significant decrease in stand transpiration during drought for both mixtures and T. amazonia monocultures, while Dalbergia retusa monocultures were most water use efficient at both the tree and stand level. Treatments showed different levels of resistance to drought, with D. retusa monocultures being the most resistant, with non-significant changes of growth and transpiration before and during drought. Combining species with complementary traits and avoiding combinations where one species dominates the other, may maximize complementary interactions and reduce competitive interactions, leading to greater resistance to drought conditions.


2019 ◽  
Author(s):  
Jing Zhang ◽  
Wuwu Wen ◽  
Hui Li ◽  
Qiyu Lu ◽  
Bin Xu ◽  
...  

Abstract Background: Switchgrass (Panicum virgatum L.) is a prime candidate for non-grain-based bioenergy feedstock production. Improved the drought tolerance and higher water use efficiency are important traits for its successful field establishment and production especially in marginal land. Aquaporins are key channels and regulators for water transportation and maintenance of cellular water status. In this study, the functional role of an aquaporin gene, PvPIP2;9, in switchgrass drought tolerance was studied.Results: Expression of PvPIP2;9 was regulated by the diurnal oscillation and osmotic stress. Constitutive over-expressing PvPIP2;9 in switchgrass significantly improved its drought tolerance and water use efficiency with less electrolyte leakage rates but higher relative water contents, photochemical efficiencies, and chlorophyll contents. Moreover, expression patterns of all 14 switchgrass PIP2 subfamily genes were checked in wildtype and transgenic plants during the water-withdrawal treatment, and the result showed that over-expressing PvPIP2;9 also affected transcript levels of most other PIP2 genes. Conclusions: Together, this study showed that improved drought tolerance and higher water use efficiency can be achieved by manipulating the expression level of PvPIP2;9 and also suggested PIP2 subfamily genes were transcriptionally regulated in a coordinated manner.


2004 ◽  
Vol 40 (2) ◽  
pp. 201-214 ◽  
Author(s):  
R. A. L. KANTON ◽  
M. D. DENNETT

Growth and water use of sole crops and intercrops of morphologically contrasting maize and pea cultivars were measured in two years. The maize cultivars were Nancis with erectophile and Sophy with planophile leaves and the pea cultivars Maro a leafy pea and Princess a semi-leafless pea. In the first part of the season water use was lower for sole maize but intercrops and sole pea used similar amounts of water. By 90 days after sowing, when peas had matured, all crops had used similar amounts of water. Maize had slightly greater water use efficiency than peas. Cultivars Nancis and Princess tended to have greater water use efficiency than Sophy and Maro respectively. Intercrops produced more dry matter than sole crops and therefore had consistently greater water use efficiencies.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1290
Author(s):  
Taia A. Abd El-Mageed ◽  
Eman E. Belal ◽  
Mohamed O. A. Rady ◽  
Shimaa A. Abd El-Mageed ◽  
Elsayed Mansour ◽  
...  

Drought is one of the major threats to global food security. Biochar use in agriculture has received much attention and improving it through chemical modification offers a potential approach for enhancing crop productivity. There is still limited knowledge on how acidified biochar influences soil properties, and consequently its influences on the agricultural productivity of drought stressed plants. The water use efficiency (I-WUE) of drought stressed faba beans was investigated through the effects of acidified biochar (ACBio) (a 3:100 (w:w) combination of citric acid and biochar) on soil properties, growth, productivity, nutrient uptake, water productivity (WP), and irrigation. Two field experiments (2016/2017 and 2017/2018) were conducted in saline soil (ECe, 7.2 dS m−1) on faba been plants grown under three irrigation regimes (i.e., 100, 80, and 60% of crop evapotranspiration (ETc)) combined with three levels of ACBio (0, 5, and 10 t ha−1). Plants exposed to water stress presented a significant decrease in plant height, dry matter, leave area, chlorophyll content (SPAD), the quantum efficiency of photosystem II (Fv/Fm, Fv/F0, and PI), water status (membrane stability index and relative water content), and seed yield. Acidified biochar soil incorporation improved soil properties (chemical and physical), plant growth, physiological responses, WP, I-WUE, and contents of N, P, K, and Ca. Results revealed that the application of ACBio at 10 t ha−1 and 5 t ha−1 significantly increased seed yield by 38.7 and 25.8%, respectively, compared to the control. Therefore, ACBio incorporation may find application in the future as a potential soil amendment for improving growth and productivity of faba bean plants under deficit irrigation.


Author(s):  
Luiz Fernando Ganassali de Oliveira Júnior ◽  
Patrícia Lima de Souza Santos ◽  
Roberta Samara Nunes de Lima ◽  
Maria Priscilla Celestino Silveira ◽  
Jailson Lara Fagundes ◽  
...  

Abstract: The objective of this work was to evaluate the effects of CaO-based particle film on the physiological parameters of cowpea (Vigna unguiculata) subjected to water restriction. Plants were subjected to two levels of soil moisture and three concentrations of the film, as follows: control, without film + 100% crop evapotranspiration (ETc); without film + 50% ETc; 5% CaO + 50% ETc; 10% CaO + 50% ETc; 5% CaO + 100% ETc; and 10% CaO + 100% ETc. Plants treated with 50% ETc remained stable with the application of 10% CaO particle film and showed high photosynthetic assimilation of CO2 (32 μmol m-2 s-1), moderate transpiration (5.6 mmol m-2 s-1), maintenance of chlorophyll content, and greater intrinsic water-use efficiency (IWUE, 226.65 μmol mol-1) and instantaneous water-use efficiency (6.06 μmol mmol-1) than plants of the other treatments. Control plants and plants at 5% CaO + 50% ETc showed, respectively, photosynthetic assimilation of CO2 at 15.34 and 15.94 μmol m-2 s-1, transpiration at 3.51 and 3.45 mmol m-2 s-1, and IWUE at 177.7 and 198.9 μmol mol-1. The CaO-based particle film is effective in protecting bean plants subjected to water restriction.


2021 ◽  
Author(s):  
Mutiara K. Pitaloka ◽  
Robert S. Caine ◽  
Christopher Hepworth ◽  
Emily L. Harrison ◽  
Jen Sloan ◽  
...  

Abstract BackgroundRice (Oryza sativa) is one of the world’s most important crops and is especially important in Asia. Because irrigated rice consumes about 34–43% of the total water used for irrigation globally, increasing drought and global temperature will increase the risk of rice crop loss. However, rice is among the least efficient crops in terms of water use, whereby most of the uptaken water is used for transpirational cooling via stomatal pores on the leaf blades and sheaths. To increase the water-use efficiency of rice, alterations in stomatal density and size may help to reduce transpiration and thereby increase water-use efficiency (WUE). ResultsWe identified four stomatal model lines—with either high-density (HD) or low-density (LD) stomata and small-sized (SS) or big-sized (BS) stomata—from the Mutant Core Collection (MCC) of 216 mutants. Gas exchange analysis revealed that the stomatal model lines have similar photosynthetic assimilation (A) and chlorophyll fluorescence. With increasing CO2 concentration, A of all stomatal model lines was observed to respond similarly at 100–600 ppm CO2, but beyond this point, SS was more responsive to increasing CO2 concentration than the other stomatal model lines. HD had higher stomatal conductance (gs) and gsmax than the other stomatal model lines. In response to a mild heat at 30 °C, both SS and LD had higher canopy temperature than HD, BS, and JHN-wt as a result of heat retention. All stomatal model lines are also similar in their rhythmic stomatal responses to ten-minute dark/light transition cycles, except that initial stomata closure in SS was more rapid than in BS. The stomatal model lines did not show any significant differences in the response to short-term water stress. Long-term water stress had less impact on leaf drying, Fv/Fm, grain yield, and harvest index in LD and SS. In the field, all stomatal model lines and JHN-wt had similar WUE in the sufficient-water treatment. LD had the highest WUE and biomass/plant than any stomatal model lines in the long-term restricted-water treatment. ConclusionsTaken together, our results suggest that induced alterations in stomata density and size influence rice WUE and the responses to drought and heat stresses, providing further understanding of the roles of stomata density and size in related processes. The low-density and small stomata lines have high potential as genetic donors for improving WUE and drought in climate-ready rice.


2020 ◽  
Vol 36 (1) ◽  
pp. 87-100 ◽  
Author(s):  
Getachew Assefa ◽  
Mengistu Urge ◽  
Getachew Animut ◽  
Getnet Assefa

Maize varieties BH540, BH660, BH661, and MVFG (unknown variety as local check) were evaluated at low (5.6 kg m-2), medium (7.6 kg m-2), and high (9.6 kg m-2) seed rate for hydroponic fodder productivity. A 3 ? 4m wide and 3 m height low-cost plastic house made of translucent plastic and a plastic trays made by bisecting a 25 liter capacity plastic oil container into two equal parts were used for growing the hydroponic fodder. The bottoms of the trays were drilled to open holes to drain excess water during irrigation and placed on shelves.The BH661 exhibited significantly (p<0.01) higher dry fodder yield (6.63 kg) per square meter and per kg seed than the other varieties. Among the seed rates, the high seed rate has a higher (P< 0.01) Dry Mater (DM) fodder yield, but the medium and low seed rates had greater DM fodder conversion efficiency and lower cost per kg DM fodder production. Water use efficiency was lower for BH540 (64 kg DM fodder per cubic meter water) as compared to the other varieties that had similar values (90 to 95kg DM fodder per cubic meter water). Medium and high seed rates exhibited similar water use efficiency, and it is higher than the low seed rate. Therefore, the use of BH661 variety at medium seeding rate is recommended for maize hydroponic fodder production.


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 ◽  
...  

&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;The experiment was carried out in a greenhouse in the Federal Rural University of Pernambuco (UFRPE), northeastern of Brazil (8&amp;#176; 01&amp;#8217; 07&amp;#8221; S and 34&amp;#176; 56&amp;#8217; 53&amp;#8221; 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 Pich&amp;#233; 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.&lt;/p&gt;&lt;p&gt;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&lt;sup&gt;-1&lt;/sup&gt;; 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&lt;sup&gt;-1&lt;/sup&gt; and 1.60 kg m&lt;sup&gt;-3&lt;/sup&gt;) compared to a single application (8.14 t ha&lt;sup&gt;-1&lt;/sup&gt; and 1.22 kg m&lt;sup&gt;-3&lt;/sup&gt;), 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.&lt;/p&gt;


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