scholarly journals Improving Water use Efficiency of Annual Crops in the Rainfed Farming Systems of West Asia and North Africa

1987 ◽  
Vol 23 (2) ◽  
pp. 113-158 ◽  
Author(s):  
P. J. M. Cooper ◽  
P. J. Gregory ◽  
D. Tully ◽  
H. C. Harris

SummaryFarming systems in west Asia and north Africa have evolved to cope with the problems of highly variable and, frequently, chronically deficient rainfall. Cereals (mainly wheat and barley) are the dominant arable crops with food legumes (chickpea, lentil and faba bean) occupying only 5 to 10% of the area planted to cereals. Livestock is closely integrated into the farming system and crop production practices often reflect the importance of animals as a major source of income, particularly on the smaller farms. Soils of the region are predominantly calcareous, frequently phosphate deficient, and their depth and texture are important in determining the maximum amount of water that can be stored which, in turn, may determine the effective length of the growing season.Rain falls mainly during the winter months so that crops must often rely on stored soil moisture when they are growing most rapidly. Analysis of equations relating crop growth and water use shows that there are three ways in which the ‘water use efficiency’ of dry matter production can be increased. First, the amount of dry matter produced per unit of water transpired might be increased; second, if the water supply is limited, the amount of water transpired might be increased relative to evaporation from the soil surface; and third, the total amount of water used might be increased to produce extra growth provided that this results in increased transpiration rather than simply increasing evaporation from the soil surface.These three possible routes to increased crop growth are reviewed in relation to possible improvements in water management and crop genotypes in the Mediterranean environment. Scope for improving transpiration efficiency is limited although genotypic differences exist and may be useful in the future. More immediately, changes in crop management, such as applications of fertilizer, improved tillage and better weed control, will all increase the amount of water transpired. Application of mulches will also reduce evaporation from the soil surface but crop residues are usually eaten by livestock and are, therefore, often unavailable.The barley/livestock farming system of west Asia is used as a case study to illustrate how the Fanning Systems Programme of ICARDA has developed on-farm research programmes of direct relevance to current farming systems. Research on experimental sites directed at improving water use efficiency has been developed into on-farm trials and into collaborative trials with the Syrian Soils Directorate.

1997 ◽  
Vol 77 (3) ◽  
pp. 359-366 ◽  
Author(s):  
H. W. Cutforth ◽  
B. G. McConkey

In the semiarid region of the western Canadian prairies, seeding directly into standing cereal stubble is gaining popularity. This four year study was conducted at Swift Current, SK, to determine how seeding into tall (>30 cm high), short (about 15 cm high) and cultivated cereal stubble altered the microclimate thereby affecting the growth and yield of hard red spring wheat (Triticum aestivum L.). The treatments were deployed immediately before seeding on plots that had overwintered with tall stubble. Seeding wheat into tall stubble increased grain yield and water use efficiency by about 12% compared to wheat seeded into cultivated stubble. Yield and water use efficiency for wheat seeded into short stubble were intermediate to the other stubble treatments. As well, wheat seeded into tall stubble grew taller than wheat seeded into the cultivated stubble. Further, there was a tendency for spring wheat grown in tall stubble to produce more dry matter and more leaf area, to have a lower proportion of dry matter as leaves and a higher proportion as stems, and to have a lower harvest index than the other treatments.Growing season evapotranspiration (ET) was not affected by stubble height. When the seedlings were small, compared to cultivated stubble, tall stubble altered the microclimate near the soil surface by reducing the daily average windspeed, soil temperature, and incoming solar radiation, and increasing the reflected solar radiation. Throughout much of the growing season, potential ET at the soil surface, measured with minilysimeters, was significantly lower in the tall stubble. Tall stubble, compared to cultivated stubble, increased the proportion of ET that was transpired by the wheat. As well, reduced windspeeds and increased photosynthetic area may have increased the efficiency of net carbon assimilation. To increase grain yields, producers in the semiarid prairies who direct-seed spring wheat are advised to seed into stubble left standing as tall as practical (at least 30 cm). Key words: Standing stubble, wheat, microclimate, water use, yield


2020 ◽  
Author(s):  
Yaojun Zhang ◽  
Jiaqi Ding ◽  
Hong Wang ◽  
Lei Su ◽  
Cancan Zhao

Abstract Background: Environmental stress is a crucial factor restricting plant growth as well as crop productivity, thus influencing the agricultural sustainability. Biochar addition is proposed as an effective management to improve crop performance. However, there were few studies focused on the effect of biochar addition on crop growth and productivity under interactive effect of abiotic stress (e.g., drought and salinity). This study was conducted with a pot experiment to investigate the interaction effects of drought and salinity stress on soybean yield, leaf gaseous exchange and water use efficiency (WUE) under biochar addition. Results: Drought and salinity stress significantly depressed soybean phenology (e.g. flowering time) and all the leaf gas exchange parameters, but had inconsistent effects on soybean root growth and WUE at leaf and yield levels. Salinity stress significantly decreased photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate by 20.7%, 26.3%, 10.5% and 27.2%, respectively. Lower biomass production and grain yield were probably due to the restrained photosynthesis under drought and salinity stress. Biochar addition significantly enhanced soybean grain yield by 3.1-14.8%. Drought stress and biochar addition significantly increased WUE-yield by 27.5% and 15.6%, respectively, while salinity stress significantly decreased WUE-yield by 24.2%. Drought and salinity stress showed some negative interactions on soybean productivity and leaf gaseous exchange. But biochar addition alleviate the negative effects on soybean productivity and water use efficiency under drought and salinity stress. Conclusions: The results of the present study indicated that drought and salinity stress could significantly depress soybean growth and productivity. There exist interactive effects of drought and salinity stress on soybean productivity and water use efficiency, while we could employ biochar to alleviate the negative effects. We should consider the interactive effects of different abiotic restriction factors on crop growth thus for sustainable agriculture in the future.


2002 ◽  
Vol 42 (7) ◽  
pp. 945 ◽  
Author(s):  
J. L. Jacobs ◽  
G. N. Ward ◽  
A. M. McDowell ◽  
G. Kearney

Effect of cultivation practice and sowing time on soil moisture retention at sowing, growth rates, dry matter yield, water use efficiency and nutritive characteristics (metabolisable energy, crude protein, neutral detergent fibre, water-soluble carbohydrates and starch) of turnip, pasja and rape was determined on 2 soil types (site A and B) over 2 years. Cultivation treatments were: optimum full inversion, an optimum non-inversion cultivation and over cultivated. At each site, cultivation treatments were imposed at 2 different times (early and late).Results showed few differences in soil moisture at sowing between the 3 cultivation systems. Where seedbeds were prepared earlier rather than later, soil moisture at sowing was higher. Given that there was relatively little difference in soil moisture between cultivation treatments within a sowing time, it is likely that rainfall events may have confounded cultivation effects.Apart from year 2 at site A, the water use efficiency of turnip was higher than for pasja and rape. It is proposed that the lower value in year 2 may be due to root development being retarded by low moisture availability, particularly at the later sowing date, thus leading to a lower dry matter yield.Despite no cultivation effects on soil moisture at sowing, there appeared to be clear advantages for the full inversion technique in terms of subsequent weed germination. Generally, weed numbers post germination were lower for this cultivation method compared with both non-inversion techniques. In conclusion, the cultivation techniques used had little effect on soil moisture at sowing and subsequent dry matter yields, provided the resultant seedbed was well-prepared, fine, firm and weed free. Full inversion cultivation techniques in areas where broad-leaved weeds are a problem may substantially reduce subsequent weed burdens. Early sowing where possible may reduce the likelihood of crop failure through the provision of adequate soil moisture at sowing and increase the incidence of rain during the growing period. Timing of sowing will vary according to paddock requirements during early spring (e.g. grazing or forage conservation), soil type, and trafficability for cultivation.


1997 ◽  
Vol 37 (6) ◽  
pp. 667 ◽  
Author(s):  
W. M. Strong ◽  
R. C. Dalal ◽  
J. E. Cooper ◽  
J. A. Doughton ◽  
E. J. Weston ◽  
...  

Summary. Continuous cereal cropping in southern Queensland and northern New South Wales has depleted native soil nitrogen fertility to a level where corrective strategies are required to sustain grain yields and high protein content. The objective of this study was to examine the performance of chickpea in chickpea–wheat rotations in terms of yields, water use and N2 fixation. The effects of sowing time and tillage practice have been studied. Chickpea grain yields varied from 356 kg/ha in 1995 to 2361 kg/ha in 1988; these were significantly correlated with the total rainfall received during the preceding fallow period and crop growth. Almost 48% of total plant production and 30% of total plant nitrogen were below-ground as root biomass. Mean values of water-use efficiency for grain, above-ground dry matter, and total dry matter were 5.9, 14.2 and 29.2 kg/ha.mm, respectively. The water-use efficiency for grain was positively correlated with the total rainfall for the preceding fallow and crop growth period although cultural practices modified water-use efficiency. The potential N2 fixation was estimated to be 0.6 kg nitrogen/ha.mm from 1992 total dry matter nitrogen yields assuming all of the nitrogen contained in chickpea was derived from the atmosphere. Sowing time had a much larger effect on grain yield and N2 fixation by chickpea than tillage practice (conventional tillage and zero tillage) although zero tillage generally increased grain yields. The late May–early June sowing time was found to be the best for chickpea grain yield and N2 fixation since it optimised solar energy use and water use, and minimised frost damage. Nitrogen fixation by chickpea was low, less than 40% nitrogen was derived from atmosphere, representing less than 20 kg nitrogen/ha.year. The potential for N2 fixation was not attained during this period due to below-average rainfall and high soil NO3-N accumulation because of poor utilisation by the preceding wheat crop. Increased soil NO3-N due to residual from fertiliser N applied to the preceding wheat crop further reduced N2 fixation. A simple soil nitrogen balance indicated that at least 60% of crop nitrogen must be obtained from N2 fixation to avoid continued soil nitrogen loss. This did not occur in most years. The generally negative soil nitrogen balance needs to be reversed if chickpea is to be useful in sustainable cropping systems although it is an attractive cash crop. Sowing time and zero tillage practice, possibly combined with more appropriate cultivars, to enhance chickpea biomass, along with low initial soil NO3-N levels, would provide maximum N2 fixation.


1993 ◽  
Vol 33 (2) ◽  
pp. 245 ◽  
Author(s):  
PG Tow

The persistence and water use efficiency of Digitaria eriantha spp. eriantha and Hunter river lucerne were compared on red solodic soil with a hardsetting surface and poor internal drainage, on the North- West Slopes of New South Wales. After prolonged watering, the profile was wet to a depth of 48 � 1.5 cm, with an available moisture store of 90 mm. Over 3 years, persistence of digitaria was excellent. The population of lucerne was reduced following flooding at summer temperatures, Dry matter production of nitrogen (N) fertilised digitaria per mm warm season rainfall was similar to that of tropical grasses adapted to comparable rainfall environments in subtropical Queensland. Lucerne dry matter per mm rainfall was only about half that of digitaria (3.2 v. 6.3 kg). Lucerne grew well in mixture with digitaria except under prolonged wet soil conditions in summer. Artificial solodic profiles were constructed in the glasshouse to compare digitaria and lucerne in monoculture and mixture under varying temperature, moisture, and N regimes. Lucerne showed sensitivity to both high and low moisture levels at summer temperatures but performed very well at spring temperatures and moderate moisture levels where the mean evapotranspiration ratio was 400 g water per g dry matter. Water use efficiency was higher in digitaria than in lucerne, except at spring temperatures without added N. Water use efficiency of the mixture was always similar to that of the most efficient monoculture of the particular treatment.


1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.


Soil Research ◽  
1995 ◽  
Vol 33 (4) ◽  
pp. 659 ◽  
Author(s):  
RJ French

This paper reviews changes in farming practices that helped farmers to reduce soil erosion, and increase water-use efficiency and yield on their specific soils and climate. The program initially involved working with Soil Conservation Boards and conducting research on farmers' properties and on research stations. This work then extended from evaluating single factor effects to assessing the combined factors limiting yield in specific crop and pasture rotations. Benchmarks were established for different soils and climates as guides for farmers to measure their success. These included yield and water use efficiency, adequate and lower limit levels of soil organic nitrogen, and the need to maintain a nutrient input-output balance to provide a sustainable agriculture. The paper highlights the need for future research to adopt an integrated systems approach to overcome the major limitations to growth. This will require a cooperative effort between farmer groups and teams of soil scientists and agronomists to conduct multifactor research in farmers' paddocks.


2003 ◽  
Vol 48 (7) ◽  
pp. 191-196 ◽  
Author(s):  
P.J. Goyne ◽  
G.T. McIntyre

The Cotton and Grains Adoption Program of the Queensland Rural Water Use Efficiency Initiative is targeting five major irrigation regions in the state with the objective to develop better irrigation water use efficiency (WUE) through the adoption of best management practices in irrigation. The major beneficiaries of the program will be industries, irrigators and local communities. The benefits will flow via two avenues: increased production and profit resulting from improved WUE and improved environmental health as a consequence of greatly reduced runoff of irrigation tailwater into rivers and streams. This in turn will reduce the risk of nutrient and pesticide contamination of waterways. As a side effect, the work is likely to contribute to an improved public image of the cotton and grain industries. In each of the five regions, WUE officers have established grower groups to assist in providing local input into the specific objectives of extension and demonstration activities. The groups also assist in developing growersÕ perceptions of ownership of the work. Activities are based around four on-farm demonstration sites in each region where irrigation management techniques and hardware are showcased. A key theme of the program is monitoring water use. This is applied both to on-farm storage and distribution as well as to application methods and in-field management. This paper describes the project, its activities and successes.


Sign in / Sign up

Export Citation Format

Share Document