scholarly journals Break-crop effects on wheat production across soils and seasons in a semi-arid environment

2015 ◽  
Vol 66 (6) ◽  
pp. 566 ◽  
Author(s):  
T. M. McBeath ◽  
V. V. S. R. Gupta ◽  
R. S. Llewellyn ◽  
C. W. Davoren ◽  
A. M. Whitbread
Keyword(s):  
Field Experiments ◽  
Primary Source ◽  
Arid Environment ◽  
Soil Types ◽  
Cereal Crops ◽  
Arid Environments ◽  
Beneficial Effects ◽  
Cereal Production ◽  
High Level ◽  
Semi Arid

In low-rainfall environments, a high frequency of cereal crops has been favoured for optimising productivity and risk. However, cereals at high intensity often lead to declining water-use efficiency and increasing inputs to cope with emergent nutritional, disease and weed problems. The value of including breaks in the cropping sequence can involve a high level of uncertainty in low-rainfall areas where non-cereal crops are more risky and profitability is largely determined by the subsequent benefit to cereal productivity. In this study, we aimed to improve understanding of the magnitude and primary source of break benefits such as nutrition, water and disease management in a low-rainfall environment where a high level of within-field soil variability can also contribute to uncertainty about the value of breaks. In on-farm field experiments near Karoonda in the South Australian Mallee, breaks were grown in 2009 or 2010 on four distinct soil types across a dune–swale catena. The effect of these breaks on subsequent cereal production was measured for up to 3 years. In addition, the effect of breaks on nutrition and water available, along with disease infection in subsequent cereal crops, was explored and actual yields were compared with nitrogen and water-limited potential yields. Consistent cumulative benefits to subsequent cereal crops of at least 1 t ha–1 after 3 years accrue from breaks grown on the different soil types. The inclusion of breaks had beneficial effects on the cycling and supply of nutrients along with some short-term impacts on infection by Rhizoctonia solani AG8 in subsequent cereals, whereas there were no conclusive effects of breaks on the supply of water to subsequent crops. This study suggests that the inclusion of both legume and brassica breaks is likely to be beneficial to subsequent cereal production where nitrogen is a factor limiting productivity in low-rainfall, semi-arid environments.

scholarly journals A Long Journey of CICA-17 Quinoa Variety to Salinity Conditions in Egypt: Mineral Concentration in the Seeds

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 407
Author(s):  
Juan A. González ◽  
Leonardo Hinojosa ◽  
María I. Mercado ◽  
José-Luis Fernández-Turiel ◽  
Didier Bazile ◽  
...  
Keyword(s):  
Field Experiments ◽  
Chemical Elements ◽  
Chenopodium Quinoa ◽  
Soil Types ◽  
Arid Environments ◽  
Mineral Concentration ◽  
Marginal Lands ◽  
Promising Alternative ◽  
Pattern Distribution ◽  
Induced Changes

Quinoa may be a promising alternative solution for arid regions, and it is necessary to test yield and mineral accumulation in grains under different soil types. Field experiments with Chenopodium quinoa (cv. CICA-17) were performed in Egypt in non-saline (electrical conductivity, 1.9 dS m−1) and saline (20 dS m−1) soils. Thirty-four chemical elements were studied in these crops. Results show different yields and mineral accumulations in the grains. Potassium (K), P, Mg, Ca, Na, Mn, and Fe are the main elements occurring in the quinoa grains, but their concentrations change between both soil types. Besides, soil salinity induced changes in the mineral pattern distribution among the different grain organs. Sodium was detected in the pericarp but not in other tissues. Pericarp structure may be a shield to prevent sodium entry to the underlying tissues but not for chloride, increasing its content in saline conditions. Under saline conditions, yield decreased to near 47%, and grain sizes greater than 1.68 mm were unfavored. Quinoa may serve as a complementary crop in the marginal lands of Egypt. It has an excellent nutrition perspective due to its mineral content and has a high potential to adapt to semi-arid and arid environments.

Resilience of floodplain ecosystems in a semi-arid environment

2010 ◽  
Vol 32 (3) ◽  
pp. 305 ◽  
Author(s):  
Matthew J. Colloff ◽  
Darren S. Baldwin
Keyword(s):  
Stable State ◽  
Arid Environment ◽  
Ecosystem Functions ◽  
Arid Environments ◽  
Ecosystem Resilience ◽  
Floodplain Ecosystems ◽  
Murray Darling Basin ◽  
Single State ◽  
Floods And Droughts ◽  
Semi Arid

Implicit to loss of ecosystem resilience is that systems can shift from one stable state to another as a result of disturbance. We present a conceptual model of ecosystem resilience of floodplains and wetlands in semi-arid environments like those of the Murray–Darling Basin. The model is based on a single state characterised by fluctuating wet and dry phases driven by episodic floods and droughts. It might appear that such a single state is inherently unstable, but stability, and the measure of resilience, is conferred by the capacity of floodplains and wetlands to undergo drought and yet return to a functioning wet phase following inundation as well as to undergo flooding and return to the dry phase following flood recession. Floodplains and wetlands are driven by strong, periodic abiotic disturbances and their ecosystem functions and biogeochemical processes are highly rate-limited, spatiotemporally variable and driven by relatively species-poor assemblages of plants and animals adapted to withstand drought and flooding. Extreme drying due to climatic change and over-allocation of water resources represents the primary mechanism via which resilience is lost.

scholarly journals Adaptation of Extra Short Duration Pigeonpea to Rainfed Semi-Arid Environments

1993 ◽  
Vol 29 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Y. S. Chauhan ◽  
C. Johansen ◽  
Laxman Singh
Keyword(s):  
Grain Yield ◽  
Short Duration ◽  
Cajanus Cajan ◽  
Soil Types ◽  
Arid Environments ◽  
Rate Of Growth ◽  
Semi Arid

SummaryThe adaptation of extra short duration (ESD) pigeonpea (Cajanus cajan) genotypes to rainfed environments was studied on Alfisols and Vertisols at the ICRISAT Center between 1987 and 1989. Despite a slightly shorter crop duration, the grain yield of ESD genotypes was twice as large on Alfisols as on Vertisols. On both soil types, the rate of growth and grain yield were better in crops sown on time than in those where sowing was delayed. The population levels necessary to maximize yield varied among genotypes on Alfisols, where the grain yield of several ESD genotypes compared favourably with that of ICPL 87, a standard short duration genotype. However, none of the ESD genotypes yielded more than ICPL 87 on the Vertisols.

scholarly journals Long Term Hydrodynamic Effects in a Semi-Arid Mediterranean Multilayer Aquifer: Campo de Cartagena in South-Eastern Spain

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1320 ◽  
Author(s):  
Juan Domingo-Pinillos ◽  
Javier Senent-Aparicio ◽  
José García-Aróstegui ◽  
Paul Baudron
Keyword(s):  
Arid Environment ◽  
Anthropogenic Activity ◽  
Arid Environments ◽  
Aquifer System ◽  
Intensive Exploitation ◽  
The Mediterranean ◽  
Hydrodynamic Effects ◽  
Flow Transfer ◽  
Semi Arid ◽  
Campo De Cartagena

The Mediterranean basin contains many semi-arid environments where aquifers are subject to intensive exploitation, generally to meet irrigation demands. The Campo de Cartagena aquifer is a clear example from such a semi-arid environment, and its hydrodynamic effects have aroused great scientific interest. The main objective of this study is to evaluate the hydrodynamic effects that have occurred in the last century of anthropogenic activity in this aquifer system. This aquifer is subject to intensive exploitation and shows clear deficits in times of drought, with recharge by irrigation playing an important role. This study’s methodology includes groundwater modelling to reconstruct the transient evolution of the aquifer system during the last century, to generate water balances and to illustrate how the evolution of irrigation has, in many ways, changed the aquifer’s groundwater flow pattern. The results delineate the hydraulic communication of the aquifer stratums through specific geological structures, as well as the flow transfer from the Quaternary layer to the Mar Menor and the Mediterranean Sea. The reconstruction of the entire system’s temporal evolution shows a fragile water balance that is supported by surface-water contributions.

Ecotypic variation between and within two populations of Trifolium tomentosum (woolly clover) from Syria and Western Australia: its success as a colonising species

1999 ◽  
Vol 50 (8) ◽  
pp. 1443 ◽  
Author(s):  
Sarita Jane Bennett
Keyword(s):  
Western Australia ◽  
Function Analysis ◽  
Acid Soils ◽  
Arid Environment ◽  
Arid Environments ◽  
Alkaline Soils ◽  
Field Station ◽  
Ecotypic Variation ◽  
Site Variation ◽  
Semi Arid

Ecotypic variation was studied between and within populations of Trifolium tomentosum (woolly clover) using seed that was collected from 2 semi-arid environments: Tel Hadya, Syria, and Pingrup, Western Australia. The seed was collected from 64 subplots within a 40-m2 grid at each site and the material was grown at the University of Western Australia Field Station at Shenton Park, Perth. Fifteen morphological characters were scored and were analysed using analysis of variance, principal components analysis, and discriminant function analysis. Material from the 2 sites was separated using multivariate analysis, with the seed from Tel Hadya containing more within-site variation. It is suggested that the lack of within-site variation observed at Pingrup is the result of a number of factors: a limited amount of genetic diversity being present in the original introduced material, a preference of T. tomentosum for alkaline soils rather than the acid soils predominantly occurring in Western Australia, the harsh selection pressures present in a semi-arid environment, and a limited time for genotypes to adapt to specific micro-niches within each environment. The results are used to contribute to our understanding of the success of colonising species in semi-arid environments.

EVALUATION OF VELVETLEAF INTERFERENCE WITH MAIZE HYBRIDS AS INFLUENCED BY RELATIVE TIME OF EMERGENCE

2011 ◽  
Vol 48 (1) ◽  
pp. 127-137 ◽  
Author(s):  
ILIAS S. TRAVLOS ◽  
PANAGIOTIS J. KANATAS ◽  
GARIFALIA ECONOMOU ◽  
VASILIS E. KOTOULAS ◽  
DIMOSTHENIS CHACHALIS ◽  
...  
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Arid Environments ◽  
Initial Growth ◽  
Maize Hybrids ◽  
Canopy Area ◽  
Semi Arid

SUMMARYThe presence of velvetleaf (Abutilon theophrasti) in crops is increasing in arid and semi-arid environments. Field experiments were conducted in Greece in 2009 and 2010 to determine the influence of velvetleaf emergence time and maize (Zea mays) hybrids with different growth rates on maize yield and velvetleaf growth and fecundity. Velvetleaf was uniformly seeded in order to emerge at the 1, 3, 5 and 7-leaf stage of maize (V1, V3, V5 and V7 growth stages, respectively). Velvetleaf biomass, canopy area and seed production were significantly affected by the date of velvetleaf emergence. Velvetleaf plants emerging just after maize (V1) produced 7–17 times lower seed number, compared with the V5 growth stage. Maximum maize grain yield loss ranged from 26 to 37% for early emerging velvetleaf, and less than 6% yield loss occurred from velvetleaf seedlings emerging at V7 growth stage. Maize hybrids with high initial growth rate seem to be more competitive than the other hybrids. The results of this study are essential in the development of an integrated weed management strategy for maize in semi-arid environments, since they highlight the importance of the careful selection of a competitive maize hybrid and avoidance of early velvetleaf emergence.

Genotype by environment interactions for productivity and resistance to gastro-intestinal nematode parasites in Red Maasai and Dorper sheep

2004 ◽  
Vol 79 (3) ◽  
pp. 343-353 ◽  
Author(s):  
R. L. Baker ◽  
J. M. Mugambi ◽  
J. O. Audho ◽  
A. B. Carles ◽  
W. Thorpe
Keyword(s):  
Smallholder Farmers ◽  
Arid Environment ◽  
Productive Efficiency ◽  
Metabolizable Energy ◽  
Arid Environments ◽  
Genotype By Environment ◽  
Nematode Parasites ◽  
Humid Environment ◽  
Dorper Sheep ◽  
Semi Arid

AbstractRed Maasai and Dorper sheep were evaluated for their resistance to gastro-intestinal (GI) nematode parasites (predominantly Haemonchus contortus), productivity and productive efficiency (assessed on a metabolizable energy basis) in experiments undertaken at the Kenyan coast (sub-humid environment) and the Kenya highlands (semi-arid environment). In both ewes and lambs there were few significant genotype by environment (G X E) interactions for either resistance (assessed by faecal egg counts-FEC) or resilience (assessed by blood packed red cell volume-PCV) to GI nematodes. Red Maasai sheep were consistently more resistant (low FEC) and more resilient (high PCV) than Dorper sheep. However, there were significant G X £ interactions for ewe reproductive performance and for ewe and lamb mortality rates and live weights. These interactions were due to very poor performance of the Dorper compared to the Red Maasai in the sub-humid coastal environment and to the much improved performance of the Dorper in the semi-arid environment. When these component traits were combined into estimates of flock productivity and productive efficiency there were highly significant GXE interactions with the Red Maasai sheep being considerably more efficient than Dorper sheep in the sub-humid environment, while in the semi-arid environment there was a negligible breed difference in productive efficiency. The results are discussed in terms of breeding strategies for smallholder farmers and pastoralists managing sheep in low-input systems in sub-humid and semi-arid environments.

Bats of a semi-arid environment in south-eastern Australia: biogeography, ecology and conservation

1995 ◽  
Vol 22 (2) ◽  
pp. 217 ◽  
Author(s):  
IF Lumsden ◽  
AF Bennet
Keyword(s):  
Species Richness ◽  
Conservation Status ◽  
Activity Patterns ◽  
Arid Environment ◽  
Arid Environments ◽  
Minor Variation ◽  
South Eastern ◽  
Eastern Australia ◽  
Semi Arid ◽  
South Eastern Australia

A total of 2075 captures of 11 taxa of bats was recorded during an extensive survey of the vertebrate fauna of the semi-arid Mallee region of Victoria. A further two species, Pteropus scapulatus and Saccolaimus flaviventris, are known from previous records, thus bringing the total to 13 taxa known from the region. There was a marked seasonality in activity patterns and in reproduction. Activity, as revealed by trap captures, peaked over the spring to early autumn months when daytime temperatures are high and nights are mild. Births occurred from October to December, lactating females were recorded from November to February, and juveniles were trapped between December and late February, with minor variation in timing between species. Morphometric measurements revealed that females were generally larger and heavier than males. There was a high level of overlap of species between broad vegetation types. Woodland habitats, especially Riverine Woodland, tended to have a higher frequency of capture and a greater species richness of bats per trapping event than did Mallee Shrubland. The assemblage of bats in the Mallee region, Victoria, like those in other semi-arid regions of southern Australia, includes species that are widespread in Australia (e.g. Chalinolobus gouldii and Nyctophilus geoffroyi), together with species that primarily occur in semi-arid and arid environments (e.g. N. timoriensis, Scotorepens balstoni and Vespadelus baverstocki). This region, which includes mesic riverine habitats, also supports a group of species that are characteristic of temperate south-eastern Australia (e.g. C. morio, V. regulus and V. vulturnus). In comparison with assemblages from temperate and tropical environmental regions, those from the semi-arid region tend to have a lower species richness with fewer families represented, a higher level of insectivory, and a smaller modal body size. The conservation status of bats from the Mallee region, Victoria, is believed to be secure, although the status of N. timoriensis warrants further attention.

scholarly journals Performance of Modern and Traditional Spelt Wheat (Triticum spelta) Varieties in Rain-Fed and Irrigated, Organic and Conventional Production Systems in a Semi-Arid Environment; Results from Exploratory Field Experiments in Crete, Greece

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 890
Author(s):  
Juan Wang ◽  
Marcin Baranski ◽  
Recep Korkut ◽  
Hassan Ashraa Kalee ◽  
Liza Wood ◽  
...  
Keyword(s):  
Field Experiments ◽  
Production Systems ◽  
Arid Environment ◽  
Organic Production ◽  
Grain Protein ◽  
Bread Making ◽  
Grain Yields ◽  
Spelt Wheat ◽  
Conventional Production ◽  
Semi Arid

Background: Consumer demand for organic spelt wheat has increased rapidly and production has expanded into semi-arid regions, where it was not traditionally grown. Methods: Here, we report the results of a factorial field experiment designed to compare the performance of four spelt varieties grown in rain-fed and irrigated, conventional and organic production systems in a semi-arid environment. Results: Irrigation resulted in 2.5-fold higher grain yields, a reduction in grain protein, taller plants and an increase in stem lodging. While yields of all varieties were similar and low in rain-fed production, the variety Züricher Oberländer Rotkorn (ZOR) produced the highest, Filderstolz and Oberkulmer intermediate and the variety Rubiota the lowest grain yields in irrigated systems. Organic production with chicken or sheep manure as fertilizer resulted in 15% higher yields that mineral NPK fertilizer-based conventional production protocols. Conclusions: Rain-fed spelt production results in very low yields and is therefore unlikely to be commercially viable. Results suggest that organic fertilization regimes and the variety ZOR will result in the highest yields in irrigated systems, while the two traditional spelt varieties Filderstolz and Oberkulmer will more reliably produce grain protein levels that comply with bread-making quality standards.

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