Effects of waterlogging and soil salinity on irrigated agriculture in the Murray Valley: a review

1986 ◽  
Vol 26 (6) ◽  
pp. 761 ◽  
Author(s):  
AM Grieve ◽  
E Dunford ◽  
D Marston ◽  
RE Martin ◽  
P Slavich

A physical model was used to assess the effects of surface waterlogging and soil salinity on the productivity of winter cereals and irrigated dairy pastures on irrigation farms in the Berriquin and Wakool Irrigation Districts of the Murray Valley region of New South Wales. Parameters describing the physical properties of major soil types were combined with statistically derived estimates of rainfall excess over evapotranspiration to establish the incidence of waterlogging. Soils predisposed to waterlogging occupy 150000 ha of Berriquin District (45% of District) and 24 800 ha of Wakool District (73%). Estimates of yield losses from waterlogging ranged from 12.5% in annual subterranean clover-based pastures, 20% in winter cereals, to 25% for perennial ryegrass-white clover pastures. The relationships between yield and soil salinity were determined for barley, wheat, white clover, subterranean clover, and irrigated annual and perennial pastures growing under existing management practices in shallow watertable areas of the 2 Districts. Response functions were applied to soil salinity frequency distributions to derive production loss coefficients. Surveys showed that average soil salinities were lower in Berriquin than in Wakool. In 1984, 43% the soils in shallow watertable areas of Berriquin could be classed as saline, whereas, in 1982 the corresponding figure for Wakool was 72%. A further survey taken in 1984, 2 years after the inception of a deep drainage scheme, showed that saline soils in Wakool had decreased to 46% of the total area.We assessed economic losses associated with soil salinity and waterlogging by applying the derived loss coefficients to achievable yields for known production areas. Total annual losses for the 2 Districts exceeded $A13 million, or 16% of the 1984 value of the District's agricultural production. This figure underestimates real losses because we excluded livestock enterprises other than dairying, as well as summer cropping, from the study. Losses due to waterlogging ($A10 million overall) were more serious than those due to soil salinity (nearly $A4 million), particularly in Berriquin where shallow watertables were less extensive. In Wakool, 2 years' operation of the deep drainage scheme reduced losses due to soil salinity by $A750 000.Thus surface waterlogging and soil salinity cause serious economic losses in the irrigated areas of southern New South Wales. Research into appropriate techniques for on-farm irrigation management may reduce these losses, and delay further development of shallow watertables and soil salinisation, with sub of stantial economic and environmental benefits.

2004 ◽  
Vol 44 (12) ◽  
pp. 1165 ◽  
Author(s):  
A. M. Bowman ◽  
W. Smith ◽  
M. B. Peoples ◽  
J. Brockwell

Total productivity and legume nitrogen fixation (N2 fixation) in dryland pastures were examined in a 2 year study (1999–2001) on 118 farms in central-western New South Wales. Pasture exclosure cages, placed at 217 on-farm sites, were harvested on 7 occasions and the foliage hand-sorted according to species in order to measure shoot dry matter (DM). The separated legume shoot material collected in spring 1999 (52 different legume samples) and 2000 (76 different legume samples) from a subset of representative pastures (41 cages on 28 different farms in 1999, 32 cages on 25 different farms in 2000) was also analysed for concentration of nitrogen (%N) and 15N natural abundance. These data were subsequently used to calculate the proportion of the legume shoot N derived from atmospheric N (%Ndfa), comparative measures of the relative efficiency of N2 fixation (kg N fixed/t DM accumulated) and the amounts of shoot N fixed (kg N/ha). The survey encompassed 8 common pasture types, and 5 others that were less common, ranging from native perennial grass pastures with little legume content to lucerne (Medicago sativa L.) pastures with and without companion clovers. Fifteen legume species were found in the pastures, some only occasionally. Lucerne and white clover (Trifolium repens L.) were the only perennials. Mean spring estimates of %Ndfa were similar in 1999 and 2000 for lucerne (72 and 81%, respectively), rose clover (T. hirtum All., 82 and 77%) and annual medics (Medicago spp., 89 and 86%). For the remaining 12 legume species, measures of %Ndfa ranged from 64 to 95% and averaged 83%. Shoot %N contents were greater for lucerne than for the other 14 legumes and this was reflected in the comparative measures of N2 fixation which ranged from 14.5 kg N/t DM for rose clover to 25.7 kg N/t DM for lucerne in 2000. The most productive pasture type comprised lucerne plus balansa clover [T. michelianum Savi var. balansae (Boiss.) Azn.], white clover or arrowleaf clover (T. vesiculosum Savi), but all pasture types that contained lucerne were highly productive. Spring was the most productive season and summer the least. Lucerne was overwhelmingly the most productive legume and was responsible for >83% of the fixed N in those pastures that contained both lucerne and other legumes. Lucerne productivity was approximately uniform throughout the year whereas, for other pastures, especially those based on rose clover or subterranean clover (T. subterraneum L.), there were sharp peaks in spring and little or no dry matter production over summer. The presence of lucerne in pastures significantly (P<0.05) reduced broadleaf weeds. It was concluded that, where there are requirements in central-western New South Wales agriculture for uniform forage production throughout the year and a high input of fixed N, lucerne is substantially superior to other species.


2002 ◽  
Vol 42 (1) ◽  
pp. 15 ◽  
Author(s):  
D. R. Kemp ◽  
D. L. Michalk ◽  
M. Goodacre

Seven experiments were established across a range of environments (latitude 33°S) in central New South Wales to evaluate 52 legume cultivars and lines against currently recommended cultivars. Plots were grazed by either sheep or cattle after each harvest. Criteria for inclusion were that lines were either commercially available or in the process of being registered. Three experiments also included chicory. Sites had from 600 to 900 mm annual rainfall and were at altitudes of 440–1000 m. The 4-year program included the dry summer of 1990–91. White clover and subterranean clover were the most productive species over time. Among subterranean clovers, the subspecies subterraneum cultivars were more productive than the yanninicum or brachycalycinum subspecies. Other species such as balansa, Persian, strawberry, red and crimson clovers, lotus major and murex medic were more variable in production. These legumes often grew well in the establishment year, but failed to persist. Lucerne was in general, not as productive as white or subterranean clover. Caucasian clover and yellow serradella should be evaluated further as conclusive judgements could not be formed. Chicory was often the most productive species in the experiments, especially over the warmer 6 months of the year. It persisted under a 6-week harvest regime and during the drought year. The newer subterranean clover cultivars, Leura, Goulburn and Denmark all exceeded the production from the previously recommended cultivars, Woogenellup and Karridale, even though no major disease was evident in the later group. The lines 89820D and 89841E were sufficiently productive to warrant further evaluation and possible development as cultivars. In contrast, while Huia, Tahora, Bonadino and Tamar were often as productive as the recommended white clover cultivar Haifa, they were not consistently better. Where summer rainfall occurs and the annual rainfall exceeds 650 mm, the greater potential yield of white clover compared with subterranean clover justifies its use. However, no white clover cultivars survived the summer drought in 1990–91 as intact plants. Further work is needed to develop more drought-tolerant cultivars.


2000 ◽  
Vol 40 (2) ◽  
pp. 267 ◽  
Author(s):  
R. E. White ◽  
K. R. Helyar ◽  
A. M. Ridley ◽  
D. Chen ◽  
L. K. Heng ◽  
...  

A field study was carried out in the high rainfall zone (HRZ, >600 mm p.a.) of southern Australia from March 1994 to August 1997 to test the hypothesis that sown perennial grasses and liming could make the existing pastures more sustainable through better use of water and nitrogen. The site, on an acid duplex soil at Book Book near Wagga Wagga in southern New South Wales, was typical of much of the HRZ grazing country in southern New South Wales and north-east Victoria. The experiment consisted of 4 replicate paddocks (each 0.135 ha) of 4 treatments: annual pasture (mainly ryegrass Lolium rigidum, silver grass Vulpia spp., subterranean clover Trifolium subterraneum and broadleaf weeds) without lime, annual pasture with lime, perennial pasture (phalaris Phalaris aquatica, cocksfoot Dactylis glomerata and subterranean clover T. subterraneum) without lime, and perennial pasture with lime. Soil pH (0–10 cm) in the limed treatments was maintained at 5.5 (0.01 mol/L CaCl2), compared to 4.1 in the unlimed treatments. The pastures were rotationally grazed with Merino ewe or wether hoggets at a stocking rate which varied with the season, but was 10–25% higher on the limed pastures [14.8–17.3 dry sheep equivalent (dse)/ha] than the unlimed pastures. One replicate set of pasture treatments was intensively monitored for surface runoff, subsurface flow (at the top of the B horizon), water potential gradients and ammonium volatilisation. Other measurements of nitrogen inputs, transformations and losses were made on all paddocks. In a normal to wet year, surface runoff, subsurface flow and deep drainage (>180 cm depth) were about 40 mm less from the perennial than the annual pastures. The reduction in deep drainage under the perennials was about one-third to one-half (20–29 mm/year). The smaller loss of solution NO3– from the perennial pastures (up to 12 kg N/ha.year) suggested soil acidification under perennials was reduced by about 1 kmol H+/ha.year. Denitrification and volatilisation losses of N were small (1–12 kg N/ha.year). Nitrogen fixed by subterranean clover (above ground parts) ranged from 2–8 kg N/ha in the drought of 1994–95 to 128 kg N/ha in a normal year (1996). The soil-pasture nitrogen balance was positive for all treatments and averaged 76 kg N/ha.year over 2 years. The abundance of introduced and native earthworms increased from 85 to 250/m2 in the limed pastures between 1994 and 1997. Introduced species, such as Aporrectodea trapezoides, were especially responsive to lime. Animal production per hectare was 10–25% higher on pastures with lime. Critical gross margins per dse were lowest ($16/ha) for a long-lived perennial pasture (>15 years), and highest ($20/ha) for a short-lived perennial (5 years). Overall, there were substantial benefits in animal production, improved soil quality and water use from establishing perennial grass pastures with lime on these strongly acid soils.


1962 ◽  
Vol 2 (7) ◽  
pp. 228 ◽  
Author(s):  
CR Kleinig ◽  
J Loveday

The low availability of zinc on a number of calcareous grey and brown soils of heavy texture with pH>8, in the Coleambally Irrigation and Balranald areas of New South Wales, resulted in marked deficient symptoms in, and responses to zinc by, Bacchus Marsh subterranean clover (Trifolium subterranean L.), grown on these soils. An interaction between zinc and manganese occurred but there was no yield advantage in applying manganese in place of, or together with, zinc. Healthy subterranean clover grew on the surface soil (0-4 in.) of Yooroobla clay, a gilgai puff, but plants on the subsoil, which is exposed when the soil is leveled for irrigation, were extremely, zinc deficient. The pH of the subsoil is generally about 0.5 units higher than that of the surface soil. Legume species and strains differed in their response to zinc. Ladino white clover (Trifolium repens L.) and Clare subterranean clover responded less to applied zinc than Bacchus Marsh subterranean clover, and barrel medic 173 (Medicago tribuloides Desr.) responded less than Ladino white clover. When no zinc was applied barrel medic 173 yielded better than Ladino white clover, and Ladino white clover and Clare subterranean clover better than Bacchus Marsh subterranean clover.


1981 ◽  
Vol 21 (112) ◽  
pp. 485 ◽  
Author(s):  
KA Archer

A range of temperate legumes was evaluated for winter and spring production for use as either short-term ley pastures, or, when sown from the air, as introduced species into natural pastures on the higher northern slopes of New South Wales. The species were evaluated with and without the annual application of a compound phosphorus and sulfur fertilizer in four experiments from 1975 to 1978. Haifa white clover (Trifolium repens cv. Haifa) was generally the most productive and persistent species with dry matter production in winter and spring ranging from 21 30 to 3600 kg/ha when sown into prepared seedbeds. In natural pastures with applied fertilizer, yields of Haifa ranged from 100 kg/ha in a dry year to 5000 kg/ha. Other persistent species in both ley and natural pastures were Namoi woolly pod vetch (Vicia dasycarpa cv. Namoi) (1110-3520 kg/ha and 470-3350 kg/ha, respectively) and Hunter River lucerne (Medicago sativa cv. Hunter River) (1290-2500 kg/ha and 480-2350 kg/ha, respectively). These were the only species to establish themselves satisfactorily in the natural pastures. Other species that showed good potential for ley pastures were Hamua red clover (T. pratense cv. Grasslands Hamua), Clare subterranean clover (T. subterraneum cv. Clare) and Kondinin rose clover (T. hirtum cv. Kondinin), but further evaluation of these legumes is required. The barrel medics were productive in their establishment year averaging 2560 kg/ha dry matter but mean yields in subsequent years were less than 100 kg/ha due to poor regeneration. The natural pastures needed fertilizer to ensure adequate levels of production from the sown legumes. In the ley pastures, a response occurred only in the second year of one experiment. The natural species did not respond to fertilizer. It is concluded that Haifa white clover, woolly pod vetch and lucerne offer significant potential for use in both ley and natural pastures on the north-western slopes


2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.


1975 ◽  
Vol 15 (77) ◽  
pp. 795 ◽  
Author(s):  
JA Thompson

A range of temperate annual and perennial legumes, naturalized or commonly sown in the area, was examined at three field sites in low fertility soils derived from granite on the south western slopes of the New England Region, New South Wales. They were compared over a four year period in terms of their persistence, dry matter and nitrogen production and their compatibility with associated temperate perennial grasses, The response of sown grass to nitrogen fertilizer application was also examined in the absence of legume. Ten legumes were examined at one site and six of these at the other two sites. In general, nitrogen yields were ranked similarly to total dry matter yields of all treatments, including grasses in the absence of legume. However, the legumes were ranked differently in terms of productivity of the legume component and productivity of associated grass. At all sites lucerne gave the highest yields of total dry matter and of legume and the lowest yield and persistence of associated grass-comparable to grass growing in the absence of legume or applied nitrogen. Subterranean clover was ranked second or third in total dry matter yield, depending on site, but provided the highest yield of associated grasscomparable to grass receiving high levels of applied nitrogen. Under this legume soil nitrogen levels tended to be highest. Rose clover, sown at one site only, yielded more legume dry matter than subterranean clover but grass yield was comparable to that with lucerne. The results suggest that subterranean clover is the superior legume for successful mixed sowings although inclusion of white clover could be justified. Lucerne appears to be best sown as a pure sward.


1988 ◽  
Vol 28 (5) ◽  
pp. 561 ◽  
Author(s):  
HL Davies ◽  
E Devaud

A March-April joining of Merino ewes was compared with a June-July joining in central New South Wales at a low stocking rate on subterranean clover based pastures over 3 years. In all years, ewes joined in June were heavier (P < 0.05) than ewes joined in March (55 v. 52 kg). Liveweights at the start of lambing and liveweight change from joining to lambing were also high and favoured the later lambing group. The proportion of ewes lambing (97% March v. 93% June) and proportion of ewes twinning (29% March v. 20% June) were not significantly different between the 2 groups, but consistently favoured the March-April joining. Perinatal mortality was low (9.4% March v. 7.1% June) and not significantly different between the 2 groups, but was consistently lower in the June joined group. Number of lambs weaned per 100 ewes joined was also not significantly different, but was higher each year in the March joined group (1 13% March v. 105% June). The growth rate of the lambs (both singles [24% greater, 248 v. 200 g/day] and twins [37% greater, 2 13 v. 155 g/day]) was consistently in favour of March joined ewes. Mean greasy fleece weights of the ewes were not significantly different between the 2 groups, but were in favour of the late joined group (4.83 v. 4.50 kg). Time of joining significantly affected liveweights and greasy and clean fleece weights of the progeny at the shearing in the year following their birth in favour of March joining. These data suggest that, despite a nutritional advantage to the ewes in late pregnancy and milder weather at lambing with a June-July joining, a March- April joining is the preferred option on the Central Tablelands of New South Wales.


Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 199 ◽  
Author(s):  
Brian R. Wilson ◽  
Ivor Growns ◽  
John Lemon

Over large areas of south-eastern Australia, the original cover of native woodland has been extensively cleared or modified, and what remains is often characterised by scattered trees beneath which the ground-storey vegetation is largely grazed or otherwise managed. This study investigated the influence of scattered Blakely’s red gum (Eucalyptus blakelyi) trees on both near-surface and deeper soil layers in temperate grazed pastures on the Northern Tablelands of New South Wales, Australia. A significant canopy effect was observed with elevated soil pH, carbon, and nutrient status inside the tree canopy indicating soil enrichment in a zone around the tree. This effect, however, was largely restricted to the surface (0–0.20 m) soil layers. Chloride concentrations were elevated near to trees but only in the deeper soil layers, suggesting that a modified water use and deep drainage mechanism occurred near the trees. Close to the tree, however, a significant acidification was observed between 0.40–0.60 m depth in the soil, without any obvious depletion in other soil element concentrations. It is concluded that this acidification provides strong evidence in support of a ‘biological pumping’ mechanism that has been proposed elsewhere. Key questions remain as to the management implications of these results, whether the subsurface acidification that was observed is common among native Australian trees, if it might be persistent through time, and if this might be a soil issue that requires management.


1989 ◽  
Vol 40 (3) ◽  
pp. 605 ◽  
Author(s):  
KA Archer ◽  
GG Robinson

This paper reports the findings of a five-year study on the growth patterns, production and means of persistence of white clover in a cool temperate environment with summer dominant rainfall, on the Northern Tablelands of New South Wales. White clover essentially persisted as a perennial, but large and rapid declines in plant frequency occurred during late summer if soil moisture levels became depleted. The critical combination of conditions at which plant frequency was adversely affected occurred when available soil moisture levels declined below 35 mm and mean weekly maximum temperatures exceeded 20�C; conditions which often occur in late summer in this environment. During one prolonged period of moisture stress in the second spring and summer period of the study, all plants died. Regeneration was due to germination of seeds and seedling establishment, but plants subsequently persisted as perennials. Relationships were developed to predict the probability of survival of white clover over the range of temperatures and soil moistures recorded in these experiments. Germination occurred to a variable extent each year, but was observed only during winter and spring. Seedling establishment was effective in only one year, which followed the death of white clover in summer, 1980-81. The sward was slow to recover after seedling regeneration owing to low winter temperatures and competition from established temperate perennial grasses in spring. Seedlings contributed little to dry matter production in spring. These results indicate that white clover is unlikely to be of value as an annual in temperate pastures. Strategies aimed at improving white clover in cool temperate environments, either by management or selection/breeding programs, should therefore focus upon improving the ability of white clover to persist as a perennial.


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