Change in infiltration characteristics associated with cultivation history of soils in south-eastern Queensland

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1341 ◽  
Author(s):  
R. D. Connolly ◽  
D. M. Freebairn ◽  
B. J. Bridge

Change in soil infiltration characteristics with cultivation can result in reduced soil water storage, increased runoff and erosion, and reduced crop production. We measured changes in infiltration characteristics associated with years of cultivation for 5 soil groups in south-eastern Queensland. Soils were grouped according to soil type and texture into Sodosols, light and heavy Vertosols, Red Ferrosols, and Red Chromosols/Kandosols. Soil infiltration characteristics were determined from measurements of permeability and water-holding properties of the cultivated layer (0–0·1 m deep) and the layer immediately below the plough layer (0·1–0·2 m deep). A rainfall simulator was used to measure the hydraulic conductivity of surface seals and infiltration of bare, tilled soil in the field. Hydraulic conductivity of the soil matrix and macropores and water-holding properties of the 0·1–0·2 m layer were measured with disc permeameters and pressure plate apparatus. Hydraulic conductivity of surface seals decreased exponentially in all soil groups with period of cultivation; half of the decline occurred within 2–6 years of first cultivation. Hydraulic conductivity, macroporosity, and moisture characteristic of the 0·1–0·2 m layer were similarly affected by longer periods of cultivation in all but light-textured soils. Cultivation of light-textured, hardsetting soils (18% clay) did not adversely affect hydraulic conductivity or macroporosity of the 0·1–0·2 m layer and the loosening effect of tillage was somewhat beneficial for the water-holding properties of this layer. The low hydraulic conductivities of the surface or 0·1–0·2 m layer after long periods of cultivation reduced infiltration of rainfall in the field.

Soil Research ◽  
1998 ◽  
Vol 36 (6) ◽  
pp. 1057 ◽  
Author(s):  
R. D. Connolly ◽  
D. M. Freebairn ◽  
M. J. Bell

Cropping systems in south-eastern Queensland have led to degradation of soil physical properties and loss of infiltration capacity. Pasture leys are favoured for ameliorating soil physical properties because they add organic matter to the soil, create macroporosity, and help to re-aggregate soil. We measured change in hydraulic conductivity with period of ley for 5 major soil groups in south-eastern Queensland (Sodosols, light and heavy Vertosols, Red Ferrosols, and Red Chromosols/Kandosols). We characterised 2 soil layers that are susceptible to degradation when cropped: surface soil exposed to raindrop impact, and the layer immediately below the cultivated layer (0·1-0·2 m deep). A rainfall simulator was used to measure hydraulic conductivity of surface seals under high intensity rainfall. Disc permeameters and pressure plate apparatus were used to measure hydraulic conductivity of the soil matrix in the 0·1-0·2 m layer. Hydraulic conductivity of both soil layers improved with period of pasture for all but the light-textured Red Chromosols/Kandosols. The estimated period of pasture required to return hydraulic conductivity to pre-cultivated levels ranged from 5 to 40 years, depending on soil type and layer. This is about 2-3 times the period of cultivation that caused the degradation. Grazing reduced the effectiveness of pasture in ameliorating surface sealing on Sodosols. Beneficial effects of a 2·5-4·5 year, ungrazed ley pasture on surface soil persisted for up to 5 years after recultivation, but were lost in the 0·1-0·2 m layer within 1 year. These rates of decline in hydraulic conductivity were faster than observed on previously uncultivated soils. The APSIM model was used to predict the effect of measured improvements in soil hydraulic conductivity on average runoff from summer fallows. The model predicted that most benefits for fallow runoff would be achieved with 2-5 years of ley. The surface seal was the major limitation to infiltration when the soil was bare. Subsurface soil layers limited infiltration if surface sealing was reduced by ameliorating soil properties or maintaining cover on the soil surface. The results suggest that despite amelioration of soil structure with leys, appropriate tillage and cover management is still required to maintain high infiltration rates.


Author(s):  
А.П. ЛАКТИОНОВ ◽  
Е.В. МАВРОДИЕВ

The history of the putative endemic of the Lower Volga valley (the South-Eastern European Russia) Rorippa wolgensis Fursajev ex Laktionov et Mavrodiev nom. nov. is briefly discussed.


1959 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
AM Olsen

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956. In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years. Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females. In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of Australia may be required. Measures for conservation are discussed.


2013 ◽  
Vol 46 (2) ◽  
pp. 263-273 ◽  
Author(s):  
Viachaslau Yarashevich ◽  
Yuliya Karneyeva

The history of Yugoslavia continues to attract academic attention more than twenty years after the violent break-up of this federative state. Analyzing why it happened can be instructive in dealing with many unsolved problems in the region. The article will argue that deteriorating economics triggered all other factors leading to eventual disintegration of Yugoslavia. Specifically, during the 1980s external and internal economic imbalances, coupled with substantial regional disparities, resulted in a situationwhichwas no longer acceptable to some constituent republics, especially the wealthier ones. Unfortunately, their secessionwas followed by a violent conflict which still resonates throughout South-Eastern Europe.


2011 ◽  
Vol 361-363 ◽  
pp. 1946-1949
Author(s):  
Yi Fei Li ◽  
Tian Wei Qian ◽  
Li Juan Huo

In this paper,the effect of surfactant to the infiltration and the change of saturated hydraulic conductivity was studied by GUELPH PERMEAMETER. We investigated effects on soil infiltration by three representative surfactants.The results show that the existing of sodium dodecyl benzene sulfonate (SDBS), cetyl trimethyl ammonium bromide bromide (CTAB) and polyxyethylene fatty alcohol (AEO9) would decrease soil saturated hydraulic conductivity.


Author(s):  
Wojciech Sowa

Thracian belongs to the group of languages spoken over the entire period of Antiquity in the areas of south-eastern Europe (mostly the Balkans) and which, like other vernaculars spoken in this and neighbouring areas, had died out by the end of the Roman period leaving but scanty evidence. This chapter provides an introduction into the state of our current knowledge about the Thracian language and epigraphy and the perspectives of research of this language. Since our comprehension and understanding of grammatical system of Thracian is limited, the current knowledge of the language makes any translation of attested inscriptions impossible. It is however expected that the progress in studying development and history of the Greek script may provide us with new and relevant data for interpretation of Thracian.


2021 ◽  
pp. 229-241
Author(s):  
Maciej Rak

The article has three goals. The first is to present the history of research on Polish dialectal phrasematics. In particular, attention was paid to the last five years, i.e. the period 2015–2020. The works in question were ordered according to the dialectological key, taking into account the following dialects: Greater Polish, Masovian, Silesian, Lesser Polish, and the North and South-Eastern dialects. The second goal is to indicate the methodologies that have so far been used to describe dialectal phrasematics. Initially, component analysis was used, which was part of the structuralist research trend, later (more or less from the late 1980s) the ethnolinguistic approach, especially the description of the linguistic picture of the world, began to dominate. The third goal of the article is to provide perspectives. The author once again (as he did it in his earlier works) postulates the preparation of a dictionary of Polish dialectal phrasematics.


2001 ◽  
Vol 52 (3) ◽  
pp. 329 ◽  
Author(s):  
G. D. Li ◽  
K. R. Helyar ◽  
M. K. Conyers ◽  
B. R. Cullis ◽  
P. D. Cregan ◽  
...  

A long-term trial, known as ‘managing acid soils through efficient rotations’ (MASTER), commenced in 1992 to develop and demonstrate a cropping system that is economically viable on the highly acid soils of the traditional permanent pasture region in south-eastern Australia, so that their fertility is sustained or improved. There were 2 permanent pasture systems and 2 pasture–crop rotations, each with and without lime. This paper reports the effect of lime on crop production over the first cycle (6 years). On annual pasture–crop rotations, lime significantly increased the dry matter production at anthesis and grain yields of wheat (cv. Dollarbird) compared with the unlimed treatments. Averaged across years from 1992 to 1997 (excluding the severe drought year 1994), wheat crops produced 1.6 t/ha more grain on the limed treatments than on the unlimed treatments (3.6 v. 2.0 t/ha). On perennial pasture–crop rotations, the lime effects varied with crops grown at each phase and year. For example, despite being tolerant of acidity, oats (cv. Yarran) responded to lime in 1996. Likewise, triticale (cv. Abacus) responded to lime in 1997. Wheat (cv. Dollarbird) that is moderately tolerant to acidity responded to lime in phase 6 from 1992 to 1997 excluding 1994 (3.5 v. 1.7 t/ha). Acid-tolerant wheat varieties, triticale, and narrow-leaf lupins are considered the most viable crops for the soil and climatic conditions encountered in this high rainfall (5000—800 mm per annum) area of south-eastern Australia.


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