Comparison of four phalaris cultivars under grazing: drought survival and subsequent performance under rotational grazing versus set stocking

2000 ◽  
Vol 40 (8) ◽  
pp. 1047 ◽  
Author(s):  
R. A. Culvenor
Keyword(s):  
Soil Profile ◽  
Severe Drought ◽  
Rotational Grazing ◽  
Site Factors ◽  
Deep Soil ◽  
Subsequent Performance ◽  
Basal Cover ◽  
Grazing Experiment ◽  
Drought Survival ◽  
A Site

Four cultivars of phalaris were evaluated for their ability to survive a severe drought in 1994 in an existing grazing experiment at 2 sites near Canberra. The effect of rotational grazing and set stocking on persistence of phalaris measured as basal cover, pasture composition in spring and animal production from the pastures was assessed over the next 4 years. Basal cover of all cultivars declined sharply in 1994, but had recovered by August 1995 at a site with a relatively deep soil profile. Recovery was slower at a site with a shallower soil profile. Sirosa declined more in basal cover than Holdfast and Australian at the latter site. All of the cultivars survived the drought well but Sirosa may be more sensitive to overgrazing in drought. Compared with set stocking, rotationally grazed pastures had a higher (P<0.001) proportion of phalaris for all cultivars 2 years after management treatments began, and a higher (P<0.005) basal cover for 2 winter-active cultivars after 3 years. Overall, a divergent effect of grazing management on basal cover (management × year interaction) could only be demonstrated at P = 0.08 because of a large effect of site variation for another winter-active cultivar, Sirosa. Phalaris basal cover did not decline with set stocking and it was concluded that rotational grazing was beneficial, but not crucial, for the persistence of winter-active phalaris cultivars in this environment. Site factors and their manipulation by management were also important for the persistence of phalaris. A review of the persistence of phalaris over the entire 9 years of the grazing experiment concluded that all cultivars displayed good persistence under conditions of reasonable soil fertility. The importance of good establishment for a high presence of phalaris in later years was emphasised.

Modelling uranium leaching from agricultural soils to groundwater as a criterion for comparison with complementary safety indicators

2006 ◽  
Vol 932 ◽  
Author(s):  
D. Jacques ◽  
J. Šimůnek ◽  
D. Mallants ◽  
M.Th. van Genuchten
Keyword(s):  
Soil Profile ◽  
Reactive Transport ◽  
Transport Model ◽  
Agricultural Soils ◽  
Solid Phase ◽  
Water Flux ◽  
Fertilizer Application ◽  
Mineral Fertilizers ◽  
Deep Soil ◽  
Long Time

ABSTRACTNaturally occurring radionuclides can also end up in soils and groundwater due to human practices, such as application of certain fertilizers in agriculture. Many mineral fertilizers, particularly (super)phosphates, contain small amounts of 238U and 230Th which eventually may be leached from agricultural soils to underlying water resources. Field soils that receive P-fertilizers accumulate U and Th and their daughter nuclides, which eventually may leach to groundwater. Our objective was to numerically assess U migration in soils. Calculations were based on a new reactive transport model, HP1, which accounts for interactions between U and organic matter, phosphate, and carbonate. Solid phase interactions were simulated using a surface complexation module. Furthermore, all geochemical processes were coupled with a model accounting for dynamic changes in the soil water content and the water flux. The capabilities of the code in calculating natural U fluxes to groundwater were illustrated using a semi-synthetic 200-year long time series of climatological data for Belgium. Based on an average fertilizer application, the input of phosphate and uranium in the soil was defined. This paper discusses calculated U distributions in the soil profile as well as calculated U fluxes leached from a 100-cm deep soil profile. The calculated long-term leaching rates originating from fertilization are significantly higher after 200 years than estimated release rates from lowlevel nuclear waste repositories.

Differential responses by sympatric macropodids to severe drought.

2004 ◽  
Vol 26 (2) ◽  
pp. 185
Author(s):  
PE Hornsby ◽  
EY Corlett
Keyword(s):  
South Australia ◽  
Severe Drought ◽  
The North ◽  
Flinders Ranges ◽  
Drought Conditions ◽  
Differential Responses ◽  
A Site ◽  
Significant Mortality

Responses to severe drought by two sympatric macropodids, the yellow-footed rock-wallaby (Petrogale xanthopus) and the euro (Macropus robustus erubescens) were examined at a site in the North Flinders Ranges of South Australia. The results indicate that the two species respond differentially to drought conditions. It was observed that small fluctuations occurred in the P. xanthopus population. In contrast, M. r. erubescens evidenced significant mortality, especially among larger animals.

DROUGHT SURVIVAL OF SELECTED FORAGE GRASSES COMMONLY SEEDED IN THE NORTHERN GREAT PLAINS

1982 ◽  
Vol 62 (4) ◽  
pp. 949-955 ◽  
Author(s):  
PAT O. CURRIE ◽  
RICHARD S. WHITE
Keyword(s):  
Great Plains ◽  
Leaf Growth ◽  
Basal Area ◽  
Grass Species ◽  
Northern Great Plains ◽  
Severe Drought ◽  
Forage Grasses ◽  
Drought Tolerant ◽  
Drought Survival ◽  
Moisture Conditions

Prolonged drought between 1979 and 1981 killed or severely reduced stands of a number of grass species presumably adapted and frequently recommended for seeding rangelands in the Northern Great Plains. The drought damage took place on recently planted as well as established 2 years or older seedings. Cultivars of the intermediate-pubescent wheatgrass complex were killed or most severely damaged. Damage was also severe on seeded stands of the native green needlegrass, western and thickspike wheatgrasses and big bluegrass. Crested wheatgrass was only moderately drought tolerant, but two cultivars of Russian wild ryegrass established well even with adverse moisture conditions in the seeding year. Altai wild ryegrass seedlings established well but did not survive the drought. An established stand of Vinall Russian wild ryegrass increased in basal area and produced leaf growth and seedstalks during the most severe drought periods. These periodic droughts are sporadic in occurrence but need to be considered in reference to species recommendations for range seedings in the Northern Great Plains.

scholarly journals How the soil chemical composition is affected by seven tree species planted at a contaminated and remediated site

Web Ecology ◽  
2015 ◽  
Vol 15 (1) ◽  
pp. 45-48 ◽  
Author(s):  
T. Marañón ◽  
C. M. Navarro-Fernández ◽  
M. T. Domínguez ◽  
P. Madejón ◽  
J. M. Murillo
Keyword(s):  
Chemical Composition ◽  
Carbon Sequestration ◽  
Tree Species ◽  
Forest Floor ◽  
Biological Properties ◽  
Chemical Concentration ◽  
Deep Soil ◽  
Physico Chemical ◽  
A Site

Abstract. Trees modify the physico-chemical and biological properties of the soil underneath. Here we present results for seven tree species planted at a site that was contaminated by a mine spill – after which soil was cleaned up and remediated – and later was afforested. We studied the chemical composition (24 elements) in five ecosystem compartments (leaves, forest floor, roots, topsoil and deep soil). The variation in chemical concentration was highest at the level of canopy leaves and lowest at deep soil. The identity of tree species significantly affected the composition of all elements in the canopies but none in the deep soil underneath. Although the observed tree effects on topsoil chemistry were weak, the footprint is expected to be reinforced with age of the plantation, contributing to the phytostabilization of contaminating elements and to the carbon sequestration.

scholarly journals Drought Survival and Recuperative Ability of Bentgrass Species Associated with Changes in Abscisic Acid and Cytokinin Production

2007 ◽  
Vol 132 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Michelle DaCosta ◽  
Bingru Huang
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Creeping Bentgrass ◽  
Primary Objective ◽  
Rapid Decline ◽  
Plant Responses ◽  
Severe Drought ◽  
Cytokinin Content ◽  
Drought Survival ◽  
Aba Content

Abscisic acid (ABA) and cytokinins are two groups of plant hormones that play important roles in regulating plant responses to decreases in soil water availability. The primary objective for this study was to determine whether species variability in drought survival and recovery for colonial bentgrass (Agrostis capillaris L.), creeping bentgrass (A. stolonifera L.), and velvet bentgrass (A. canina L.) were related to changes in ABA and cytokinin content. Plants of ‘Tiger II’ colonial bentgrass, ‘L-93’ creeping bentgrass, and ‘Greenwich’ velvet bentgrass were subjected to two soil moisture treatments: 1) well-watered controls, irrigated three times per week; and 2) drought, irrigation completely withheld for 16 days. For recovery, previously drought-stressed plants were rewatered and irrigated three times per week to evaluate the recovery potential for each species. Drought stress resulted in significant declines in turf quality (TQ), shoot extension rates, canopy net photosynthetic rate (Pn), daily evapotranspiration rate (ET), and cytokinin content, and significant increases in ABA content for all three bentgrass species. Velvet bentgrass exhibited less severe drought injury, as exhibited by higher TQ, Pn, and daily ET rate compared with colonial bentgrass and creeping bentgrass. Velvet bentgrass also had significantly less ABA accumulation, which could allow for continued gas exchange and sustained plant survival during drought stress compared with colonial bentgrass and creeping bentgrass. Upon rewatering after drought stress, colonial bentgrass exhibited more rapid recovery in turfgrass growth and water use compared with creeping bentgrass and velvet bentgrass. The higher recuperative ability of colonial bentgrass could be associated with its more rapid decline in ABA content and increases in cytokinin content compared with creeping bentgrass and velvet bentgrass.

scholarly journals Soil Layers Properties of a Profile Developed on the Past Depositional Series on Merbabu Volcano Central Java Indonesia

2019 ◽  
Vol 24 (2) ◽  
pp. 53
Author(s):  
Mohammad Nurcholis ◽  
Susila Herlambang ◽  
Sri Aminah Suwartikaningsih ◽  
Dian Fiantis ◽  
Dwi Fitri Yudiantoro
Keyword(s):  
Soil Profile ◽  
Soil Morphology ◽  
Deep Soil ◽  
Sand Fraction ◽  
Soil Layers ◽  
Central Java ◽  
Development Processes ◽  
Different Characteristics ◽  
Physical And Chemical ◽  
Black Color

A wide and deep soil profile (around 1200 cm) was observed at Ketep Park West Slope of Merbabu volcano Central Java, Indonesia to identify the soil morphology, physical and, chemical and mineralogical properties.  Results showed that several soil development processes occurred in each volcanic deposits with different characteristics.  Most soil layers met some of andic soil properties criteria such bulk density <0.9 g.cm-3, P retention of >85%, and (Alo + ½ Feo) >2.0%.  A thin melanic material showing black color layer was found at the lower part of the soil profile, i.e. in depth from 726 to 798 cm.  The dominant material in most soil layers is an allophane.  Minerals in the sand fraction were dominated by labradorite and augite, with some layers were hypersthene and green hornblende.

scholarly journals Variations Regularity of Soil Nitrate Nitrogen in Hebei Piedmont Plain

2015 ◽  
Vol 9 (1) ◽  
pp. 98-102
Author(s):  
Huiyan Gao ◽  
Luhua Yang
Keyword(s):  
Soil Profile ◽  
Nitrate Nitrogen ◽  
Rotation Period ◽  
Growth Period ◽  
Utilization Efficiency ◽  
Nitrate Content ◽  
Soil Nitrate ◽  
Deep Soil ◽  
Piedmont Plain ◽  
Groundwater Environment

Field experiment was carried out to study on the spatial and temporal distribution of soil nitrate nitrogen at Ranzhuang water resources experiment station in Hebei piedmont plain from 2011 to 2012. The results show that nitrate nitrogen content varies in sinusoidal curve at shallow tilth soil and shows in “W” shape at deep soil profile during the wheat-maize rotation period. Nitrate nitrogen is mainly accumulated in 0~100cm soil and the maximum value occur at reviving stage in the wheat growth period. In the maize growth period, the distribution of nitrate nitrogen is double peak curve in 0∼500cm soil profile. The maximum peak emerges at 150∼260cm, the peak of soil nitrate content is between 36.7∼106.36mg/kg. In 0∼500cm soil layers, the cumulative amount of nitrate nitrogen is 1430.56∼5126.05 kg/hm2. The amount of nitrate nitrogen leaching is 1294.13kg/hm, which is 52.29% of the total amount of annual fertilization. It is scientific and technical groundwork to improve the utilization efficiency of nitrogen fertilizer and protect groundwater environment.

scholarly journals Variation in the access to deep soil water pools explains tree-to-tree differences in drought-triggered dieback of Mediterranean oaks

2020 ◽  
Vol 40 (5) ◽  
pp. 591-604 ◽  
Author(s):  
Francesco Ripullone ◽  
J Julio Camarero ◽  
Michele Colangelo ◽  
Jordi Voltas
Keyword(s):  
Soil Water ◽  
Isotope Composition ◽  
Tree Height ◽  
Tree Size ◽  
Rooting Depth ◽  
Severe Drought ◽  
Deep Soil ◽  
Mediterranean Oaks ◽  
Water Values ◽  
Alternative Processes

Abstract Individual differences in the access to deep soil water pools may explain the differential damage among coexisting, conspecific trees as a consequence of drought-induced dieback. We addressed this issue by comparing the responses to a severe drought of three Mediterranean oak species with different drought tolerance, Quercus pubescens L. and Quercus frainetto Ten., mainly thriving at xeric and mesic sites, respectively, and Quercus cerris L., which dominates at intermediate sites. For each species, we compared coexisting declining (D) and non-declining (ND) trees. The stable isotope composition (δ2H, δ18O) of xylem and soil water was used to infer a differential use of soil water sources. We also measured tree size and radial growth to quantify the long-term divergence of wood production between D and ND trees and non-structural carbohydrates (NSCs) in sapwood to evaluate if D trees presented lower NSC values. The ND trees had access to deeper soil water than D trees except in Q. frainetto, as indicated by significantly more depleted xylem water values. However, a strong δ2H offset between soil and xylem water isotopes observed in peak summer could suggest that both tree types were not physiologically active under extreme drought conditions. Alternative processes causing deuterium fractionation, however, could not be ruled out. Tree height and recent (last 15–25 years) growth rates in all species studied were lower in D than in ND trees by 22 and 44%, respectively. Lastly, there was not a consistent pattern of NSC sapwood concentration; in Q. pubescens, it was higher in ND trees while in Q. frainetto, the D trees were the ones exhibiting the higher NSC concentration. We conclude that the vulnerability to drought among conspecific Mediterranean oaks depends on the differential access to deep soil water pools, which may be related to differences in rooting depth, tree size and growth rate.

Field and laboratory investigations of the clay tills at the test bed site at the Building Research Establishment, Garston, Hertfordshire

1991 ◽  
Vol 7 (1) ◽  
pp. 229-238 ◽  
Author(s):  
A. Marsland ◽  
J. J. M. Powell
Keyword(s):  
Soil Profile ◽  
Laboratory Tests ◽  
Research Station ◽  
Test Bed ◽  
Building Research ◽  
Soil Fabric ◽  
Different Types ◽  
Loading Tests ◽  
Laboratory Investigations ◽  
A Site

AbstractDetailed investigations have been made of the clay tills on a site located at the Building Research Station about 30km NW of central London. Inspection of the soil macrofabric suggests that two advances of the ice occurred in this area.Results from insitu tests using cone penetrometers, pressuremeters, 100mm diameter screw plate tests, 292 and 865 mm diameter deep insitu loading tests, and laboratory tests are given. The results obtained from different types of tests are compared against the background of the modes of deposition, post depositional conditions and the variations in the soil fabric down the soil profile.

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