Soil water regimes of annual and perennial forages during drought years in the Aspen Parkland ecoregion of Alberta

2007 ◽  
Vol 87 (5) ◽  
pp. 523-533 ◽  
Author(s):  
D L Bradshaw ◽  
D S Chanasyk ◽  
V S Baron ◽  
M A Naeth

Periodic and prolonged drought can be devastating to pasture production, which increases the financial risk for grazing enterprises. A study was conducted during 2 drought years (2002 and 2003) in the aspen parkland at Lacombe, Alberta, Canada, to compare the soil water regime of meadow bromegrass (Bromus riparius Rhem.), alfalfa (Medicago sativa L.), and annual [oat (Avena sativa L.) and winter triticale (X Triticosecale Wittmack)] pastures with a naturalized, old grass pasture consisting of quackgrass (Elytrigia repens L.), smooth bromegrass (Bromus inermis Leyss.), and Kentucky bluegrass (Poa partensis L.). The pasture soil was an Orthic Black Chernozem of fine sandy loam to loam texture. Soil water measurements were conducted between May and October over 2 yr using a neutron scattering hydroprobe to a depth of 1.6 m. Annual and meadow bromegrass had similar and highest cumulative and volumetric water contents and old grass had the lowest. All pastures tended to use all water available by the end of the season, but annual pasture had higher soil water in spring and early summer due to delayed canopy development. Soil in the upper 40 cm of annual and meadow bromegrass pastures was at wilting point 5 to 10% of all measurement times compared with 65 to 71% of measurement times for alfalfa and old grass. Annual and meadow bromegrass pastures did not extract water below 1.2 m, while the other pastures did, and on the basis of soil water regimes, appear to be lower risk options than status quo old grass and alfalfa pastures during drought. Key words: Soil water, forages, rotational grazing, drought, wilting point, field capacity

1998 ◽  
Vol 41 (3) ◽  
pp. 239-254 ◽  
Author(s):  
J. M. Steyn ◽  
H. F. Du Plessis ◽  
P. Fourie ◽  
P. S. Hammes

1968 ◽  
Vol 48 (2) ◽  
pp. 129-137 ◽  
Author(s):  
A. R. Maurer ◽  
H. F. Fletcher ◽  
D. P. Ormrod

Pea plants growing in "weighing lysimeters" were subjected to five soil-water regimes to determine their response to varying conditions of soil water imposed at different stages of development. Plants subjected to a minimal water stress developed luxuriantly and continued to grow up to the harvest period. Pea yield and plant height were not reduced, but fresh weight and dry matter were less if irrigation was applied when soil water fell to 60% rather than 88% of that available. A severe water stress after blossom reduced pea yield, irrespective of soil-water conditions prior to blossom. Plants which had been given ample soil water before blossom wilted visibly when a severe stress was imposed in the post-blossom period, yet wilting did not occur in plants subjected to severe water stress both before and after blossom. Severe water stress prior to blossom did not cause a decrease in pea yield if ample soil moisture was made available after blossom.


2021 ◽  
Author(s):  
Chengpeng Sun ◽  
Wenzhi Zhao ◽  
Hu Liu ◽  
Yongyong Zhang ◽  
Hong Zhou

<p>Textural layering of soil plays an important role in distributing and regulating resources for plants in many semiarid and arid landscapes. However, the spatial patterns of textural layering and the potential effects on soil hydrology and water regimes are poorly understood, especially in arid sandy soil environments like the desert-oasis ecotones in northwestern China. This work aims to determine the distribution of textural layered soils, analyze the effects of different soil-textural configurations on water regimes, and evaluate which factors affect soil water infiltration and retention characteristics in such a desert-oasis ecotone. We measured soil water content and mineral composition in 87 soil profiles distributed along 3 transects in the study area. Constant-head infiltration experiments were conducted at 9 of the soil profiles with different texture configurations. The results showed that textural layered soils were patchily but extensively distributed throughout the study area (with a combined surface area percentage of about 84%). Soil water content in the profiles ranged from 0.002 to 0.27 g/cm<sup>3</sup> during the investigation period, and significantly and positively correlated with the thickness of a medium-textured (silt or silt loam) layer (<em>P</em> < 0.001). The occurrence of a medium-textured layer increased field capacity (FC) and wilting point (WP), and decreased available water-holding capacity in soil profiles. Burial depth of the medium-textured layer had no clear effects on water retention properties, but the layer thickness tended to. In textural layered soils, smaller water infiltration rate and cumulative infiltration, and shallower depths of wetting fronts were detected, compared with homogeneous sand profiles. The thickness and burial depth of medium-textured layers had obvious effects on infiltration, but the magnitude of the effects depended on soil texture configuration. The revealed patterns of soil textural layering and the potential effects on water regimes may provide new insight into the sustainable management of rainfed vegetation in the desert-oasis ecotones of arid northwestern China and other regions with similar environments around the world.</p>


2014 ◽  
Vol 34 (2) ◽  
pp. 203-210 ◽  
Author(s):  
Fernando da S. Barbosa ◽  
Rubens D. Coelho ◽  
Rafael Maschio ◽  
Carlos J. G. de S. Lima ◽  
Everaldo M. da Silva

Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250 during the early development using different levels of water deficit on four soil depths. The experiment was conducted at the Department of Biosystems at Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP) in a greenhouse in soil classified as Oxisol, sandy loam texture (Series "Sertãozinho"). Once exhausted the level of available water in the soil, the dry strength of the studied strains are relatively low. Water balance with values less than -13 mm cause a significant decrease in the final population of plants, regardless of the variety, and values below -35 mm, leads to the death of all plants.


1990 ◽  
Vol 115 (5) ◽  
pp. 712-714 ◽  
Author(s):  
Doyle A. Smittle ◽  
Melvin R. Hall ◽  
James R. Stansell

Sweetpotatoes [Ipomoea batatas (L.) Lam cv. Georgia Jet] were grown on two soil types in drainage lysimeters under controlled soil water regimes during 1982 and 1983. Water regimes consisted of irrigating the sweetpotatoes throughout growth when soil water tension at 23 cm exceeded 25, 50, or 100 kPa or by allowing a 100-kPa water stress before root enlargement, during early root enlargement, or throughout root enlargement. Water use and marketable yields were greater when sweetpotatoes were grown on a Tifton loamy sand (fine loamy, siliceous, thermic, Plinthitic Paleudult) than when grown on a Bonifay sand (loamy, siliceous, thermic, Grossarenic, Plinthitic Paleudult). Water use, marketable yield, and yield of U.S. #1 grade roots generally decreased when soil water tensions exceeded 25 kPa before irrigation, although soil water stress of 100 kPa during storage root development did not significantly affect yield. Regression equations are provided to describe the relationships of water use to plant age and to compute daily evapotranspiration: pan evaporation ratios (crop factors) for sweetpotatoes irrigated at 25, 50, and 100 kPa of soil water tension.


Author(s):  
J.A. Baars ◽  
G.J. Goold ◽  
M.F. Hawke ◽  
P.J. Kilgarriff ◽  
M.D. Rolm

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates


Nativa ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 415
Author(s):  
Morgana Scaramussa Gonçalves ◽  
Wilian Rodrigues Ribeiro ◽  
Edvaldo Fialho Dos Reis ◽  
Antônio Carlos Cóser

A irrigação é usada para conter os efeitos da sazonalidade de produção garantindo maior intensificação dos sistemas de produção a pasto, assim, contribuindo para o aumento da produção e do valor bromatológico das gramíneas. Dessa forma, objetivou-se com esse trabalho avaliar o valor bromatológico de gramíneas tropicais cultivadas em condições de ambiente protegido, submetidas a diferentes tensões de água no solo. Foram realizados três experimentos com as gramíneas Mombaça, Marandu e Tifton 85, onde cada qual, foi conduzida em um esquema de parcelas subdivididas, tendo nas parcelas os níveis do fator tensão de água no solo (20, 40, 50, 60 e 70 kPa) e nas subparcelas níveis 1º, 2º e 3º do fator corte, em um delineamento inteiramente casualizado com cinco repetições. Nas tensões de água no solo de 20 (Mombaça) e 50 kPa (Marandu e Tifton 85) as gramíneas expressaram seu máximo de valor nutritivo. Os maiores teores de PB foram obtidos nas gramíneas Mombaça e Tifton 85. Para as variáveis FDN e FDA o fator tensão de água no solo não foi significativo.Palavras-chave: proteína bruta, fibra, irrigação, forrageiras. BROMATOLOGY OF TROPICAL GRASSES UNDER DIFFERENT SOIL WATER TENSIONS IN PROTECTED ENVIRONMENT ABSTRACT:The irrigation is used to contain the effects of seasonality of production, ensuring a greater intensification of pasture production systems, thus contributing to the increase of production and the bromatological value of grasses. Thus, the objective of this work was to evaluate the nutritive value of tropical grasses grown under protected environment conditions, subject to different soil water stresses. Three experiments, using Mombasa, Marandu and Tifton 85 grasses under a protected environment were carried out and each one was conducted in a subdivided plots scheme, with the levels of soil water tension factor (20, 40, 50, 60 and 70 kPa) and in the subplots levels 1, 2 and 3 of the cut factor, in a completely randomized design with five replicationss. At soil water stresses of 20 (Mombasa) and 50 kPa (Marandu and Tifton 85) the grasses expressed their maximum nutritive value. The highest CP levels were obtained in the Mombasa and Tifton 85 grasses. For the NDF and ADF variables, the soil water stress factor was not significant.Keywords: crude protein, fiber, irrigation, forages.


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