Evaluation of Very High Soil-Water Tension Threshold Values in Sensor-Based Deficit Irrigation Systems

2014 ◽  
Vol 140 (9) ◽  
Author(s):  
Sebastian Kloss ◽  
Niels Schütze ◽  
Urs Schmidhalter
Keyword(s):  
Soil Water ◽  
Deficit Irrigation ◽  
Threshold Values ◽  
Irrigation Systems ◽  
Soil Water Tension ◽  
High Soil ◽  
Water Tension ◽  
Very High

Citrus Carbohydrate Levels were Related to Irrigation Frequency but Not Arbuscular Mycorrhizal Fungal (AMF) Inoculum

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498a-498
Author(s):  
Matthew W. Fidelibus ◽  
Chris A. Martin
Keyword(s):  
Soil Water ◽  
Arbuscular Mycorrhizal ◽  
Irrigation Frequency ◽  
Soil Water Tension ◽  
Root Starch ◽  
Carbohydrate Levels ◽  
Amf Communities ◽  
Sugar Levels ◽  
Shoot Mass ◽  
Water Tension

Sugar and starch concentrations in leaves and roots of Citrus volkameriana Tan and Pasq were measured in response to irrigation frequency and AMF inoculum. Non-mycorrhizal seedlings were treated with a soil inoculum from one of five different communities of AMF; two AMF communities from Arizona citrus orchard soils, and three communities from undisturbed desert soils. Plants were assigned to frequent (soil water tension > –0.01 MPa) or infrequent (soil water tension > –0.06 MPa) irrigation cycles and were container-grown in a glasshouse for 4 months before tissues were analyzed. Fungal inoculum source did not affect shoot or root carbohydrate levels. Plants grown under high irrigation frequency had increased leaf and root starch levels and increased root sugar levels compared with those under low irrigation frequencies. High irrigation frequency also increased shoot mass.

scholarly journals Effects of Irrigation Regimes on Yield and Water Use by Sweetpotato

1990 ◽  
Vol 115 (5) ◽  
pp. 712-714 ◽  
Author(s):  
Doyle A. Smittle ◽  
Melvin R. Hall ◽  
James R. Stansell
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Water Use ◽  
Ipomoea Batatas ◽  
Regression Equations ◽  
Marketable Yield ◽  
Water Regimes ◽  
Soil Water Tension ◽  
Water Tension ◽  
Storage Root Development

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.

scholarly journals BROMATOLOGIA DE GRAMÍNEAS TROPICAIS SOB DIFERENTES TENSÕES DE ÁGUA NO SOLO EM AMBIENTE PROTEGIDO

Nativa ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 415
Author(s):  
Morgana Scaramussa Gonçalves ◽  
Wilian Rodrigues Ribeiro ◽  
Edvaldo Fialho Dos Reis ◽  
Antônio Carlos Cóser
Keyword(s):  
Soil Water ◽  
Crude Protein ◽  
Nutritive Value ◽  
Production Systems ◽  
Pasture Production ◽  
Tropical Grasses ◽  
Soil Water Tension ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Water Tension

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.

scholarly journals Soil Water Characteristics of Gleysols in the Bamenda (Cameroon) Wetlands and Implications for Agricultural Management Strategies

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Alice Mufur Magha ◽  
Primus Azinwi Tamfuh ◽  
Lionelle Estelle Mamdem ◽  
Marie Christy Shey Yefon ◽  
Bertrand Kenzong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Water ◽  
Total Variance ◽  
Organic Carbon Content ◽  
Available Water ◽  
High Soil ◽  
Local Soil ◽  
Very High

Water budgeting in agriculture requires local soil moisture information as crops depend mainly on moisture available at root level. The present paper aims to evaluate the soil moisture characteristics of Gleysols in the Bamenda (Cameroon) wetlands and to evaluate the link between soil moisture content and selected soil characteristics affecting crop production. The work was conducted in the field and laboratory, and data were analyzed by simple descriptive statistics. The main results showed that the soils had a silty clayey to clayey texture, high bulk density, high soil organic carbon content, and high soil organic carbon stocks. The big difference between moisture contents at wilting point and at field capacity testified to very high plant-available water content. Also, the soils displayed very high contents of readily available water and water storage contents. The soil moisture characteristics give sigmoid curves and enabled noting that the Gleysols attain their full water saturation at a range of 57.68 to 91.70% of dry soil. Clay and SOC contents show a significant positive correlation with most of the soil moisture characteristics, indicating that these soil properties are important for soil water retention. Particle density, coarse fragments, and sand contents correlated negatively with the soil moisture characteristics, suggesting that they decrease soil water-holding capacity. The principal component analysis (PCA) enabled reducing 17 variables described to only three principal components (PCs) explaining 73.73% of the total variance; the first PC alone expressed 45.12% of the total variance, associating clay, SOC, and six soil moisture characteristics, thus portraying a deep correlation between these eight variables. Construction of contoured ditches, deep tillage, and raised ridges management techniques during the rainy season while channeling water from nearby water bodies into the farmland, opportunity cropping, and usage of water cans and other irrigation strategies are used during the dry season to combat water constraints.

scholarly journals Rooting Depth, Growth and Yield of Sorghum as Affected by Soil Water Availability in an Ultisol and an Oxisol

1969 ◽  
Vol 60 ◽  
pp. 329-335
Author(s):  
A. Wahab ◽  
H. Talleyrand ◽  
M. A. Lugo-López
Keyword(s):  
Soil Moisture ◽  
Plant Growth ◽  
Soil Water ◽  
Grain Filling ◽  
Growth And Yield ◽  
Rooting Depth ◽  
Weather Factors ◽  
Soil Water Tension ◽  
Available Soil Moisture ◽  
Water Tension

Grain and stover yields of RS 671 grain sorghum were measured at Barranquitas in an Oxisol and at Corozal in an Ultisol. Measurements were made of weather factors, soil moisture content and tension, plant growth, water deficits and rooting depths. At each site a plot was irrigated as often as necessary to maintain a soil water tension of less than 1 bar. Nonirrigated plots at Corozal were watered whenever necessary to prevent plants from wilting permanently. During a prolonged drought and at grain filling, sorghum extracted water in the Oxisol to a depth of 120 cm. Plants became water stressed after the soil water tension at a depth of 90 cm reached 15 bars. In the Ultisol, sorghum plants were unable to effectively extract available soil moisture at depths below 45 cm. Both plant growth and grain yield were greater in the Oxisol than in the Ultisol. The relative soil compaction of the Ultisol was greater than that of the Oxisol.

scholarly journals Monitoring of Soil Water Content in Maize Rotated with Pigeonpea Fallows in South Africa

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2761
Author(s):  
Misheck Musokwa ◽  
Paramu L. Mafongoya ◽  
Paxie W. Chirwa
Keyword(s):  
South Africa ◽  
Water Content ◽  
Soil Water ◽  
Water Distribution ◽  
Smallholder Farmers ◽  
Block Design ◽  
Maize Production ◽  
Soil Water Tension ◽  
Continuous Maize ◽  
Water Tension

Maize production under smallholder systems in South Africa (RSA) depends on rainfall. Incidences of dry spells throughout the growing season have affected maize yields negatively. The study examined water distribution and water use efficiency (WUE) of maize rotated with two-year pigeonpea fallows as compared to continuous maize without fertilizer. A randomized complete block design, replicated three times, was used with four treatments, which included continuous unfertilized maize, natural fallow-maize, pigeonpea + grass-pigeonpea-maize, and two-year pigeonpea fallow-maize. Soil water mark sensors were installed 0.2; 0.5; and 1.2 m on each plot to monitor soil water tension (kPa). Soil samples were analyzed using pressure plates to determine water retention curves which were used to convert soil water tension to volumetric water content. Maize rotated with two-year pigeonpea fallows had higher dry matter yield (11,661 kg ha−1) and WUE (20.78 kg mm−1) than continuous maize (5314 kg ha−1 and 9.48 kg mm−1). In this era of water scarcity and drought incidences caused by climate change, maize rotated with pigeonpea fallows is recommended among smallholder farmers in RSA because of its higher WUE, hence food security will be guaranteed.

scholarly journals Effect of Irrigation Threshold on Crop Performances in Wet Seeded Rice

2019 ◽  
Vol 22 (1) ◽  
pp. 73-81
Author(s):  
S Parveen ◽  
E Humphreys ◽  
M Ahmed
Keyword(s):  
Soil Water ◽  
Water Productivity ◽  
Grain Filling ◽  
Greenhouse Experiment ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Wet Season ◽  
Soil Water Tension ◽  
Labour Requirement ◽  
Water Tension

Decreasing availability and increasing costs of water and labour are driving researchers and farmers to find management strategies that increase input water productivity and reduce labour requirement in rice production. Wet seeding instead of transplanting greatly reduces the labour requirement for crop establishment, whereas use of alternate wetting and drying (AWD) instead of continuous flooding reduces irrigation input. However, the safe threshold for irrigating wet seeded rice (WSR), and how this varies with growth stage, has not been established. Therefore, a greenhouse experiment was conducted to determine the effects of different degrees of irrigation threshold during different crop growth stages on crop performance of WSR. This was done in greenhouse experiment in the 2011 wet season at the International Rice Research Institute, Los Baños, Philippines. In the experiments, water stresses were applied by withholding irrigation until soil water tension increased to 10, 20 or 40 kPa at 10 cm below the soil surface. Soil water tension was measured using 30 cm long gauge tensiometer installed with the center of the ceramic cup. The stresses were applied during three crop stages: 3-leaf (3L) to panicle initiation (PI), PI to flowering (FL), and FL to physiological maturity (PM). The experiment was also included a continuously flooded (CF) treatment. Stress during 3L to PI increased the time to PI (by 2 to 4 days) but reduced the duration of grain filling by 3 to 5 days, the larger values with 20 and 40 kPa thresholds. There was no effect of stress thresholds of 10 to 40 kPa during PI-FL on crop duration. Stress during grain filling reduced the duration of grain filling by 6 days for all thresholds. Stresses of 20 and 40 kPa during 3L to PI reduced green leaf and tiller density at PI, but this effect disappeared with the imposition of CF after PI. There were consistent trends for lower final biomass as the level of water deficit stress increased, and imposition of stresses of 20 and 40 kPa at any or all three stages significantly reduced biomass compared with CF. These results suggest that, for shortening the ripening period, water stress may be imposed as 10 to 20 kPa during FL to PM. Bangladesh Rice j. 2018, 22(1): 73-81

PREDICTION OF SOIL STRENGTH FROM HYDROLOGIC AND MECHANICAL PROPERTIES

1979 ◽  
Vol 59 (3) ◽  
pp. 301-311 ◽  
Author(s):  
C. L. PAUL ◽  
J. DE VRIES
Keyword(s):  
Soil Water ◽  
Empirical Relationship ◽  
Organic Soil ◽  
Soil Strength ◽  
Limited Range ◽  
Late Winter ◽  
Cone Penetration ◽  
Soil Water Tension ◽  
Mineral Soils ◽  
Water Tension

Cone penetration resistance (an index of soil strength) was found to be linearly dependent upon soil water tension within a limited range of tensions close to saturation. This relationship was established with data collected from three soil types in farmers’ fields located in the Lower Fraser Valley of British Columbia during late winter and spring over a 2-yr period. For the mineral soils the slope of the relationship was predicted quite well by a theoretically-based equation. The slope could not be predicted for an organic soil. Solution of the equation required a number of simplifying assumptions and direct measurement of the angle of shearing resistance, [Formula: see text]. This equation was integrated and the constant of integration, the value of which depended upon the particular depth intervals at which measurements of cone penetration were made, was replaced by the intercept from the empirical strength-tension relationship. In this way, a semi-empirical model was developed for the prediction of soil strength from soil water tension, or vice versa, for the mineral soils. Prediction for the organic soil could be carried out with the empirical relationship.

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