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

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.

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Pigeonpea Yield and Water Use Efficiency: A Savior under Climate Change-Induced Water Stress

Agronomy ◽

10.3390/agronomy11010005 ◽

2020 ◽

Vol 11 (1) ◽

pp. 5

Author(s):

Misheck Musokwa ◽

Paramu Mafongoya

Keyword(s):

Climate Change ◽

Grain Yield ◽

Water Use Efficiency ◽

Soil Water ◽

Water Use ◽

Smallholder Farmers ◽

Block Design ◽

Soil Water Tension ◽

Use Efficiency ◽

Water Tension

Frequent droughts have threatened the crop yields and livelihoods of many smallholder farmers in South Africa. Pigeonpea can be grown by farmers to mitigate the impacts of droughts caused by climate change. An experiment was conducted at Fountainhill Farm from January 2016 to December 2017. The trial examined grain yield in addition to water use efficiency (WUE) of pigeonpea intercropped with maize versus sole pigeonpea and maize. A randomized complete block design, replicated three times, was used. Soil water tension was measured at 20, 50, and 120 cm within plots. The highest and lowest soil water tension was recorded at 20 m and 120 m respectively. Combined biomass and grain yield were significantly different: pigeonpea + maize (5513 kg ha−1) > pigeonpea (3368 kg ha−1) > maize (2425 kg ha−1). A similar trend was observed for WUE and land equivalent ratio (LER), where pigeonpea + maize outperformed all sole cropping systems. The inclusion of pigeonpea in a traditional mono-cropping system is recommended for smallholder farmers due to greater WUE, LER and other associated benefits such as food, feed and soil fertility amelioration, and it can reduce the effects of droughts induced by climate change.

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533 Monitoring Soil Water Content in Tropical Fruit Orchards in Southern Florida with Multi-sensor Capacitance Probes and Tensiometers

HortScience ◽

10.21273/hortsci.35.3.487c ◽

2000 ◽

Vol 35 (3) ◽

pp. 487C-487 ◽

Cited By ~ 1

Author(s):

R. Nuñez-Elisea ◽

B. Schaffer ◽

M. Zekri ◽

S.K. O'Hair ◽

J.H. Crane

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Volumetric Soil Water Content ◽

Tropical Fruit ◽

Soil Water Tension ◽

Scheduling Irrigation ◽

Southern Florida ◽

Fruit Orchards ◽

Water Tension

Tropical fruit trees in southern Florida are grown in porous, oolitic limestone soil that has very low organic matter content and water-holding capacity. Thus, trees require frequent irrigation during dry periods. In these soils, a quantitative basis for monitoring soil water content to determine when and how much to irrigate has been lacking. Multi-sensor capacitance probes (EnviroSCAN™, Sentek, Australia) were installed in commercial carambola, lime, and avocado orchards to continuously monitor changes in soil water content at depths of 10, 20, 30, and 50 cm. Eight probes were installed per orchard. Volumetric soil water content was recorded at 15-min intervals with a solar-powered datalogger. Results were downloaded to a laptop computer twice a week. Monitoring the rate of soil water depletion (evapotranspiration) allowed irrigation before the onset of water stress. The time at which soil reached field capacity could be determined after each irrigation (or rain) event. Soil water tension was recorded periodically using low-tension (0–40 cbars) tensiometers placed adjacent to selected capacitance probes at 10- and 30-cm depths. Soil water tension was better correlated with volumetric soil water content at a 10-cm depth than at 30-cm depth. Using multi-sensor capacitance probes is a highly accurate, although relatively expensive, method of monitoring soil water content for scheduling irrigation in tropical fruit orchards. Whereas tensiometers require periodic maintenance, the multi-sensor capacitance probe system has been virtually maintenance free. The correlation between soil water content and soil water tension obtained in situ indicates that tensiometers are a less precise, but considerably cheaper, alternative for scheduling irrigation in tropical fruit orchards in southern Florida.

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Variability of soil water tension and soil water content

Agricultural Water Management ◽

10.1016/0378-3774(90)90026-u ◽

1990 ◽

Vol 18 (2) ◽

pp. 135-148 ◽

Cited By ~ 13

Author(s):

J.M.H. Hendrickx ◽

P.J. Wierenga ◽

M.S. Nash

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Water Tension ◽

Water Tension

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Determination of soil water tension for irrigation management of sweet sorghum

Semina Ciências Agrárias ◽

10.5433/1679-0359.2016v37n3p1189 ◽

2016 ◽

Vol 37 (3) ◽

pp. 1189

Author(s):

Karen Marcelle de Jesus Silva ◽

Ignacio Aspiazú ◽

Arley Fiqueiredo Portugal ◽

Renato Mendes de Oliveira ◽

Polyanna Mara de Oliveira ◽

...

Keyword(s):

Soil Water ◽

Sweet Sorghum ◽

Block Design ◽

Irrigation Management ◽

Soluble Solids ◽

Water Retention Curve ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Soil Water Tension ◽

Water Tension

Culturing of sweet sorghum is being considered as an excellent option for ethanol production, from an agronomical and industrial point of view. At present, information regarding the best soil water tension for beginning sweet sorghum irrigation is not available; hence, this study aimed to determine the adequate soil water tension under field conditions for beginning irrigation of four cultivars of sorghum. Two experiments were conducted at Nova Porteirinha, MG, in a randomized block design with sub-subdivided plots having four replications. Each experiment comprised six treatments of soil water tension (plots)-20, 40, 60, 80, 100, and 120 kPa-for resuming sweet sorghum irrigation, and four sweet sorghum cultivars (subplots)-BRS 508, BRS 509, BRS 511, and CMSXS647. After planting, the soil water level in the plots was elevated to field capacity (10 kPa), and then the treatments were applied. During treatment application, irrigation was resumed when the soil water tension reached the limit established in order to elevate the soil water tension to 10 kPa. The amount of water replaced during each irrigation was determined by generating a soil water retention curve for the experimental area. The following parameters were evaluated: green mass production, juice volume, soluble solids (Brix), and tons of Brix per hectare (TBH). The different soil water tensions and cultivars, agricultural year, and interaction between tension and year significantly affected (p ? 0.05) the characteristics evaluated, according to the F test. The agronomical characteristics of the evaluated cultivars showed linear relationship with water supply in the soil. According to TBH, irrigation of sweet sorghum needs to be performed when the soil tension reaches 20 kPa. The TBH values did not differ significantly among the four cultivars at the 5% significance level according to Tukey test.

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Water balance in soil covered by regenerating rainforest in the Paraíba Valley region, São Paulo, Brazil

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2482 ◽

2019 ◽

Vol 14 (6) ◽

pp. 1

Author(s):

Marcelo Dos Santos Targa ◽

Emilson Pohl ◽

Ana Aparecida da Silva Almeida

Keyword(s):

Soil Moisture ◽

Water Balance ◽

Water Content ◽

Soil Water ◽

Characteristic Curve ◽

Residual Water ◽

Deep Drainage ◽

Soil Water Tension ◽

Experimental Area ◽

Water Tension

The objective of this study was to evaluate the water balance in a Red-Yellow Latosol covered by a regenerating rainforest for 30 years in the Una River Basin between April 2016 and March 2017. Field capacity (FC) and permanent wilting-point values (PWP) used to calculate the available water capacity (AWC) in the soil were determined by the soil moisture characteristic curve obtained in pots, which made it possible to determine the soil residual water content (g / g) from the measurement of water tension in 15 Watermark (TM) sensors installed at depths of 40, 60 and 120 cm. Precipitation during the period (1962 mm) was obtained from the automatic weather station located 300 m from the experimental area. Soil surface runoff was obtained from 5 collectors distributed in the experimental area. Precipitation was characterized by a maximum of 454 mm in January 2017 and no rain in July 2016. The actual evapotranspiration was 744 mm. There were 56 runoff events (SR) totaling 60 mm. The average soil water tension remained below 37 kPa in 67% of the studied period, a condition that kept the soil moisture content high. The soil water balance of the tropical forest area, up to 120 cm deep, kept soil water content near its maximum capacity (173 mm) 49% of the time and saturated 51% of the time, so that it generated deep drainage beyond 120 cm deep and 1023 mm deep.

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Response of broccoli to soil water tension under drip irrigation

Semina Ciências Agrárias ◽

10.5433/1679-0359.2016v37n1p7 ◽

2016 ◽

Vol 37 (1) ◽

pp. 7

Author(s):

Bartolomeu Felix Tangune ◽

Geraldo Magela Pereira ◽

Rovilson José de Souza ◽

Rafael Frees Gatto

Keyword(s):

Soil Water ◽

Drip Irrigation ◽

Block Design ◽

Average Diameter ◽

Marketable Yield ◽

Mean Values ◽

Soil Water Tension ◽

Randomized Block Design ◽

Granular Matrix ◽

Water Tension

We evaluated the effect of different soil water tensions on the production of broccoli cultivated in a protected environment under drip irrigation in order to establish criteria for the adequate management of irrigation. A completely randomized block design was used, comprising six treatments and four replicates. The treatments included six soil water tensions (15, 30, 45, 60, 75 and 90 kPa). Soil water tension was monitored with granular matrix sensors installed at depths of 0.2 m (decision sensors) and 0.4 m (seepage control sensors). Total and marketable fresh weight of broccoli heads, average diameter of marketable heads, height of marketable heads, and total and marketable yield were greatest when the soil water tension at a depth of 0.2 m was 15 kPa, at which the mean values of the evaluated variables were 0.84 kg, 0.76 kg, 20.5 cm, 11.7 cm; 26.5 t ha?1, and 23.7 t ha?1, respectively. Treatments did not significantly affect efficiency of water use or height of marketable heads.

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Peat depth as a control on moss water availability during drought

10.22541/au.160735596.64463109/v1 ◽

2020 ◽

Author(s):

Paul Moore ◽

Benjamin Didemus ◽

Alexander Furukawa ◽

James Waddington

Keyword(s):

Climate Change ◽

Water Content ◽

Soil Water ◽

Water Table ◽

Summer Drought ◽

Drought Period ◽

Near Surface ◽

Soil Water Tension ◽

Water Tension

Peatlands are globally important long-term sinks of carbon, however there is concern that enhanced moss moisture stress due to climate change mediated drought will reduce moss productivity making these ecosystems vulnerable to carbon loss and associated long-term degradation. Peatlands are resilient to summer drought moss stress because of negative ecohydrological feedbacks that generally maintain a wet peat surface, but where feedbacks may be contingent on peat depth. We tested this ‘survival of the deepest’ hypothesis by examining water table position, near-surface moisture content, and soil water tension in peatlands that differ in size, peat depth, and catchment area during a summer drought. All shallow sites lost their WT (i.e. the groundwater well was dry) for considerable time during the drought period. Near-surface soil water tension increased dramatically at shallow sites following water table loss, increasing ~5–7.5× greater at shallow sites compared to deep sites. During a mid-summer drought intensive field survey we found that 60%–67% of plots at shallow sites exceeded a 100 mb tension threshold used to infer moss water stress. Unlike the shallow sites, tension typically did not exceed this 100 mb threshold at the deep sites. Using species dependent water content - chlorophyll fluorescence thresholds and relations between volumetric water content and water table depth, Monte Carlo simulations suggest that moss had nearly twice the likelihood of being stressed at shallow sites (0.38 ± 0.24) compared to deep sites (0.22 ± 0.18). This study provides evidence that mosses in shallow peatland may be particularly vulnerable to warmer and drier climates in the future, but where species composition may play an important role. We argue that a critical ‘threshold’ peat depth specific for different hydrogeological and hydroclimatic regions can be used to assess what peatlands are especially vulnerable to climate change mediated drought.

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Bell Pepper Development and Water Potential as Affected by Soil Water Tensions and Nitrogen Doses

Journal of Agricultural Studies ◽

10.5296/jas.v8i2.16651 ◽

2020 ◽

Vol 8 (2) ◽

pp. 574

Author(s):

Helane Cristina Aguiar Santos ◽

Joaquim Alves De Lima Junior ◽

William Lee Carrera De Aviz ◽

Deiviane De Souza Barral ◽

Renan De Souza ◽

...

Keyword(s):

Soil Water ◽

Block Design ◽

Technical Information ◽

Northern Region ◽

Bell Pepper ◽

Soil Water Tension ◽

Randomized Block Design ◽

Significant Difference ◽

Shoot Mass ◽

Water Tension

Considering the lack of technical information on the water depth and nitrogen fertilization via fertigation in bell pepper cultivation, this work aimed to provide management data for its production in the northern region of Brazil. The experiment was carried out in a greenhouse at FEIGA / UFRA, with a 1.0 x 0.50 m spacing, in a randomized block design, with a 5 x 4 factorial scheme, with three replications. The treatments consisted of five water tensions in the soil (15, 25, 35, 45 and 65 kPa) and four nitrogen doses (0, 135, 265 and 395 kg.ha-1). There was no interaction between the factors of water tension in the soil and nitrogen doses for any of the variables analyzed. Height of plants, fresh shoot mass and dry shoot mass showed significant differences only for nitrogen doses. Predawn potential, showed significant difference for soil water tensions and nitrogen doses. Ahead of the conditions under which this work was carried out and the results obtained for the variables analyzed for the bell pepper cultivation in a protected environment, we found that the soil water tension of 15 kPa and the nitrogen dose of 265 kg.ha-1 were ideal for the crop.

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

HortScience ◽

10.21273/hortsci.33.3.498a ◽

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.

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