scholarly journals Soil water potential during different phenological phases of coffee irrigated by center pivot

2013 ◽  
Vol 33 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Adão W. P. Evangelista ◽  
Luiz A. Lima ◽  
Antônio C. da Silva ◽  
Carla de P. Martins ◽  
Moisés S. Ribeiro

Irrigation management can be established, considering the soil water potential, as the limiting factor for plant growth, assuming the soil water content between the field capacity and the permanent wilting point as available water for crops. Thus, the aim of this study was to establish the soil water potential interval during four different phenological phases of coffee irrigated by center pivot. The experiment was set at the experimental area of the Engineering Department at the Federal University of Lavras, in Brazil. The coffee variety planted is designated as Rubi, planted 0.8 meters apart, with rows spaced 3.5 meters apart. The treatments corresponded to the water depths applied based on different percentages of Kc and reference evapotranspiration (ET0) values. Sensors were used to measure the soil water potential interval, installed 25 centimeters depth. In order to compare the results, it was considered as the best matric potential the one that was balanced with the soil water content that resulted in the largest coffee productivity. Based on the obtained results, we verified that in the phases of fruit expansion and ripening, the best results were obtained, before the irrigations, when the soil water potential values reached -35 and -38 kPa, respectively. And in the flowering, small green and fruit expansion phases, when the values reached -31 and -32 kPa, respectively.

2005 ◽  
Vol 9 (6) ◽  
pp. 596-606 ◽  
Author(s):  
J. Roberts ◽  
P. Rosier

Abstract. The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood) and pasture (Bridgets Farm), growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration) as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.


Author(s):  
I Nyoman Rai ◽  
I Ketut Suada ◽  
M. Praborini ◽  
I Wayan Wiraatmaja

Cultivation of organic snake fruit in Bali which is done on dry land with the irrigation depends on rainfall and the fertilization generally only uses uncertain amount of fallen leaves, it reduces the productivity, quality, and continuity of fruit production over time. In rhizosphere of snake fruit there are various types of indigenous endomycorrhiza that potentially can be developed as biofertilizer, but as a biofertilizer, the low number of spores population for inoculum becomes a limiting factor in using indigenous endomycorrhiza. The effort that can be done are to propagate the spores by giving water stress treatment. This study aimed to obtain the best rhizosphere location of snake fruit as the source of spores and the level of soil water content to multiply the spores. The research was conducted in the green House, Farm Station, Agriculture Faculty, Udayana University at Jalan Pulau Moyo, Denpasar, from October 2017 to January 2018. The spore propagation used nested experiment with Randomized Block Design patterns. The treatments were rhizosphere location as the source of indigenous endomycorrhizas spore consists of three levels (Bebandem District Karangasem Regency, Payangan District Gianyar Regency, and Pupuan District Tabanan Regency) and soil water content consists of three levels (100%, 70%, and 40% field capacity). The results of the research showed that the source of indigenous endomychorrizae from snake fruit rhizosphere in Payangan District gave the highest number of spores found and the highest percentage of the spore increase after propagation. While in the soil water content treatments, the highest number of spores found and the percentage of the spore increase after propagation were obtained at soil water content of 40% field capacity. The percentage of root infections from different sources of indigenous endomychorrhizae and different levels of soil water content is same i.e 100%.


2011 ◽  
Vol 31 (2) ◽  
pp. 260-268 ◽  
Author(s):  
Alan K. Rêgo Segundo ◽  
José H. Martins ◽  
Paulo M. de B. Monteiro ◽  
Rrubens A. de Oliveira ◽  
Delly Oliveira Filho

The irrigation management based on the monitoring of the soil water content allows for the minimization of the amount of water applied, making its use more efficient. Taking into account these aspects, in this work, a sensor for measuring the soil water content was developed to allow real time automation of irrigation systems. This way, problems affecting crop yielding such as irregularities in the time to turn on or turn off the pump, and excess or deficit of water can be solved. To develop the sensors were used stainless steel rods, resin, and insulating varnish. The sensors measuring circuit was based on a microcontroller, which gives its output signal in the digital format. The sensors were calibrated using soil of the type “Quartzarenic Neosoil”. A third order polynomial model was fitted to the experimental data between the values of water content corresponding to the field capacity and the wilting point to correlate the soil water content obtained by the oven standard method with those measured by the electronic circuit, with a coefficient of determination of 93.17%, and an accuracy in the measures of ±0.010 kg kg-1. Based on the results, it was concluded that the sensor and its implemented measuring circuit can be used in the automation process of irrigation systems.


2020 ◽  
Vol 36 (1) ◽  
pp. 39-54
Author(s):  
Gary W. Marek ◽  
Thomas H. Marek ◽  
Kevin R. Heflin ◽  
Dana O. Porter ◽  
Jerry E. Moorhead ◽  
...  

Abstract. The use of soil water sensors is commonly advocated to aid and improve irrigation management in crop production systems. However, there are concerns about how sensor type, installation technique, sensor orientation, and soil texture may affect sensor accuracy. A field study was conducted to compare the performance of three commercially available soil water sensors (Acclima 315L, Decagon GS1, and Campbell Scientific 655) and a soil water potential sensor (Watermark 200SS) using different installation orientations of horizontal insertion, laid horizontal placement, and vertical insertion at depths of 15, 46, and 76 cm (6, 18, and 30 in.) in an irrigated clay loam soil field. Results indicated all sensors demonstrated similar trends of soil water content in response to wetting events (precipitation and irrigation) at the 15 cm depth following a 4-month settling period prior from the start of the growing season. Comparatively, the Acclima 315L performed well using horizontal insertion compared to calibrated neutron moisture meters (NMMs) at depths of 46 and 76 cm with R2 of 0.73 and 0.96 and slopes of 1.36 and 1.47, respectively. In addition, water storage in the 0.9 m soil profile integrated using the horizontally inserted Acclima 315L across the three depths matched closely with profile water storage determined by the NMMs with a mean difference (MD) and root mean square error (RMSE) of 25.7 and 36.4 mm. However, site-specific corrections or calibrations for each sensor type are required for accurate soil water content estimations with this clay loam soil for irrigation management applications. Keywords: Corn, Irrigation management, Neutron moisture meter, Soil water content, Soil water sensors, Semi-arid region.


1983 ◽  
Vol 23 (123) ◽  
pp. 407 ◽  
Author(s):  
PS Cornish

A temporary watertable was established in large undisturbed cores of a podzolic (duplex) soil in a glasshouse. The upward flow of water from the watertable to the soil surface through a 7 d drying cycle was assessed by measuring soil water content and matric potential, and the rate of evaporation from the soil surface (by weighing). Evaporation from the soil surface (Ea) closely followed evaporation from a free water surface (Eo), with little change in surface water potential or content until the watertable was depleted. This indicated that soil evaporation was balanced by the upward flux from the watertable, at rates up to 0.37 mm/h. Surface water potential was maintained above - 0.04 MPa for 7 d, and 12% of ryegrass seeds established themselves on the bare soil surface. When the A horizon was wet to field capacity but no watertable was established, Ea was much less than Eo especially in periods of high evaporation. Also, the soil surface dried to below - 0.04 MPa within the first day and no seeds germinated. It appears that sowing on sites with temporary watertables could assist germination and establishment after aerial sowing.


2020 ◽  
Vol 7 (03) ◽  
pp. 97-103
Author(s):  
Risal Ardika ◽  
Andi Nur Cahyo

Rubber is one of the economically important tropical trees that produces natural rubber, an essential industrial raw material in Indonesia. In general, rubber can grow well in areas with 1,500 - 3,000 mm rainfall per year that evenly distributed round the year. During the dry season, water availability is reduced so that water becomes a limiting factor for the growth and production of the rubber tree. This paper aimed to determine minimum soil water content that must be maintained to prevent the reduction of PB 260 rubber production based on field water balance. This research was carried out at the Indonesian Rubber Research Institute Experimental Field, South Sumatra, Indonesia, between 2014 to 2019. This experiment used PB 260 clone which was planted in 2001 using a 6 x 3 m plant spacing. Soil analysis showed that the Sembawa had a clay loam soil texture. The measured parameters were latex production (kg per ha per year), rainfall, and evapotranspiration (mm). The results from our six years of study showed that rubber production always decreased when soil water content started to decline below field capacity (33.7 %, or equal to 337 mm with 1m depth of root zone).


Author(s):  
MUHAMMAD ASLAM ALI ◽  
SANJIT CHANDRA BARMAN ◽  
MD. ASHRAFUL ISLAM KHAN ◽  
MD. BADIUZZAMAN KHAN ◽  
HAFSA JAHAN HIYA

Climate change and water scarcity may badly affect existing rice production system in Bangladesh. With a view to sustain rice productivity and mitigate yield scaled CH4 emission in the changing climatic conditions, a pot experiment was conducted under different soil water contents, biochar and silicate amendments with inorganic fertilization (NPKS). In this regard, 12 treatments combinations of biochar, silicate and NPKS fertilizer along with continuous standing water (CSW), soil saturation water content and field capacity (100% and 50%) moisture levels were arranged into rice planted potted soils. Gas samples were collected from rice planted pots through Closed Chamber technique and analyzed by Gas Chromatograph. This study revealed that seasonal CH4 emissions were suppressed through integrated biochar and silicate amendments with NPKS fertilizer (50–75% of the recommended doze), while increased rice yield significantly at different soil water contents. Biochar and silicate amendments with NPKS fertilizer (50% of the recommended doze) increased rice grain yield by 10.9%, 18.1%, 13.0% and 14.2%, while decreased seasonal CH4 emissions by 22.8%, 20.9%, 23.3% and 24.3% at continuous standing water level (CSW) (T9), at saturated soil water content (T10), at 100% field capacity soil water content (T11) and at 50% field capacity soil water content (T12), respectively. Soil porosity, soil redox status, SOC and free iron oxide contents were improved with biochar and silicate amendments. Furthermore, rice root oxidation activity (ROA) was found more dominant in water stress condition compared to flooded and saturated soil water contents, which ultimately reduced seasonal CH4 emissions as well as yield scaled CH4 emission. Conclusively, soil amendments with biochar and silicate fertilizer may be a rational practice to reduce the demand for inorganic fertilization and mitigate CH4 emissions during rice cultivation under water stress drought conditions.


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