scholarly journals MONITORING XYLEM SAP IN SUGARCANE THROUGH TDR

2020 ◽  
Vol 28 ◽  
pp. 100-108
Author(s):  
Júlia Rodrigues Simione ◽  
Gláucia Cristina Pavão ◽  
Claudinei Fonseca Souza

The TDR can be used to measure water content and nutrients in several media with a potential to monitor the xylem sap flow in plants. The objective of this study was to determine whether there is a correlation between the xylem sap content and water available in the soil for sugarcane cultivation using TDR. The study was conducted in a protected environment with eight boxes (500 L). The boxes were divided into two treatments with different water application rates (1.6 and 3.4 L h-1) through subsurface irrigation. In each box TDR probes were inserted in the medium part of sugarcane stalk, totaling three probes per box to monitoring the sap flow. The soil water content was monitored using 20 net-placed probes. Therefore, the simultaneous monitoring of xylem sap and soil water content occurred for five months. As a result, it was obtained that the xylem content monitoring through TDR is moderately related to soil moisture, with a response to the absorption and translocation of the solution in the stem of sugarcane plants as a consequence of irrigation applications and/or fertirrigation. Thus, it was concluded that there is a weak relations between water contents in the soil and plant, especially for the treatment that used the highest flow rate (3.4 L h-1).

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.


2020 ◽  
Vol 68 (4) ◽  
pp. 351-358
Author(s):  
Miroslav Fér ◽  
Radka Kodešová ◽  
Barbora Kalkušová ◽  
Aleš Klement ◽  
Antonín Nikodem

AbstractThe aim of the study was to describe the impact of the soil water content and sulfamethoxazole, SUL, (antibiotic) concentration in soil on the net CO2 efflux. Soil samples were taken from topsoils of a Haplic Fluvisol and Haplic Chernozem. Soil samples were packed into the steel cylinders. The net CO2 efflux was measured from these soil columns after application of fresh water or SUL solution at different soil water contents. The experiments were carried out in dark at 20°C. The trends in the net CO2 efflux varied for different treatments. While initially high values for water treatment exponentially decreased in time, values for solution treatment increased during the first 250–650 minutes and then decreased. The total net CO2 effluxes measured for 20 hours related to the soil water content followed the second order polynomial functions. The maximal values were measured for the soil water content of 0.15 cm3 cm−3 (Haplic Fluvisol with water or solution, Haplic Chernozem with solution) and 0.11 cm3 cm−3 (Haplic Chernozem with water). The ratios between values measured for solution and water at the same soil water contents exponentially increased with increasing SUL concentration in soils. This proved the increasing stimulative influence of SUL on soil microbial activity.


2015 ◽  
Vol 719-720 ◽  
pp. 187-192
Author(s):  
Heru Purnomo ◽  
Rahmat N.D. Syah ◽  
Mochammad R. Syaifulloh ◽  
Srikandi W. Arini ◽  
Essy Arijoeni Basoenondo ◽  
...  

The paper discusses strength-time relation of unfired soil-lime bricks in presence of different water content of soil as one of principal materials for the brick making. Two batches of soil-lime bricks were made with a mixture of lime, soil and water with a mass proportion of 1: 5.7: 1. Water contents of the first and second batch of soil are 30% and 40.581% respectively. Both batches of brick underwent compression and three point bending test. Absorption and physical change of bricks were also evaluated. Experimental investigation reveals that for both batches of bricks, up to 90 days compressive strength decreases a little but modulus of rupture rapidly decreases with time. The study shows that unfired soil-lime bricks with lower soil water content resulted in better strength performances compared to those with higher soil water content.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 293
Author(s):  
Jifeng Zhang ◽  
Zhenhua Wang ◽  
Bihang Fan ◽  
Yusheng Hou ◽  
Yunqing Dou ◽  
...  

Xinjiang is one of the most prolific tomato-planting areas in China. Here, we carried out a two-year (2017–2018) field experiment in Xinjiang to study the effects of different nitrogen (N) application rates on the spatial distribution of water and salt in the root zone, as well as their impacts on the yield and quality of tomatoes under mulched drip irrigation. The ideal ranges of N application rates for tomato yield and quality were examined under different salinity levels. Results indicated that soil water content and salinity increased with soil depth. Soil water content was closely related to soil salinity but not to N. Among the tested application rates, tomato yield was highest under the medium-high N (225–300 kg/ha) and low salt (4 g/kg) treatment. Under the highest salt level (10 g/kg), the low nitrogen treatment (150 kg/ha) was better than the high N treatment (300 kg/ha) at boosting tomato yield. Moreover, we found that salinity had a stronger effect on tomato quality than N. Based on these results, we were able to recommend ideal ranges for N (155–201 kg/ha) and salt (3.56–5.59 g/kg) while both are present in the soil.


2020 ◽  
Vol 113 (4) ◽  
pp. 1927-1932
Author(s):  
Cai-hua Shi ◽  
Jing-rong Hu ◽  
You-jun Zhang

Abstract The production of Chinese chives is reduced throughout China due to a root-feeding dipteran pest Bradysia odoriphaga Yang et Zhang (Diptera: Sciaridae), therefore deciphering the conditions influencing its growth and development are important in developing ecological control strategies. A study was conducted from 2014 to 2017 to determine the relationship between the abundance of B. odoriphaga and temperature (atmospheric and soil), soil water content, and atmospheric humidity in a Chinese chive field in Beijing City, China. Numbers of adults peaked in March and October to November and were lowest in July to August and December to next February; numbers of larvae were highest in December to next February and lowest in July to August. From 2014 to 2017, the numbers of adults and larvae were significantly correlated with monthly mean atmospheric temperatures and soil temperatures, but were not significantly correlated with monthly mean atmospheric relative humidity and soil water content. However, for both adults and larvae, numbers were significantly greater with high soil water contents compared with drought treatment. The results of this study suggest that the very low soil water contents, high atmospheric temperatures, and high soil temperatures were critical for regulating field populations of B. odoriphaga.


2013 ◽  
Vol 316-317 ◽  
pp. 464-468
Author(s):  
Yao Lei Wang ◽  
Ping Ting Guan ◽  
Si Wei Jiang ◽  
Xiao Ke Zhang

Applying a combination of classical and geostatistical analysis, we investigated the distribution properties of soil water contents in broad-leaved Korean Pine forest (A) and secondary Polar-Birch forest (B) in Changbai Mountain, Northeast China. The results showed soil water content was significantly different between plots A and B (P < 0.05). The variation coefficient (CV) for soil water content was lower in plot A than in plot B at 0-10 cm depth, while the CV was higher in plot A than in plot B at 10-20 cm depth. Geostatistical analysis revealed that the exponential models were the optimality models for the soil water content in both plots. The spatial structured variance accounted for the largest proportion of total variance in soil water content in both plots. The autocorrelation range value for the semivariogram of soil water content was 8.9 m at 0-10 cm depth and 12.6 m at 10-20 cm depth in plot A, which was more than those in plot B (8.0 m) at both depths. Maps obtained by kriging showed that soil water contents in both plots exhibited different spatial distribution patterns. It could be conclude that the differences of rain time, precipitation form, topography and forest type may contributed to the distribution of soil water content in Changbai Mountain.


Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 825 ◽  
Author(s):  
BJ Bridge ◽  
J Sabburg ◽  
KO Habash ◽  
JAR Ball ◽  
NH Hancock

The dielectric behaviour of 3 soils, a sandy loam (Red Chromosol), a highly structured non-swelling clay (Red Ferrosol), and a self-mulching swelling clay (Black Vertosol), was investigated using a waveguide and network analyser technique in the frequency range 3.0 GHz to 4.5 GHz. Curves relating the real part of the relative permittivity to water content are presented and compared with the general Topp curve. The Chromosol generally followed the Topp curve, but the Ferrosol and Vertosol both had curves below the Topp curve. The Ferrosol showed a maximum horizontal offset of 0.05 m3/m3 from the Topp curve in the mid soil-water content range of 0.2–0.3 m3/m3 offset from the Topp curve of 0.10 m3/m3, with a maximum of 0.12 m3/m3 occurring at a soil water content of 0.4 m3/m3. Similar dielectric curves were obtained for the Chromosol and Vertosol using time domain reflectometry (TDR). With this method, the Chromosol showed very close agreement with the Topp curve, but the Vertosol again gave a curve below the Topp curve, similar to the one obtained using the waveguide and network analyser, but with a smaller maximum horizontal offset of 0.08 m3/m3. The difference between the waveguide and TDR Vertosol curves was mainly attributed to low bulk densities in the waveguide where packing was difficult. Some was also attributed to the wider spectrum of frequencies used by TDR. Use of the Topp curve for TDR measurements in the Vertosol would underestimate its water content by at least 0.06 m3/m3. These results are in good agreement with others obtained from similar soils. Deviations from the Topp curve are attributed to bound water associated with the clay particles and this depends on clay mineralogy and clay content. The presented calibration curves improve the accuracy of TDR measurements in these types of clay soils. A field comparison between water contents measured by TDR and gravimetric sampling in a similar Black Vertosol is presented. This calibration showed that soil water contents can be severely overestimated by using TDR with long probes and cables. This unexpected and opposite result is discussed in terms of attenuated high frequencies in the 15-m-long connecting cable used, errors in depth of probe placement, and changes in bulk density and DC conductivity.


2013 ◽  
Vol 284-287 ◽  
pp. 287-290
Author(s):  
Jie Lun Chiang ◽  
Shih Hao Jien

To provide a simple and fast alternative in measuring soil water content (SWC), a spectrometer was used to detect SWC because of different soil water contents, leading to different reflectance spectrums. Two commonly seen soil types in Taiwan are red soil and younger alluvial soil, which were used as test materials in this study. Fifty red soil samples and 50 younger alluvial soil samples were used as testing samples for comparative study. The root mean square error of SWC estimation of red soil and younger alluvial soil is 3.65 and 7.26, respectively. The results show that the estimation accuracy of red soil is higher than that of younger alluvial soil. The estimation error is random for red soil, and decreases exponentially for younger alluvial soil. Spectrometers have the potential to detect soil water content, especially in red soil. After full development of this technology, remote sensing will be applied to detect soil water content or even water-induced landslides.


Soil Research ◽  
1976 ◽  
Vol 14 (1) ◽  
pp. 67 ◽  
Author(s):  
EKS Nambiar

Effects of water content of the topsoil on root growth and 65Zn absorption by oats were measured. Seminal roots of oats grew through a labelled uptake layer that had been initially wetted to various water contents. The uptake layer was separated from adjacent layers of wet sand or soil by a thin layer of wax. When the uptake layer was wetted initially and allowed to dry during the uptake period, water content affected root growth and 65Zn uptake similarly. 65Zn absorption by unbranched seminal roots decreased linearly as soil water suction increased from 0.3 to 5 bar. Nevertheless significant amounts of 65Zn were absorbed (40% of that from wet soil) even when the soil water suction exceeded 15 bar, with negligible concomitant uptake of water. Provided the roots had access to water in a subjacent layer, rates of 65Zn absorption from dry soil increased with the age of the plants. The exudation of mucilage from the root was enhanced locally where the soil was dry. The mucilage may facilitate the transfer of zinc to the root in dry soil.


1997 ◽  
Vol 77 (4) ◽  
pp. 565-570 ◽  
Author(s):  
Verlan L. Cochran ◽  
Elena B. Sparrow ◽  
Sharon F. Schlentner ◽  
Charles W. Knight

Methane and nitrous oxide are important radiatively active gases that are influenced by agricultural practices. This study assesses long-term tillage, crop residue management, and N fertilization rates on the flux of these two gases at a high latitude site representing the northern fringe of large-scale agriculture. Cumulative methane uptake for the summer was higher from no-tillage plots than tilled plots. This was associated with lower soil water contents with tillage. Thus, the reduction in CH4 uptake was attributed to water stress on methane oxidizers. At planting, soil water contents were near field capacity, and the no-till plots had the lowest uptake which was attributed to restricted diffusion of methane to active sites. A similar pattern of methane uptake to soil water content was found with the residue management treatments. Removing the straw lowered the soil water content and for most of the season methane uptake was also lower than where the straw had been left on the plots. Nitrogen fertilizer rate had little effect on methane uptake over the summer, but high N rates lowered consumption during the time of active nitrification early in the season. This corresponded to the time of maximum efflux of nitrous oxide. Nitrous oxide efflux was greatest at the high N rate where straw was retained on the plots. Key words: Methane, nitrous oxide, nitrification, denitrification, barley


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