Drying of surface soil decreased Lupinus angustifolius root length and manganese uptake in a split-root experiment

1998 ◽  
Vol 49 (7) ◽  
pp. 1119 ◽  
Author(s):  
W. L. Crabtree ◽  
A. D. Robson ◽  
G. S. P. Ritchie

In a glasshouse, a split-root experiment was used to determine the ability oflupins (Lupinus angustifolius L.) to take up manganese(Mn) from dry soil either when young or at mid-flowering of the primarybranches. Three soil-watering regimes (maintained at field capacity,maintained below wilting point, and alternating from field capacity to wellbelow wilting point) were imposed after taproots had grown through topsoil andinto a nutrient solution below. Four sequential harvests (11, 22, 37, and 49days after sowing) were taken to determine the effect of soil drying on lupingrowth, Mn uptake, and soil-extractable Mn.Soil drying early in the lupin plant's life stopped the growth of lateralroots in the soil and slowed the growth of roots grown in subsoil solution andthe growth of lupin tops. Soil drying decreased uptake of Mn in the tops to13% of that under continuous wet soil conditions. Of the 13%,most (11%) was taken up while the soil was drying. Soil re-wettingenabled the plants to resume uptake of Mn and soil re-drying (just beforeanthesis) decreased the Mn concentration in the lupin stems to 4·8µg/g, whereas stems of lupins grown in the wet and dry soilscontained 10·3 and 3·3 µg/g, respectively. Easilyreducible and plant-available soil Mn were not affected by soil wetting anddrying treatments.This study confirms that the uptake of Mn by lupin may be severely restrictedby drying of surface soil at both the beginning and the end of the lupinplant's life. The decrease in root length rather than the chemical form of Mn restricted Mn uptake.

1992 ◽  
Vol 43 (1) ◽  
pp. 19 ◽  
Author(s):  
KY Chan ◽  
JA Mead

Root growth and distribution of wheat under different tillage practices was studied in a 4-year-old tillage experimental site at Cowra, N.S.W. Tillage affected root density as well as distribution. Up to 98 days after sowing, root length density was lower (P < 0.05) in the 0.05-0.10 m layer of the direct-drilled soil than the conventionally cultivated soil. Poor root growth found in direct-drilled soils, which was significantly related to the poor shoot growth, was not caused by soil physical conditions, viz. higher bulk density and soil strength. Rather, biological factors were involved because fumigation completely eliminated the poor shoot growth and significantly increased root length density of the direct drilled soils. Compared to a compaction treatment, roots grown under direct drilling, in addition to having lower density, also had impaired function. Under conventional cultivation, significantly lower root length density was found in the surface soil layer (0-0.05 m) and maximum root length density was found in the 0-05-0.10 m layer. Fumigation did not change the root distribution pattern. This tillage-induced difference in root distribution reflected less favourable surface soil conditions as a result of cultivation, e.g. seedbed slumping, compared to the soil under direct drilling.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Tekin Öztekin

There are few studies conducted on the short-term effects of land leveling on soil water holding capacity. The objectives of this study were to analyze the short-term effects of land leveling on the magnitudes, variances, spatial variability, and distributions of surface (0–20 cm) and subsurface (20–40 cm) soil properties of bulk density, field capacity, permanent wilting point, water holding capacity and particle size fractions. The study was conducted in a 1.2 ha field with clay loam soil located on the low terraces of Yesilirmak River, Tokat, Turkey. According to the pairedt-test results, water holding capacity, and bulk density significantly increased, while permanent wilting point (P ≤ 0.001) and field capacity (P ≤ 0.05) significantly decreased for surface soil due to land leveling. The reasons for the increases in WHC values in both cut and fill areas (29%, and 12%, resp.) of surface soil are look like the much more decreases in PWP values than those of FC values and the increases in BD values. The moderate positive linear relationship between the surface soil clay contents and cut depths through cut areas (r= 0.64) was also determined in this study.


Soil Research ◽  
1995 ◽  
Vol 33 (2) ◽  
pp. 241 ◽  
Author(s):  
WW Emerson

Samples taken from the two textural phases of the surface soil of an irrigated natrixeralf and its clay subsoil were dried at wilting point and in air. Water retention increased linearly with C content, with values extrapolated to zero C content proportional to clay content. Emerson et al. (1994) (Aust. J. Soil Res., 32, 939-51) had already shown that water held by the surface samples at 10 kPa suction increased approximately linearly with C content, independently of clay content. Similar linear relations were deduced for other soils using values of field capacity and wilting point reported in the literature. A constant amount of water is considered to be held by portions of the silt/clay matrix. As the C content of the soil is increased, polysaccharide gels gradually fill additional 1-3 �m wide pores within the portions. It was calculated that, after a long period in grass, gel present increases available water on a weight basis, by 34% and 125% in loamy sand and sandy clay A horizons respectively. Where farmyard manure (FYM) was incorporated, gel only formed from the added C. Nevertheless the large increase in field capacity of a sandy loam produced by rotavation was temporarily preserved by prior addition of FYM. It is suggested that the gel here was mainly on microbial filaments.


1978 ◽  
Vol 58 (3) ◽  
pp. 369-379 ◽  
Author(s):  
J. L. DIONNE ◽  
A. R. PESANT

Alfalfa (Medicago sativa L. cv. Vernal) and birdsfoot trefoil (Lotus corniculatus L. cv. Leo) were grown under greenhouse conditions in order to determine changes in boron response and availability following variations in soil pH and soil moisture regimes. Three rates of boron applications were selected: 0, 1.5, and 3.0 ppm of B. Soil pH was adjusted to 5.0, 6.5 and 7.5, respectively. The soil moisture regimes were fixed as following: (1) very dry (H1) with soil moisture between 50% of field capacity and wilting point, (2) dry (H2), with soil moisture between field capacity and wilting point. (3) optimum (H3), with soil moisture between field capacity and 70% of this value. Boron fertilization was more useful to alfalfa than to birdsfoot trefoil. Optimum rate was found to be 1.5 ppm of B. On Ste-Rosalie clay, the yield increase due to boron was 22% on soils under the dry regime (H2) but was almost non-existant at the very dry (H1) and optimum water regime (H3). Boron application on Greensboro loam was more efficient on soils undergoing dry (H2) and very dry soil moisture regime (H1) than on soils where moisture conditions were optimum (H3). Dry matter yields were increased by a factor of 10 under dry (H2) and very dry (H1) soil moisture regimes compared to a factor of 4 under optimum soil moisture regime (H3). Under acid soil conditions, no yield increase was obtained following boron applications. Boron availability and response of the two legumes to B was also decreased by overliming soils to pH 7.4. The cyclic drought periods that happened under dry (H2) and very dry (H1) soil moisture regime produced similar effects. Boron availability and efficiency as plant nutrient was greatly reduced, if not annihilated, by the combined effect of repeated drought cycles and by either excessive soil acidity or overliming.


2020 ◽  
Vol 110 (10) ◽  
pp. 1693-1703
Author(s):  
D. R. Cruz ◽  
L. F. S. Leandro ◽  
D. A. Mayfield ◽  
Y. Meng ◽  
G. P. Munkvold

Fusarium graminearum is an important soybean pathogen that causes seedling disease, root rot, and pre- and postemergence damping-off. However, effects of soil conditions on the disease are not well understood. The objective of this greenhouse study was to determine the impacts of soil texture, pH, and soil moisture on seedling root rot symptoms and detrimental effects on seedling development caused by F. graminearum. F. graminearum-infested millet was added (10%, vol/vol) to soil with four different textures (sand, loamy sand, sandy loam, and loam). Soil moisture was maintained at saturation, field capacity or permanent wilting point at soil pH levels of 6 or 8. Seedlings were evaluated 4 weeks after planting for root rot, root length, root and shoot dry weights, leaf area, and F. graminearum colonization (by qPCR). There was a significant interaction between soil moisture and soil texture for root rot assessed visually (P < 0.0001). Highest severity (67%) and amount of F. graminearum DNA were observed at pH 6 and permanent wilting point in sandy loam soils. Pot saturation resulted in the lowest levels of disease in sandy loam and loam soils (11.6 and 10.8%, respectively). Reductions in seedling growth parameters, including root length, foliar area, shoot and root dry weights, and root tips, relative to the noninfested control, were significantly greater in sandy loam soils. In contrast, there were no significant growth reductions in sand. This study showed that levels of root rot increased under moisture-limiting conditions, producing detrimental effects on plant development.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Admas Alemu ◽  
Tileye Feyissa ◽  
Marco Maccaferri ◽  
Giuseppe Sciara ◽  
Roberto Tuberosa ◽  
...  

Abstract Background Genetic improvement of root system architecture is essential to improve water and nutrient use efficiency of crops or to boost their productivity under stress or non-optimal soil conditions. One hundred ninety-two Ethiopian durum wheat accessions comprising 167 historical landraces and 25 modern cultivars were assembled for GWAS analysis to identify QTLs for root system architecture (RSA) traits and genotyped with a high-density 90 K wheat SNP array by Illumina. Results Using a non-roll, paper-based root phenotyping platform, a total of 2880 seedlings and 14,947 seminal roots were measured at the three-leaf stage to collect data for total root length (TRL), total root number (TRN), root growth angle (RGA), average root length (ARL), bulk root dry weight (RDW), individual root dry weight (IRW), bulk shoot dry weight (SDW), presence of six seminal roots per seedling (RT6) and root shoot ratio (RSR). Analysis of variance revealed highly significant differences between accessions for all RSA traits. Four major (− log10P ≥ 4) and 34 nominal (− log10P ≥ 3) QTLs were identified and grouped in 16 RSA QTL clusters across chromosomes. A higher number of significant RSA QTL were identified on chromosome 4B particularly for root vigor traits (root length, number and/or weight). Conclusions After projecting the identified QTLs on to a high-density tetraploid consensus map along with previously reported RSA QTL in both durum and bread wheat, fourteen nominal QTLs were found to be novel and could potentially be used to tailor RSA in elite lines. The major RGA QTLs on chromosome 6AL detected in the current study and reported in previous studies is a good candidate for cloning the causative underlining sequence and identifying the beneficial haplotypes able to positively affect yield under water- or nutrient-limited conditions.


2021 ◽  
pp. 44-57
Author(s):  
Kh. A. Shaban ◽  
M. A. Esmaeil ◽  
A. K. Abdel Fattah ◽  
Kh. A. Faroh

A field experiment was carried out at Khaled Ibn El-waleed village, Sahl El-Hussinia, El-Sharkia Governorate, Egypt, during two summer seasons 2019 and 2020 to study the effect of NPK nanofertilizers, biofertilizers and humic acid combined with or without mineral fertilizers different at rates on some soil physical properties and soybean productivity and quality under saline soil conditions. The treatments consisted of: NPK-chitosan, NPK-Ca, humic acid, biofertilzer and control (mineral NPK only). In both seasons, the experiment was carried out in a split plot design with three replicates. The results indicated a significant increase in the soybean yield parameters as compared to control. There was also a significant increase in dry and water stable aggregates in all treatments as compared to control. The treatment NPK-Chitosan was the best in improving dry and stable aggregates. Also, hydraulic conductivity and total porosity values were significantly increased in all treatments due to increase in soil aggregation and porosity that led to increase in values of hydraulic conductivity. Values of bulk density were decreased, the lowest values of bulk density were found in NPK-chitosan treatment as a result of the high concentration of organic matter resulted from NPK-chitosan is much lighter in weight than the mineral fraction in soils. Accordingly, the increase in the organic fraction decreases the total weight and bulk density of the soil. Concerning soil moisture constants, all treatments significantly increased field capacity and available water compared to control. This increase was due to improvement of the soil aggregates and pores spaces which allowed the free movement of water within the soil thereby, increasing the moisture content at field capacity.


1998 ◽  
Vol 25 (3) ◽  
pp. 353 ◽  
Author(s):  
C.R. Jensen ◽  
V.O. Mogensen ◽  
H.-H. Poulsen ◽  
I.E. Henson ◽  
S. Aagot ◽  
...  

Drought responses in leaves of lupin (Lupinus angustifolius L., cv. Polonez) were investigated in plants grown in lysimeters either in a sand or in a loam soil in the field. Abscisic acid (ABA) content, water potential (ψl) and conductance to water vapour (gH2O) were determined in leaves of both irrigated plants and in plants exposed to gradual soil drying. Amorning-peak of leaf ABA content was found in both fully watered and droughted plants. During soil drying which, on both soils types, only decreased soil water potential of the upper soil layers, mid-day leaf ABA content increased relative to that in fully irrigated plants before any appreciable decreases occurred in ψl. In the part of the soil profile from which water was taken up (0–60 cm depth), gH2O decreased when the relative available soil water content (RASW) on sand was below 12% and RASW on loam, below 30%. At this point the average soil water matric potential (ψsoil) on sand was less than –0.13 MPa and the fraction of roots in ‘wet’ soil was 0.12, while on loam, the fraction of roots in ‘wet’ soil was 0.44 while y soil was similar to that on sand. A critical leaf ABA content of 300–400 ng/g FW was associated with the onset of stomatal closure on both soil types. We suggest that the initial stomatal closure is controlled by ABA which originates from the roots where its production is closely related to ψsoiland the water potential of the root surface and that ψsoil is a more important parameter than RASW or the fraction of roots in ‘wet’ soil for affecting leaf gas exchange. Further drying on both soils led to further increases in leaf ABA and declines in ψl and gH2O. In order to gain further insight, experiments should be designed which combine signalling studies with simulation studies, which take account of soil water potential, root contact area and water flux when calculating the water status at the root surface in the soil-plant-atmosphere-continuum.


2003 ◽  
Vol 40 (1) ◽  
pp. 127-138 ◽  
Author(s):  
D. J. NIXON ◽  
L. P. SIMMONDS

There are currently concerns within some sugar industries that long-term monoculture has led to soil degradation and consequent yield decline. An investigation was conducted in Swaziland to assess the effects of fallowing and green manuring practices, over a seven-month period, on sugarcane yields and the physical properties of a poorly draining clay soil. In the subsequent first sugarcane crop after planting, yields were improved from 129 t ha−1 under continuous sugarcane to 141–144 t ha−1 after fallowing and green manuring, but there were no significant responses in the first and second ratoon crops. Also, in the first crop after planting, root length index increased from 3.5 km m−2 under continuous sugarcane to 5.2–6.8 km m−2 after fallowing, and improved rooting was still evident in the first ratoon crop where there had been soil drying during the fallow period. Soil bulk density, total porosity and water-holding capacity were not affected by the fallowing practices. However, air-filled porosity increased from 11 % under continuous sugarcane to 16% after fallowing, and steady state ponded infiltration rates were increased from 0.61 mm h−1 to 1.34 mm h−1, but these improvements were no longer evident after a year back under sugarcane. Levels of soil organic matter were reduced in all cases, probably as a result of the tillage operations involved. In the plant crop, root length was well correlated with air-filled porosity, indicating the importance of improving belowground air supply for crop production on poorly draining clay soils.


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