Root Response to Water Stress in Rainfed Lowland Rice

1990 ◽  
Vol 26 (3) ◽  
pp. 287-296 ◽  
Author(s):  
M. Thangaraj ◽  
J. C. O'Toole ◽  
S. K. De Datta
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Root Length Density ◽  
Soil Layer ◽  
Sprinkler Irrigation ◽  
Mechanical Impedance ◽  
Field Studies ◽  
Soil Drying ◽  
Rainfed Lowland ◽  
Response To Water

SUMMARYThe relation between soil mechanical impedance as a result of soil drying, and root system growth (mass and length density) of rice was investigated in greenhouse and field studies. In a greenhouse experiment, soil drying for 16 days increased mechanical impedance in the 0–20 cm soil layer from near 0 to 2.5 MPa, and decreased root growth by 47% compared to the continuously flooded control. Root length density decreased with decreasing soil moisture and increasing soil mechanical impedance. In a lowland field experiment using a sprinkler irrigation gradient treatment for 19 days during the vegetative growth stage, soil mechanical impedance as low as 0.01 MPa inhibited root growth while values greater than 0.3–0.5 MPa decreased root growth and extension by 75%. The relative loss of potential root growth was continued after reflooding. Root length density, measured at flowering, was linearly related to yield.

Tillage-induced differences in the growth and distribution of wheat-roots

1992 ◽  
Vol 43 (1) ◽  
pp. 19 ◽  
Author(s):  
KY Chan ◽  
JA Mead
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Root Distribution ◽  
Shoot Growth ◽  
Surface Soil ◽  
Root Length Density ◽  
Soil Layer ◽  
Soil Conditions ◽  
The Poor ◽  
Direct Drilling

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.

Root characteristics of vigorous wheat improve early nitrogen uptake

2006 ◽  
Vol 57 (10) ◽  
pp. 1097 ◽  
Author(s):  
Mingtan Liao ◽  
Jairo A. Palta ◽  
Ian R. P. Fillery
Keyword(s):  
Root Growth ◽  
Soil Profile ◽  
Root Length ◽  
Root Length Density ◽  
Stem Elongation ◽  
N Uptake ◽  
Soil Layer ◽  
Mapping Technique ◽  
Genotypic Differences ◽  
Root Characteristics

Root growth is important for the acquisition of nitrogen (N) and water in deep sandy soil profiles with high leaching potential. Root growth characteristics and the N uptake of wheat genotypes differing in early vigour were investigated in 2 glasshouse experiments. In both experiments the vigorous breeding lines Vigor18 and B18 and the well-adapted commercial cultivar Janz were grown in glass-walled growth boxes in a controlled-temperature glasshouse up to the onset of stem elongation. In Expt 1, rooting parameters and detailed measurements of root growth and proliferation were made at 2-day intervals using a root mapping technique. In Expt 2 the glass-walled growth boxes were segmented into upper (0–0.2 m), middle (0.2–0.7 m), and bottom (0.7–1.0 m) soil layers, and the contribution of N fertiliser uptake by roots from each soil layer to the total plant N uptake was determined by applying 15N-urea to a single soil layer each time. The accumulated total root length across the soil profile from the 1-leaf stage to the onset of stem elongation was 33–83% higher in the vigorous lines Vigor18 and B18 than in Janz. The roots of the 3 genotypes grew vertically down the soil profile at a similar rate, but the roots of vigorous lines branched earlier and grew horizontally faster and more extensively than those of cv. Janz, resulting in a greater root-length density and root number in the top 0.7-m soil layer. Uptake of N fertiliser by roots in the upper 0–0.2 m of the soil profile was 60–68% higher in the vigorous lines than in Janz. Roots of the vigorous lines located in the segment 0.2–0.7 m of the soil profile captured twice as much N fertiliser than those of Janz. Uptake of N fertiliser by roots in the lower 0.7–1.0 m of the soil profile was similar in the vigorous lines and Janz. This indicates that the early and more extensive horizontal growth of the roots in the 0.2–0.7 m of the soil profile was responsible for the superior uptake of N by the vigorous lines. The implications of these genotypic differences in root growth and proliferation and their relationship with the early acquisition of N are discussed with emphasis on their role in improving the efficiency of N fertiliser uptake and reducing nitrate leaching, particularly in the sandy soils of the Mediterranean climatic region of Australia.

scholarly journals Pre-Sowing Irrigation Plus Surface Fertilization Improves Morpho-Physiological Traits and Sustaining Water-Nitrogen Productivity of Cotton

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 772
Author(s):  
Zongkui Chen ◽  
Hongyun Gao ◽  
Fei Hou ◽  
Aziz Khan ◽  
Honghai Luo
Keyword(s):  
Nitrate Reductase ◽  
Root Growth ◽  
Root Length ◽  
Crop Production ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Soil Layer ◽  
Dry Mass ◽  
Cotton Production ◽  
Nitrogen Productivity

The changing climatic conditions are causing erratic rains and frequent episodes of moisture stress; these impose a great challenge to cotton productivity by negatively affecting plant physiological, biochemical and molecular processes. This situation requires an efficient management of water-nutrient to achieve optimal crop production. Wise use of water-nutrient in cotton production and improved water use-efficiency may help to produce more crop per drop. We hypothesized that the application of nitrogen into deep soil layers can improve water-nitrogen productivity by promoting root growth and functional attributes of cotton crop. To test this hypothesis, a two-year pot experiment under field conditions was conducted to explore the effects of two irrigation levels (i.e., pre-sowing irrigation (W80) and no pre-sowing irrigation (W0)) combined with different fertilization methods (i.e., surface application (F10) and deep application (F30)) on soil water content, soil available nitrogen, roots morpho-physiological attributes, dry mass and water-nitrogen productivity of cotton. W80 treatment increased root length by 3.1%–17.5% in the 0–40 cm soil layer compared with W0. W80 had 11.3%–52.9% higher root nitrate reductase activity in the 10–30 cm soil layer and 18.8%–67.9% in the 60–80 cm soil layer compared with W0. The W80F10 resulted in 4.3%–44.1% greater root nitrate reductase activity compared with other treatments in the 0–30 cm soil layer at 54–84 days after emergence. Water-nitrogen productivity was positively associated with dry mass, water consumption, root length and root nitrate reductase activity. Our data highlighted that pre-sowing irrigation coupled with basal surface fertilization is a promising option in terms of improved cotton root growth. Functioning in the surface soil profile led to a higher reproductive organ biomass production and water-nitrogen productivity.

Root depth of native and sown perennial grass-based pastures, North-West Slopes, New South Wales. 1. Estimates from cores and effects of grazing treatments

2006 ◽  
Vol 46 (3) ◽  
pp. 337 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Mass Density ◽  
Perennial Grass ◽  
Soil Layer ◽  
Volume Density ◽  
Root Mass ◽  
Root Depth ◽  
Root Volume ◽  
Native Pasture

Studies were undertaken on native and sown perennial grass-based pastures as part of the Sustainable Grazing Systems National Experiment to estimate root depth and describe root distribution in these pastures. Samples from soil cores (0–210 cm maximum sampling depth) taken in 1997 (before grazing treatments were imposed) and 4 years later in spring 2001 were used to examine the effects of different grazing regimes on root length density (cm/cm3), root mass density (mg/cm3), root volume density (cm3/cm3), and diameter (mm) at each of 3 sites. In spring 1997, mean maximum root depth was 107 cm for a native perennial grass pasture near Barraba and 74 cm for a pasture sown with phalaris (Phalaris aquatica) and subterranean clover (Trifolium subterraneum) near Nundle, with values being lower for a native pasture near Manilla (65 cm for a Brown Vertosol and 97 cm for a Red Chromosol). For all pasture types, >20% of root mass density, root length density or root volume density was in the 0–5 cm soil layer and >60% was at a depth of 0–30 cm. At all sites, mean total root mass was around 1000 kg DM/ha. After 4 years of grazing (spring 2001) there were relatively few significant effects of grazing treatment on root length density, root mass density, root volume density, or root diameter. Effects that were significant mostly occurred at 0–5 cm for the native pastures and 0–50 cm for the sown pasture. For the Barraba native pasture, root length, volume and mass densities (0–5 cm) were higher (P<0.05) in the continuously grazed, low stocking rate treatment compared with all other treatments. Similarly, for the Manilla native pasture, root length density was higher (P<0.05) in this treatment at soil depths of 0–5 and >5–10 cm compared with all other treatments. In contrast, for the Nundle sown pasture, root length density (0–5 cm) was lowest (P<0.05) in 2 continuously grazed treatments compared with those that were strategically grazed in autumn and spring.

Associations Between Productivity, Root Growth and Carbon Isotope Discrimination in Phaseolus vulgaris Under Water Deficit

1990 ◽  
Vol 17 (2) ◽  
pp. 189 ◽  
Author(s):  
JW White ◽  
JA Castillo ◽  
J Ehleringer
Keyword(s):  
Phaseolus Vulgaris ◽  
Gas Exchange ◽  
Root Growth ◽  
Water Deficit ◽  
Root Length ◽  
Root Length Density ◽  
Crop Growth ◽  
Cultivar Differences ◽  
Rooting Depth ◽  
Rainfed Conditions

Recent theoretical and empirical studies have indicated that isotopic discrimination against 13C (Δ) during photosynthesis in C3 plants reflects variation in intercellular CO2 concentration (ci). Under water deficit, cultivar differences in Δ may indicate differences in leaf gas exchange characteristics. Cultivar differences in Δ may also result indirectly from genetic variation in root characteristics affecting the level of water stress experienced by the canopy. Differences in root growth affecting the degree of dehydration postponement could prolong gas exchange activity and the maintenance of relatively high ci and Δ. To evaluate relations between root growth, productivity and Δ in common bean (Phaseolus vulgaris L.), Δ and crop growth parameters, including biomass production, grain yield and root length density, were determined for ten bean genotypes grown under rainfed conditions at two sites in Colombia which differed primarily in soil fertility and effective rooting depth. The 10 genotypes were also grown under irrigation at the more fertile site. Under rainfed conditions, root length density was positively correlated with Δ in the fertile Mollisol at Palmira, and was also positively correlated with Δ in the infertile Oxisol at Quilichao if one possibly abberent genotype was excluded. At Palmira, reduced crop growth and seed yield were associated with low Δ values. At Quilichao, intermediate Δ values were associated with the greatest growth and yield. Under irrigation at Palmira there was no association between growth or yield and Δ.

An evaluation of the minirhizotron technique for estimating root distribution in potatoes

1991 ◽  
Vol 116 (3) ◽  
pp. 341-350 ◽  
Author(s):  
C. J. Parker ◽  
M. K. V. Carr ◽  
N. J. Jarvis ◽  
B. O. Puplampu ◽  
V. H. Lee
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Root Length Density ◽  
Quantitative Measure ◽  
Total Root Length ◽  
Root Tips ◽  
Core Sampling ◽  
Glass Tubes ◽  
Poor Soil ◽  
Made In

SUMMARYThe minirhizotron technique was evaluated for estimating root length density in potatoes (Solanum tuberosum‘Record’) by comparing observations in angled 45° glass tubes with corresponding root length densities obtained by (a) destructive core sampling, and from (b) counts of root tips on the soil face of excavated trenches. Measurements were made in a field experiment in Bedfordshire, UK, in 1985, with shallow and deep cultivation as variables, and in a glasshouse trial.Only at depths below 0·3 m did root lengths observed with minirhizotrons reflect at all closely those estimated from core sampling and even then there was a tendency to overestimate root density. In the surface cultivated layers, where 80–90% of the total root length was present, results from minirhizotrons were unreliable, probably because of poor soil–tube contact and, in soils which shrink on drying, preferential root growth at the interface between the soil and the glass.Minirhizotrons can provide a realistic estimate of the rate of root growth of potatoes with depth over time when compared with maximum depths of water extraction, but appear to be unreliable for providing a quantitative measure of total root length density.

scholarly journals Root growth dynamics and productivity of quinoa (Chenopodium quinoa Willd.) in response to fertilization and soil tillage

2019 ◽  
Vol 31 (2) ◽  
pp. 285-299 ◽  
Author(s):  
Ioanna P. Kakabouki ◽  
Ioannis Roussis ◽  
Dimitra Hela ◽  
Panayiota Papastylianou ◽  
Antigolena Folina ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Length Density ◽  
Mass Density ◽  
Soil Aggregates ◽  
Soil Layer ◽  
Chenopodium Quinoa ◽  
Total Porosity ◽  
Soil Tillage ◽  
Sheep Manure ◽  
Applied Nitrogen

AbstractQuinoa is a gluten-free pseudocereal crop recognized for its exceptional nutritional properties. A 3-year field experiment was conducted to evaluate the influence of soil tillage and fertilization on root growth and productivity of quinoa. The experiment was laid out in a split-plot design with two replicates, two main plots [conventional (CT) and minimum tillage (MT)] and four sub-plots [fertilization treatments: untreated, inorganic fertilization with 100 (N1) and 200 kg N ha−1 (N2), and sheep manure]. Mean weight diameter (MWD) of soil aggregates, total porosity, organic matter and soil total nitrogen increased with the long-term fertilization with sheep manure. The major part of the roots (approximately 70%) is concentrated in the 0-30 cm soil layer. Root length density increased with increased rate of applied nitrogen, and a higher value (1.172 cm cm−3) was found in N2 plots. Additionally, higher root mass density (1.114 mg cm−3) was observed under MT. Plant height and dry weight were clearly affected by fertilization, with higher values obtained in N2 plots. Moreover, it was observed that quinoa cultivated under CT and N2 treatment produced a higher seed yield (2595 kg ha−1). As a conclusion, increasing the levels of applied nitrogen up to 200 kg N ha−1 improves root growth and consequently the yields of quinoa.

scholarly journals ROOT GROWTH OF CHINESE JUNIPER DURING THE FIRST THREE YEARS AFTER PLANTING

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1064e-1064 ◽  
Author(s):  
Edward F. Gilman ◽  
Michael E. Kane
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Length ◽  
Root Length Density ◽  
Root Diameter ◽  
Root Weight ◽  
Root Area ◽  
Black Plastic ◽  
Shoot Weight ◽  
Root Spread

Shoot and root growth were measured on Chinese juniper (Juniperus chinensis L.) Var. `Torulosa', `Sylvestris', `Pfitzeriana' and `Hetzii' 1, 2 and 3 years after planting into a simulated landscape from 10-liter black plastic containers. Mean diameter of the root system increased quadratically averaging 1, 2 m/year; whereas, mean branch spread increased at 0, 33 m/year, Three years after planting, root spread was 2, 75 times branch spread and roots covered an area 5.5 times that covered by the branches. Percentage of total root length located within the dripline of the plants remained fairly constant (71-77%) during the first 3 years following planting. Root length density per unit area increased over time but decreased with distance from the trunk. In the first 2 years after planting shoot weight increased faster than root `weight. However, during the third year after planting, the root system increased in mass and size at a faster rate than the shoots. Root length was correlated with root weight within root-diameter classes, Root spread and root area were correlated with trunk area, branch spread and crown area.

scholarly journals Effect of nitrogen fertilization on maize yield responses to soil microbial activity and root length density in the North China Plain

2021 ◽  
Vol 237 ◽  
pp. 01042
Author(s):  
Qiuhua Li ◽  
Jingjing Sun ◽  
Jun Yao ◽  
Qunhui Wang
Keyword(s):  
Microbial Activity ◽  
Root Length ◽  
Root Length Density ◽  
Soil Layer ◽  
Maize Yield ◽  
Soil Microbial Activity ◽  
N Fertilizer ◽  
Soil Microbial ◽  
The North ◽  
N Fertilizer Rate

A maize field experiment in the North China Plain was conducted to understand the effect of different N fertilizer rate on the yield of maize, using soil microbial activity and root length density (RLD) as performance parameters, due to their possibility to enhance productivity. The four N fertilizer rates were 0 (N0), 120 (N120), 210 (N210) and 300 (N300) kg N hm-2. The results indicated that nitrogen (N) fertilizer had a significant influence not only on yield (p<0.05), but also on root length density (p<0.05) and soil microbial activity (p<0.05). In addition, the soil microbial activity and RLD were significantly related with maize yield. RLD differences were generally evident within the 100 cm soil layer, whereas there was no difference in the deeper soil under different N treatments. The most RLD concentrated in 0-60cm soil layer under N0, N120 and in 0-90cm soil layer under N210, N300. The microbial growth rate constant (k) was greater in N210 than other treatments. Generally, N fertilizer application can stimulate root growth and microbial activity, meanwhile, they can interact with each other, heighten the availability of N fertilizer in soil, thus enhanced yield of maize. According to our study, 210 kg N hm-2 was the optimum N fertilizer rate to achieve maximum yield and sustain the soil productivity.

scholarly journals Effects of tillage on soil physical properties and root growth of maize in loam and clay in central China  

2013 ◽  
Vol 59 (No. 7) ◽  
pp. 295-302 ◽  
Author(s):  
B. Ji ◽  
Y. Zhao ◽  
X. Mu ◽  
K. Liu ◽  
C. Li
Keyword(s):  
Root Growth ◽  
Water Content ◽  
Bulk Density ◽  
Root Length ◽  
Root Length Density ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Conventional Tillage ◽  
Central China ◽  
Deep Tillage

Subsoil compaction can result in unfavourable soil physical conditions and hinder the root growth of maize. The effects of deep tillage and conventional tillage on soil physical properties and root growth of maize were studied during 2010&ndash;2011 at two sites (loam at Hebi and clay at Luohe) in central China. The results showed that soil penetration resistance, bulk density, water content and root length density were significantly affected by tillage, soil depth and year. Deep tillage had lower penetration resistance and lower soil bulk density, but higher soil water content than conventional tillage across years and depths. Averaged over the whole soil profile, deep tillage not only significantly decreased penetration resistance and soil bulk density, but significantly increased soil water content and root length density on loam, while deep tillage only significantly increased the root length density on clay. We conclude that deep tillage on the loam is more suitable for the root growth of summer maize.

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