Comparison of Fine Root Biomass under Grevillea robusta and Juniperus procera in Gera Indigenous Agro- forestry systems, Southwest Ethiopia (original) (raw)
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Growth Dynamics following Planting of Cultivars of Juniperus chinensis
Journal of the American Society for Horticultural Science, 1991
Shoot and root growth were measured on Chinese juniper (Juniperus chinensis L. `Torulosa', `Sylvestris', `Pfitzeriana', and `Hetzii') 1, 2, and 3 years after planting from 1l-liter black plastic containers. Mean diameter of the root system expanded quadratically, whereas mean branch spread increased linearly. 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 for each cultivar during the 3 years following planting. Root length density increased over time but decreased with distance from the trunk. During the first 2 years after planting, shoot mass increased faster than root mass. In the 3rd year, the root system increased in mass at a faster rate than the shoots. Root length was correlated with root weight. Root spread and root area were correlated with trunk cross-sectional area, bran...
Plant and Soil, 2000
Complementarity in the distribution of tree and crop root systems is important to minimise competition for resources whilst maximising resource use in agroforestry systems. A field study was conducted on a kaolinitic Oxisol in the sub-humid highlands of western Kenya to compare the distribution and dynamics of root length and biomass of a 3-year-old Grevillea robusta A. Cunn. ex R. Br. (grevillea) tree row and a 3-year-old Senna spectabilis DC. (senna) hedgerow grown with Zea mays L. (maize). Tree roots were sampled to a 300 cm depth and 525 cm distance from the tree rows, both before and after maize cropping. Maize roots were sampled at two distances from the tree rows (75–150 cm and 450–525 cm) to a maximum depth of 180 cm, at three developmental stages. The mean root length density (Lrv) of the trees in the upper 15 cm was 0.55 cm cm−3 for grevillea and 1.44 cm cm−3 for senna, at the start of the cropping season. The Lrv of senna decreased at every depth during the cropping season, whereas the Lrv of grevillea only decreased in the crop rooting zone. The fine root length of the trees decreased by about 35% for grevillea and 65% for senna, because of maize competition, manual weeding, seasonal senescence or pruning regime (senna). At anthesis, the Lrv of maize in the upper 15 cm was between 0.8 and 1.5 cm cm−3. Maize root length decreased with greater proximity to the tree rows, potentially reducing its ability to compete for soil resources. However, the specific root length (m g−1) of maize was about twice that of the trees, so may have had a competitive uptake advantage even when tree root length was greater. Differences in maize fine root length and biomass suggest that competition for soil resources and hence fine root length may have been more important for maize grown with senna than grevillea.
Current science, 2022
Fine roots (diameter less than 2 mm) comprise a significant portion of the plant biomass. They are important for water absorption, cycling of nutrients and the carbon budget on a global scale. The aim of the present study was to quantify fine root biomass in the Nainital district, Central Himalaya, India, which has several dominant forest types. A total of 81 samples were collected from nine sample plots for each forest type in three distinct directions. The results showed that sal forest (1.11 0.04 t ha-1) had the largest fine root biomass, followed by oak forest (0.72 0.06 t ha-1) and pine forest (0.61 0.06 t ha-1). We observed that the trend in fine root biomass across different forest types was as follows: sal forest > oak forest > pine forest, significant at 0.05 level. Fine root biomass was also observed to decrease similarly with increasing soil depth in each forest type, following the trend: 0-20 cm > 20-40 cm > 40-60 cm, which was significant at 0.05 level. Researchers will benefit from this study since it will help them comprehend fine root biomass variation and offer baseline data for future research on nutrient cycling and the global carbon budget.
Plant Ecology, 1996
Seasonal variation and depthwise distribution of dry matter in roots of different diameter classes and their annual production were studied using sequential core sampling. The investigations were carried out in three stands of a subtropical humid forest of north-east India representing different stages of regrowth after tree cutting. The mean annual standing crop of fine (<2 mm in diameter) and coarse (2–15 mm diameter) roots increased gradually from 5.4 Mg ha-1 and 0.7 Mg ha-1 in 7-yr old regrowth to 9.4 Mg ha-1 and 2.8 Mg ha-1 in 16-yr old regrowth, respectively. The contribution of fine roots to the total root mass declined from 88% in 7-yr old regrowth to 77% in both 13 and 16-yr old regrowths, while that of coarse roots increased from 12 to 23%. A major portion of fine roots (59–62%) was present in 0–10 cm soil layer, but the coarse roots were concentrated in 10–20 cm soil depth (38–48%). In all the three stands, biomass of both fine and coarse roots followed a unimodal growth curve by showing a gradual increase from spring/pre-rainy season to autumn/post-rainy season. Biomass to necromass ratio increased from 2.5 in the 7-yr old to 3.2 in the 16-yr old stand. The annual fine root production increased from 5.9 Mg ha-1 to 7.7 Mg ha-1 and total root production from 7.6 Mg ha-1 to 14.7 Mg ha-1 from 7-yr to 16-yr old regrowth.