Effects of Buried Wood on the Development of Populus tremuloides on Various Oil Sands Reclamation Soils

Buried wood is an important but understudied component of reclamation soils. We examined the impacts of buried wood amounts and species on the growth of the common reclamation tree species trembling aspen (Populus tremuloides). In a greenhouse study, aspen seedlings were planted into four soil types, upland derived fine forest floor-mineral mix (fFFMM), coarse forest floor-mineral mix (cFFMM), and lowland derived peat and peat-mineral mix (PMM), that were mixed with either aspen or pine wood shavings at four concentrations (0%, 10%, 20% and 50% of total volume). Height and diameter growth, chlorophyll concentration, and leaf and stem biomass were measured. Soil nutrients and chemical properties were obtained from a parallel study. Buried wood primarily represents an input of carbon to the soil, increasing the C:N ratio, reducing the soil available nitrogen and potentially reducing plant growth. Soil type had the largest impact on aspen growth with fFFMM = peat > PMM > cFFMM. Buried wood type, i.e., aspen or pine, did not have an impact on aspen development, but the amount of buried wood did. In particular, there was an interaction between wood amount and soil type with a large reduction in aspen growth with wood additions of 10% and above on the more productive soils, but no reduction on the less productive soils.

Effects of Soil Physico-Chemical Properties on Plant Species Composition and Diversity Along an Elevation Gradient Over Alpine Grassland on the Qinghai-Tibetan Plateau, China

Background and aims Alpine grassland on the Qinghai-Tibetan Plateau (QTP) is sensitive and fragile, and it is subject to serious degradation. It is essential to determine the effects of soil parameters on plant species to explain grassland degradation. Methods We classified plant communities into six types based on hierarchical clustering. Then we analyzed the effects of soil physico-chemical properties on plant species composition and diversity by canonical ordination and spatial regression from an elevation perspective. Results Elevation class had significant effects on soil moisture content, soil pH, and soil available nitrogen content. The primary soil parameter affecting plant species composition and diversity in alpine grassland was soil available nitrogen content. The effect of soil available nitrogen content on plant species richness varied at different elevations. For Gramineae plants (G), plant species richness declined with the increase in soil available nitrogen content at low elevation, but rose at middle elevation. Soil available nitrogen content had a more significant limiting effect on species richness at high elevation. Conclusion Analyzing the relationship between plant species and soil physico-chemical properties increases our understanding of grassland degradation, and will improve grassland restoration programs and responses to climate change.

EFFECT OF FULZYME FERTILIZER, RICE RESIDUES AND DAP ON AVAILABLE OF SOME NUTRIENTS FOR THE SOIL OF BUDDED APRICOT SEEDLINGS PRUNUS ARMENIACA L. CV. "ZAGHINIA"

The study was conducted in the nursery of Hort. Dept., College of Agriculture and Forestry, Mosul University, Iraq, during 2018 season to study the response of budded "Zaghinia" apricot on seedlings rootstock to bio, organic and chemical fertilizers, and their effects on seedling growth. The studied factors were as follows: Bio fertilizer Fulzyme (0,1and 2 g. seedling-1 ), organic fertilizer (Rice residue) (0, 1 and 2 kg. seedling-1 ) and DAP fertilizers (0, 5 and 10 g. seedling-1 ). The study was performed by using split-split plots within factorial experiment in randomized complete block design (RCBD), with 3 factors and 3 replicates, by using 6 seedlings for each treatment. Treatment means were compared by using Duncan multiple levels at 5% p. the most important results obtained were as follows: 1 and 2 gm.seedling-1 of bio fertilizer (Fulzyme) and Chemical fertilizer (DAP) at the levels 5 and 10 g. seedling-1 affected significantly resulted in a significant increase in soil available nitrogen, while the addition of organic fertilizer (rice residues) and for both levels 1 and 2 kg. Seedling-1 gave a significant increase in nitrogen, phosphorus, ready-made potassium and pH of the seedling soil, and the bilateral interaction had a significant role in the growth of seedlings, especially the treatment of the interaction between the fertilizer (Fulzym) and organic fertilizer (Rice residues), which have a significant effect in giving the best results in available nitrogen, phosphorus and potassium in the soil, and the triple interference also gave a significant increase in all studied traits.

Effect of Applying Organic Amendments and Chickpea Integration on Soil Chemical Properties in Different Cropping Systems in Central Kenya

A study was carried out to determine the effect of applying farm yard manure (FYM) and Minjingu rock phosphate (MRP) on soil available nitrogen, phosphorus and organic carbon. The study involved field experiments under varying precipitation pattern, soil fertility levels and cropping systems over four growth seasons. The experimental design was a randomized complete block (RCBD) with four replications in a split plot arrangement where the main plots were the three cropping systems; monocropping, intercropping and crop rotation and the split plots were FYM and MRP and sampling done at crop physiological maturity. Soil pH, N, P K and C increased in the different treatments in the following order control < MRP < FYM in the three cropping systems across the four growing seasons at both sites. In maize under rotation with chickpea control had; 0.281% N, 2.82% C and 10.68 ppm P. FYM; 0.554% N, 4.41% C and18.24 ppm P. MRP; 0.45% N, 3.6% C and 41.08 ppm P. Maize chickpea intercrop control; 0.389% N, 3.192% C and 13.4 ppm P. FYM; 0.531% N, 4.98% C and 41.02 ppm P. MRP; 0.49% N, 4.08% C and 50.9 ppm P. Soil under maize monocrop exhibited; control; 0.2% N, 2.59% C and11.26 ppm P. FYM; 0.416% N, 3.83% C and 18.01 ppm P. MRP; 0.28% N, 3.13% C and 26.1ppm P. Almost a similar trend was observed in maize and tomato plots at both sites in all the growing seasons. Thus it can be deduced that, FYM and MRP application and legume integration in cropping systems improves soil fertility.