Density and Diversity of Rotifers from Shore of a Flood Plain, Balloki Head Works Density & Diversity of Rotifers in Balloki Head Works

The present research work is an investigation of Rotifers from flood plains of Balloki Head Works using diversity indices. Objective: To study the density and diversity of rotifers of flood plain. Methods: collection of rotifers was done from the shore of flood plains from September to July. In total, 15 different species were identified. Rotifers were extracted from soil sample by a customized Baermann Funnel method. A moderate diversity of rotifers was explored by Shannon – Weaver. Simpson index of dominance supported this result. Analysis of variance (ANOVA) showed that there was no significant difference in population density of rotifers among months as the p-value was greater than 5% (α= 0.05). Population density of rotifers was negatively correlated with water temperature and pH whereas a positive correlation was observed with electrical conductivityResults: Overall a moderate diversity was observed. Rotifer density and distribution was under the influence of physico-chemical parameters.

Impacts of Biochar and Tillage Practices on Nitrogen Use Efficiency in Cotton Gossypium Hirsutum L. -Wheat Triticum Aestivum L. Crop Rotation

This study was conducted to evaluated the effects of two tillage treatments [conventional (CT) and reduced tillage (RT)], three biochar treatments [no-biochar, Green waste biochar (GW- 450), and poultry waste biochar (PW-450)], and three N rates (0, 60, and 120 kg ha-1) on productivity and economic profitability of wheat–cotton rotation systems in Multan, Pakistan for two continuous cropping seasons (2014/2015 and 2015/2016) on sandy loam soil. The soil samples were taken and analyzed after the completion second rotation. Reduced tillage and biochar application, supplemented with inorganic N fertilizers led to increased growth, yield, quality, and N uptake and utilization. RT positively impacted the soil physicochemical properties. The RT in combination with biochar increased the soil organic carbon contents. The increase of soil organic carbon leads to soil aggregations which improved the proportion of soil macro aggregates. This result into low bulk density, high porosity and low tensile strength. The presence of soil macro aggregates also facilitates the water infiltration rate. The PW-450 as compared GW-450 showed better response on soil physical properties. The PW- 450 and GW-450 increased the soil organic carbon by 24% and 20% over control, respectively while the increase was 104% and 48% over control for total soil nitrogen in RT plots. The water stable aggregates (WSA) were more all size fractions in RT-PWB than CT-PWB but the increase was more pronounced in 5-8 mm. The macro aggregates were 81% of the soil mass under RT-PWB. Soil under RT had a higher proportion of macro aggregated of 5-8 mm while lower proportion of 2-5, 1-2, 0.5-1, 0.25-0.5 and micro aggregate (≤0.25mm) at 10 cm depth. Despite benefits of biochar application on wheat–cotton rotation system and soil properties, it was not profitable within the two cropping seasons due to higher biochar application rate and price. However, the increased in biomass, grain yield, protein contents and N uptake in 2015/2016 growing season as compare to 2014/2015 indicates the potential for long-term benefit of biochar application. We can conclude from this study that RT and biochar combine application could increase the nitrogen use efficiency with minimizing the N losses under changing climate scenario. The objectives of this mulch study were to determine to what degree conventional mulch materials will affect carbon dioxide and oxygen concentrations in the root zone and gas exchange across the soil-atmosphere interface. We used mesocosms filled with a soil-compost mix and covered their surface with different mulches. The experimental treatments included a no mulch (control), no mulch with biochar mixed into the soil, arborist wood chips mulch, cardboard mulch, landscape fabric mulch, and polyethylene film mulch. The flux of CO2 across the soil-atmosphere boundary was measured with the flow-through chamber method. Concentrations of CO2 and O2 were measured in the mesocosms at two depths (6.5 and 13.5 cm) for a total of 16 days after covering the mesocosms with the mulches. The polyethylene film restricted diffusion of both CO2 and O2 as compared to the other mulches. Diffusion coefficients of CO2 through mulch materials were of the order of 10-3, 10-4, 10-5, and 10-6 cm2 s-1 for wood chips, cardboard, landscape fabric, and polyethylene film, respectively. These results indicate that typical mulches (wood chips, cardboard, landscape fabric, polyethylene film) used in agriculture, nursery, and landscape management, do not cause harmful build ups of CO2 or reductions of O2 concentrations in soil. While mulches reduce CO2 and O2 diffusion across the soil-atmosphere interface, the reduction in diffusion is typically not sufficient to cause significant changes in CO2 and O2 concentrations as compared to a no-mulch condition, with the exception of polyethylene mulch film, where CO2 concentrations in soil can increase by up to an order of magnitude and O2 concentrations decrease by 20%. However, these peak increases of CO2 and decreases O2 concentrations are likely not long-lived in soil, because the diffusion gradients will cause the diffusive fluxes to increase proportionally, leading to less extreme CO2 and O2 concentrations within a few days. Given that our experiments were carried out in sealed systems in the laboratory, and thus represent a worst-case scenario with respect to gas diffusion, the effects of mulches in a field soil, where mulch are punctured and not sealing the soil surface perfectly, will be even less pronounced. Overall, the application of mulches (wood chips, Landscape fabric, cardboard, and polyethylene) will likely not increase and decrease the concentration of CO2 and O2 respectively, to a level that could impair plant root and soil microorganisms activities.