High tolerance to simulated root herbivory in hydroponically grown cuttings of Salix phylicifolia

The shortage of information regarding the effects of root damage on forest plants, especially trees and shrubs, is the most critical gap in our knowledge of belowground insect herbivory. This study examines how the tea-leaved willow, Salix phylicifolia, responds to simulated root herbivory and how nutrient availability affects these responses. Hydroponically grown cuttings were used to precisely apply the desired levels of root damage. Root: shoot ratios increased proportionally to the intensity of root damage, whereas specific leaf area, leaf water content and chlorophyll fluorescence were not affected. The removal of 2–64% of roots once in early summer and the removal of 25% of roots three times during the summer did not change biomass production by cuttings. The repeated removal of 50 and 75% of roots decreased shoot biomass and, to a lesser extent, total root production. The tolerance of tea-leaved willow to root damage was greater in low nutrient treatment than in high nutrient treatment, thus supporting the Growth Rate Model. According to this model, in low resource conditions plants do not attain their maximum growth rate and therefore have a higher capacity for regrowth after damage. We conclude that, in the absence of water limitations, tea-leaved willow shows high tolerance to root losses and is unlikely to be affected by realistic levels of root herbivory.

Effects of nutrient availability and light intensity on the sterol content of Saccharina latissima (Laminariales, Phaeophyceae)

Seaweed phytosterols are associated with potential health benefits, affording them and the seaweeds that produce them commercial interest. However, little is known about how their production is affected by the cultivation environment, limiting the efficiency with which these compounds can be exploited. Therefore, we performed a pilot study on the effect of nutrient availability and light stress on the sterol content of Saccharina latissima, a rapid growing brown alga of increasing interest in western mariculture. Individuals of S. latissima were subjected to a nutrient-replete and nutrient-depleted regime for 5 weeks, followed by the introduction of light-limited and light-saturated conditions in the sixth week; sampling occurred each week. No significant inter-treatment differences were found in the sterol content in week 1–5. However, significant intra-treatment differences were found in weeks 3–5 regardless of nutrient treatment, wherein the fucosterol, 24-methylenecholesterol, and squalene contents of both treatment groups were found to correlate inversely with photosynthetic performance. Factorial treatment of differential nutrient availability and light stress resulted in marked differences between the sterol content of all groups in week 6. Here, squalene and cycloartenol increased in concentration with increasing irradiance regardless of nutrient treatment. Concentrations of all other sterolic components increased with increasing irradiance and low nutrient conditions while decreasing or remaining unchanged with increasing irradiance and high nutrient conditions. Our data shows that within our cultivation conditions and time frame, the sterol content of S. latissima is unaffected by nutrient availability alone but changes with combined alterations in irradiance and nutrient availability. Graphical abstract

Biomethane Yield from Different European Phragmites australis Genotypes, Compared with Other Herbaceous Wetland Species Grown at Different Fertilization Regimes

Phragmites australis, Typha latifolia, T. angustifolia and Arundo donax are tall wetland graminoids with the potential to replace fossil fuels under sustainable cultivation conditions. We investigated the biomethane (CH4) production of these four species, including four different genotypes of P. australis, which represent the high intraspecific diversity of European reed. All plants were grown under three different macronutrient supplies (no nutrients added, an equivalent of 75 kg N ha−1 year−1 added and an equivalent of 500 kg N ha−1 year−1 added). Biomethane production was measured in four independent batch digestion tests. Across all experiments, fertilization regime had little effect on CH4 yield, which was on average 222 ± 31 L kg−1 volatile solids (VS). The lowest yield was produced by T. angustifolia (140 L kgVS−1) receiving no nutrients, while the highest yield was produced by A. donax (305 L kgVS−1) in the highest nutrient treatment. The intraspecific diversity of P. australis did not affect biomethane production. All P. australis genotypes produced on average 226 ± 19 L CH4 kgVS−1, which, although high, was still lower than conventional biogas species. The biomass production of P. australis was less increased by fertilization than that of Typha sp. and A. donax, but all species had similar biomass without fertilization.

Bacterial community shift in nutrient-treated oil-bearing sandstones from the subsurface strata of an onshore oil reservoir and its potential use in Microbial Enhanced Oil Recovery

Microbial Enhanced Oil Recovery (MEOR) is a promising strategy to improve recovery of residual oil in reservoirs, which can be performed by promoting specific indigenous microorganisms. In this study, bacterial communities and the effects of elemental nutrient treatment of oil-bearing sandstone cores originated from six oil wells of an onshore reservoir was determined by tagged 16S rRNA gene amplicon sequencing, using Ion Torrent Metagenomic Sequencing Analysis. A total number of sequences were taxonomically classified into 43 phyla, 320 families, and 584 genera, with the dominant bacterial populations being related to Deinococcus-Thermus, and Betaproteobacteria. The nutrient treatment resulted in markedly increase in the relative abundance of Gammaproteobacteria. Thermus, Acinetobacter, and Pseudomonas were the most abundant genera. To our knowledge, this is the first report on the effect of elemental nutrients on alteration of bacteria communities attached to the oil-bearing rock. It provides comprehensive data on bacterial, physical, and chemical structures within a reservoir and demonstrates how these parameters can be co-analyzed to serve as a basis for designing a MEOR process. It also provides a model of how a bacterial community in reservoirs’ strata can be altered by nutrient treatment to enhance the efficiency of MEOR applications.

Kajian Penggunaan Nutrisi Anorganik terhadap Pertumbuhan Kangkung (Ipomoea reptans Poir) Hidroponik Sistem Wick

This study aims to determine the effect of giving different types of nutrients on the growth of kale in hydroponic wick system. The study was a single factor experiment with two treatments using Completely Randomized Design (CRD) with 7 replications. The treatment given was inorganic fertilizer AB Mix and NPK plus inorganic fertilizer. Nutritional concentration was given as much as 10 ml/liter. The results showed that the type of nutrient treatment was significantly affected the growth of plant height at age 14 days after planting (DAP) and 21 DAP. At age 28 DAP there was no real effect. The producing of leaves number was differences at all stages. Provision of nutrition AB mix produced higher plant height at 14 DAP (15.9 cm) and 21 DAP (19.3 cm). The parameter of leaf number, AB mix yield more leaves at 14 hst (8,1 strand), 21 hst (11,1 strands) and 28 DAP (13,4 strands) respectively.

Variety × Nutrient management interaction in greengram for important yield attributes under rainfed red lateritic inceptisol

The effect of five nutrient management practices on the yield and yield attributes, nutrient uptake and rain water use efficiency in four greengram varieties (Dhauli, Pusa-9531, OBGG-52 and Nayagarh Local) in rainfed upland inceptisol with sandy- loam soil was studied in factorial RBD with three replications during Kharif 2009 to 2012. Significant variety × nutrient interaction was observed with respect to seed yield, nodulation and other yield attributing characters. Based on the mean data over four years (2009-2012), highest seed yield of 5.84 q ha-1 was observed in Pusa 9531 with lime+50% organic+ 50% inorganic treatment followed by Dhauli (5.53 q ha-1) with the same nutrient treatment. Highest RWUE was found in Lime + 50% organic + 50% inorganic treatment in all the varieties followed by 100% organic treatment in Dhauli, Pusa-9531 and OBGG-52 but in 50% organic + 50% inorganic treatment in case of Nayagarh Local. The uptake of N, P and K was also observed to be the highest in Lime + 50% organic + 50% inorganic treatment in all the varieties.