Effect of days postburning and calcium oxide on the fermentation,aerobic stability and nutritional characteristics of sugarcane silage for finishing Nellore steers

In this study, the effects of days postburning and calcium oxide (CaO) on the fermentation, aerobic stability and nutritional characteristics of sugarcane silages for finishing Nellore steers were investigated. Silages were prepared in minisilos from in natura and burned sugarcane that remained in the field 1 and 10 days postburning (1‐day burned and 10‐day burned, respectively). Next, forages were left untreated or treated with CaO (10 g/kg fresh forage). Compared to that in untreated silages, CaO application increased the dry‐matter (DM) recovery of in natura, 1‐day and 10‐day burned silages (p < 0.001) by 67, 179 and 209 g/kg DM respectively. The CaO treatment increased (p < 0.001) the aerobic stability of the in natura and 10‐day burned silages by 62.7 and 24.7 hr respectively. In a feedlot experiment, feeding 1‐day burned silage reduced DM intake of steers throughout the feedlot period (0–93 days; p < 0.05) compared with that of steers fed in natura silage diet, but the average daily gain (ADG) was lower (p = 0.006) only during the adaptation period (?0.16 kg/day; 0–28 days). The CaO application decreased DM intake (p = 0.007; ?1.17 kg/day) and ADG (p < 0.001; ?0.13 kg/day) of steers only during the adaptation period likely owing to low silage palatability caused by increased Ca and butyric acid concentrations (≥11.6 g/kg DM). We recommend feeding beef cattle with CaO‐treated burned sugarcane silages in low‐dietary concentration because of its high butyric acid concentration.     

Effect of Steel Slag to Improve Soil Quality of Tsunami-Impacted Land while Reducing the Risk of Heavy Metal Bioaccumulation

After the tsunami caused by the Great East Japan Earthquake, marine sediment was taken from the sea bottom and deposited over local agricultural fields. The marine sediment already contained an unknown amount of heavy metals, due to anthropogenic activities prior to the tsunami, which might affect plants, animals, and humans. Furthermore, soil salinity in tsunami-inundated land greatly increased. Three different amounts of steel slag were employed as pretreatment agent in order to improve agricultural soil quality. The soil samples treated with 2% of steel slag present a remarkable increase of A. thaliana biomass production with low BCF and TF values for most of the heavy metals. It was concluded that steel slag pretreatment used in the tsunami-inundated agricultural lands produced a noteworthy improvement in soil quality which lead to a positive stimulative effect on plant growth, and the slag addition treatment proved to be a promising treatment that might be used for phytostabilization of slightly contaminated soils.     

Biosorption of Mercury by Reed (<Emphasis Type="Italic">Phragmites australis</Emphasis>) as a Potential Clean Water Technology

Heavy metals are causing serious environmental and health problems worldwide, especially in places where mining is one of the major drivers of the country’s economy. Conventional technologies are considered expensive when providing the safe water; for this reason, new clean water technologies are needed. Biosorption has gained attention as a cost-effective system that uses biological materials to remove heavy metals from water; however, it can be noted that an efficient and proven biosorbent for several heavy metal has not been found. Reed (Phragmites australis) has demonstrated to be a potential biosorbent to remove several heavy metals because it is commonly found as heavy metal accumulator in wetlands. This study is focused on mercury (Hg) removal by using reed as biosorbent. Batch experiments were conducted and the microstructure of the biosorbent was analyzed by scanning electron microscope. The Langmuir isotherm and Freundlich isotherm model was applied for the data obtained. The pseudo-first-order and pseudo-second-order models were used to test adsorption kinetics data to investigate the mechanism of biosorption. A comparison with the performance of various adsorbents reported in literature was made. The results contribute to understand the use of Phragmites australis as potential biomass for biosorbent technology since it removed mercury (Hg) effectively in high concentrations. This study supports a variety of researches to achieve clean water technologies, and biosorption has proved to be a useful alternative to the conventional systems for the removal of heavy metal ions from aqueous solution.     

Nitrogen mineralization dynamics in acid vineyard soils amended with bentonite winery waste

An excess of available nitrogen (N) in vineyard soil is considered detrimental for vine growth, making a thorough assessment of N mineralization dynamics in vineyard soils before the addition of winery waste necessary. This study assesses the changes in N mineralization in acid vineyard soils amended with bentonite winery waste (BW). Non-amended soil (control), BW and soil-waste mixtures (SBWM) with a low (+L) or high (+H) dose of BW were incubated for six weeks. After 7, 14, 21 and 42 days of incubation, the control soils, BW and SBWM were analysed for net ammonified N, net nitrified N and net mineralized N. Parameters related to the kinetics of N mineralization were also determined. The addition of BW increased the potentially mineralizable N (N₀) in the amended soils (58–144% for the highest BW dose), although the mineralization rate was governed by the soil characteristics. Mineralizable N was only a small fraction (<4%) of the total organic nitrogen added to the soil through the BW addition, mainly due to the dominance of the nitrification process in the BW amended soils. These experimental results suggest that the addition of BW may be a suitable amendment for nitrogen fertilization in acid vineyard soil.     

Native soil organic matter as a decisive factor to determine the arbuscular mycorrhizal fungal community structure in contaminated soils

The present study of arbuscular mycorrhizal (AM) fungi is focused on the identification of AM ecotypes associated with different plants species (Poa annua, Medicago polymorpha, and Malva sylvestris) growing in three contaminated soils with different organic matter, phosphorus, and trace element (TE; Cu, Cd, Mn, and Zn) contents. Soils were amended with biosolid and alperujo compost. Shifts in AM fungal community structure, diversity, richness, root colonization, and plant TE uptake were evaluated. Soil properties and plant species had a significant effect on AM fungal community composition as well as on root colonization. However, AM fungal diversity and richness were only affected by soil properties and especially by soil organic matter that was a major driver of AM fungal community. As soil quality increased, Glomeraceae decreased in favor of Claroideoglomeraceae in the community, AM fungal diversity and richness increased, and root colonization decreased. No effect due to amendment (exogenous organic matter) addition was found either in AM fungal parameters measured or TE plant uptake. Our results revealed that the role of TE contamination was secondary for the fungal community behavior, being the native organic matter content the most significant factor.     

Field surveys of egg mortality and indigenous egg parasitoids of the brown marmorated stink bug, <Emphasis Type="Italic">Halyomorpha halys</Emphasis>, in ornamental nurseries in the mid-Atlantic region of the USA

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species native to regions of China, Japan, Korea, and Taiwan. In its native and introduced range, H. halys is considered a pest of tree fruits, vegetables, legumes, and ornamental trees. The highly polyphagous nature of this insect as well as its vast dispersal capabilities, require an integrated approach to management. Here we focus on the potential impact of indigenous natural enemies on H. halys in woody ornamental nurseries in Maryland, USA. We sampled naturally field laid H. halys egg masses for mortality and parasitism rates in 2012 and 2013. Overall, egg mortality averaged 54% for both years, and increased within season and between years. The largest source of mortality was from egg parasitoids with mean parasitism rates of 30.73 and 39.63% in 2012 and 2013, respectively. Mortality from predation was much lower and averaged 4.61% by chewing and 2.53% by sucking predators. We found seven species of Hymenopteran egg parasitoids attacking H. halys eggs, with Anastatus reduvii being the dominant species comprising 61.17 and 79.12% of all parasitoids in 2012 and 2013, respectively. The observed increase in parasitism over time and female biased sex ratio of parasitoids suggests that native parasitoids may be responding to the novel host, H. halys. Consequently, the use of these native eupelmid egg parasitoids in augmentative or conservation biological control may be a viable H. halys management strategy in ornamental nurseries.     

Mineral nitrogen impairs the biological nitrogen fixation in soybean of determinate and indeterminate growth types

Soybean (Glycine max Merrill) crop production in Brazil relies mainly on biological nitrogen fixation (BNF) for nitrogen (N) supply. Recent adoption of indeterminate growth-type genotypes has raised doubts on the need for supplemental mineral N that might negatively affect the BNF. We assessed the effects of mineral N on BNF attributes of soybean genotypes grown in central and southern Brazil. Genotypes were inoculated with Bradyrhizobium sp. and/or received mineral N in three sets of experiments. In the first set, two genotypes received increasing rates of mineral N in nutrient solution, which consistently reduced the BNF. In the second set, mineral N applied at sowing and/or topdressing reduced nodulation and ureides-N in determinate and indeterminate growth-type genotypes. In the third set, mineral N applied at R5.3 stage, foliar or as topdressing, did not increase grain yield in four field experiments. Mineral N impaired BNF irrespective of the growth type and had no effect on grain yield.