Soil and Plant Responses to Phosphorus Inputs from Different Phytase-Associated Animal Diets

The over-supplementation of animal feeds with phosphorus (P) within livestock-production systems leads to high rates of P excretion and thus to high P loads and losses, which negatively impact the natural environment. The addition of phytase to pig and poultry diets can contribute to reducing P excretion; however, cascading effects of phytase on plant–soil systems remain poorly understood. Here, we addressed how three different diets containing various levels of exogenous phytase, i.e., (1) no-phytase, (2) phytase (250 FTU), and (3) superdose phytase (500 FTU) for pigs (Sus scrofa domesticus) and broilers (Gallus gallus domesticus) might affect P dynamics in two different plant–soil systems including comfrey (Symphytum ×uplandicum) and ryegrass (Lolium perenne). We found that differences in phytase supplementation significantly influenced total P content (%) of broiler litter and also pig slurry (although not significantly) as a result of dietary P content. P Use Efficiency (PUE) of comfrey and ryegrass plants was significantly higher under the intermediate ‘phytase’ dose (i.e., commercial dose of 250 FTU) when compared to ‘no-phytase’ and ‘superdose phytase’ associated with pig slurry additions. Soil P availability (i.e., water soluble P, WSP) in both comfrey and ryegrass mesocosms significantly decreased under the intermediate ‘phytase’ treatment following pig slurry additions. Dietary P content effects on P losses from soils (i.e., P leaching) were variable and driven by the type of organic amendment. Our study shows how commercial phytase levels together with higher dietary P contents in pig diets contributed to increase PUE and decrease WSP thus making the plant–soil system more P conservative (i.e., lower risks of P losses). Our evidence is that dietary effects on plant–soil P dynamics are driven by the availability of P forms (for plant uptake) in animal excretes and the type of organic amendment (pig vs. broiler) rather than plant species identity (comfrey vs. ryegrass).

Assessment of the early growth of agarwood (Aquilaria crassna) seedlings under different sources of nutrients

The effect of different sources of nutrients on the growth of Aquilaria crassna seedlings was assessed by raising seedlings in polybags treated with inorganic fertilizer (IF), organic fertilizer (OF) and biofertilizer (BF) either alone or in combinations. The pots were established following a completely randomized block design with eight treatments: (T1) soil without IF, OF or BF ‒ control; (T2) soil + IF; (T3) soil + OF; (T4) soil + BF; (T5) soil + IF + OF; (T6) soil + IF + BF; (T7) soil + OF + BF; (T8) soil + IF + OF + BF each replicated five times. Plant height, stem diameter, dry weight of shoots and roots, leaf area and chlorophyll index were measured six months after planting. Soil pH (H₂O) and available soil P content were measured as soil parameters. The best growth performances (54.30 cm, 6.48 mm, 7.10 and 5.92 g·plant^–1, 435.33 cm² and 58 for plant height, stem diameter, shoot and root dry weight, leaf area and chlorophyll index, respectively) were recorded in T8, which also resulted in the highest available P content (18.96 mg·kg–1 soil). The lowest soil pH (H₂O) value (6.02) was recorded in T7 followed by T6 (6.17). The application of IF, OF and BF as a combination could be recommended to promote the growth of Aquilaria seedlings.

The nutrient content of N, P, K in Andisols and Arabica coffee leaves in Bener Meriah Regency, Indonesia

Bener Meriah Regency is one of the arabica coffee areas in Indonesia. Generally, most of arabica coffees are grown in Andisols. This research aims to determine the nutrient content of N, P, K in andisols and arabica coffee leaves in the Bener Meriah regency. Data were collected from a 10-year-old arabica coffee tree planted on Andisols located at an altitude of 1200-1400 m above mean sea level and divided in five classes with different slopes, using the survey method and analysed descriptively. The results showed that andisols Bener Meriah had a total N content ranging from 0.09-0.51%. The P-available ranged from 0.3-12.81 mg.kg-1 and P-total content of 159.4-1246.7 mg.kg-1. The K-exchangeable content ranged from 0.17-0.52 cmol kg-1. Arabica coffee leaves contain N ranging from 0.85%-3.00%. The P content ranged from 0.10%-0.23%. Meanwhile, the K content ranged from 1.55%-2.33%. Furthermore, there is a close relationship between soil N-total and the N-nutrient of coffee leaves, soil P-available and P-nutrient of coffee leaves, and soil K-exchangeable and K nutrient contents of coffee leaves with r values of 0.78, 0.97, and 0.68 respectively.

Yield and phosphorus use efficiency of carrot cultivars

Phosphate fertilization is indispensable for carrot cultivation, as it contributes to plant development, formation of marketable roots and higher yields. In this context, the objective of this study was to evaluate the production and nutritional efficiency of carrot cultivars under phosphate fertilization. The experiments were carried out from July to November 2016 and from June to October 2017, at the Rafael Fernandes experimental farm, District of Alagoinha, Mossoró, RN, Brazil. The experimental design was in randomized blocks, in a 4×4 factorial scheme with 4 replicates. The treatments consisted of the combination of carrot cultivars (Brasília, Planalto, Suprema and Nativa) with phosphorus (P) doses (0, 90, 180 and 270 kg ha-1 P2O5). The characteristics analyzed were: P content in the diagnostic leaf, plant dry matter, plant height, marketable and total yields, and the classification of cultivars for efficiency and response to phosphate fertilization. The increments promoted by phosphate fertilization were 64% in plant height, 444% in dry matter and 284% in marketable yield. The maximum marketable yield was obtained with doses from 186.8 to 243.5 kg ha-1, depending on the cultivar. The Native cultivar was classified as more efficient in the use of P.

Coated Diammonium Phosphate Combined With Humic Acid Improves Soil Phosphorus Availability and Photosynthesis and the Yield of Maize

Controlled release phosphorus (P) fertilizers and humic acid (HA) applications are two effective and significant techniques or measures for preventing P loss and enhancing maize development. However, the underlying physiological mechanism of how the controlled release P fertilizers combined with HA affect the maize production and P-use efficiency (PUE) remains unknown. The effects of applying coated diammonium phosphate (CDAP) and HA together on soil nutrient supply intensity, soil phosphatase activity, photosynthesis, endogenous hormone contents, and yield of maize, as well as PUE, were examined in this study. In a pot experiment, two types of P fertilizers—CDAP and diammonium phosphate (DAP)– as well as two HA application rates (0 and 45 kg ha–1) and two P levels (60 and 75 kg P2O5 ha–1) were utilized. Results showed that the key elements that influence the growth and yield of the maize were the availability of P content in soil, plant photosynthesis, and hormone levels. The combination of CDAP and HA had a greater impact on yield and PUE over the course of 2 years than either DAP alone or DAP combined with HA. Besides, using CDAP in combination with HA increased the yield and PUE by 4.2 and 8.4%, respectively, as compared to the application of CDAP alone at 75 kg P2O5 ha–1. From the twelve-leaf to milk stages, the available P content in the soil was increased by an average of 38.6% with the combination of CDAP and HA compared to the application of CDAP alone at 75 kg P2O5 ha–1. In addition, the application of CDAP combined with HA boosted the activities of ATP synthase, as well as the content of cytokinin (CTK), and hence improved the maize photosynthetic rate (Pn). When compared to the application of CDAP alone or DAP combined with HA, the Pn of CDAP + HA treatments was enhanced by 17.9–35.1% at the same P rate. In conclusion, as an environmentally friendly fertilizer, the combined application of CDAP and HA improved the intensity of the soil nutrient supply, regulated photosynthetic capabilities, and increased the yield and PUE, which is important for agricultural production, P resource conservation, and environmental protection.

Microbial Diversity and P Content Changes after the Application of Sewage Sludge and Glyphosate to Soil

Pesticides, despite their side effects, are still being used in almost every agriculture, horticulture, maintaining municipal greenery in urban areas and even in home gardens. They influence human life and health and the functioning of entire ecosystems, including inanimate elements such as water and soil. The aim of the study was the evaluation of the suitability of sewage sludge in improving the quality of soil treated with a non-selective herbicide-glyphosate, applied as Roundup 360 SL. A pot experiment was conducted with the use of two arable soils (MS and OS), which were amended with sewage sludge (SS), glyphosate (GL) and sewage sludge with glyphosate (SS+GL). Soil samples were taken after 24 h, 144 h and 240 h and total phosphorus (TP) content (TP), total number of bacteria/fungi, activity of dehydrogenases (Dha), acidic phosphatase (Acp), alkaline phosphatase (Alp), genetic biodiversity of bacteria/fungi using the terminal restriction fragment length polymorphism method were determined. The application of SS and GL to OS caused an increase in Acp (approximately 35%) and a decrease in Alp activity (approximately 20%). Additionally, GL may influence on an increase in the number of fungi and the decrease in the number of bacteria. In soil with SS+GL increase in the fungal diversity in MS and OS was also observed. Moreover, a positive between TP and the number of bacteria and the activity of phosphatases correlation was reported. The obtained results indicate that analyzed sewage sludge could be potentially applied into soil in in situ scale and could constitute a valuable reclamation material.

Breeding Practice Improves the Mycorrhizal Responsiveness of Cotton (Gossypium spp. L.)

Maximizing the function of indigenous arbuscular mycorrhizal (AM) fungi by choosing specific crop genotypes offers one of the few untapped opportunities to improve the sustainability of agriculture. In this study, the differences in mycorrhizal responsiveness (MR) in plant growth and shoot phosphorus (P) content among cotton (Gossypium spp. L.) genotypes from different release dates were compared and then the relationships between MR and P uptake-related traits were determined. The experimental design in a greenhouse included 24 genotypes released from 1950 to present in Xinjiang Province, inoculation with or without AM fungi, and P levels (15 and 150 mg P kg–1 added as KH2PO4). Results showed that the modern cotton genotypes exhibited a higher degree of mycorrhizal colonization, the hyphal length density (HLD), and mycorrhizae-induced changes in shoot growth than the old genotypes when inoculated with indigenous AM fungi at both the P levels. Moreover, MR was highly correlated with the HLD at low P levels and the HLD may provide useful insights for future cotton breeding aimed at delivering crop genotypes that can benefit more from AM fungi.

Improving Online Accessibility for Individuals with Photosensitive Epilepsy

Content with flashes, bright colors, and repeated patterns can cause seizures and migraines when viewed by people with photosensitivity. Exposure to seizure-inducing content is a serious risk in online environments, as evidenced by documented instances of people with photosensitivity being exposed to seizure-inducing material while playing video games or using social media.My thesis focuses on improving online safety and accessibility for people with photosensitivity by measuring the prevalence of seizure-inducing content online, developing new tools for detecting seizure-inducing content, and constructing a broad framework for protecting against seizure-inducing content at the level of content creators, platforms, and content consumers. Through this work, I hope to help build a better understanding of the current state of photosensitive risk online and contribute new solutions for mitigating seizure-inducing content with minimal adverse effects on the browsing experience for users with photosensitivity.

Content and Text Analysis Methods for Organizational Research

Content analysis is to words (and other unstructured data) as statistics is to numbers (also called structured data)—an umbrella term encompassing a range of analytic techniques. Content analyses range from purely qualitative analyses, often used in grounded theorizing and case-based research to reduce interview data into theoretically meaningful categories, to highly quantitative analyses that use concept dictionaries to convert words and phrases into numerical tables for further quantitative analysis. Common specialized types of qualitative content analysis include methods associated with grounded theorizing, narrative analysis, discourse analysis, rhetorical analysis, semiotic analysis, interpretative phenomenological analysis, and conversation analysis. Major quantitative content analyses include dictionary-based approaches, topic modeling, and natural language processing. Though specific steps for specific types of content analysis vary, a prototypical content analysis requires eight steps beginning with defining coding units and ending with assessing the trustworthiness, reliability, and validity of the overall coding. Furthermore, while most content analysis evaluates textual data, some studies also analyze visual data such as gestures, videos and pictures, and verbal data such as tone. Content analysis has several advantages over other data collection and analysis methods. Content analysis provides a flexible set of tools that are suitable for many research questions where quantitative data are unavailable. Many forms of content analysis provide a replicable methodology to access individual and collective structures and processes. Moreover, content analysis of documents and videos that organizational actors produce in the normal course of their work provides unobtrusive ways to study sociocognitive concepts and processes in context, and thus avoids some of the most serious concerns associated with other commonly used methods. Content analysis requires significant researcher judgment such that inadvertent biasing of results is a common concern. On balance, content analysis is a promising activity for the rigorous exploration of many important but difficult-to-study issues that are not easily studied via other methods. For these reasons, content analysis is burgeoning in business and management research as researchers seek to study complex and subtle phenomena.