Evaluation of Soil P and K Extractants for Soils and Crops of Hawaii

Four greenhouse pot experiments were conducted to evaluate the performance of P and K extractants on two Hawaiian soils in terms of their correlations with the performance of two crops that are grown in Hawaii. The extractants assessed were Modified Truog, Mehlich3, Olsen, and Resin for P and NH4OAC, Mehlich3, and Resin for K. The Modified Truog, Olsen, and NH4OAC extractants are commonly used in Hawaii. The Mehlich3 and Resin extractants have not been well tested here yet, but their capacity to extract both P and K simultaneously is a potential advantage over the other methods. The soils were an Ultisol and an Andisol, both of which were amended to establish a wide range of soil P and K concentrations. For both soils, Mehlich3 P and Resin P were as well related with plant response parameters (dry matter yield and P uptake) as were Modified Truog P and Olsen P. Test values from all four methods were very well correlated with one another, with Resin P being slightly less well correlated than other three. In term of the accuracy of diagnoses, the sensitivity of P test values to change of soil P levels, and C.V. for sampling, Mehlich3 usually ranked between Olsen and Modified Troug extraction methods while Resin P performed worst overall. Mehlich3 K performed as well as NH4OAC K in both soils for crop tested in terms of the coefficients of determination for regressions of K uptake and K applied with K extracted, and in terms of the sensitivity of K test values to the change of soil K levels and the C.V. for sampling. In both soils, however, Resin K was as well correlated with NH4OAC K as was Mehlich3 K. However, in terms of the sensitivity of K test values and the C.V. for sampling, Resin K usually did not perform as well as the other methods. These results suggest that it would be practical to switch from the conventional procedures, with separate extractions for P and K, to a simultaneous P and K extraction with Mehlich3 for these soil-crop combinations. Use of a simple linear regression model would allow conversion between results obtained from a Mehlich3 P and K extraction and those obtained from Modified Truog P, Olsen P, and NH4OAC K extractions

Teaching by Example and Learning by Doing

Through our sustainability program, Urbana University has introduced several projects that enhance our educational offerings both to our students and to the broader community. This poster summarizes some of our major accomplishments.https://fuse.franklin.edu/ss2016/1007/thumbnail.jp

Time-varying skills (versus luck) in U.S. active mutual funds and hedge funds

In this paper, we develop a nonparametric methodology for estimating and testing time-varying fund alphas and betas as well as their long-run counterparts (i.e., their time-series averages). Traditional linear factor model arises as a special case without time variation in coefficients. Monte Carlo simulation evidence suggests that our methodology performs well in finite samples. Applying our methodology to U.S. mutual funds and hedge funds, we find most fund alphas decrease with time. Combining our methodology with the bootstrap method which controls for ‘luck’, positive long-run alphas of mutual funds but hedge funds disappear, while negative long-run alphas of both mutual and hedge funds remain. We further check the robustness of our results by altering benchmarks, fund skill indicators and samples

馮文炳長篇小說《橋》的幾個轉變及故事意義

廢名（本名馮文炳）小說中的詩意或禪意表達總是為研究者稱頌，遣詞用句有其獨特風格。他一生創作了兩部長篇小說，《橋》和《莫須有先生傳》（下稱《莫》）。雖長篇小說數目遠遠不及其短篇小說，但已經展現出兩種截然不同的創作風格。簡而言之，前者比後者要晦澀很多（像《莫》這種帶點遊戲筆墨的可能更難懂），篇幅結構鬆散，一如普遍評論家的意見，像散文式小說。 關於作者的作品風格、意象、主題等表現，學界已有不少討論。本文嘗試把焦點回歸故事本身，重新審視前人研究中被忽略的人物和細節，輔以研究作者的創作觀等其他因素，觀察《橋》的故事或其變化可能隱含的意義。儘管作者寫長篇小說的技巧有所欠缺，但當中對於「人」和「苦難」的思考，卻是值得關注的

Methane adsorption constrained by pore structure in high rank coals using FESEM, CO2 adsorption and NMRC techniques

This research was funded by the National Natural Science Fund (grant nos. 41830427, 41772160 and 41602170), the National Major Research Program for Science and Technology of China (grant no. 2016ZX05043-001), Key Research and Development Projects of The Xinjiang Uygur Autonomous Region (grant no. 2017B03019-01) and the Fundamental Research Funds for Central Universities (grant no. 2652018002).Peer reviewedPublisher PD