PERSEPSI SISWA TERHADAP PENGGUNAAN GAME EDUKASI DIGITAL PADA PEMBELAJARAN MATEMATIKA

This paper examined the students’ view on advantages of using digital educational game in learning mathematics. The background of this paper is the appearance of people perception phenomenon about the negative effect of using games for learning. The method of this paper conducted descriptive qualitative design for the questionnaire and interview as the instruments. The data analysis technique used is the Miles and Huberman model (Analysis Interactive Model). This paper was conducted at Vocational High School for 21 students. The result of data analysis indicated that almost all of the students (86%) agree for using educational game can facilitate the students to learn mathematic. On the other hand, there were only 3 students claimed that the they were not sure or even do not know of using educational game can facilitate the students to learn mathematic. And there were no students who disagree if using educational games can not facilitate the students to learn mathematic

IDENTIFIKASI BAKTERI DENITRIFYING-METHANOTROPHIC PENURUN EMISI GAS METANA DI LAHAN SAWAH KERING DAN SAWAH TERGENANG

Metana merupakan salah satu gas rumah kaca dan penyebab utama pemanasan global dengan efektivitas penangkapan radiasi termal yang sangat tinggi, bahkan mencapai 60 kali lipat dibandingkan karbon dioksida. Tingginya pengaruh metana terhadap pemanasan global membuat berbagai upaya untuk mengurangi keberadaanya di alam. Wye (2010) menyebutkan bahwa sumber produksi gas metana yang terbesar adalah metabolisme mikroorganisme dengan total kontribusi metana global sebesar 69% dan lahan pertanian padi merupakan salah satu habitat terpenting dalam produksi metana global sebesar 10%. Negara luar, seperti belanda telah berupaya untuk mengurangi emisi gas metana, yaitu dengan bantuan mikroorganisme. Emisi metana dapat direduksi melalui proses oksidasi metana yaitu proses pemecahan senyawa metana oleh mikroorganisme metanotrofik dengan menggunakan enzim methane monooxygenase yang mampu mengoksidasi metana menjadi karbon dioksida melalui serangkaian reaksi kimiawi dengan menghasilkan senyawa metabolik intermediet seperti metanol, formate, dan formaldehyde (Topp & Pattey, 1997). Proses oksidasi metana secara anaerobic dapat dilakukan oleh konsorsium bakteri denitrifying anggota genus Stenotrophomonas, Hyphomicrobium dan Mesorhizobium dengan bakteri metanotrofik anggota genus Methylocystis (Ettwig et al., 2010), serta strain bakteri denitrifying-methanotrophic anggota spesies Candidatus Methylomirabillis oxyfera (Ettwig et al., 2009). Peranan bakteri denitrifying-methanotrophic dapat mengurangi emisi gas metana sekaligus meningkatkan ketersediaan karbondioksida, selain itu juga dapat membantu menyediakan unsur N tersedia di tanah dalam bentuk amonium (NH 4 + ). Bakteri denitrifying akan menguraikan nitrat di alam, dibanding dengan amonium, hara N tersedia dalam bentuk nitrat lebih merugikan. Nitrat (NO 3 -) sangat mudah tercuci sehingga kurang optimal dimanfaatkan tanaman. Bakteri Denitrifying akan mempercepat penguraian nitrat sehingga harapannya hara N akan tersedia dalam amonium. Pentingnya peranan bakteri denitrifying-methanotrophic menjadikan bakteri ini perlu dikaji lebih lanjut. Penelitian tentang bakteri ini di Indonesia masih tergolong sangat minim, sehingga dengan penelitian ini diharapkan untuk kedepannya aplikasi bakteri ini dapat dilakukan di lahan dan mengurangi pemikiran bahwa pertanian merupakan salah satu penyebab pemanasan global. Kata Kunci : Pemanasan global, denitrifying-methanotrophic, emisi metan

PAK EDI BAPER “Potensi Ekstrak Daun Iler (Coleus scutellarioides) Sebagai Bahan Alami Pengukur pH Tanah Ramah Lingkungan”

Pengukuran pH (derajat keasaman) dilakukan untuk mengetahui sifat yang dimiliki oleh suatu benda apakah masam, netral, maupun basa. Pengukuran pH juga penting pada tanah, karena pH tanah akan mempengaruhi semua reaksi – reaksi kimia yang terjadi pada tanah, baik diatas permukaan tanah, di dalam tanah, maupun di bawah permukaan tanah. pH tanah akan mempengaruhi kesuburan tanah, baik kesuburan fisika, kimia, maupun biologi tanah. Sehingga diperlukan pengukuran pH pada tanah guna menentukan tingkat kesuburan tanah, dan kecocokan terhadap budidaya tanaman. Metode yang selama ini lazim digunakan pada pengukuran pH tanah adalah dengan menggunakan bahan - bahan kimia atau bahan – bahan sintetis yang jumlahnya sangat terbatas, mencemari lingkungan, dan mahal harganya. Zat timol yang dikandung dalam tumbuhan tertentu merupakan bahan pembuatan pengukur pH tanah. Tanaman iler (Coleus scutellarioides) merupakan salah satu tumbuhan yang mengandung timol biru. Kenyataan tersebut mendorong upaya untuk menggali potensi ekstrak daun Iler sebagai bahan alami pengukur pH tanah. Penelitian yang akan dilakukan ini bertujuan untuk mengetahui bagaimana proses membuat bahan alami pengukur pH tanah yang memanfaatkan daun iler, bagaimana trayek pH yang dihasilkan dari ekstrak daun iler sebagai pengukur pH tanah, dan seberapa efektif penggunaan ekstrak daun iler sebagai bahan alami pengukur pH tanah. Metode yang digunakan adalah metode percobaan secara langsung. Bahan yang digunakan dalam penelitian ini adalah ekstrak daun iler sebagai pengukur pH tanah. Penentukan skala pH tanah digunakan larutan pembanding asam – basa antara pH 1 – 14. Analisis data yang digunakan adalah uji t. Kata kunci : daun iler, timol biru, bahan alami, pengukur pH tana

Soil quality status under Hazton’s paddy farming: A case study in Banyumas Regency, Indonesia

Soil quality is the ability of the soil to perform its function, such as providing nourishment to the plants. However, intensive paddy farming, such as Hazton’s paddy farming method, is suspected to deteriorate soil quality status and degrade land sustainability. This study aimed to analyze soil quality under Hazton’s paddy farming. This study was conducted on paddy fields in Banyumas Regency using a randomized block design with treatment consisting of 1) conventional method as a control, 2) Hazton’s method + organic fertilizer, 3) Hazton’s method + organic fertilizer + decomposer, and 4) Hazton’s method + organic fertilizer + decomposer + leaf fertilizer. Soil quality was determined according to a minimum data set (MDS) that consisted of organic C, pH, total N, available phosphorus (P) and potassium (K), base saturation (BS), cation exchange capacity (CEC), bacterial density, soil respiration, and C/N ratio. The MDS was scored and calculated using the soil quality index formula and then classified from very low to very high (<0.19-1). This study highlighted that the soil quality in paddy farm using Hazton’s method in Banyumas Regency ranged from low (0.444) to very low (0.308). The application of organic fertilizer is not sufficient enough to refill the nutrient pool equal to harvested plant biomass. This leads to soil quality deterioration and affects land sustainability. Therefore, yield and biomass production should be included as soil quality indicators in future studies. Additionally, further soil degradation can be avoided by continuously assessing soil quality and the necessary conservation measures for preventing and minimizing further land degradation can be applied

WATER RESOURCES MANAGEMENT MODEL BASED ON REGIONAL DEVELOPMENT: CASE STUDY OF MAGETAN REGENCY, INDONESIA

Background. The need for water in Magetan Regency, Indonesia, continues to increase along with regional development. Objective. To identify the condition of the water balance and water critical index in Magetan Regency; and forming a regional development-based water management model in Magetan Regency. Methodology. Formation of a water management model based on regional development, both demographically and regional economic development (agriculture, livestock, fisheries, industry, and tourism), and the environment (river and lake maintenance). This study uses water availability data from seven watersheds. The water management model uses a dynamic system model, with an analysis coverage throughout the Magetan Regency area. The annual water balance of Magetan Regency shows that the water balance and water critical index of Magetan Regency are in near critical condition. Integrated water management is needed to avoid critical water conditions in Magetan Regency in the future. Results. Based on the results of model simulations with the application of policy simulations, the water balance in Magetan Regency during the period 2016 to 2030 is still in a near critical condition, but critical water conditions only occur during the 2018-2020 period. Implications. Critical water conditions in the future can be avoided by implementing policy scenarios. The policy scenarios include: (1) reforestation, planting 500,000 tree seedlings each year, (2) maintenance of rivers and lakes twice a year, (3) construction of a reservoir with a capacity of 5000 m3 each year. However, water availability is still fluctuating because the main factor for water availability is rainfall. Conclusion. the policy scenario is proven to be able to increase the availability of water in Magetan Regency