Judul: Pengaruh Trichoderma sp. dan Molase terhadap Sifat Biologi Tanah di Sekitar Lubang Resapan Biopori pada Latosol Darmaga
Abstrak: Organic waste addition into the biopore infiltration hole could improve soil biological properties due the increase of soil biological activities. The decomposition organic waste in the biopore infiltration hole could be accelerated by adding activator. The activators that could be added were Trichoderma sp. and molasses. This research aimed at finding out the effect of giving Trichoderma sp. and molasses in soil biological properties including population and diversity of soil fauna, microbes and fungi population at arround the biopore infiltration hole. Design model that used was randomized block design (RBD) with Least Significant Difference (LSD) test on the level of trust 5%. The treatment of this research were, P0: without treatment of organic waste (SO) + molasses (M) + Trichoderma sp. (T), P1: with addition of SO, P2: with addition of SO + M, P3: with addition of SO + T, and P4: with addition of SO + M + T. The result of this research showed that the addition of Trichoderma sp. (SO+T) and molasses (SO + M) treatments in biopore infiltration hole could improve the soil biological properties. It was indicated by the high of soil microbes population 1.59 x 106 CFU (Colony Forming Unit)/g ADW (Absolute Dry Weight) soil to the both treatments and significantly higher compared to the P0. Both of the treatments also had the highest population of soil fauna than other treatments, that were 6071 individual/m2 (SO + T) and 1908 individual/m2 (SO + M), and had high population of soil fungi, that were 1.26 x 104 CFU/g ADW soil (SO + T) and 1.42 x 104 CFU/g ADW soil (SO + M), nevertheless they all did not have significantly effect in increasing the diversity of soil fauna.
Keyword: Biopore Infiltration Hole, molasses, soil biological properties, Trichoderma sp.

Judul: Populasi Mikrob Tanah Latosol Darmaga yang diinkubasi Soil Conditioner Berbahan Kompos Jerami Padi
Abstrak: Latosol that is found widespread in Indonesia, has characteristics such as it contains much aluminium and Iron oxides, deficient in plant nutrients due to excessive leaching, reddish in color, horizons in the soil profile are not distinct and deep solumn (over 150 cm). Soil conditioner has an important role in improving soil phyical properties such as stimulating granulation, soil aeration and water holding capacity. Soil conditioner from rice straw compost could also enhance beneficial microbial population and their activity, such as nitrogen fixers, phosphate solubilzers and cellullose decomposers. Organic matter accumulation, nutrient cycles and the formation of stable soil structure are strongly influenced by soil organism activities. Thus, the use of soil conditioner on Latosols is expected to improved the physical, chemical and biological properties of soils. This research aims 1) to evaluate the microbial (bacteria and fungi) population in soils incubated by soil conditioner made from rice straw compost, 2) to study the relationship between microbial population and some soil physical properties (aggregate stability and soil moisture). The experiment was arranged using completely randomized designed with two factors i.e. 1) the treatment of soil conditioners (with and without soil conditioner) and 2) incubation time (2 and 6 months). The treatment was replicated three times, thus resulted in 12 experimental units. The result showed that soil conditioner significantly increased soil moisture content, compared to the control. After six months incubation, soil conditioner had no effect yet on the soil aggregate stability and soil microbial population, compared to the control
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf