Judul: Pengaruh Ketebalan Mulsa Jerami dan Frekuensi Irigasi terhadap Pertumbuhan dan Produksi Tanaman Kacang Hijau (Vigna radiata L.)
Abstrak: Water availability is a limiting factor of the plant growth. Mulching may help to improve water use efficiency. The objective of the research was to determine the thickness of straw mulch and irrigation frequency that giving optimum growth and yield of green beans. The experiment was arranged in a randomized completed block design with factorial pattern, consisting of two factors with three replications. The first factor was straw mulch thickness, consisted of five levels: M1 (without mulch), M2 (mulch thickness 3 cm), M3 (mulch thickness 6 cm), M4 (mulch thickness 9 cm) and M5 (mulch thickness 12 cm). The second factor was irrigation frequency, consisted of four levels: I1 (2 days interval), I2 (4 days interval), I3 (6 days interval), and I4 (8 days interval). The results show that the thickness of straw mulches and frequency of irrigation showed the different effect on plant height, branches and pods, seed wet weight and dry weight, evapotranspiration value, and water use efficiency of green beans. Straw mulching with thickness 9 cm and frequency irrigation 6 days interval gave the best yield than the other treatments.
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Judul: Pengaruh Pemberian Mulsa Jerami Jagung dan Kepadatan Tanah terhadap Pertumbuhan dan Produksi Jagung (Zea mays)
Abstrak: Intensive land cultivation can damage soil structure and further enable soil to be compact, and reduce water availability in the soil. Mulch application to cover the soil surface will reduce evaporation rate and increase availability of water in the soil. The research was aimed to study the effect of corn straw mulching and soil density application on physical characteristics of the soil, to determining soil bulk density and dose of mulch which is most suitable for corn growth and production of corn. The experiment was designed using a completely randomized factorial design. The first factor is the density of soil which is consist of soil bulk density 0.8, 1.0, dan 1.2 g/cm3 (K1, K2, dan K3). The second factor was corn straw mulch application which was divided into three doses i.e. 0%, 30%, 60%, and 90% (M0, M1, M2, and M3). Data were analyzed using analysis of variance (ANOVA) and further testing using Tukey Test at the level of 5%. The results of the research show the interaction of soil compaction with mulch were significantly affect on plant height at age 11-14 weeks after growing, the number of leaves at the age of 10, 11, 12, and 14 weeks after growing, dry weight of corncob both with and without husk, and dry weight of seed.The increasing of soil compaction were significantly affect on field capacity, soil resistance before planting, both total and reproductive phase evapotranspiration in single growing season, weight of roots, plant biomass, plant growth and production, also soil physics characteristic after harvest. Mulch application significantly affect on evapotranspiration of vegetative phase, plant height at 8-14 weeks after growing, stem diameter at 10 weeks after growing, and production except dry weight of seed. Soil bulk density and mulch cover suitable for the growth and production of corn is 0.8 g/cm3 and 90%.
Keyword: soil compaction, mulch, field capacity, corn growth and production

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix