Judul: Bentuk-bentuk beri dalam tanah yang disawahkan pada dua tingkat pengelolaan air dan pengaruhnya terhadap tanaman padi
Abstrak: Tanah kering dengan tingkat pelapukan relatif lanjut yang pada umumnya berkemasaman tinggi yang mulai dibuka. sebagai areal sawah menampilkan sejumlah masalah. Salah satunya yang berpengaruh buruk terhadap tanaman padi yang ditanam disana adalah meningkatnya kandungan Fe larut dalam air mencapai level toksik. Pengamatan terhadap trans- formasi bentuk besi pada tanah-tanah yang mulai disawahkan dimaksudkan untuk memahami perilaku besi di bawah kondisi penggenangan, agar dapat dicarikan pemecahan masalahnya. Penelitian ini dilaksanakan di Rumah Kaca Jurusan Ilmu Tanah dan Laboratorium Kimia dan Kesuburan Tanah IPB, serta Laboratorium Biokimia Balai Penelitian Tanaman Pa- ngan Cimanggu, yang dilaksanakan dalam suatu time series. Contoh tanah diambil dari Darmaga (Fluventic Humitropept dan Typic Tropohumult) Haplohumult). dan dari Gajrug (Typic Perlakuan tingkat pengelolaan air yang diberikan adalah penggenangan terus menerus dan penggenangan berkala. Inkubasi dilakukan selama 25 hari, lalu tanaman ..dst
Keyword: Rice, Bobot gabah, Kandungan Fe, Amonium oxalat

Judul: Pengaruh tebak baja terhadap sifat kimia tanah dan produksi padi sawah pada tanah gambut mukok, Sanggau
Abstrak: Utilization of peat lands as agricultural land especially for wetland rice Eeld faces some prob!ems such as low availability of macro and micro nutrients. Some research results indicated that the availability of silicate in p a t land of Kalimantan and Sumatra is low. The role of silicate oi, wetland rice are increasing the resistafice to lodging, pzst, and disease ss well as improving photosynthesis. This research were conducted ir two steps incubztio~a nd field experiment. In the two experiments, the dosage sf steel slag applied were : 3.0 , 2.5; 5.0; 7.5, and 10 ton /ha or eyuivclen? to 0,3.65,7.03, 11.03 and 14.70 g /kg for kcubation experiment. Result of incubztion experiment indicated that the effect of steel slag on chemical properties of soil were significant. The contents of exchangeable K, Ca and Mg; available Si, Fe, Mr., a~laC u; and soil pH were incresed with incresing the dgsage of steel slag. Results of field experiment indicated that application of steel slag as silicon fertilizer significantly incresed plant height, dry weight of total and filled spikelets; and decreased the percentage of unfillet spikellets. On the other land, the effect of steel slag treatments OI? number of inaximum and productive tilier rice werc not significant. The plant height, dry weight of total and filled spikelets were increased 14-22 %, 61-67 % and 65-96 %; respectively, with application of steel slag; and the percentage of unfilled spikelets was decreased 2.63-4.42 %.
Keyword: 

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
Keyword: