Judul: Evaluation of Chicken Manure Rate in Andisols Wonokitri Based on Phosphorus Sorption And Fractionation Dynamics
Abstrak: Andisol memiliki kendala pada efisiensi pemupukan fosfor (P) yang rendah akibat tingginya retensi P. Fosfor pada Andisol dapat terakumulasi dalam bentuk tidak tersedia bagi tanaman. Petani pada Andisol umumnya menambahkan bahan organik seperti pupuk kandang ayam dalam dosis tinggi dan kontinu untuk mengurangi kendala tersebut, oleh karena itu perlu dilakukan evaluasi untuk melihat dinamika erapan dan fraksi P setelah penambahan bahan organik berupa pupuk kandang ayam. Penelitian ini dibutuhkan dalam upaya efisiensi pemupukan dan mitigasi pencemaran lingkungan. Penelitian dilaksanakan pada bulan Februari-November 2022. Pengambilan contoh tanah dilakukan di Desa Wonokitri, Kecamatan Tosari, Kabupaten Pasuruan, Provinsi Jawa Timur. Analisis laboratorium dilakukan di Laboratorium Kimia dan Kesuburan Tanah, Laboratorium Bioteknologi Tanah dan Lingkungan, Departemen Ilmu Tanah dan Sumberdaya Lahan, Fakultas Pertanian, IPB, serta di Badan Standardisasi Instrumentasi Pertanian (BSIP) Kementerian Pertanian Republik Indonesia. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) yang terdiri dari 5 perlakuan dosis pupuk kandang ayam yaitu tanpa pemberian pupuk kandang ayam (PM0), 10 t ha-1 (PM10), 20 t ha-1 (PM20), 30 t ha-1 (PM30) dan 40 t ha-1 (PM40). Setiap perlakuan diulang 3 kali sehingga diperoleh 15 unit percobaan. Tanah perlakuan dimasukkan ke dalam toples, kelembaban tanah dipertahankan dengan menambahkan air destilasi hingga mencapai 85% dari kapasitas lapang. Kemudian tanah diinkubasi selama 2 minggu, dan dilakukan analisis sifatnya. Percobaan rumah kaca dengan tanaman indikator gandum (Triticum spp.) menggunakan rancangan percobaan yang sama dan dipelihara selama 14 hari. Parameter yang diamati di antaranya erapan P, pelepasan P, kinetika erapan P, fraksionasi P dan serapan P. Analisis keragaman dilakukan pada selang kepercayaan 95% kemudian dilanjutkan uji Tukey pada selang kepercayaan 95%. Berdasarkan hasil analisis diketahui bahwa Andisol Wonokitri memiliki kadar P yang sangat tinggi, hal ini dapat disebabkan oleh aplikasi pupuk baik anorganik maupun organik secara tinggi dan terus menerus. Pada percobaan erapan yang disimulasikan dengan isoterm Langmuir menunjukkan bahwa penambahan pupuk kandang ayam pada dosis 10-40 t ha-1 menurunkan nilai energi ikatan tanah (k) terhadap P, walaupun tidak menurunkan nilai erapan maksimum (b). Pada pecobaan erapan terdapat 2 tapak erapan dan terjadi penurunan nilai k pada semua tapak erapan seiring dengan peningkatan dosis pupuk kandang ayam. PM40 diketahui merupakan perlakuan dengan nilai k terendah, namun pada tapak erapan 2 diketahui secara statistik tidak berbeda nyata dengan PM20. Pada percobaan pelepasan P diketahui hanya terdapat 1 tapak dan menunjukkan hasil nilai k pada PM40 tidak berbeda nyata dengan PM10. Pada simulasi erapan menggunakan isoterm Freundlich diketahui bahwa terjadi penurunan konstanta erapan Freundlich (K) pada setiap penambahan dosis pupuk kandang ayam baik pada percobaan erapan maupun pelepasan P. Pada percobaan kinetika erapan P, aplikasi pupuk kandang ayam diketahui menurunkan konstanta laju erapan P (k) namun pada PM20-PM40 tidak terjadi perbedaan signifikan. Pada percobaan fraksionasi P, pemberian pupuk kandang ayam diketahui meningkatkan fraksi resin P, NaHCO3-Pi dan NaOH-Pi secara signifikan seiring dengan peningkatan dosis pupuk kandang ayam. Pemberian pupuk kandang ayam tidak menurunkan kadar fraksi HCl-Pi dan Residual-Pi. Peningkatan fraksi P mudah tersedia (resin P dan NaHCO3-Pi) akibat penambahan pupuk kandang ayam berkaitan dengan peningkatan serapan P tanaman pada percobaan rumah kaca, namun pada PM40 sebagai perlakuan dosis tertinggi tidak menunjukkan hasil berbeda nyata
Keyword: Amorf, Bahan Organik, Efisiensi, Eutrofikasi, Pemupukan

Judul: Evaluation of Chicken Manure Rate in Andisols Wonokitri Based on Phosphorus Sorption And Fractionation Dynamics
Abstrak: Andisols have problems with the low efficiency of phosphorus (P) fertilization due to the high retention of P. Phosphorus in Andisols can accumulate in unavailable form. Farmers in Andisols generally applied organic matter such as chicken manure in high doses to reduce these problems, therefore it is necessary to evaluate the dynamics of P sorption and P fraction after the addition of chicken manure. This research is needed to increase fertilizer efficiency and reduce the potential for environmental pollution. This research was conducted in February-November 2022. The soil sample was collected from Wonokitri Village, Tosari District, Pasuruan Regency, East Java Province. Laboratory analyzes were conducted at Soil Chemistry and Fertility Laboratory, Soil and Environmental Biotechnology Laboratory, Department of Soil Science and Land Resources, Faculty of Agriculture, IPB, and at Agricultural Instrumentation Standardization Agency (BSIP) of the Indonesian Ministry of Agriculture. This research was used a completely randomized design (CRD) which consisted of 5 rates of chicken manure addition in Andisols Wonokitri, namely without added chicken manure (PM0), 10 t ha-1 (PM10), 20 t ha-1 (PM20), 30 t ha-1 (PM30), 40 t ha-1 (PM40). Each treatment was repeated 3 times to obtain 15 experimental units. The treated soil was put in a jar, and watering with distilled water until reaches 85% of field capacity and incubated for 2 weeks, then analyzed to determine the soil properties. Greenhouse experiment was carried out using wheat (Triticum spp.) for 14 days. The observed parameters were P sorption, P release, P sorption kinetics, P fractionation and P uptake by plants. Analysis of variance was performed at 95% confidence intervals followed by Tukey test at 95% confidence interval. The results showed that the P content in Andisols Wonokitri was at very high level, which caused by high rates and continuous application of inorganic and organic fertilizers. The Langmuir isoterm simulation showed that the chicken manure addition at rate of 10-40 t ha-1 significantly reduced the values of P bonding energy (k) in Andisols Wonokitri, although not reduced the sorption maxima (b). The sorption experiment simulated with Langmuir isoterm reveal two sorption sites and showed a decreasing value of k along with increasing rates of chicken manure. PM40 had the lowest k value in all sorption sites compared to all treatments, however PM40 was not significantly different with PM20 in second sorption site. In the P desorption experiment, showed only one sorption site and PM40 was not significantly different from PM10. The sorption-desorption simulation using the Freundlich isotherm showed that the sorption constant value (K) decreased along with increasing a rate of chicken manure addition. The P sorption kinetic experiment showed that the application of chicken manure decrease the P sorption rate constant (k), however there was no significant difference in PM20-PM40. The P fractionation analysis showed the application of chicken manure increase the P resin, NaHCO3-Pi and NaOH-Pi along with increasing rate of chicken manure. The addition of chicken manure did not decrease the HCl-Pi and Residual-Pi fractions. The increased levels of available-P fractions (P resin and NaHCO3-Pi) due to the addition of chicken manure correlated with an
Keyword: Amorf, Bahan Organik, Efisiensi, Eutrofikasi, Pemupukan

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.
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