Penelitian ini bertujuan untuk mengetahui keanekaragaman aksesi aren yang tersebar di Kabupaten Tapanuli Selatan dan mengelompokkan populasi seleksi untuk mendapatkan produksi yang tinggi. Delapan puluh aksesi aren populasi alam asal empat kecamatan telah di identifikasi menurut IPGRI (International Plant Genetic Resources Institute, 1995) dan dianalisis. Hasil menunjukkan terbentuknya 4 cluster yang disimpulkan bahwa cluster 1 merupakan kelompok aksesi aren dengan karakter fenotip yang sesuai untuk memproduksi buah dari mayang bunga betina. Sedangkan cluster 3 merupakan kelompok aksesi aren dengan karakter fenotip yang sesuai untuk memproduksi nira (bahan baku gula aren) dari mayang bunga jantan.

The Non-Forest Area is an outside of forest area which can be used for other reconstruction sector activities, one of them is for agricultural land area sector. At Sitellu Tali Urang Julu, Pakpak Bharat district, the potential utilized land for agricultural cultivation activities is largest and expecting will improve the welfare of local farmers. This research aimed was to determine the land suitability in Sitellu Tali Urang Julu, Pakpak Bharat district for oil palm plantation (ElaeisguenensisJacq). The research method was survey in Sitellu Tali Urang Julu, Pakpak Bharat. This research conducted by taking soil samples in field then analyzed in laboratory. The survey activities consist of 5 stages; there were pra-survey, main survey, soil analysis in Laboratorium and also processing data. The survey results showed that retention and nutrients availability were the most limiting factor on Non-forest area Sitellu Tali Urang Julu for developing oil palm plantation, moreover the regional air temperature should be considering. Actual land conditions that cultivated in Sitellu Tali Urang Julu Subdistrict is oil palm is 939.11 ha. Than potential area land that cultured in Sitellu Tali Urang Julu is: Oil Palm around 939.11 hectares, cannot be understood.

<p>The oil palm empty fruit bunches are solid waste produced from the processing of oil palms which have a large amount of potential to be used as compost and are expected to improve the physical, biological and chemical properties of the subsoil. This study aimed to evaluate the best combination between oil palm empty fruit bunches compost and rice husk charcoal on soil chemical properties in tomato. This research was conducted in Sona Village, Labuhanbatu Regency on December 2019-March 2020. Analysis of soil chemical properties was conducted at the Socfindo Seed Production and Laboratories (SSPL) Laboratory of PT. Socfin Indonesia. The study was conducted with a factorial randomized block design with 2 factors. The first factor was the application of oil palm empty bunches which consists of no oil palm empty bunches (control), 0.5 kg/polybag, 0.7 kg/polybag and 1 kg/polybag. The second factor was the application of rice husk charcoal which consists of non-husk charcoal (control), consisting of 0.2 kg/polybag and 0.4 kg/polybag. Data that had a significant effect after analysis of variance continued with DMRT at the level of α = 5%. The results showed that application of oil palm empty fruit bunches (0.7 kg/polybag) significantly increased pH and C-organic. Application of rice husk charcoal (0.2 kg/polybag) significantly increased C-organic and P-available.</p>

This study was aimed to elucidate the effect of the application of urea fertilizer and goat manure on some soil chemical properties and yield of a green mustard plant (Bressicca juncea L). This study was conducted with a randomized block design consisting of two factors. The first factor was the application of goat manure (K) consisting of three levels, i.e. (K1) 1 t goat manure ha -1 , (K2) 1.5 t goat manure ha -1 , and (K3) 2 t goat manure ha -1 . The second factor was the application of urea fertilizer consisting of two dose levels, i.e. (U1 75 kg) urea fertilizer ha -1 , and (U2) 100 kg urea fertilizer ha -1 . The measured parameters were soil organic-C content, soil total N content, and fresh weight of the green mustard plant. Results of the study showed that the combination of 2 t goat manure ha -1 and 100 kg urea fertilizer ha -1 was the best treatment that significantly affected soil organic-C content, soil total N, soil C/N r atio, and yield of fresh weight of the mustard green plant.

The potential of various genera and species of rhizosphere bacteria is well known. This study aims to determine the diversity and physiological characteristics of the rhizosphere bacterial isolates of oil palm plants at PTPN III Aek Nabara Labuhanbatu North Sumatra. This research was conducted in July 2018 to October 2018 in laboratory of STIPER Labuhanbatu. This research was conducted by isolating bacteria from the root rhizosphere of oil palm plants, characterizing the morphology and physiology of isolates by phosphate dissolution test and indole acetic acid production test. Furthermore, the data was analyzed descriptively. Based on the isolation results obtained 10 bacterial isolates with different macroscopic and microscopic morphological characteristics with the largest amount of dissolved phosphate produced by isolate R05 (0.211 mg / l) and the largest amount of IAA produced by isolate R04 (0.097 mg / l). Isolates R05 and R04 have the potential to be further tested.