Salah satu faktor yang menyebabkan menurunnya produksi kedelai yaitu serangan hama penghisap polong (Riptortus linearis). Pada penelitian ini pengendalikan hama penghisap polong pada kedelai menggunakan pestisida nabati ekstrak daun sirsak (Annona muricata). Penelitian ini bertujuan untuk mengetahui pengaruh pestisida nabati ekstrak daun sirsak terhadap intensitas serangan hama penghisap polong dan berat polong. Penelitian ini dilaksanakan pada bulan Januari 2018 hingga April 2018 di lahan Desa Kebonsari Kidul, Kecamatan Yosowilangun, Kabupaten Lumajang. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) non faktorial yang terdiri dari 5 perlakuan yaitu P0 (Deltametrin 25gr/l), Ekstrak daun sirsak dengan konsentrasi : P1 (10%), P2 (30%), P3 (60%) dan P4 (90%) dengan 5 ulangan. Uji data menggunakan ANOVA (Analyze of Varians) dan uji lanjut dengan BNT 5%. Hasil penelitian menunjukkan bahwa 5 perlakuan tersebut berpengaruh nyata terhadap intensitas serangan umur 63 HST dan tidak berbeda nyata pada intensitas serangan umur 56 HST,70 HST dan 77 HST dan parameter berat polong. Intensitas serangan hama penghisap polong berkorelasi negatif terhadap berat polong.

Nyaru Menteng Arboretum is one of Conservation area in Palangka Raya for biodiversity protection width 65,2ha and in that area have established an Orang Utan Reintroduction Center from Borneo Orangutan Save Foundation (BOSF). The aims of this research are to estimated the population density of Kelasi in this area and to know many kinds of Kelasi food and the part of trees that Kelasi put to eat. The result of this research that has found one species (young class) in January 2017, then we can find 3 species again in April 2017 there is one male, one female, and one young kelasi. Population density rate of Kelasiof 2017 is 0,06 species/ha that meaning is population density of Kelasi have a degraded experience if comparing with the same population density data on 2007 that found 15 species in the area (in 2 group)with 0,23 species/ha. Food sort of Kelasi is juvenile of : Jambu-jambu (Syzgium cerinum), Saga (Adenathera microsperma), cassava (Manihot utilisima), rubber (Hevea brasiliensis), pineapple (Ananas comosus), Kelakai (Stenochlaena ralustris) dan jackfruit (Artocarpus integra), other fruits and residue of orangutan food in Reintroduction area lie pineapple and papaya.

Gelam commonly grows in clumps in peat swamp forests of South and Central Kalimantan. This study aims to determine the effects of growing sites on the biomass content of gelam stands. The study was carried out by analyzing the soil content of growing sites toward the growth of gelam (i.e. the number of individuals and biomass per hectare). The study was conducted at two sites, with the following habitat types: site A – shallow peat with a depth of 51-100cm and only inundated on a high tide, and site B – a moderate peat with a depth of 101-200cm, not flooded but with a groundwater depth of less than 50cm at high tide. A forest fire at site B resulted in higher soil fertility (especially the element K) compared to site A, due to the presence of a pile of ash and charcoal. Also, the fire at site B created more open space, controlled weeds, and at the same time, killed some seedlings and saplings, thinning the site out. The growth rate of gelam at site B was higher than that of site A; at site B, the average height was 10.9m and the average diameter was 10.9cm while at site A, the average height was 9.97m and the average diameter was 10.3cm. The presence of ash, charcoal and more open space after the forest-fire resulted in a higher biomass content at site B (147.223 tons/ha) compared to site A (131.578 tons/ha).

Tujuan penelitian ini adalah untuk mengetahui keragaman Fungi Mikoriza Arbuskula(FMA) lahan gambut konversi hutan alam menjadi perkebunan kelapa sawit diKotawaringin Timur. Penelitian dilaksanakan pada 4 (empat) lokasi di KabupatenKotawaringin Timur, yakni: (1) Hutan rawa gambut alami di Kecamatan Kota Besi (2)Lahan gambut untuk perkebunan kelapa sawit umur tanam kurang dari 4 tahun diKecamatan Parenggean; (3) Lahan gambut perkebunan kelapa sawit umur tanam 4-10tahun di Kecamatan Cempaga; dan (4) Lahan gambut perkebunan kelapa sawit umurtanam di atas 10 tahun di Kecamatan Mentawa Baru Ketapang. Pembuatan petakpengamatan ukuran 20 m x 20 m dibuat pada setiap lokasi sesuai metode ICRAF.Pengambilan sampel tanah dan akar secara komposit 5 (lima) titik pengambilan sampeltanah pada kedalaman 20 cm di masing-masing lokasi sekaligus sebagai ulangan. Berattanah sampel setiap titik sebanyak 500 gr, sehingga total sampel tanah tiap petakpengamatan adalah 2.500 gr. Sampel tanah tiap titik dalamsatu petak dicampur dalamsatu tempat hingga homogen untuk mewakili satu petak amatan, selanjutnya diambil 100g per titik. Analisis data dilakukan dengan metode deskriptif dan dibantu gambar, grafik,dan tabel. Hasil penelitian menunjukkan struktur infeksi yang membentuk struktur FMAberupa hifa dan vesikel, sedangkan struktur FMA berupa arbuskula tidak dijumpai.Kepadatan spora (100 g tanah gambut) tertinggi terjadi pada lahan gambut untukperkebunan kelapa sawit dengan usia tanam kurang dari 4 tahun (320,40), kelapa sawitusia antara 4-10 tahun (276,20), dan disusul tanaman kelapasawit usia di atas 10 tahun(211,20). Kepadatan spora terendah pada hutan gambut alami (152,20). Hasil identifikasispora FMA menemukan 12 (dua belas) spesies spora FMA genus Glomus sp. SporaFMA genus Glomus sp merupakan satu-satunya jenis spora FMA, baik pada hutangambut alami maupun lahan gambut untuk perkebunan kelapa sawit dengan berbagaiusia tanam. Rata-rata kelimpahan Spora FMA Genus Glomus sp (100 g tanah gambut)tertinggi pada lahan gambut untuk perkebunan kelapa sawit usia tanam kurang 4 tahun(112,80), disusul kelapa sawit usia tanam antara 4-10 tahun (104,10), dan hutan gambutalami (64,20). Rata-rata terendah pada lahan gambut untuk perkebunan kelapa sawit usiatanam di atas 10 tahun (47,40). Rata-rata kelimpahan relatif Spora FMA Genus Glomus sp (100 g tanah gambut) tertinggi pada hutan gambut alami (42,64%), kemudian lahan gambut untuk perkebunan kelapa sawit usia tanam antara 4-10 tahun (37,69%), kelapa sawit usia tanam kurang 4 tahun (35,34%). Rata-rata terendah pada lahan gambut untukperkebunan kelapa sawit usia tanam di atas 10 tahun (22,48%).Kata kunci : mikoriza, lahan gambut, kelapa sawit, identifikasi, struktur, kelimpahan

The purpose of this study was to examine changes in the physical and chemical properties of natural peat forests and peatlands designated for oil palm plantations at various ages of oil palm planting. The research was carried out in 4 (four) locations in East Kotawaringin Regency, namely: (1) Natural peat swamp forest in Kota Besi District (2) Peat land designated for oil palm plantations planting age less than 4 years in Parenggean District; (3) Peat land designated for oil palm plantations with a planting age of 4-10 years in Cempaga District; and (4) peat land designated for oil palm plantations with a planting age of more than 10 years in Mentawa Baru District, Ketapang. The results showed that the peat land designated for oil palm plantations caused changes in the physical and chemical properties of the peat soil. Changes in the physical properties of peat soil are indicated by the color of the peat soil which changes from very dull red in natural peat forests to reddish black in oil palm plantations. Peat maturity changes from fibric in natural peat forest to hemic and sapric on peatland designated for oil palm plantations. The water content has decreased significantly, the older the age of the oil palm plant, the water content will decrease. In terms of bulk density, the older the age of oil palm plantations, the higher the density of peat soils. The water level in oil palm plantations has increased when compared to natural peat forests. Changes in chemical properties were indicated by an increase in peat soil pH, total N, and available P, while a decrease occurred in the C-Organic content. An increase also occurred in the content of K-dd, Ca-dd, Mg-dd, Na-dd, and CEC with increasing age of oil palm plants. When viewed from the relationship pattern of each physical characteristic, water content has a positive relationship with fiber content, the higher the water content will be followed by the higher fiber content or vice versa. Bulk density has a negative relationship with fiber content and moisture content, which means that an increase in the bulk density of peat soil will be followed by a decrease in fiber content and moisture content. The relationship pattern of chemical properties shows that the pH (H2O) of peat soil has a positive relationship with organic C, total N, available P, and Cation Exchange Capacity (CEC). High or low peat acidity will be proportional to the high or low -organic, N-total, P-available, and Cation Exchange Capacity (CEC).