Analyse of soil chemical properties in the encriment of oil palm production on sandy soil at Selangkun oli palm plantationSoil is one of basic components in the development of oil palm plantation. Limitation of land causes many companies expand their areas to the sub-optimal land, such as sandy soil. This research was aimed to analyzed chemical soil properties and its relation with bunch number and bunch weight in oil palm plantation, Arut Selatan sub-district, Central Kalimantan. Survey was made in sample points that were determined based on grid system, and each sample was taken in the depth of 30 cm. This research was descriptive and used double regression equation with backward-stepwise method. Several parameters have been analyzed, such as pH, organic carbon, CEC, total N, total P, P-availability, K, Ca, Mg, Cu, Zn, Mn, and B. The result showed that the pH was categorized acid, macro nutrients were medium to very low, except total P and P-availability, while micro nutrients were enough, except boron which had very high amount. Furthermore, statistical analysis showed that some chemical properties, such as total N, CEC, and exchangeable Al were parameters which influenced production of bunch number per oil palm plant.Keywords: Oil palm, Soil nutrient, Sandy soilABSTRAKTanah merupakan salah satu komponen dasar dalam pembangunan perkebunan kelapa sawit. Keterbatasan lahan menyebabkan banyaknya perusahaan yang memperluas areal perkebunan ke lahan sub-optimal, seperti tanah pasir. Penelitian ini bertujuan mengkaji sifat-sifat kimia yang ada pada tanah pasir dan hubungannya dengan produksi tandan per pohon dan berat tandan rata-rata tanaman kelapa sawit di kecamatan Arut Selatan, Kalimantan Tengah. Survei dilakukan pada titik sampel didasarkan pada metode grid, dan sampel diambil pada kedalaman 30 cm. Penelitian ini merupakan penelitian deskriptif dan menggunakan model persamaan regresi berganda metode backward-stepwise. Beberapa parameter yang dianalisis adalah pH, C-organik, KTK, N-total, P-total, P-tersedia, K, Ca, Mg, Cu, Zn, Mn, dan B. Hasil analisis menunjukkan bahwa pH tanah tergolong rendah, kandungan hara makro berkisar sedang sampai sangat rendah, kecuali P-total dan P-tersedia, sementara kandungan hara mikronya cukup, kecuali boron yang tergolong tinggi. Sifat kimia tanah seperti N-total, KTK, dan Al-dd merupakan parameter yang meningkatkan jumlah tandan per pohon.Kata Kunci: Kelapa sawit, Hara tanah, Tanah pasir

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<em>Tea (</em>Camellia sinensis<em> [L.] O. Kuntze) is one of priority commodities in West Java. Extensification of tea plantation in lowland and suboptimal areas is believed to contribute significantly in improving the farmers welfare. Temperature differences between the lowland and highland areas affects the metabolism of tea plants. In technical culture, centering (pruning) is required to form the shrub with ideal branching. This study aimed to determine cytokinin effects on the growth of tea plants after centering in the lowland areas. The experiment was conducted at the Experimental Station of Faculty of Agriculture, Padjadjaran University, Jatinangor, from November 2016 until June 2017 using 10 months old tea plant materials. The experiments used a randomized block design with 4 replications. The treatment used was cytokinin derived from coconut water with concentration of 25%, 50%, and 75%, cytokinin in the form of benzyl amino purin (BAP) with concentration of 60 ppm, 90 ppm, and 120 ppm, and control (without cytokinin). The results showed that cytokinin derived from coconut water or in the form of BAP applied in tea plants after centering, was only effective up to 3 months after application. At 1 and 3 months after application, 50% coconut water or BAP 60 ppm increased the length of stem diameter, number of leaves, shoot length, and number of shoots. Therefore, coconut water with 50% concentration or BAP 60 ppm can be used as source of cytokinins for tea plants in the lowlands after centering.</em>

Penelitian ini bertujuan untuk mengetahui pengaruh pemberian berbagai macam dosis Pupuk Kalium Hasil Inovasi (PKHI) terhadap peningkatan pertumbuhan dan hasil tanaman jagung manis pada jenis tanah inceptisol. Penelitian ini menggunakan rancangan acak kelompok pola sederhana dengan faktorial tunggal. Faktor perlakuan tunggal yang diujikan pada penelitian ini yaitu variasi dosis Pupuk Kalium Hasil Inovasi (PKHI) yang terdiri dari variasi dosis dan kontrol, yakniA(N,P Tunggal), B(N,P,K Tunggal), C(1/4 K + N,P Tunggal), D(1/2 K+ N,P Tunggal), E(3/4 K+ N,P Tunggal), F(1 K+ N,P Tunggal), G(1 1/4 K+ N,P Tunggal), H(1 1/2 K+ N,P Tunggal), I(1 3/4 K+ N,P Tunggal), dan J (Kontrol). Masing-masing perlakuan diulang tiga kali, sehingga jumlah seluruhnya didapat 30 plot percobaan. Hasil penelitian menunjukan bahwa pemberian Pupuk Kalium Hasil Inovasi (PKHI) memberikan pengaruh nyata terhadap pertumbuhan dan hasil meliputi tinggi tanaman, jumlah daun, bobot tongkol, diameter tongkol, dan panjang tongkol. Dosis Pupuk Kalium Hasil Inovasi (PKHI) paling memberikan pengaruh nyata terhadap pertumbuhan atau hasil yaitu pada dosis 1 1/2 K dengan 240 Kg/Ha Pupuk Kalium yang diuji dan menghasilkan 18 Ton tongkol per hektar.Kata kunci : Inovasi Pupuk Kalium, Jagung Manis, Hasil Pertanian

Rosniawaty, dkk: Pemanfaatan urin kelinci dan urin sapi sebagai alternatif pupuk organik cair pada pembibitan kakao (Theobroma cacao L.) Rosniawaty, S. • R. Sudirja • H. AfriantoPemanfaatan urin kelinci dan urin sapi sebagai alternatif pupuk organik cairpada pembibitan kakao (Theobroma cacao L.) Utilizing of rabbit and cow urine as organic fertilizer liqiud alternative on cocoa (Theobroma cacao L.) seedlingAbstract Seedling is the beginning of plant growth. Good seedling will produce high yields.Fertilization is one of the important things in obtaining good seeds. Utilization of rabbit urine and cow urine is expected to be an alternative fertilizer for cocoa seedling. The experiments wereconducted in April-August 2013 at the experimental Ciparanje Padjadjaran University Faculty of Agriculture, with the order Inceptisol and precipitation type C according to the classification of Schmidt Ferguson. The treatment used was some concentration of rabbit urine, cow urine and urine combination with inorganic fertilizer. Rabbit urine and cow urine each fermented were usedbefore. The experimental design wasused a randomized block design, there are 15 treatment repeated 3 times. The results were showed that there significant effect of rabbit urine and cow urine that had been fermented for leaf area, root volume and dry weight of cocoa seedlings at the age of 16 MST. The used of cow urine with 25 % concentration did not differ with the use of inorganic fertilizers on cocoa seedling.

The use of organic materials and minerals as fertilizer needs to be developed in order to increase agricultural productivity, especially in soils marginal that are widely distributed on the Indonesian. This study aims to determine the productivity of soil and corn plants by using various formulations of organo-mineral materials in the Ultisols Jatinangor. The experiment was conducted from April to November 2017 at Ciparanje Experimental Garden, Faculty of Agriculture, Universitas Padjadjaran, using a simple randomized block design consisting of 10 treatments and replicated 3 times. The organo-mineral ingredients used consist of a combination of Humic Acid (6; 8; 10 kg/ha); Dolomites (100; 150; 200 kg/ha); Natural Phosphates (250; 300; 350 kg/ha); also Zeolites (150; 200; 250 kg/ha). The results showed that ameliorant combination had significant effects on soil pH, P-available, and Mn Total, also the yield of maize. Dosage of 8 kg/ha of Humid Acids + 200 kg/ha of Dolomites + 350 kg/ha of Natural Phosphates + 250 kg/ha Zeolite, has indicated better result based on variable experiment.Keywords: maize, organo-mineral, Humic acid, dolomite, phosphate, ultisols

Azotobacter inoculation could play an important role to enhance the effectiveness of bioremediation since bacterial exopolysachharides form a complex with heavy metal. So that metal mobility in soil and its uptake by plants increased. Azotobacter also produce phytohormone which induce roots growth and subsequently the uptake of nutrients. The objective of this research was to obtain optimal incubation temperature and time in Azotobacter sp. LKM6 liquid inoculants production in the fermentor to maximize the synthesis of exopolysachharides and phytohormones. The experiment arranged in Completely Randomized Design consisted of two incubation temperature (room temperature and 30 0 C). At 24, 36, and 48 hours incubation, the concentration of EPS and phytohormone cytokinin and giberrelin were occurred. The experimental results were 1) the best temperature and incubation time to produce Azotobacter sp. LKM6 liquid for bioremediation of heavy metal-contaminated soil was 30 o C and 48 hours, and 2) inoculants production at 30 0 C for 48 jam produce liquid inoculants containing 2.87 mg L -1 exopolysachharides, 81.0 mg L -1 cytokinins and 18.7 mg L -1 giberrelin, and 13.12 x 10 8 cell ml -1 .